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Background: In the PEGASUS trial, the complement C3 inhibitor, pegcetacoplan, showed superiority to eculizumab in improving haematological outcomes in adult patients with paroxysmal nocturnal haemoglobinuria and suboptimal response to eculizumab at 16 weeks. The aim of the open-label period was to evaluate the long-term efficacy and safety of pegcetacoplan through to 48 weeks. Methods: PEGASUS was a phase 3, randomised, open-label, active-comparator controlled trial conducted in 44 centres in Australia, Belgium, Canada, France, Germany, Japan, Russia, South Korea, Spain, the UK, and the USA. Eligible participants were aged 18 years or older, had paroxysmal nocturnal haemoglobinuria, and had a haemoglobin concentration of less than 10·50 g/dL after 3 months or longer of stable eculizumab treatment. After a 4-week run-in with eculizumab plus pegcetacoplan, patients were randomly assigned (1:1) by interactive response technology to pegcetacoplan (1080 mg subcutaneously twice weekly) or eculizumab (according to their regimen at enrolment) for 16 weeks and could continue to the open-label period (32 weeks of pegcetacoplan monotherapy [pegcetacoplan-to-pegcetacoplan] or 28 weeks of pegcetacoplan monotherapy [eculizumab-to-pegcetacoplan]). Randomisation was stratified by platelet count and number of previous blood transfusions. The primary endpoint was change from baseline in haemoglobin at week 16, which has previously been reported. The outcomes of the open-label period (week 16 to week 48) are reported here. At 48 weeks, efficacy (including mean haemoglobin concentration and quality of life measured on the Functional Assessment of Chronic Illness Therapy [FACIT]-Fatigue scale) was assessed in the intention-to-treat population and safety was assessed per protocol. This trial was registered with ClinicalTrials.gov, NCT03500549, and has been completed. Findings: Between June 14, 2018, and Nov 14, 2019, 80 patients were randomly assigned to receive treatment with pegcetacoplan (41 patients) or eculizumab (39 patients). Most participants were women (49 [61%]) and 31 (39%) were men; 12 (15%) were Asian, two (3%) were Black, 49 (61%) were White, and 17 (21%) were another race or did not report their race. The open-label period had 77 participants (38 pegcetacoplan-to-pegcetacoplan, 39 eculizumab-to-pegcetacoplan). Patients in the pegcetacoplan-to-pegcetacoplan group maintained high mean haemoglobin concentrations between 16 weeks (11·54 g/dL [SD 1·96]) and 48 weeks (11·30 g/dL [1·77]; p=0·14). Patients in the eculizumab-to-pegcetacoplan group had significantly greater mean haemoglobin concentrations at 48 weeks (11·57 g/dL [2·21]) versus 16 weeks (8·58 g/dL [0·96]; p

Aplastic anemia is a relatively rare but potentially fatal disorder, with a reported higher incidence in developing countries in comparison to the West. There are significant variations in epidemiological as well as etiological factors of bone marrow failure syndromes in the developing countries in comparison to the developed world. Furthermore, the management of bone marrow failure syndromes in resource constraint settings has significant challenges including delayed diagnosis and referral, limited accessibility to healthcare facilities, treatment modalities as well as limitations related to patients who require allogeneic stem cell transplantation. Here we will provide a review of the available evidence related to specific issues of aplastic anemia in the developing countries and we summarize suggested recommendations from the Eastern Mediterranean blood and bone marrow transplantation (EMBMT) group and the severe aplastic anemia working party of the European Society of blood and marrow transplantation (SAAWP of EBMT) related to the diagnosis and therapeutic options in countries with restricted resources.

The experience of third-generation tyrosine kinase inhibitor ponatinib treatment in Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph'+ ALL) patients post-allogeneic transplantation is limited. We retrospectively collected data on 25 Ph'+ ALL patients who were started on ponatinib after allogeneic transplantation between July 2015 and July 2019 from nine transplantation centers in Italy. Ponatinib was given in prophylaxis in five (20%), as pre-emptive treatment in seven (28%), and as salvage therapy in thirteen (52%) patients. It was combined with donor leukocyte infusions in ten patients. Half of the patients (12/25) harbored T315I mutation of BCR/ABL1, while in the remaining mutational analysis was negative or not performed. Among the 20 patients who received ponatinib as pre-emptive/salvage treatment, complete molecular response was achieved in 15 (75%) patients. Estimated overall survival at 2-year post-initiation of treatment in the whole cohort was 65% (respectively 60%, 60%, and 78% for the prophylaxis, pre-emptive, and salvage therapy groups). In patients with T315I-positive mutational status, the estimated 2-year survival was 40%. Fourteen patients (56%) experienced toxicity, requiring temporary or definitive suspension of treatment. In conclusion, treatment of Ph'+ ALL patients with ponatinib after transplantation is effective, although the question of adequate drug dose and treatment duration remains unanswered.

Ravulizumab, a novel long‐acting complement component 5 (C5) inhibitor administered every 8 weeks (q8w), was non‐inferior to eculizumab for all efficacy outcomes in two randomised, open‐label, phase 3 trials in C5 inhibitor‐naïve (Study 301) and eculizumab‐experienced (Study 302) adult patients with paroxysmal nocturnal haemoglobinuria (PNH). This pre‐specified analysis characterised ravulizumab pharmacokinetics (PK), pharmacodynamics (PD; free C5 levels), and PD differences between medications (Study 301, n = 246; Study 302, n = 195). Ravulizumab PK parameters were determined using non‐compartmental analysis. Serum free C5 was quantified with a Gyros‐based fluorescence assay (ravulizumab) and an electrochemiluminescence ligand‐binding assay (eculizumab). Ravulizumab PK parameters were numerically comparable in both studies; the median time to maximum concentrations ranged from 2·3 to 2·8 and 2·3 to 2·6 h in studies 301 and 302, respectively. Ravulizumab steady‐state serum concentrations were achieved immediately after the first dose and sustained throughout treatment. For ravulizumab, the mean (SD) post hoc terminal elimination half‐life was 49·7 (8·9) days. Serum free C5 concentrations

Idiopathic aplastic anemia is a rare and life-threatening disorder, and hematopoietic stem cell transplantation (HSCT) from a matched sibling donor (MSD) is the standard treatment strategy for young patients. Alternative donor transplantation (ADT) from a matched unrelated donor or an HLA haploidentical donor is not commonly used in the frontline setting. This systematic review/meta-analysis was conducted to compare ADT as an upfront, rather than delayed, treatment strategy in the absence of an MSD to immunosuppressive therapy (IST) in severe aplastic anemia (SAA). We searched PubMed/MEDLINE and Embase (1998 to 2019) for studies that compared the outcomes of ADT with IST as upfront therapy in patients with SAA. We included studies with 5 patients or more in each arm. Studies that included patients with inherited forms of bone marrow failure syndromes were excluded. The primary outcome was the 5-year overall survival (OS) rate. Five studies met the inclusion criteria and were included in this meta-analysis. The pooled 5-year odds ratio (OR) for OS was statistically significant at 0.44 (95% confidence interval [CI], 0.23 to 0.85) in favor of upfront ADT. In addition, survival was compared between upfront ADT versus salvage ADT in 6 studies. The pooled 5-year OR for OS was statistically significant at 0.31 (95% CI, 0.15 to 0.64) in favor of upfront ADT. Although this analysis has some limitations, including the retrospective nature of the included studies, the lack of ethnic diversity, the predominantly pediatric population, and the relatively suboptimal IST regimen used in some of the studies, it indicates that upfront ADT is a potential alternative treatment option in young and pediatric SAA patients who lack an HLA identical sibling donor, particularly when optimal IST is not available. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Paroxysmal nocturnal haemoglobinuria (PNH) is characterized by complement-mediated intravascular haemolysis, severe thrombophilia and bone marrow failure. While for patients with bone marrow failure the treatment follows that of immune-mediated aplastic anaemia, that of classic, haemolytic PNH is based on anti-complement medication. The anti-C5 monoclonal antibody eculizumab has revolutionized treatment, resulting in control of intravascular haemolysis and thromboembolic risk, with improved long-term survival. Novel strategies of complement inhibition are emerging. New anti-C5 agents reproduce the safety and efficacy of eculizumab, with improved patient convenience. Proximal complement inhibitors have been developed to address C3-mediated extra-vascular haemolysis and seem to improve haematological response.

Idiopathic aplastic anemia (IAA) is a rare autoimmune bone marrow failure (BMF) disorder initiated by a human leukocyte antigen (HLA)-restricted T-cell response to unknown antigens. As in other autoimmune disorders, the predilection for certain HLA profiles seems to represent an etiologic factor; however, in this disease the structure-function patterns involved in the self-presentation in this disease remain unclear. Herein, we analyzed the molecular landscape of HLA complexes of a cohort of 300 IAA patients and almost 3000 healthy and disease controls by deeply dissecting their genotypic configurations, functional divergence, self-antigen binding capabilities, and T-cell receptor (TCR) repertoire specificities. Specifically, analysis of the evolutionary divergence of HLA genotypes (HED) showed that IAA patients carried class II HLA molecules whose antigen-binding sites were characterized by a high level of structural homology, only partially explained by specific risk allele profiles. This pattern implies reduced HLA binding capabilities, confirmed by binding analysis of hematopoietic stem cell (HSC)-derived self-peptides. IAA phenotype was associated with the enrichment in a few amino acids at specific positions within the peptide-binding groove of DRB1 molecules, affecting the interface HLA-antigen-TCR β and potentially constituting the basis of T-cell dysfunction and autoreactivity. When analyzing associations with clinical outcomes, low HED was associated with risk of malignant progression and worse survival, underlying reduced tumor surveillance in clearing potential neoantigens derived from mechanisms of clonal hematopoiesis. Our data shed light on the immunogenetic risk associated with IAA etiology and clonal evolution and on general pathophysiological mechanisms potentially involved in other autoimmune disorders.

Congenital sideroblastic anaemias (CSA) are a rare group of disorders characterized by the presence of pathologic iron deposits within the mitochondria of erythroid precursors (ring sideroblasts) in the bone marrow due to heterogenous germline mutations leading to defects in mitochondrial heme synthesis, iron-sulfur (Fe-S) cluster biogenesis, or protein synthesis. Patients present with anaemia and relative reticulocytopenia, and systemic iron overload secondary to chronic ineffective erythropoiesis, leading to end-organ damage. The disease is heterogenous underlying the genetic variability and the variable response to treatment. Although a number of CSA patients have received a bone marrow transplant, the outcomes and toxicities are not known. This status makes it very difficult to understand the role of BMT in the management of CSA. A search in the EBMT database identified 28 patients receiving a HSCT for CSA between 1998 to 2018 by 24 participating centres. The median year of transplantation was 2014 (IQR 2004-2016). The distribution was equal between males (n=14) and females (n=14). The median age at transplantation was 7 years of age (3-10 years). Fifteen patients had a sibling HSCT (88%), one a family matched donor HSCT (6%) and one an unrelated matched (6%), the type of transplant being unknown in others (n=11). The source of stem cells was bone marrow in 20 cases (74%), peripheral blood in 4 cases (15%), cord blood in 2 (7%) and combined bone marrow and cord in one (4%). Five cases had a Bu/Cy based conditioning regimen, 4 had Bu/fludarabine based regimen and three fludarabine/treosulfan based conditioning with the rest having a variety of approaches. Eighty-six percent of cases had serotherapy with ATG or alemtuzumab. The median follow-up was 31.6 months (95% CI, 12.2-74.1%). The overall survival at 12 and 24 months was 88% (76-100) and 82% (66-99), respectively (figure 1). The median neutrophil engraftment was 18 (15-21) days and platelet engraftment >20 x 109/L was 29 (20-51) days, with a graft failure incidence of 7% (0-17) at 12 months. Two patients suffered from VOD. There were four deaths, three of which were related to transplant complications. The event free survival (survival without graft failure, relapse and second transplant) at 12 and 24 months was 85% (72-99) (figure 2). Six patients developed acute GvHD grade II and one case grade III; giving a grade II/III incidence of 28% (10-46). There was one case of limited and one of chronic GvHD, giving an incidence of 11% (0-26%) at 12 months and 24 months. In conclusion, whilst HSCT for CSA is a rare occurrence, these data demonstrate that HSCT for this condition is feasible and the outcomes are in keeping with those obtained for transplantation for transfusion dependent anaemias during the same time-period. Disclosures Handgretinger: Amgen: Honoraria. Moraleda:Gilead: Consultancy, Other: Travel Expenses; Jazz Pharmaceuticals: Consultancy, Research Funding; Novartis: Consultancy, Other: Travel Expenses; Sandoz: Consultancy, Other: Travel Expenses; Takeda: Consultancy, Other: Travel Expenses. Risitano:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Alnylam: Research Funding; Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Jazz: Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees; Samsung: Membership on an entity's Board of Directors or advisory committees; Amyndas: Consultancy; RA pharma: Research Funding; Biocryst: Membership on an entity's Board of Directors or advisory committees; Apellis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Achillion: Membership on an entity's Board of Directors or advisory committees; Pfizer: Speakers Bureau. Peffault De Latour:Amgen: Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Apellis: Membership on an entity's Board of Directors or advisory committees; Alexion Pharmaceuticals Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Introduction Young patients with idiopathic aplastic anemia (AA) respond better to immunosuppressive therapy (IST) but the long-term outcome is suboptimal with non-response in 30% of patients as well as significant risks of relapse, ciclosporine (CSA) dependence and clonal evolution. Excellent results of up-front unrelated donor (UD) hematopoietic stem cell transplantation (HSCT) have been reported in a cohort of 29 children with idiopathic AA using an Alemtuzumab-based regimen, with low Graft versus Host Disease (GvHD) rates and only 1 death (Dufour C, BJH 2015). We took advantage of the SAAWP registry of the European Blood and Marrow Transplantation (EBMT) to analyze the outcomes of 65 young patients who received up-front UD HSCT in Europe. Methods : Patients who had received an UD HSCT for AA, between 2010 and 2018, registered in the SAAWP registry were included. Patients who had received IST (CSA or anti-thymocyte globulin (ATG)) before HSCT, cord blood, haplo-identical transplant were excluded as well as patients suffering from congenital bone marrow disorders. The primary endpoint was overall survival (OS) at 2 years. Secondary endpoints were GVHD-free/relapse-free survival (GRFS) - defined at 2 years as being alive, engrafted without acute GVHD grade III-IV, and extensive chronic GVHD during follow-up. Results : Sixty-five patients were included between 2010 and 2018; median age was 16 years old (9-26). Time to HSCT was 6.5 months (IQR 3.6-11.7). Thirty-nine patients were transplanted from a matched unrelated donor (at least 8/8 HLA matched), 11 patients had mismatched UD (HLA data missing for 14 patients). The two-year overall survival rate was 92% (95% CI, 85-99%) (figure 1,A) with a median follow-up of 32 months (25-43). Main cause of death was infection (2 out of 5 deaths). Failure occurred in 8% (1-15%) of the patients. Acute GVHD grade II-IV was observed in 13% (5-22%) of the patients and Grade III and IV happened for two patients (3%). Chronic GVHD at 2 years occurred for 12% (4-21%) of the patients, with no extensive case. GRFS was 87% (77-96%) at 2-years (Figure 1, B). In our cohort, 57 patients received in vivo T cell depletion using either ATG (n=33, 60%) or anti-lymphocyte globulin (n=4, 7%) or alemtuzumab (n=20, 30%). Due to low rate of events happening during outcome, no risk factor analysis could be driven. Conclusion: In this retrospective cohort of 65 patients with idiopathic aplastic anemia, up-front UD transplantation leads to promising results, confirming previous studies on a smaller cohort of patients. Moreover, we did not find any difference according to in vivo T-cell depletion type, suggesting excellent results are not exclusively related to alemtuzumab-based regimen. Because of obvious limitation related to retrospective studies, unreported events and information bias cannot be excluded. Prospective trials are on their way in the United States and in Europe to formally confirm upfront UD transplantation as standard of care for pediatric patients with idiopathic aplastic anemia. Disclosures Rambaldi: Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Research grant from Amgen Inc.; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Advisory board and speaker fees from Pfizer.; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support from Gilead.; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support of parent study and funding of editorial support. Received travel support., Research Funding; University of Milan: Current Employment; BMS/Celgene: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Astellas: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Sanofi: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Omeros: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Griškevičius:Novartis: Research Funding. Dalle:Sanofi-Genzyme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Orchard: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Medac: Consultancy, Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria; Bellicum: Consultancy, Honoraria; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; bluebird bio: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Risitano:Pfizer: Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Alnylam: Research Funding; Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amyndas: Consultancy; Samsung: Membership on an entity's Board of Directors or advisory committees; RA pharma: Research Funding; Biocryst: Membership on an entity's Board of Directors or advisory committees; Apellis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Achillion: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Jazz: Speakers Bureau. Peffault De Latour:Apellis: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Research Funding; Alexion Pharmaceuticals Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Summary Background We previously showed that human anti-T-lymphocyte globulin (ATLG) plus ciclosporin and methotrexate given to patients with acute leukaemia in remission, having allogeneic haemopoietic stem-cell transplantation with peripheral blood stem cells from an HLA-identical sibling donor after myeloablative conditioning, significantly reduced 2-year chronic graft-versus-host disease (cGVHD) incidence and severity, without increasing disease relapse and infections, and improves cGVHD-free and relapse-free survival (cGRFS). The aim of an extended follow-up study was the assessment of long-term outcomes, which are, in this context, scarcely reported in the literature. We report unpublished data on quality of life (QoL) from the original study and the results of a follow-up extension. Methods In the original open-label study, patients with acute myeloid and lymphoblastic leukaemia in first or subsequent remission, having sibling HLA-identical allogeneic peripheral blood stem-cell transplantation, were randomly assigned (1:1) to receive ATLG plus standard GVHD prophylaxis with ciclosporin and short-term methotrexate (ATLG group) or standard GVHD prophylaxis without ATLG (non-ATLG group). Conditioning regimens were cyclophosphamide 120 mg/kg with either total body irradiation (12 Gy) or busulfan (12·8 mg/kg intravenously or 16 mg/kg orally), with or without etoposide (30–60 mg/kg). Randomisation was stratified according to centre and disease risk. The primary endpoint was cumulative incidence of cGVHD at 2 years. The primary and secondary endpoints, excluding QoL, have been published. QoL, assessed using European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-HDC29 questionnaires, was an unpublished secondary endpoint, which we now report here. A follow-up extension was then done, with the primary endpoint cumulative incidence of cGVHD. Enrolment has been completed for both studies. The original trial (number, NCT00678275 ) and follow-up extension (number, NCT03042676 ) are registered at ClinicalTrials.gov . Findings In the original study, from Dec 14, 2006, to Feb 2, 2012, 161 patients were enrolled and 155 were randomly assigned to either the ATLG group (n=83) or to the non-ATLG group (n=72). In the follow-up study, which started on Feb 7, 2017, and was completed on June 30, 2017, 61 patients were included in the ATLG group and 53 were included in the non-ATLG group. Global health status showed a more favourable time course in the ATLG group compared with the non-ATLG group (p=0·02; treatment by visit interaction). ATLG was descriptively superior to non-ATLG at 24 months for physical function (points estimate −14·8 [95% CI −26·4 to −3·1]; p=0·014) and social function (–19·1 [–38·0 to −0·2]; p=0·047), gastrointestinal side-effects (8·8 [2·5–15·1]; p=0·008) and effect on family (13·5 [1·2–25·8]; p=0·032). Extended follow-up (median 5·9 years [IQR 1·7–7·9]) confirmed a lower 5-year cGVHD incidence (30·0% [95% CI 21·4–41·9] vs 69·1% [59·1–80·1]; analysis for entire follow-up, p Interpretation The addition of ATLG to standard GVHD prophylaxis improves the probability of surviving without disease relapse and cGVHD after myeloablative peripheral blood stem-cell transplantation from an HLA-identical sibling donor for patients with acute leukaemia in remission. Further additional benefits are better QoL and shorter immunosuppressive treatment compared with standard GVHD prophylaxis without ATLG. Therefore, in this setting, ATLG plus standard GVHD prophylaxis should be preferred over the standard GVHD prophylaxis alone. Funding Neovii Biotech.

Persistent cytopenia due to poor graft function (PoGF) is a relatively common complication which may affect up to 20% of patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Treatment options for PoGF remain limited, and reinfusion of additional HSC is often the only way to rescue hematopoiesis. Here we describe a retrospective single-center experience with the thrombopoietin-mimetic agent eltrombopag for the treatment of PoGF. Thirteen patients have received eltrombopag for either PoGF (n = 12) or primary graft failure (n = 1). In the 12 PoGF patients eltrombopag was started at the median time of 79 days after HSCT, due to persistent thrombocytopenia, with concomitant anemia and neutropenia in 7 and 3 patients, respectively. The treatment was started at the dose of 50 mg per day, and eventually increased up to 150 mg in case of lack of response. Hematological response was seen in 7 patients, with 6 complete responses. Hematological responses were seen both in patients with evidence of immune-mediated pathophysiology, and with possible infectious/iatrogenic causes. In responding patients, eltrombopag was discontinued in 6/7 patients without further relapse. These results suggest that eltrombopag is safe and possibly effective in the setting of the treatment of PoGF, and pave the way for future prospective studies.

Data on stem cell transplantation (SCT) for Diamond-Blackfan Anemia (DBA) is limited. We studied patients transplanted for DBA and registered in the EBMT database. Between 1985 and 2016, 106 DBA patients (median age, 6.8 years) underwent hematopoietic stem cell transplantation from matched-sibling donors (57%), unrelated donors (36%), or other related donors (7%), using marrow (68%), peripheral blood stem cells (20%), both marrow and peripheral blood stem cells (1%), or cord blood (11%). The cumulative incidence of engraftment was 86% (80% to 93%), and neutrophil recovery and platelet recovery were achieved on day +18 (range, 16 to 20) and +36 (range, 32 to 43), respectively. Three-year overall survival and event-free survival were 84% (77% to 91%) and 81% (74% to 89%), respectively. Older patients were significantly more likely to die (hazard ratio, 1.4; 95% confidence interval, 1.06 to 1.23; P < .001). Outcomes were similar between sibling compared to unrelated-donor transplants. The incidence of acute grades II to IV of graft-versus-host disease (GVHD) was 30% (21% to 39%), and the incidence of extensive chronic GVHD was 15% (7% to 22%). This study shows that SCT may represent an alternative therapeutic option for transfusion-dependent younger patients. (C) 2021 Published by Elsevier Inc. on behalf of The American Society for Transplantation and Cellular Therapy.

Allogeneic hematopoietic cell transplantation (HCT) is the only curative option for bone marrow failure or hematopoietic malignant diseases for Fanconi anemia (FA) patients. Although results have improved over the last decades, reaching more than 90% survival when a human leukocyte antigen (HLA)-identical donor is available, alternative HCT donors are still less reported. We compared HCT outcomes using HLA-mismatched unrelated donors (MMUD; n = 123) or haplo-identical donors (HDs), either using only in vivo T cell depletion (n = 33) or T cells depleted in vivo with some type of graft manipulation ex vivo (n = 59) performed for FA between 2000 and 2018. Overall survival (OS) by 24 months was 62% (53–71%) for MMUD, versus 80% (66–95%) for HDs with only in vivo T cell depletion and 60% (47–73%) for HDs with in vivo and ex vivo T cell depletion (p =.22). Event-free survival (EFS) was better for HD-transplanted FA patients with only in vivo T cell depletion 86% (73–99%) than for those transplanted from a MMUD 58% (48–68%) or those with graft manipulation 56% (42–69%) (p =.046). Grade II-IV acute graft-versus-host disease (GVHD) was 41% (MMUD) versus 40% (HDs with no graft manipulation) versus 17% (HDs with T cell depleted graft), (p =.005). No differences were found for the other transplant related outcomes. These data suggest that HDs might be considered as an alternative option for FA patients with better EFS using unmanipulated grafts. © 2021 Wiley Periodicals LLC., The authors are particularly thankful to all centers from the Severe Aplastic Anemia Working Party and the Pediatric Diseases Working Party of the European Society for Blood and Marrow Transplantation, who kindly agreed to participate in this study (see Appendix S1). We would also like to thank Anne E. Lippinkhof, Study Coordinator, Severe Aplastic Anemia Working Party for her invaluable help.

Context: Pegcetacoplan (PEG) is a C3 complement inhibitor recently approved by the FDA for the treatment of paroxysmal nocturnal hemoglobinuria (PNH). PEG was superior to eculizumab (ECU; C5-inhibitor) in improving hemoglobin levels at week 16 during the phase 3 PEGASUS trial (NCT03500549) in patients with suboptimal response to prior ECU treatment. Objective: We report on efficacy and safety of PEG and results from a post hoc time-aligned analysis based on start of PEG dosing. Design: Eighty PNH patients (≥18 years, hemoglobin levels Results: PEG-to-PEG patients achieved sustained improvements in hemoglobin levels at week 16 through the OLP (week 48 mean hemoglobin level: 11.3 g/dL; CFB: 2.5 g/dL). ECU-to-PEG patients displayed improved hemoglobin levels during the OLP (week 48 mean hemoglobin level: 11.6 g/dL; CFB: 2.9 g/dL). Timepoint alignment demonstrated no significant difference (p=0.64) between improvements in hemoglobin levels at 28 and 48 weeks among PEG-to-PEG and ECU-to-PEG groups, respectively. Thirty percent of patients reported a serious AE, 6% possibly PEG-related. Common AEs for PEG-treated patients were injection site reactions (36%), hemolysis (24%), and diarrhea (21%). Twelve patients (15%) discontinued PEG due to AEs: 3 in RCP, 8 in OLP, 1 during follow-up, including one death due to COVID-19, unrelated to PEG. Conclusions: PEG-treated patients experienced sustained improvements in hemoglobin levels at week 48, and the safety profile of PEG was consistent with previously reported data. The treatment effect of PEG on hemoglobin levels over time was similar between PEG-to-PEG and ECU-to-PEG groups. Thus, PEG represents a new effective therapeutic option for PNH patients.

Context The standard of care in PNH is anti-C5 monoclonal antibody (MAb) treatment with eculizumab (ECU) or ravulizumab (RAV), but hematological responses can be heterogenous. Iptacopan (LNP023) is a first-in-class, oral, small-molecule, selective and reversible complement factor B inhibitor that inhibits both intra- and extravascular hemolysis. In an ongoing Ph2 study (NCT03439839), iptacopan add-on treatment demonstrated improvements in hematological response and biomarkers of disease activity in adult PNH patients with active hemolysis despite ECU treatment. Objective APPLY-PNH (NCT04558918) will assess efficacy and safety of iptacopan monotherapy in adult PNH patients with residual anemia despite prior anti-C5 MAb treatment by evaluating its superiority to anti-C5 MAb treatment. Design The study comprises an ≤8-wk screening period; 24-wk, randomized, open label, active controlled, parallel group treatment period; and 24-wk treatment extension period. Patients (N≈91) are randomized (8:5) to iptacopan monotherapy 200mg orally BID (seamless switch from prior treatment) or intravenous ECU/RAV (continue prior treatment). Patients are stratified based on prior anti-C5 treatment and transfusion history. On completion of Wk 24 visit, patients may enter 24-wk iptacopan treatment extension. Eligible patients must have confirmed diagnosis of PNH (RBCs and WBCs [granulocyte/monocyte] clone size ≥10%) and residual anemia (mean Hb Conclusions This study will be the first head-to-head comparison of iptacopan vs an anti-C5 MAb in PNH patients. Study sponsored by Novartis Pharmaceuticals Corporation.

Some patients with paroxysmal nocturnal hemoglobinuria (PNH) remain persistently anemic despite treatment with eculizumab and may have significant extravascular hemolysis. Kulasekararaj and colleagues report a phase 2 trial of danicopan, a first-inclass oral complement factor D inhibitor, added to ongoing eculizumab therapy in PNH patients who still needed transfusions. This small study of 12 patients reveals that the combination has acceptable safety while substantially increasing the hemoglobin concentration, reducing extravascular hemolysis, and improving the fatigue score., Key Points Danicopan, a first-in-class oral factor D inhibitor showed clinical benefit when given in addition to eculizumab in patients with PNH.Addition of danicopan reduced extravascular hemolysis and improved anemia in patients with PNH with suboptimal eculizumab response., Visual Abstract, Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by uncontrolled terminal complement activation and subsequent intravascular hemolysis (IVH). C5 inhibitors prevent membrane attack complex formation, but patients may experience extravascular hemolysis (EVH) and continue to require blood transfusions. Danicopan, an oral proximal complement inhibitor of alternative pathway factor D (FD), is designed to control IVH and EVH. In a phase 2 dose-finding trial, eculizumab-treated transfusion-dependent patients with PNH (n = 12) received danicopan, 100 to 200 mg thrice daily, in addition to their eculizumab regimen for 24 weeks. End points included hemoglobin (Hgb) change vs baseline at week 24 (primary), reduction in blood transfusions, and patient-reported outcomes. Safety, tolerability, and pharmacokinetics/pharmacodynamics were measured. Twelve patients received ≥1 danicopan dose; 1 patients discontinued from a serious adverse event deemed unlikely related to danicopan. Eleven patients completed the 24-week treatment period. Addition of danicopan resulted in a mean Hgb increase of 2.4 g/dL at week 24. In the 24 weeks prior to danicopan, 10 patients received 31 transfusions (50 units) compared with 1 transfusion (2 units) in 1 patient during the 24-week treatment period. Mean Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue score increased by 11 points from baseline to week 24. The most common adverse events were headache, cough, and nasopharyngitis. Addition of danicopan, a first-in-class FD inhibitor, led to a meaningful improvement in Hgb and reduced transfusion requirements in patients with PNH who were transfusion-dependent on eculizumab. These benefits were associated with improvement of FACIT-Fatigue. This trial was registered at www.clinicaltrials.gov as #NCT03472885.

Eculizumab is first-line treatment for paroxysmal nocturnal hemoglobinuria (PNH); however, approximately 11%-27% of patients may experience breakthrough hemolysis (BTH) on approved doses of eculizumab. Ravulizumab, a new long-acting C5 inhibitor with a four-times longer mean half-life than eculizumab, provides immediate, complete, and sustained C5 inhibition over 8-week dosing intervals. In two phase 3 studies, ravulizumab was noninferior to eculizumab (Pinf ≤0.0004) for the BTH endpoint; fewer patients experienced BTH with ravulizumab versus eculizumab in both studies (301 [complement inhibitor-naive patients], 4.0% vs 10.7%; 302 [patients stabilized on eculizumab at baseline], 0% vs 5.1%). In the current analysis, patient-level data were evaluated to assess causes and clinical parameters associated with incidents of BTH reported during the 26-week treatment periods in the ravulizumab phase 3 PNH studies. Of the five BTH events occurring in ravulizumab-treated patients across the studies, none were temporally associated with suboptimal C5 inhibition (free C5 ≥0.5 μg/mL); four (80.0%) were temporally associated with complement-amplifying conditions (CACs). Of the 22 events occurring in eculizumab-treated patients, eleven were temporally associated with suboptimal C5 inhibition, including three events also associated with concomitant infection. Six events were associated with CACs only. Five events were unrelated to free C5 elevation or reported CACs. These results suggest that the immediate, complete, and sustained C5 inhibition achieved through weight-based dosing of ravulizumab reduces the risk of BTH by eliminating BTH associated with suboptimal C5 inhibition in patients with PNH. Clinicaltrials.gov identifiers: Study 301, NCT02946463; Study 302, NCT03056040.

This retrospective study assessed the effectiveness of eltrombopag (EPAG), a thrombopoietin receptor agonist, in the treatment of poor graft function (PGF) following an allogeneic haemopoietic stem cell transplantation (HSCT). Complete response was defined as normalization of blood counts, whereas partial response was defined as transfusion independence. A total of 48 patients with full donor chimerism after HSCT, received EPAG for a median of 120 days (range 10–591). Patients with uni- bi- or tri-lineage cytopenia started treatment at a median of 95 days (range 17–877) after HSCT. The overall response rate was 75%: 24 patients had a complete response and 12 had a partial response. Positive predictors of response were an HLA-matched donor, a CD34+ dose at transplant > 4 × 106/kg, and starting EPAG treatment at least 90 days after HSCT. Patients with more than one positive predictor had a response rate of 92% for the overall patient cohort and 94% for patients with tri-lineage cytopenia. One-year survival was 89% for complete responders, 60% for partial responders and 20% for non-responders (p = 0.0004). EPAG improves peripheral blood counts in patients with poor graft function following HSCT. Response to EPAG can be predicted and has a significant impact on survival.

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by complement-mediated intravascular hemolysis due to the absence of complement regulators CD55 and CD59 on affected erythrocytes. Danicopan is a first-in-class oral proximal, complement alternative pathway factor D inhibitor. Therapeutic factor D inhibition was designed to control intravascular hemolysis and prevent C3-mediated extravascular hemolysis. In this open-label, phase II, dose-finding trial, ten untreated PNH patients with hemolysis received danicopan monotherapy (100-200 mg thrice daily). Endpoints included changes in the concentrations of lactate dehydrogenase (LDH) at day 28 (primary endpoint), of LDH at day 84, and of hemoglobin. Safety, pharmacokinetics/ pharmacodynamics, and patient-reported outcomes were assessed. Ten patients reached the primary endpoint; two later discontinued treatment: one because of a serious adverse event (elevated aspartate aminotransferase/ alanine aminotransferase coincident with breakthrough hemolysis, resolving without sequelae) and one for personal reasons unrelated to safety. Eight patients completed treatment. Intravascular hemolysis was inhibited, as demonstrated by a mean decrease of LDH (5.7 times upper limit of normal [ULN] at baseline vs. 1.8 times ULN at day 28 and 2.2 times ULN at day 84; both P

Background Crovalimab is a novel anti-complement C5 antibody currently being studied as a treatment for paroxysmal nocturnal hemoglobinuria (PNH), a life-threatening disease associated with hemolytic anemia and thrombosis. Treatment with approved C5 inhibitors eculizumab or ravulizumab is effective, but can be limited by breakthrough hemolysis due to unsustained C5 inhibition, inadequate efficacy in patients with C5 mutational variants, and the requirement of regular intravenous infusions. Crovalimab is unique in that its properties allow for subcutaneous injections once every 4 weeks (Q4W) that can be self-administered. Additionally, crovalimab binds to C5 mutational variants. Promising results were obtained in the Phase I/II COMPOSER trial (NCT03157635; Röth et al, Blood. 2020) conducted in patients with PNH, with or without prior anti-C5 treatment. The efficacy and safety of crovalimab vs eculizumab will be evaluated in two Phase III, randomized, open-label trials in patients with PNH, with or without current complement C5 inhibition. Study Design and Methods COMMODORE 1 (NCT04432584) will enroll patients who are currently receiving complement C5 inhibitor therapy. This trial is divided into two parts (Figure). Patients aged ≥ 18 years will be randomized 1:1 to receive either crovalimab (Arm A) or eculizumab (Arm B) and will contribute to the primary efficacy analysis. Patients aged < 18 years can be enrolled in an exploratory descriptive arm (Arm C). Arm A and C patients will receive crovalimab loading and subsequent subcutaneous Q4W maintenance dosing from Week 5. Arm B patients will receive eculizumab intravenous maintenance dosing from Day 1, Q2W for a total of 24 weeks. Patients in Arm A and Arm C can continue to receive crovalimab, and patients in Arm B can switch to crovalimab after 24 weeks of treatment, as determined by the treating physician. The primary efficacy objective is to determine the non-inferiority of crovalimab vs eculizumab based on percentage change in lactate dehydrogenase levels from baseline, averaged over weeks 21, 23, and 25. Secondary efficacy objectives are to determine the proportion of patients who experience breakthrough hemolysis, achieve transfusion avoidance or hemoglobin stabilization, as well as determine mean change in fatigue according to the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire from baseline to Week 25. Safety and tolerability of crovalimab vs eculizumab will also be evaluated along with pharmacokinetic, immunogenicity, biomarker, and health status utility objectives. COMMODORE 2 (NCT04434092) will enroll patients not currently treated with C5 complement inhibitors. This trial is also divided into two parts (Figure). Patients aged ≥ 18 years will be randomized 2:1 to receive either crovalimab (Arm A) or eculizumab (Arm B) and will contribute to the primary efficacy analysis. Patients aged < 18 years will be enrolled in an exploratory descriptive arm (Arm C). Arm A and C patients will receive crovalimab loading and subsequent subcutaneous Q4W maintenance dosing from Week 5. Arm B patients will receive induction doses of eculizumab intravenously QW for 4 weeks followed by maintenance dosing Q2W up to 24 weeks. Patients in Arm A and Arm C can continue to receive crovalimab, and patients in Arm B can switch to crovalimab, after 24 weeks of treatment, as determined by the treating physician. The primary efficacy objective is to determine the non-inferiority of crovalimab vs eculizumab, based on the proportion of patients who 1) achieve transfusion avoidance from baseline to Week 25 and 2) with hemolysis control from Week 5-25 (co-primary efficacy endpoints). Safety and tolerability of crovalimab vs eculizumab will also be evaluated along with pharmacokinetic, immunogenicity, biomarker, and health status utility objectives. Figure 1 Figure 1. Disclosures Kulasekararaj: F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Speakers Bureau; Apellis: Consultancy; Akari: Consultancy, Honoraria, Speakers Bureau; Biocryst: Consultancy, Honoraria, Speakers Bureau; Achilleon: Consultancy, Honoraria, Speakers Bureau; Alexion: Consultancy, Honoraria, Speakers Bureau; Ra Pharma: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Alexion, AstraZeneca Rare Disease Inc.: Consultancy, Honoraria, Other: Travel support. Risitano: Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Research Funding, Speakers Bureau; Alnylam: Research Funding; Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Research Funding, Speakers Bureau; Samsung: Membership on an entity's Board of Directors or advisory committees; Amyndas: Consultancy; RA Pharma: Research Funding; Biocryst: Membership on an entity's Board of Directors or advisory committees; Achillion: Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees; Jazz: Other: Lecture fees, Speakers Bureau; F. Hoffmann-La Roche Ltd.: Membership on an entity's Board of Directors or advisory committees; Pfizer: Other: Lecture fees, Speakers Bureau; Apellis Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Speakers Bureau. Roeth: Novartis: Consultancy, Honoraria; Bioverativ, a Sanofi company: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Research Funding; Apellis Pharmaceuticals: Consultancy, Honoraria; Kira: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Alexion Pharmaceuticals Inc.: Consultancy, Honoraria. He: LongBio Pharma: Consultancy, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy. Pu: University of Arizona: Current Employment; Pennsylvania State University: Patents & Royalties; F. Hoffmann-La Roche Ltd: Membership on an entity's Board of Directors or advisory committees. Wright: Genentech, Inc.: Current Employment. Appius: F. Hoffmann-La Roche Ltd.: Current Employment, Current equity holder in publicly-traded company. Sostelly: F. Hoffmann-La Roche Ltd: Current Employment. Sreckovic: F. Hoffmann-La Roche Ltd.: Current Employment. Stanzel: F. Hoffmann-La Roche Ltd.: Current Employment, Current equity holder in publicly-traded company. Munir: F. Hoffmann-La Roche: Consultancy; Alexion: Honoraria. Nishimura: Apellis: Consultancy; Novartis: Consultancy; Chugai: Consultancy; Sanofi: Consultancy; Alexion: Consultancy; Roche: Consultancy; Biocryst: Consultancy.

The haematological benefit of standard-of-care anti-C5 treatment for haemolytic paroxysmal nocturnal haemoglobinuria is limited by residual intravascular haemolysis or emerging C3-mediated extravascular haemolysis. Therefore, the aim of this phase 2 study was to assess the safety, tolerability, pharmacokinetics and pharmacodynamics, and activity of the new complement factor B inhibitor, iptacopan, in patients with paroxysmal nocturnal haemoglobinuria who have active haemolysis despite anti-C5 therapy.In this multicentre, open-label, single-arm, phase 2 trial, we enrolled adult patients (aged 18-80 years) with paroxysmal nocturnal haemoglobinuria who showed signs of active haemolysis despite receiving eculizumab treatment. Patients were enrolled at Federico II University Hospital (Naples, Italy), Hôpital Saint-Louis (Paris, France), and University Hospital Essen (Essen, Germany). For enrolment, patients were required to show lactate dehydrogenase more than 1·5-times the upper limit of normal and a paroxysmal nocturnal haemoglobinuria type 3 erythrocyte or granulocyte clone size of 10% or greater. Patients with bone marrow failure, on systemic steroid or immunosuppressive drugs, or with severe comorbidities were excluded from the study. Iptacopan was given orally as an add-on therapy at a dose of 200 mg twice daily. The primary endpoint was the effect of iptacopan on the reduction of chronic residual intravascular haemolysis measured as change in lactate dehydrogenase from baseline value to week 13. At 13 weeks, patients could opt into a long-term study extension (ongoing), allowing for modifications of standard treatment. This trial is registered at ClinicialTrials.gov, NCT03439839.Between May 31, 2018, and April 9, 2019, ten patients had twice daily 200 mg iptacopan. Iptacopan resulted in marked reduction of lactate dehydrogenase from baseline versus at week 13 (mean 539 IU/L [SD 263] vs 235 IU/L [44], change from baseline -309·2 IU/L [SD 265·5], 90% CI -473·77 to -144·68, p=0·0081), associated with significant improvement of haemoglobin concentrations (mean 97·7 g/L [SD 10·5] vs 129·5 g/L [18·3] change from baseline 31·9 g/L [14·5], 90% CI 23·42-40·28, p0·0001). All biomarkers of haemolysis improved on iptacopan treatment. Observed haematological benefits were maintained longer than the 13-week study period, throughout the study extension, including seven patients who stopped concomitant standard-of-care treatment and continued iptacopan as monotherapy. There were no deaths or treatment-related serious adverse events during the study period. Of three non-related serious adverse events, two occurred in the same patient (one during run-in and before exposure to iptacopan).Iptacopan at a chronic dose of 200 mg twice daily was well tolerated without any major drug-related safety findings and shows lactate dehydrogenase reduction and haemoglobin normalisation in most patients with paroxysmal nocturnal haemoglobinuria at week 13 and beyond, even in monotherapy. On the basis of these data, iptacopan will be tested as monotherapy in pivotal trials investigating its haematological benefit in a broader paroxysmal nocturnal haemoglobinuria population.Novartis Institutes for Biomedical Research.

Hepatitis-associated aplastic anemia (HAAA) is a rare illness, characterized by onset of pancytopenia with a hypoplastic bone marrow that traditionally occurs within 6 months of an increase in serum aminotransferases. HAAA is observed in 1% to 5% of all newly diagnosed cases of acquired aplastic anemia. Several hepatitis viruses have been linked to the disease, but in many cases no specific virus is detected. The exact pathophysiology is unknown; however, immune destruction of hematopoietic stem cells is believed to be the underlying mechanism. HAAA is a potentially lethal disease if left untreated. Management includes immunosuppression with antithymocyte globulin and cyclosporine and allogeneic hematopoietic stem cell transplantation.

Donor selection contributes to improve clinical outcomes of T-cell–replete haploidentical stem cell transplantation (haplo-SCT) with posttransplant cyclophosphamide (PT-Cy). The impact of donor age and other non-HLA donor characteristics remains a matter of debate. We performed a multicenter retrospective analysis on 990 haplo-SCTs with PT-Cy. By multivariable analysis, after adjusting for donor/recipient kinship, increasing donor age and peripheral blood stem cell graft were associated with a higher risk of grade 2 to 4 acute graft-versus-host-disease (aGVHD), whereas 2-year cumulative incidence of moderate-to-severe chronic GVHD was higher for transplants from female donors into male recipients and after myeloablative conditioning. Increasing donor age was associated with a trend for higher nonrelapse mortality (NRM) (hazard ratio [HR], 1.05; P = .057) but with a significant reduced risk of disease relapse (HR, 0.92; P = .001) and improved progression-free survival (PFS) (HR, 0.97; P = .036). Increasing recipient age was a predictor of worse overall survival (OS). Risk of relapse was higher (HR, 1.39; P < .001) in patients aged ≤40 years receiving a transplant from a parent as compared with a sibling. Moreover, OS and PFS were lower when the donor was the mother rather than the father. Pretransplant active disease status was an invariably independent predictor of worse clinical outcomes, while recipient positive cytomegalovirus serostatus and hematopoietic cell transplant comorbidity index >3 were associated with worse OS and PFS. Our results suggest that younger donors may reduce the incidence of aGVHD and NRM, though at higher risk of relapse. A parent donor, particularly the mother, is not recommended in recipients ≤40 years.

Patients who develop steroid-refractory acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic cell transplantation have poor prognosis, highlighting an unmet therapeutic need. In this open-label phase 2 study (ClinicalTrials.gov identifier: NCT02953678), patients aged at least 12 years with grades II to IV steroid-refractory aGVHD were eligible to receive ruxolitinib orally, starting at 5 mg twice daily plus corticosteroids, until treatment failure, unacceptable toxicity, or death. The primary end point was overall response rate (ORR) at day 28; the key secondary end point was duration of response (DOR) at 6 months. As of 2 July 2018, 71 patients received at least 1 dose of ruxolitinib. Forty-eight of those patients (67.6%) had grade III/IV aGVHD at enrollment. At day 28, 39 patients (54.9%; 95% confidence interval, 42.7%-66.8%) had an overall response, including 19 (26.8%) with complete responses. Best ORR at any time was 73.2% (complete response, 56.3%). Responses were observed across skin (61.1%), upper (45.5%) and lower (46.0%) gastrointestinal tract, and liver (26.7%). Median DOR was 345 days. Overall survival estimate at 6 months was 51.0%. At day 28, 24 (55.8%) of 43 patients receiving ruxolitinib and corticosteroids had a 50% or greater corticosteroid dose reduction from baseline. The most common treatment-emergent adverse events were anemia (64.8%), thrombocytopenia (62.0%), hypokalemia (49.3%), neutropenia (47.9%), and peripheral edema (45.1%). Ruxolitinib produced durable responses and encouraging survival compared with historical data in patients with steroid-refractory aGVHD who otherwise have dismal outcomes. The safety profile was consistent with expectations for ruxolitinib and this patient population.

Aplastic anemia (AA) is a serious hematological disorder, which is solely cured by hematopoietic stem cell transplantation (HSCT). Haploidentical HSCT is an emerging modality with encouraging outcomes in several blood conditions. The present study aims to comprehensively assess the feasibility and safety of haploidentical HSCT in patients with severe and very severe AA. It is a systematic review and meta-analysis of studies related to haploidentical stem cell transplantation in idiopathic AA investigating rates of successful engraftment, acute graft-versus-host disease (aGvHD), chronic GvHD (cGvHD), transplant-related mortality (TRM), and posttransplantation viral infections (including cytomegalovirus [CMV]) in patients with AA. The effects of reduced-intensity conditioning (RIC) and nonmyeloablative conditioning (NMA), as well as various GvHD prophylaxis regimens on these outcomes were evaluated. In total 15 studies were identified, (577 patients, 58.9% males), successful engraftment was observed in 97.3% of patients (95% CI, 95.9-98.7) while grades II-IV aGvHD and cGvHD were reported in 26.6% and 25.0%, respectively. The pooled incidence of TRM was 6.7% per year (95% CI, 4.0-9.4). RIC regimens were associated with higher proportions of successful engraftment (97.7% vs 91.7%, P = 0.03) and aGvHD (29.5% vs 18.7%, P = 0.008) when compared with NMA regimens with no differences in cGvHD or mortality incidence. When compared with methotrexate-containing regimens and other regimens, posttransplant cyclophosphamide-containing regimens reduced the rates of aGvHD (28.6%, 27.8%, and 12.8%, respectively, P = 0.02), CMV viremia (55.7%, 38.6%, and 10.4%, respectively, P < 0.001), and CMV disease in initially viremic patients (2.1%, 33.0%, and 0%, respectively, P < 0.001). We have concluded that Haploidentical HSCT was associated with promising outcomes in terms of successful engraftment and reduced complications. Future prospective trials are needed to identify the preferred conditioning regimen, GvHD prophylaxis, and graft source in the setting of haploidentical transplant for AA.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is curative for bone marrow failure in patients with Fanconi anemia (FA), but the presence of a malignant transformation is associated with a poor prognosis and the management of these patients is still challenging. We analyzed outcome of 74 FA patients with a diagnosis of myelodysplastic syndrome (n = 35), acute leukemia (n = 35) or with cytogenetic abnormalities (n = 4), who underwent allo-HSCT from 1999 to 2016 in EBMT network. Type of diagnosis, pre-HSCT cytoreductive therapies and related toxicities, disease status pre-HSCT, donor type, and conditioning regimen were considered as main variables potentially influencing outcome. The 5-year OS and EFS were 42% (30-53%) and 39% (27-51%), respectively. Patients transplanted in CR showed better OS compared with those transplanted in presence of an active malignant disease (OS:71%[48-95] vs 37% [24-50],P = .04), while none of the other variables considered had an impact. Twenty-two patients received pre-HSCT cytoreduction and 9/22 showed a grade 3-4 toxicity, without any lethal event or negative influence on survival after HSCT(OS:toxicity pre-HSCT 48% [20-75%] vs no-toxicity 51% [25-78%],P = .98). The cumulative incidence of day-100 grade II-IV a-GvHD and of 5-year c-GvHD were 38% (26-50%) and 40% (28-52%). Non-relapse-related mortality and incidence of relapse at 5-years were 40% (29-52%) and 21% (11-30%) respectively, without any significant impact of the tested variables. Causes of death were transplant-related events in most patients (34 out of the 42 deaths, 81%). This analysis confirms the poor outcome of transformed FA patients and identifies the importance of achieving CR pre-HSCT, suggesting that, in a newly diagnosed transformed FA patient, a cytoreductive approach pre-HSCT should be considered if a donor have been secured.

We have treated 69 patients with steroid refractory acute graft versus host disease (SR-aGvHD), with an anti-CD26 monoclonal antibody (Begelomab): 28 patients in two prospective studies (EudraCT No. 2007-005809-21; EudraCT No. 2012-001353-19), and 41 patients on a compassionate use study. The median age of patients was 42 and 44 years; the severity of GvHD was as follows: grade II in 8 patients, grade III in 33, and grade IV in 28 patients. There were no adverse events directly attributable to the antibody. Day 28 response was 75% in the prospective studies and 61% in the compassionate use patients, with complete response rates of 11 and 12%. Response for grade III GvHD was 83 and 73% in the two groups; response in grade IV GvHD was 66 and 56% in the two groups. Non relapse mortality (NRM) at 6 months was 28 and 38%. Overall there were 64, 56, 68% responses for skin, liver, and gut stage 3-4 GvHD. The overall survival at 1 year was 50% for the prospective studies and 33% for the compassionate use patients. In conclusion, Begelomab induces over 60% responses in SR-aGvHD, including patients with severe gut and liver GvHD, having failed one or more lines of treatment.

This follow-up study of a randomized, prospective trial included 192 patients with newly diagnosed severe aplastic anemia receiving antithymoglobulin and cyclosporine, with or without granulocyte colony-stimulating factor (G-CSF). We aimed to evaluate the long-term effect of G-CSF on overall survival, event-free survival, probability of secondary myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML), clinical paroxysmal nocturnal hemoglobinuria, relapse, avascular osteonecrosis and chronic kidney disease. The median follow-up was 11.7 years (95% CI, 10.9- 12.5). The overall survival rate at 15 years was 57±12% in the group given GCSF and 63±12% in the group not given G-CSF (P=0.92); the corresponding event-free survival rates were 24±10% and 23±10%, respectively (P=0.36). In total, 9 patients developed MDS or AML, 10 only a clonal cytogenetic abnormality, 7 a solid cancer, 18 clinical paroxysmal nocturnal hemoglobinuria, 8 osteonecrosis, and 12 chronic kidney disease, without any difference between patients treated with or without G-CSF. The cumulative incidence of MDS, AML or isolated cytogenetic abnormality at 15 years was 8.5±3% for the G-CSF group and 8.2±3% for the non-G-CSF group (P=0.90). The cumulative incidence of any late event including myelodysplastic syndrome or acute myeloid leukemia, isolated cytogenetic abnormalities, solid cancer, clinical paroxysmal nocturnal hemoglobinuria, aseptic osteonecrosis, chronic kidney disease and relapse was 50±12% for the G-CSF group and 49±12% for the non-G-CSF group (P=0.65). Our results demonstrate that it is unlikely ABSTRACT A. Tichelli that G-CSF has an impact on the outcome of severe aplastic anemia; nevertheless, very late events are common and eventually affect the prognosis of these patients, irrespectively of their age at the time of immunosuppressive therapy (NCT01163942). CA extern

Dyskeratosis congenita (DC) is a genetic multisystem disorder with frequent involvement of the bone marrow. Haematopoietic stem cell transplantation (HSCT) is the only definitive cure to restore haematopoiesis, even though it cannot correct other organ dysfunctions. We collected data on the outcome of HSCT in the largest cohort of DC (n = 94) patients ever studied. Overall survival (OS) and event-free survival (EFS) at 3 years after HSCT were 66% and 62%, respectively. Multivariate analysis showed better outcomes in patients aged less than 20 years and in patients transplanted from a matched, rather than a mismatched, donor. OS and EFS curves tended to decline over time. Early lethal events were infections, whereas organ damage and secondary malignancies appeared afterwards, even a decade after HSCT. A non-myeloablative conditioning regimen appeared to be most advisable. Organ impairment present before HSCT seemed to favour the development of chronic graft-versus-host disease and T-B immune deficiency appeared to enhance pulmonary fibrosis. According to the present data, HSCT in DC is indicated in cases of progressive marrow failure, whereas in patients with pre-existing organ damage, this should be carefully evaluated. Further efforts to investigate treatment alternatives to HSCT should be encouraged.

Therapeutic complement inhibition by eculizumab has revolutionized the treatment of paroxysmal nocturnal hemoglobinuria (PNH) with a major impact on its natural history. Nevertheless, emerging unmet clinical needs may benefit from the development of novel complement inhibitors. Novel strategies of complement inhibition exploit different agents targeting C5, as well as compound intercepting the complement cascade at the level of its key component C3, or even upstream at the level of components involved in complement alternative pathway initiation. Many of these agents are already in their clinical development; preliminary data together with a deep understanding of PNH biology may help to anticipate their possible clinical effect. Novel anti-C5 agents include monoclonal antibodies (even long-lasting) as well as other small molecules bioavailable by subcutaneous administration; an anti-C5 small interfering RNA has been developed too. All these anti-C5 agents seem to recapitulate safety and efficacy of current eculizumab treatment; their main improvement pertains to better patient's convenience due to longer dosing interval and/or possible subcutaneous self-administration. The possibility of achieving a deeper C5 inhibition has been shown as well, but its actual clinical meaning remains to be elucidated. Upstream complement inhibitors include the anti-C3 small peptide compstatin (and its derivatives), and small inhibitors of complement factor D or complement factor B. This class of compounds anticipates a possible efficacy in prevention of C3-mediated extravascular hemolysis, in addition to inhibition of intravascular hemolysis, eventually leading to improved hematological responses. The availability of all these compounds will result soon in a substantial improvement of PNH management.

We studied the impact of HLA mismatching on the outcome of 318 consecutive patients who received an unmanipulated haploidentical bone marrow transplant, followed by post-transplant cyclophosphamide (PTCy). The number of HLA-mismatched antigens was tested for its impact on overall survival (OS) and nonrelapse mortality (NRM), whereas HLA mismatches in the graft-versus-host (GVH) direction were tested for prediction of graft-versus-host disease (GVHD and relapse. Finally, we studied whether graft rejection correlated with the number of HLA mismatched antigens in host-versus-graft (HVG) direction. Two hundred thirty-one donor–recipient pairs (72%) had 4/8 mismatches at the -A, -B, -C, -DRB1 HLA loci. HLA mismatches did not predict the 2-year OS (hazard ratio, .83; P = .58) and NRM (subhazard ratio, 1.08; P = .93). The cumulative incidence of acute GVHD (P = .13), 1-year chronic GVHD (P = .84), and relapse rate (P = .26) did not correlate with univectorial GVH mismatches. Similarly, no correlation was observed between the amount of HLA mismatch in the HVG direction and graft rejection. In multivariate analysis advanced disease at transplant was the strongest predictor of survival, NRM, relapse, and graft rejection. In conclusion, the degree of HLA mismatching should not be used as a criterion to select family haploidentical donors when using bone marrow as stem cell source and PTCy for GVHD prophylaxis.

Background: Paroxysmal nocturnal hemoglobinuria (PNH) is a complement-mediated, hematologic disease characterized by hemolysis, anemia, and fatigue that impairs quality of life. Pegcetacoplan (PEG), a C3-inhibitor recently approved by the Food and Drug Administration for treatment of PNH, controls intravascular hemolysis (IVH) and prevents extravascular hemolysis (EVH). The PADDOCK and PALOMINO trials demonstrated PEG's improvement of key hematologic and clinical parameters, including hemoglobin (Hb) level and Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue score. The PEGASUS trial demonstrated that PEG was more effective than eculizumab (ECU) in improving these parameters in PNH patients with suboptimal response to prior ECU treatment. Aims: This post hoc analysis categorized hematologic response to PEG in 3 trials: PADDOCK (phase 1b, open-label, two-cohort [NCT02588833]), PALOMINO (phase 2a, open-label, single-cohort [NCT03593200]), and PEGASUS (phase 3, randomized, open-label, active-comparator controlled [NCT03500549]). Methods: PADDOCK and PALOMINO included adult complement inhibitor-naïve patients, while PEGASUS included adult patients with Hb Hematologic response category was assessed at Days 113/337 for patients in the combined PADDOCK/PALOMINO trials (N=24) via manual categorization by two independent, blinded observers. Categorization was assessed at Weeks 16/48 for PEGASUS patients (N=80) using SAS 9.4M5. Statistical significance for hematologic response categories within arms at Week 16 vs. 48, and between arms at Week 48, was evaluated using Wilcoxon-Mann-Whitney and Chi-square testing. FACIT-Fatigue scores for PEGASUS patients, summarized using descriptive statistics, were also correlated to hematologic response category. Response categories were defined per the following criteria (Risitano A, et al., Front Immunol, 2019;10:1157): complete- no transfusions required, stable Hb (normal range), no evidence of hemolysis (lactate dehydrogenase [LDH]≤1.5×upper limit of normal [ULN] U/L, absolute reticulocyte count [ARC]≤150,000/µL); major- no transfusion, normal Hb, but with evidence of hemolysis (LDH>1.5×ULN U/L and/or ARC>150,000/µL); good- no transfusions, but with chronic mild anemia or evidence of hemolysis; partial- chronic moderate anemia and/or occasional transfusions (6 units/6 months). PADDOCK/PALOMINO patients missing data at an assessment timepoint, or PEGASUS patients missing data within 6 weeks prior to an assessment timepoint, were not evaluated. Results: Most PADDOCK/PALOMINO patients achieved at least a good hematologic response at Days 113 and 337 (Table 1). At Week 48, most patients in both PEGASUS arms achieved a good/major/complete hematologic response (inter-arm p=0.4390), with a significant increase in the percent of ECU-to-PEG patients achieving at least a good response after switching to PEG at Week 16 (Week 16 vs. 48: intra-arm p Conclusions: In post hoc analyses of PADDOCK, PALOMINO, and PEGASUS trial data, a substantial proportion of patients achieved and maintained good, major, or complete hematologic responses to PEG, suggesting that PEG can lead to sustained improvements in hematologic parameters. PEGASUS data also demonstrated correlation of improved hematologic response category with clinically meaningful improvements in quality of life, as measured by FACIT-Fatigue. Figure 1 Figure 1. Disclosures Risitano: Jazz: Other: Lecture fees, Speakers Bureau; Achillion: Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees; Biocryst: Membership on an entity's Board of Directors or advisory committees; RA Pharma: Research Funding; Amyndas: Consultancy; Samsung: Membership on an entity's Board of Directors or advisory committees; Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Research Funding, Speakers Bureau; Alnylam: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Research Funding, Speakers Bureau; F. Hoffmann-La Roche Ltd.: Membership on an entity's Board of Directors or advisory committees; Pfizer: Other: Lecture fees, Speakers Bureau; Apellis Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Speakers Bureau. Wong: Roche: Consultancy, Honoraria, Research Funding, Speakers Bureau; Apellis Pharmaceuticals: Research Funding, Speakers Bureau; Alexion: Consultancy, Honoraria, Research Funding, Speakers Bureau. Al-Adhami: Apellis Pharmaceuticals: Current Employment. Chen: Apellis Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Peffault De Latour: Swedish Orphan Biovitrum AB: Consultancy, Honoraria; Apellis Pharmaceuticals: Consultancy, Honoraria; Alexion Pharmaceuticals: Consultancy, Honoraria, Research Funding; Amgen: Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding.

Background: Outcomes of Haploidentical transplantation (HaploSCT) in adult patients (pts) with acute relapsed/refractory lymphoblastic leukemia (Rel/Ref ALL) are comparable to unrelated donor transplants. We have recently reported that results of HaploSCT for ALL in remission are not significantly different from those receiving transplants from matched sibling donors (MSD). However, results may differ in ALL pts with active disease. Aim: To compare outcomes of HaploSCT and MSD transplantations in pts with Rel/Ref ALL. Methods: We retrospectively analyzed adult patients (≥ 18 years) with Rel/Ref ALL who underwent their first transplantation between 2012 and 2020, either from a T cell replete Haplo or MSD donor. Multivariate analysis (MVA) adjusting for differences between the groups was performed using the Cox proportional- hazards regression model. Results: The analysis comprised 274 pts: HaploSCT-94 (34%); MSD-180 (66%). Median follow-up was 32 months. Median age was 33 (range 18-76) and 37 (18-76) years in HaploSCT and MSD, respectively. Median year of transplant was similar being 2015 and 2016, respectively. The percentage of pts transplanted in the primary refractory phase was lower in HaploSCT than in MSD (31.9% vs 55.0 %,), while more HaploSCT pts were in second Rel (33% vs 11.1%) , p < 0.0001. 53.3% had T ALL, 25.5% Philadelphia chromosome (Ph) negative (-) while 21.2% had Ph positive (+) B ALL, with no difference in ALL subtypes between the groups. Cytomegalovirus (CMV) seropositivity was 83.9% and 73.4% (p < 0.053), respectively. Karnofsky performance status score (KPS) (>90) did not differ between the donor groups (59.8% vs 64.7%, p < 0.43) .Fewer pts undergoing HaploSCT received myeloablative conditioning (67% vs 84%, p < 0.001) and total body irradiation (32% vs 68%, p < 0.0001). A higher proportion of the HaploSCTs were performed using a bone marrow graft (44% vs 10%, p < 0.0001). Graft-versus-host disease (GVHD) prophylaxis was mainly post-transplant cyclophosphamide (PTCy)-based (88%) in the HaploSCT setting, while it was mostly pharmacologic (96%) in the setting of MSD (25% and 23% respectively, received ATG, p =0.77). Cumulative incidence of engraftment at day 60 was higher in MSD transplants compared to HaploSCT (96% vs 87%, p = 0.005), respectively. Remission of Rel/Ref pts post HaploSCT and MSD transplants was achieved by 64% and 69%, respectively. Day 180 incidence of acute (a) GVHD II-IV did not differ between HaploSCT and MSD (28% vs 21%, p=0.25) while grade III-IV was higher in HaploSCT than in MSD (18% vs 9%, p=0.042), respectively. Conversely, the 2-year chronic (c) GVHD and extensive cGVHD rates were 17% vs 33% (p = 0.012) and 5% vs 17% (p = 0.011) in HaploSCT vs MSD, respectively. Main causes of death were leukemia (64% vs 63%), infection (16% vs 18%) and GVHD (13% vs 11%) for HaploSCT and MSD, respectively. Two-year ReI (57% vs 52%) and non-relapse mortality (NRM) (25% vs 18%) were similar between HaploSCT and MSD groups, respectively, while leukemia-free survival (LFS), overall survival ( OS) and GVHD-free, relapse-free survival (GRFS) in the HaploSCT group were lower compared to the MSD group with 18% vs 31%, p=0.023; 22% vs 38%, p=0.001, and 16% vs 19%, p=0.06, respectively. In the MVA, NRM was significantly higher in HaploSCT in comparison with MSD with a hazard ratio (HR) = 2.03 (95% CI 1.03-4.02, p = 0.042) which translated to a significantly lower OS with HaploSCT vs MSD transplants (HR = 1.72, 95% CI 1.15-2.58, p < 0.009). No difference was observed in other transplant outcomes between the two groups including Rel, LFS and GRFS: HR = 0.97 (95% CI 0.62-1.52, p = 0.89); HR =1.22 (95% CI 0.84-1.78, p = 0.3) and HR = 1.31 (95% CI 0.88-1.94, p = 0.18), respectively. Similarly, aGVHD and cGVHD did not differ significantly in MSD transplants vs HaploSCT (HR = 1.85, 95% CI 0.99-3.46, p = 0.054) and (HR = 0.56, 95% CI 0.26-1.21, p = 0.14),respectively. No interactions were observed between disease phenotype and status. Conclusions: Two-year OS of Rel/Ref ALL pts undergoing MSD transplants is significantly better than in HaploSCT with a higher NRM with the latter. Both procedures are hampered by high (50-~60%) relapse rates which interestingly, did not differ between HaploSCT and MSD transplants. The emerging humoral and cellular immunotherapies recently approved for ALL may enable reduction of post transplantation relapse and thus improve transplantation outcomes for Rel/Ref ALL. Figure 1 Figure 1. Disclosures Labopin: Jazz Pharmaceuticals: Honoraria. Yakoub-Agha: Jazz Pharmaceuticals: Honoraria. Kulagin: X4 Pharmaceuticals, Alexion, Apellis, Biocad: Research Funding; Novartis, Generium, Sanofi, Roche, Johnson & Johnson, Pfizer: Speakers Bureau. Angelucci: Blue Bird Bio: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene BSM: Honoraria, Other: DMC; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Crispr therapeutics: Honoraria, Other: DMC; Glaxo: Honoraria, Membership on an entity's Board of Directors or advisory committees; Vertex Pharmaceuticals: Honoraria, Other: DMC; Menarini-Stemline: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: steering commitee, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Risitano: Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Research Funding, Speakers Bureau; Samsung: Membership on an entity's Board of Directors or advisory committees; Amyndas: Consultancy; RA Pharma: Research Funding; Biocryst: Membership on an entity's Board of Directors or advisory committees; Achillion: Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees; Jazz: Other: Lecture fees, Speakers Bureau; F. Hoffmann-La Roche Ltd.: Membership on an entity's Board of Directors or advisory committees; Pfizer: Other: Lecture fees, Speakers Bureau; Alnylam: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Research Funding, Speakers Bureau; Apellis Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Speakers Bureau. Ciceri: IRCCS Ospedale San Raffaele: Current Employment. Peric: Therakos: Honoraria; servier: Honoraria; MSD: Honoraria; Astellas: Honoraria; NOVARTIS: Honoraria; Abbvie: Honoraria; Pfizer: Honoraria. Giebel: Janssen: Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau. Mohty: Sanofi: Honoraria, Research Funding; Pfizer: Honoraria; Novartis: Honoraria; Takeda: Honoraria; Jazz: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Gilead: Honoraria; Celgene: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria; Astellas: Honoraria; Amgen: Honoraria; Adaptive Biotechnologies: Honoraria.

Context Standard of care in PNH is based on complement C5 inhibition with anti-C5 monoclonal antibodies (MAbs), which are generally effective at treating intravascular hemolysis (IVH), but unmet needs remain. Hematological responses to anti-C5 antibody treatment can be heterogeneous, and a substantial number of patients experience residual anemia associated with breakthrough hemolysis (BTH). Iptacopan, a first-in-class, oral, small-molecule, selective, and reversible complement factor B inhibitor, inhibits both IVH and extravascular hemolysis. In an ongoing Ph2 study (NCT03439839), iptacopan has demonstrated improvements in hematological response and biomarkers of disease activity in PNH adult patients who had active hemolysis, despite eculizumab treatment. Objective APPOINT-PNH study (NCT04820530) will assess iptacopan efficacy and safety in PNH adult patients naive to complement inhibitors, including anti-C5 MAbs. Design The study comprises ≤8-wk screening; 24-wk, single-arm, open-label core treatment; and 24-wk, open-label treatment extension. On completion of week 24, patients who benefit from iptacopan treatment can enter extension. Eligible adult patients (N≈40) have confirmed PNH diagnosis (RBCs and WBCs [granulocyte/monocyte] clone size ≥10%); anemia (mean Hb 1.5× ULN). Key exclusion criteria: prior treatment with complement inhibitor; known or suspected hereditary complement deficiency; history of HSCT; laboratory evidence of bone marrow failure; active, systemic infection ≤14 days preceding study treatment; and history of recurrent, invasive infections caused by encapsulated microorganisms. Primary objective will assess hematologic response, defined as achieving sustained increase in Hb ≥2g/dL (in absence of RBC transfusions). Primary endpoint will evaluate proportion of patients achieving an increase from baseline in Hb ≥2g/dL between D126–D168 (in absence of RBC transfusions between D14–D168). Secondary endpoints include proportion of patients reaching Hb ≥12g/dL; absence of RBC transfusions; changes from baseline in Hb; changes in FACIT-Fatigue scores; changes from baseline in reticulocytes; % change from baseline in LDH; occurrence of BTH; and occurrence of major adverse vascular events (including thrombosis). Additional analyses include safety assessments; evolution of PNH clone size and C3d deposition on RBCs; and other PROs. Conclusions Ph3 studies to assess iptacopan efficacy in a wider population of PNH patients, including those naive to anti-C5 MAbs treatment, are needed. Study sponsored by Novartis Pharmaceuticals Corporation.

Context: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired hematologic disease characterized by complement-mediated red blood cell hemolysis. Despite treatment with C5-inhibitors to control intravascular hemolysis (IVH), anemia persists in ~70% of patients due to persistent IVH and mostly C3-mediated extravascular hemolysis. Objective: This post hoc analysis categorized the hematologic response to pegcetacoplan (C3-inhibitor recently approved by the FDA) in the PADDOCK (phase 1b, two-cohort [NCT02588833]; n=20) and PALOMINO (phase 2a, single-cohort [NCT03593200]; n=4) open-label trials, which assessed safety/efficacy of pegcetacoplan in complement inhibitor-naive patients. Design: Hematologic response to treatment was categorized at Days 113 and 337 for the combined trials (n=24), per criteria in Risitano AM, et al. Front Immunol. 2019;10:1157: complete- no transfusions required, stable hemoglobin (Hb; normal range), no evidence of hemolysis (lactate dehydrogenase [LDH] ≤1.5×upper limit of normal [ULN] U/L, absolute reticulocyte count [ARC] ≤150,000/µL); major- no transfusion, normal Hb, but with evidence of hemolysis (LDH >1.5×ULN U/L and/or ARC >150,000/µL); good- no transfusions, but with chronic mild anemia or evidence of hemolysis; partial-chronic moderate anemia and/or occasional transfusions ( 6 units/6 months). Patients with missing data at either timepoint for ≥1 parameter were not evaluated. Manual categorization was independently conducted by two blinded observers. Results: Most patients achieved at least a good hematologic response at Days 113 (75.0%; 18/24) and 337 (62.5%; 15/24). Categorized hematologic responses were as follows: Day 113— good-to-complete 75.0%, partial 4.2%, minor 8.3%, no response 4.2%; Day 337— good-to-complete 62.5%, partial 20.8%, minor 4.2%, no response 0.0%. Of patients with evaluable data, 19.0% (4/21) achieved ≥1 category of improvement in hematologic response at Day 337 versus Day 113. In PADDOCK, 2 patients at Day 113 and 3 patients at Day 337 were unevaluable due to missing data. Conclusions: In the PADDOCK and PALOMINO trials, a substantial proportion of patients achieved complete, major, or good hematological responses to pegcetacoplan at Day 113, which was sustained to Day 337, suggesting that pegcetacoplan treatment in complement inhibitor-naive patients can lead to clinical improvements in PNH symptoms.

Patients with acute graft-versus-host disease (GvHD) grade I were randomized to an observation arm (n=85) or to a treatment arm (n=86) consisting of 6-methylprednisolone 1 mg/kg/day, after stratification for age and donor type. The primary end point was development of grade II–IV GvHD. The cumulative incidence of grade II–IV GvHD was 50% in the observation arm and 33% in the treatment arm (P=0.005). However, grade III–IV GvHD was comparable (13% vs. 10%, respectively; P=0.6), and this was true for sibling and alternative donor transplants. Moderate/severe chronic GvHD was also comparable (17% vs. 9%). In multivariate analysis, an early interval between transplant and randomization (

INTRODUCTION Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired, clonal, nonmalignant hematologic disease characterized by complement-mediated red blood cell hemolysis. The current standard of care for patients with PNH is C5 inhibition. Anemia persists in up to ~70% of patients receiving eculizumab and is attributed to persistent intravascular hemolysis (IVH) and mostly to C3-mediated extravascular hemolysis (EVH). Pegcetacoplan is a pegylated pentadecapeptide C3 inhibitor targeting proximal complement to control both IVH and EVH. PEGASUS is a phase 3, open-label, active-comparator controlled study of efficacy and safety of pegcetacoplan versus eculizumab. This post hoc analysis of data from PEGASUS categorized the clinical response to pegcetacoplan or ECU in patients with PNH and hemoglobin METHODS Hematologic response to treatment was categorized (per Risitano AM, et al. Front Immunol. 2019;10:1157) as complete, major, good, partial, minor, or no response, using number of packed red blood cell transfusions required, hemoglobin level, lactate dehydrogenase (LDH) level, and absolute reticulocyte count (ARC). Complete response: no transfusions required, stable hemoglobin in the normal range, and no evidence of hemolysis (ie, LDH ≤1.5× upper limit of normal, ARC ≤150,000/µL). Major response: no transfusion, normal hemoglobin, but with evidence of hemolysis (LDH >1.5× upper limit of normal and/or ARC >150,000/µL). Good response: no transfusion, but with chronic mild anemia or evidence of hemolysis. Partial response: chronic moderate anemia and/or occasional transfusions (6 units/6 months). Nine patients (6 from the pegcetacoplan arm and 3 from the eculizumab arm) did not readily fit within the existing criteria due to the availability of data at week 16. Although these 9 patients were manually categorized identically by the lead and senior author in a blinded, independent manner, they were not included among these data. RESULTS The intention-to-treat population was comprised of 41 patients randomized to pegcetacoplan and 39 patients randomized to eculizumab. Four patients in the pegcetacoplan arm and 1 patient in the eculizumab arm were not evaluable for analysis due to incomplete data at week 16. Altogether, 61.0% of patients (25/41) in the pegcetacoplan arm have achieved at least a good hematological response, in contrast to 5.1% (2/39) of the eculizumab arm. At week 16, the distribution of response categories was as follows (Figure): in the pegcetacoplan arm and eculizumab arm, respectively, complete responses were 36.6% and 0%, good responses were 24.4% and 5.1%, partial responses were 12.2% and 33.3%, minor responses were 2.4% and 23.1%, and no responses were 0% and 28.2%. The addition of the 9 manually categorized patients did not significantly alter the proportions reported here. Among the factors that may contribute to heterogeneity of hematologic response to treatment are impaired bone marrow function, residual IVH, and residual C3-mediated EVH. Bone marrow failure was ruled out, and no difference in LDH was observed, suggesting that the major factor accounting for the difference between the 2 arms was the prevention of C3-mediated EVH (as confirmed by reduction of C3-opsonization of PNH red blood cells). CONCLUSION In PEGASUS, treatment with pegcetacoplan resulted in a greater proportion of patients with better hematological responses compared to eculizumab. These results further support the concept that proximal complement inhibition, by preventing EVH in addition to controlling IVH, leads to clinical and hematological improvement in the treatment of PNH. Disclosures Risitano: Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Alnylam: Research Funding; Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Samsung: Membership on an entity's Board of Directors or advisory committees; Amyndas: Consultancy; RA pharma: Research Funding; Biocryst: Membership on an entity's Board of Directors or advisory committees; Achillion: Membership on an entity's Board of Directors or advisory committees; Jazz: Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees; Pfizer: Speakers Bureau; Apellis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Weitz:Alexion: Consultancy, Honoraria, Speakers Bureau; Apellis: Consultancy, Honoraria. de Castro:Novartis: Honoraria, Other: Steering committee; Alexion: Honoraria, Research Funding; Biocryst: Honoraria, Other: Data monitoring committee; Apellis: Consultancy, Honoraria, Research Funding. Kiladjian:AbbVie: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; AOP Orphan: Membership on an entity's Board of Directors or advisory committees. Griffin:Biocryst: Membership on an entity's Board of Directors or advisory committees; Alexion Pharmaceuticals: Honoraria, Other: Conference Support. Hamdani:Apellis: Current Employment, Current equity holder in publicly-traded company. Ajayi:Apellis Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Baver:Apellis: Current Employment, Current equity holder in publicly-traded company. Peffault De Latour:Novartis: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Amgen: Research Funding; Alexion Pharmaceuticals Inc.: Consultancy, Honoraria, Research Funding. OffLabel Disclosure: Pegcetacoplan is an investigational drug for the treatment of paroxysmal nocturnal hemoglobinuria.

Background: PNH is a rare, life-threatening disease caused by uncontrolled terminal pathway activation leading to intravascular hemolysis (IVH). The C5 inhibitors eculizumab (ECU) and ravulizumab (RAV) prevent IVH by inhibiting terminal complement; however, some C5 inhibitor-treated patients may experience persistent anemia due to extravascular hemolysis (EVH) caused by C3 fragment deposition and opsonization driven by constitutive activation of the alternative pathway (AP). Inhibition of factor D (FD), the rate limiting enzyme of the AP, acts on the complement cascade upstream of C3. Danicopan (ALXN2040, ACH-4471) is a first-in-class oral small molecule FD inhibitor. In vitro studies with RBCs collected from PNH patients have shown that danicopan not only inhibited hemolysis but also prevented deposition of C3 fragments on PNH RBCs. In a 24-week Phase 2 study of ECU-treated PNH patients with transfusion-dependent anemia (hemoglobin [Hgb] The purpose of this randomized, double-blind, pivotal Phase 3 trial (NCT04469465; EudraCT 2019-003829-18) is to evaluate the efficacy of oral danicopan add-on therapy in PNH patients with clinically evident EVH (CE-EVH) on an approved C5 inhibitor. Study Design and Methods: This study consists of a 12-week double-blind placebo-controlled treatment period 1 followed by a 12-week danicopan+C5 inhibitor treatment period 2 and a long-term extension up to 1-year. Patients (target enrollment, N=84) will be randomized to danicopan or matched placebo TID in a 2:1 ratio for the 12-week treatment period 1. Patients randomized to placebo for treatment period 1 will switch to danicopan at week 12 (Figure). Eligible adult patients must be receiving a stable regimen of ECU or RAV (no change in drug/dose/interval for ≥24 weeks), and have CE-EVH, defined by anemia (Hgb ≤9.5 g/dL), absolute reticulocyte count ≥120 x 109/L, and ≥1 transfusion within 6 months before study entry. The starting dose of danicopan is 150 mg TID. Patients with alanine aminotransferase (ALT) or direct bilirubin values >1.5 × upper limit of normal (ULN) will start at 100 mg TID. Doses may be escalated in 50-mg increments, with ≥4 weeks between escalations, to a maximum of 200 mg TID based on safety and clinical effect at protocol-specified time points. Exclusion criteria include major organ transplant or hematopoietic stem cell transplantation (HSCT), aplastic anemia requiring HSCT, complement deficiency, or ALT >2 × ULN. The primary efficacy endpoint is change in Hgb at week 12. Secondary endpoints are proportion of patients not requiring a transfusion through week 12, change from baseline in FACIT-Fatigue scores, and change from baseline in absolute reticulocyte count at week 12. Other secondary endpoints (at weeks 12 and 24) include RBC units transfused, Hgb stabilization, laboratory markers (including bilirubin, LDH, and PNH clone size), and patient-reported outcomes (EQ-5D-3L, EORTC-QLQ-C30, WPAI, and health resource utilization). Primary and secondary efficacy analyses will be performed on the intent-to-treat population; safety analyses will include all patients who received ≥1 dose of study drug. Danicopan has the potential to be the first oral PNH therapy, and offers an opportunity to enhance the well-characterized efficacy of C5 inhibitors without compromising safety. This Phase 3, pivotal trial will be the largest clinical evaluation of danicopan to date. More importantly, the trial has the potential to generate robust data to demonstrate the efficacy and safety of add-on, oral danicopan to C5 inhibitor therapy in PNH patients with clinically evident hemolysis. Figure Disclosures Kulasekararaj: Alexion Pharmaceuticals Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees. Risitano:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Alnylam: Research Funding; Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Jazz: Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees; Samsung: Membership on an entity's Board of Directors or advisory committees; Amyndas: Consultancy; RA pharma: Research Funding; Biocryst: Membership on an entity's Board of Directors or advisory committees; Apellis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Achillion: Membership on an entity's Board of Directors or advisory committees; Pfizer: Speakers Bureau. Lee:Alexion Pharmaceuticals Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Huang:Alexion: Current Employment, Current equity holder in publicly-traded company. Nishimura:Alexion: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy, Other: All authors received editorial support for this abstract, furnished by Scott Battle, funded by F. Hoffmann-La Roche Ltd, Basel, Switzerland. ; Chugai: Consultancy. Ramirez-Santiago:Alexion: Current Employment, Current equity holder in publicly-traded company.

Introduction: WIdiopathic aplastic anemia is a rare and life threatening disorder characterized by immune mediated hematopoietic stem cells dysfunction. The standard treatment strategy of severe aplastic anemia (SAA) has been hematopoietic stem cell transplant (HSCT) for children and adults younger than the age of 40 if an HLA matched sibling donor (MSD) is available. Immunosuppressive therapy (IST) is the mainstay of treatment for older patients or when MSD is not available. The response rate to IST with the use of horse anti-thymocyte globulin (ATG) is around 70%. Despite that, many patients suffer from relapse or clonal evolution. The use of alternative donor transplant (ADT) from matched unrelated donor (MUD) or HLA haploidentical donor (HID) is not commonly used in frontline setting. We herein, conducted a systematic review and meta-analysis of retrospective studies to compare the outcome of IST versus ADT as upfront therapy for SAA. Methods: WWe conducted a comprehensive search in PUBMED/MEDLINE and EMBASE (1998-2019) for retrospective studies that compared the outcome of ADT with IST as upfront therapy in patients with SAA. The study was conducting in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We included the studies with 10 patients or more in each arm. Studies that included patients with inherited aplastic anemia or PNH are excluded. The primary outcome is the 5-year overall survival. Two authors independently screened the studies, extracted the data, and evaluated the quality of included studies and discrepancies were resolved by a third author. Study quality was evaluated by description of study characteristics, patients' characteristics, treatment details, and outcome. The odd ratio (OR) for 5-year survival was measured by Mantel-Haenszel test using random effect model. We also conducted another search and meta-analysis to compare upfront with salvage ADT. The meta-analyses were performed using Review Manager software version 5.3. Result: WWe screened a total of 697 articles (506 EMBASE, 191 PUBMED/MEDLINE). Five studies met our inclusion criteria included a total of 343 patients (176 in ADT group and 167 in IST group) for upfront ADT versus IST comparison and 6 studies with a total of 298 patients (198 in upfront ADT group and 100 in salvage ADT group) for upfront versus salvage ADT comparison. Included patients were of pediatric age group in 4 out of 5 studies. Xu ZL et al, included adult patients with median age 28 (18-49) years in upfront ADT arm and 32 (18-62) years in IST arm. Of those, only 10 patients in ADT group and 12 patients in IST group were above age of 40. In ADT versus IST comparison, the type of transplant was HID in three studies (total of 124 patients) and MUD/MMUD in two studies (total of 52 patients). The rabbit ATG was used in three studies, horse ATG in one study, and both types were used in one study (total of 68 patients received horse ATG and 99 patients received rabbit ATG). In term of disease severity, all included patients were SAA and very SAA (VSAA). Five studies were included in meta-analysis for 5-year overall survival. The pooled OR is statistically significant at 0.44 [95% CI 0.23-0.85] in favor of upfront ADT (Fig 1-A). The survival outcome was compared between upfront versus salvage ADT in 6 studies. The pooled OR is statistically significant at 0.31 [95% CI 0.15-0.64] in favor of upfront ADT (Fig 1-B). Conclusion: WThe pooled analysis of this study showed a potential survival advantage of upfront ADT over IST in patients with SAA who lack an HLA identical sibling donor. The use of ADT earlier in the disease course rather than as a salvage in young patients with severe disease, may improve survival. Data in older patients are limited, and at present, we cannot recommend ADT upfront in older patients. Given the limitations of our study including various types of IST, heterogeneity of patient population, health care systems, and retrospective nature of included studies; further studies are needed to confirm our findings. Disclosures Peffault De Latour: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Research Funding; Apellis: Membership on an entity's Board of Directors or advisory committees; Alexion Pharmaceuticals Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Schrezenmeier:Alexion Pharmaceuticals Inc.: Honoraria, Research Funding. Hoechsmann:Apellis: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Alexion: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria. Risitano:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Alnylam: Research Funding; Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Jazz: Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees; Samsung: Membership on an entity's Board of Directors or advisory committees; Amyndas: Consultancy; RA pharma: Research Funding; Biocryst: Membership on an entity's Board of Directors or advisory committees; Apellis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Achillion: Membership on an entity's Board of Directors or advisory committees; Pfizer: Speakers Bureau. DiPersio:Magenta Therapeutics: Membership on an entity's Board of Directors or advisory committees.

Background Survival after Allo-HSCT for severe idiopathic aplastic anemia (SAA) has improved over past 20 years, approaching 75% at 5 years. However, beyond survival, a SAA-adapted composite endpoint GVHD and relapse free survival (GRFS) may more accurately assess patient outcomes, becoming a meaningful study endpoint. We analyzed GRFS aiming to identify risk factors and specific causes of GRFS failure. Methods This retrospective analysis from the SAAWP Data Quality Initiative (DQI registry database) program of EBMT included patients with: diagnosis of idiopathic SAA; first Allo-HSCT from 2005 to 2016; and matched related (MRD) or unrelated donor (UD) (no cord blood). Relevant events for Kaplan-Meier calculation of GRFS were: relapse (including primary and secondary graft failure); grade 3-4 acute GVHD; extensive chronic GVHD; and death. In addition, we used a competing-risk model to analyze cumulative incidences of specific causes of GRFS failure. Results We analyzed 580 patients (385 adults and 195 younger than 18 years), with a median age of 23 years ( 6 months) and previous treatment before Allo-HSCT showed that age (HR=1.02, [1.01-1.03], p Among the 209 patients who underwent upfront Allo-HSCT from a MRD, 5-year GRFS was 77% (71-84). In multivariate analysis, time from diagnosis to Allo-HSCT (HR=2.64, [1.38-5.03], p=0.003) and age (HR=1.03, [1.00-1.05], p=0.039) independently influenced GRFS. When investigating the causes of GRFS failure in this subset of patients who underwent upfront MRD Allo-HSCT, time from diagnosis to Allo-HSCT was the only remaining factors significantly associated with the risk of death without prior failure (HR=0.29, [0.10-0.84], p=0.022). No factor was found specifically associated with any other causes of GRFS failure. Conclusions We observed 5-year GRFS of 69%, meaning that most of patients who underwent Allo-HSCT for idiopathic SAA are cured without experiencing severe forms of acute and chronic GVHD. In the context of upfront MRD Allo-HSCT, GRFS was even more promising (77%). In this particular setting, time from diagnosis to Allo-HSCT was the most important factor influencing GRFS, suggesting the need to proceed to Allo-HSCT as quick as possible when a MRD is available. Disclosures Ganser: Novartis: Consultancy; Celgene: Consultancy. Risitano:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Alnylam: Research Funding; Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Jazz: Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees; Samsung: Membership on an entity's Board of Directors or advisory committees; Amyndas: Consultancy; RA pharma: Research Funding; Biocryst: Membership on an entity's Board of Directors or advisory committees; Apellis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Achillion: Membership on an entity's Board of Directors or advisory committees; Pfizer: Speakers Bureau. Peffault De Latour:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Research Funding; Apellis: Membership on an entity's Board of Directors or advisory committees; Alexion Pharmaceuticals Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

INTRODUCTION: PNH, a rare, chronic, life-threatening disease, is characterized by hemolytic anemia due to uncontrolled activity of the complement alternative pathway (AP), bone marrow failure, and thrombosis. Inhibition of C5 by intravenously administered eculizumab and ravulizumab reduces intravascular hemolysis, but PNH red blood cells (RBCs) become opsonized and susceptible to extravascular hemolysis (Risitano et al, Blood 2009). Only approximately half of PNH patients become transfusion independent with eculizumab treatment (Hillmen et al, NEJM 2006). BCX9930 is a potent, selective, orally administered inhibitor of complement factor D. Inhibition of factor D may prevent both intravascular and extravascular hemolysis in PNH. In healthy subjects, BCX9930 showed linear pharmacokinetics and dose-related AP suppression, and was safe and generally well-tolerated over a wide dose range. Here we describe safety and laboratory data establishing proof-of-concept for BCX9930 monotherapy in PNH patients in Study BCX9930-101 (NCT04330534). METHODS: Ongoing Study BCX9930-101 includes an open-label, dose-ranging evaluation of BCX9930 in PNH subjects who may either be naïve to C5 inhibitors (and receive BCX9930 as monotherapy) or have an incomplete treatment response to eculizumab or ravulizumab (with BCX9930 added to existing treatment). Up to 4 sequential cohorts each use a forced titration design for the first 28 days (Figure 1). Subjects enrolled in South Africa can participate in an individualized 48-week extension if they derive benefit at Day 28. Clinical benefit from BCX9930 is evaluated using laboratory monitoring and symptom assessment. Safety and tolerability are evaluated via clinical and laboratory monitoring, causality of adverse events is assessed by investigators, and the study is overseen by an independent Data Monitoring Committee. Data from Cohort 1 through 28 days is reported; data from the extension and subsequent cohorts will be subsequently summarized as available. RESULTS: To date, four C5 inhibitor naïve PNH subjects in South Africa have enrolled in Cohort 1. These subjects had PNH for a median of 4.5 years; 2 subjects had a history of transfusions in the past year; 1 subject each had a history of aplastic anemia or major thrombosis. Pre-treatment lactate dehydrogenase (LDH), total bilirubin, hemoglobin (Hb), reticulocyte count, and RBC PNH Type III clone size ranged from 3.7-11.1 × ULN, 0.61-3.3 mg/dL, 6.1-11.6 g/dL, 0.13-0.29 × 106/µL, and 41.4%-88.6% respectively. Treatment over 28 days with 50 mg twice daily (BID; Days 1-14) and 100 mg BID (Days 15-28) of BCX9930 produced dose-dependent, clinically meaningful improvements across hemolysis biomarkers (Figure 2). Decreases were observed in LDH (4/4), reticulocytes (4/4), and total bilirubin (2/2 subjects with elevated pre-treatment values). Increases were observed in Hb (3/4) and PNH RBC clone size (4/4). One subject showed an initial response to BCX9930 50 mg BID, followed by worsening indicators of hemolysis temporally associated with an upper respiratory tract infection (URTI; onset on Day 7). With an increase in dose to 100 mg BID and resolution of the URTI, LDH and reticulocytes fell and Hb rose. All four subjects reported one or more PNH-associated symptoms, including hemoglobinuria, jaundice, fatigue, erectile dysfunction, headache and abdominal pain, prior to enrollment. With the exception of one subject with persistent hemoglobinuria, all symptoms resolved by Day 28 on BCX9930. Three subjects experienced moderate headache that resolved in < 3 days after initiating BCX9930. One subject developed a rash during treatment with amoxicillin for an URTI; the rash resolved while continuing BCX9930 dosing. One subject on concomitant chronic corticosteroids and azathioprine had an unrelated fatal serious adverse event of disseminated varicella during the study extension. Based on review of safety data, Cohort 2 opened at doses of 200 mg BID and 400 mg BID and, in the 3 subjects who continued into the extension, the dose was titrated to ≥ 200 mg BID. CONCLUSIONS: Oral BCX9930 elicited rapid changes in laboratory parameters indicative of reduced hemolysis and clinical benefit and was safe and generally well-tolerated over a 28-day dosing interval. These interim results establish proof of concept for monotherapy with BCX9930 in the treatment of C5-inhibitor naïve PNH patients and support evaluation of higher doses. Disclosures Kulasekararaj: Alexion:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel grants, Speakers Bureau;Ra Pharma:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel grants, Speakers Bureau;BioCryst Pharmaceuticals, Inc.:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Apellis:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel grants, Speakers Bureau;Roche:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Novartis:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel grants, Speakers Bureau;Celgene:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel grants, Speakers Bureau.Malherbe:Key Oncologics:Honoraria, Other: Conference sponsor;Novartis:Other: Conference sponsor;Astellas:Honoraria, Other: Conference sponsor;Takeda:Consultancy;Acino:Honoraria;Shire:Other: Conference sponsor;BioCryst Pharmaceuticals, Inc.:Consultancy;Janssen:Consultancy, Honoraria, Other: Conference sponsor;Roche:Honoraria, Other: Conference sponsor.McDonald:venetoclax advisory board in South Africa (in CLL context):Consultancy;Alberts Cellular Therapy:Current Employment.Cornpropst:BioCryst Pharmaceuticals, Inc.:Current Employment.Collis:BioCryst Pharmaceuticals, Inc.:Current Employment.Davidson:BioCryst Pharmaceuticals, Inc.:Current Employment.Chen:BioCryst Pharmaceuticals, Inc.:Current Employment.Tower:BioCryst Pharmaceuticals, Inc.:Current Employment.Gesty-Palmer:BioCryst Pharmaceuticals, Inc.:Current equity holder in publicly-traded company, Ended employment in the past 24 months.Sheridan:BioCryst Pharmaceuticals, Inc.:Current Employment.Risitano:Alexion:Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau;Alnylam:Research Funding;Novartis:Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau;Pfizer:Speakers Bureau;Achillion:Membership on an entity's Board of Directors or advisory committees;Apellis:Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Biocryst:Membership on an entity's Board of Directors or advisory committees;RA pharma:Research Funding;Amyndas:Consultancy;Samsung:Membership on an entity's Board of Directors or advisory committees;Roche:Membership on an entity's Board of Directors or advisory committees;Jazz:Speakers Bureau.