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The International Myeloma Working Group (IMWG) guidelines recommend using electrophoresis and immunofixation to define response and progressive disease (PD) in immunoglobulin (Ig) secretory multiple myeloma (Ig-MM), whereas the role of serum-free light chain (sFLC) is controversial. We retrospectively analyzed the value of adding sFLC assays in the definition of response and PD according to IMWG criteria in 339 Ig-MM patients treated with a first-line novel agent-based therapy (median follow-up 54 months). sFLC PD was defined according to conventional criteria plus increased sFLC levels, or sFLC escape (sFLCe); progression/sFLCe-free survival (ePFS) was the time from the start of treatment to the date of first PD or sFLCe, or death; overall survival after PD/sFLCe (OS after Pe) was the time from first PD or sFLCe to the date of death. 148 (44%) patients achieved a complete response and 198 (60%) a normal sFLC ratio (sFLCR). sFLCR normalization was an independent prognostic factor for extended PFS (HR=0.46, p=0.001) and OS (HR=0.47, p=0.006) by multivariable analysis. 175 (52%) patients experienced PD according to the IMWG criteria, whereas 180 (53%) experienced PD or sFLCe. Overall, a sFLCe was observed in 31 (9%) patients. Median PFS and ePFS were both equal to 36 (95% CI=32–42, and 32–40, respectively) months. sFLC PD adversely affected the OS after Pe compared to PD with increasing monoclonal Ig only (HR=0.52, p=0.012). Our results support the inclusion of the sFLC assay for defining response and PD in Ig-MM.

Circulating tumor DNA (ctDNA) has become the most investigated analyte in blood. It is shed from the tumor into the circulation and represents a subset of the total cell-free DNA (cfDNA) pool released into the peripheral blood. In order to define if ctDNA could represent a useful tool to monitor hematologic malignancies, we analyzed 81 plasma samples from patients affected by different diseases. The results showed that: (i) the comparison between two different extraction methods Qiagen (Hilden, Germany) and Promega (Madison, WI) showed no significant differences in cfDNA yield, though the first recovered higher amounts of larger DNA fragments; (ii) cfDNA concentrations showed a notable inter-patient variability and differed among diseases: acute lymphoblastic leukemia and chronic myeloid leukemia released higher amounts of cfDNA than chronic lymphocytic leukemia, and diffuse large B-cell lymphoma released higher cfDNA quantities than localized and advanced follicular lymphoma; (iii) focusing on the tumor fraction of cfDNA, the quantity of ctDNA released was insufficient for an adequate target quantification for minimal residual disease monitoring; (iv) an amplification system proved to be free of analytical biases and efficient in increasing ctDNA amounts at diagnosis and in follow-up samples as shown by droplet digital PCR target quantification. The protocol has been validated by quality control rounds involving external laboratories. To conclusively document the feasibility of a ctDNA-based monitoring of patients with hematologic malignancies, more post-treatment samples need to be evaluated. This will open new possibilities for ctDNA use in the clinical practice.

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Background: The phase 3 GIMEMA-MMY-3006 trial, which compared bortezomib, thalidomide, and dexamethasone (VTD) combination therapy with thalidomide and dexamethasone (TD) as induction therapy before and consolidation therapy after double autologous haematopoietic stem-cell transplantation (HSCT) for newly diagnosed multiple myeloma, showed the superiority of the triplet regimen over the doublet in terms of increased complete response rate and improved progression-free survival. We report the results from the final analysis of the study. Methods: In this randomised, open-label, phase 3 study, patients aged 18–65 years with previously untreated symptomatic multiple myeloma and a Karnofsky Performance Status of 60% or higher were enrolled at 73 centres in Italy. Patients were randomised (1:1) by a web-based system to receive three 21-day cycles of thalidomide (100 mg daily orally for the first 14 days and 200 mg daily thereafter) plus dexamethasone (total 320 mg per cycle; 40 mg on days 1–2, 4–5, 8–9, and 11–12 in the VTD regimen, and 40 mg on days 1–4 and 9–12 in the TD regimen), either alone (TD group) or with bortezomib (1·3 mg/m2 intravenously on days 1, 4, 8, and 11; VTD group). After double autologous HSCT, patients received two 35-day cycles of either the VTD or TD regimen, according to random assignment, as consolidation therapy. The primary outcome was the rate of complete response and near complete response after induction (already reported). In this updated analysis we assessed long-term progression-free survival and overall survival (secondary endpoints of the study) with an extended 10-year median follow-up, and analysed the variables influencing survival. Analysis was by intention to treat. The study is registered with ClinicalTrials.gov, NCT01134484. Findings: Between May 10, 2006, and April 30, 2008, 480 patients were enrolled and randomly assigned to receive VTD (241 patients) or TD (239 patients). Six patients withdrew consent before start of treatment. 236 (99 [42%] women) in the VTD group and 238 (102 [43%] women) in the TD group were included in the intention-to-treat analysis. The data cutoff date for this analysis was May 31, 2018. Median follow-up for surviving patients was 124·1 months (IQR 117·2–131·7). The 10-year progression-free survival estimate for patients in the VTD group was 34% (95% CI 28–41) compared with 17% (13–23) for the TD group (hazard ratio [HR] 0·62 [95% CI 0·50–0·77]; p

Interactions of malignant multiple myeloma (MM) plasma cells with the microenvironment control MM plasma-cell growth, survival, drug-resistance and dissemination. As microvascular density increases in the bone marrow in MM, we investigated whether bone marrow MM endothelial cells control disease progression via the junctional adhesion molecule-A (JAM-A). Membrane and cytoplasmic JAM-A levels were upregulated in MM endothelial cells in 111 patients with newly diagnosed MM and in 201 with relapsed/refractory MM compared to the levels in patients with monoclonal gammopathy of undetermined significance and healthy controls. Elevated membrane expression of JAM-A on MM endothelial cells predicted poor clinical outcome. Mechanistically, addition of recombinant JAM-A to MM endothelial cells increased angiogenesis, whereas inhibition of this adhesion molecule impaired angiogenesis and MM growth in two-dimensional and three-dimensional in vitro cell cultures and chorioallantoic membrane assays. To corroborate these findings, we treated MM-bearing mice with a JAM-A-blocking monoclonal antibody and demonstrated impaired MM progression, corresponding to decreased MM-related vascularity. These findings support the concept that JAM-A is an important mediator of MM progression through facilitating MM-associated angiogenesis. Elevated JAM-A expression on bone marrow endothelial cells is an independent prognostic factor for the survival of both patients with newly diagnosed MM and those with relapsed/refractory MM. Blocking JAM-A restricts angiogenesis in vitro, in utero and in vivo and represents a suitable druggable molecule to halt neo-angiogenesis and MM progression.

Aberrations on TP53, either as deletions of chromosome 17p (del17p) or mutations, are associated with poor outcome in multiple myeloma (MM), but conventional detection methods currently in use underestimate their incidence, hindering an optimal risk assessment and prognostication of MM patients. We have investigated the altered status of TP53 gene by SNPs array and sequencing techniques in a homogenous cohort of 143 newly diagnosed MM patients, evaluated both at diagnosis and at first relapse: single-hit on TP53 gene, either deletion or mutation, detected both at clonal and sub-clonal level, had a minor effect on outcomes. Conversely, the coexistence of both TP53 deletion and mutation, which defined the so-called double-hit patients, was associated with the worst clinical outcome (PFS: HR 3.34 [95% CI: 1.37–8.12] p = 0.008; OS: HR 3.47 [95% CI: 1.18–10.24] p = 0.02). Moreover, the analysis of longitudinal samples pointed out that TP53 allelic status might increase during the disease course. Notably, the acquisition of TP53 alterations at relapse dramatically worsened the clinical course of patients. Overall, our analyses showed these techniques to be highly sensitive to identify TP53 aberrations at sub-clonal level, emphasizing the poor prognosis associated with double-hit MM patients.

BRAFV600E mutation is the pathogenic driver of hairy cell leukemia (HCL) found in the vast majority of cases both at onset and during recurrences. The identification of the mutated allele in blood and marrow correlates with the presence of neoplastic cells and can be considered a marker of active disease. Likewise, the absence of themutation after treatment may indicate a state of deep response. The BRAFV600E burden was measured by droplet digital polymerase chain reaction (ddPCR) and expressed as fractional abundance in 35 HCL patients at different stages of disease (onset, relapse, complete response [CR] after treatment, long-term remission) in peripheral blood and/or bone marrow (when available). Mean values of fractional abundance for patients at diagnosis, relapse and response, respectively, were 12.26%, 16.52% and 0.02% in peripheral blood and 23.51%, 13.96% and 0.26% in bone marrow. Four patients out of 6 evaluated at response were molecularly negative for BRAFV600E in peripheral blood. Mean fractional abundance in peripheral blood tested in 14 patients with long lasting CR was 0.05%, and 10 patients were BRAFV600E negative. These preliminary results suggest that ddPCR permits to assess the active tumor burden in HCL at different disease phases and support the hypothesis that some patients in CR qualify for a molecular CR.

Tyrosine kinase inhibitors have improved survival for patients with Philadelphia chromosome–positive (Ph+) acute lymphoblastic leukemia (ALL). However, prognosis for old or unfit patients remains poor. In the INCB84344-201 (formerly GIMEMA LAL 1811) prospective, multicenter, phase 2 trial, we tested the efficacy and safety of ponatinib plus prednisone in newly diagnosed patients with Ph+ ALL ≥60 years, or unfit for intensive chemotherapy and stem cell transplantation. Forty-four patients received oral ponatinib 45 mg/d for 48 weeks (core phase), with prednisone tapered to 60 mg/m2/d from days-14-29. Prophylactic intrathecal chemotherapy was administered monthly. Median age was 66.5 years (range, 26-85). The primary endpoint (complete hematologic response [CHR] at 24 weeks) was reached in 38/44 patients (86.4%); complete molecular response (CMR) in 18/44 patients (40.9%) at 24 weeks. 61.4% of patients completed the core phase. As of 24 April 2020, median event-free survival was 14.31 months (95% CI 9.30-22.31). Median overall survival and duration of CHR were not reached; median duration of CMR was 11.6 months. Most common treatment-emergent adverse events (TEAEs) were rash (36.4%), asthenia (22.7%), alanine transaminase increase (15.9%), erythema (15.9%), and γ-glutamyltransferase increase (15.9%). Cardiac and vascular TEAEs occurred in 29.5% (grade ≥3, 18.2%) and 27.3% (grade ≥3, 15.9%), respectively. Dose reductions, interruptions, and discontinuations due to TEAEs occurred in 43.2%, 43.2%, and 27.3% of patients, respectively; 5 patients had fatal TEAEs. Ponatinib and prednisone showed efficacy in unfit patients with Ph+ ALL; however, a lower ponatinib dose may be more appropriate in this population. This trial was registered at www.clinicaltrials.gov as #NCT01641107.

Antigen-directed target therapy for B-cell acute lymphoblastic leukemia (B-ALL) is now the standard of care for relapsed/refractory (R/R) disease. A comprehensive determination of the target itself is mandatory to aid physician's choice. We determined baseline Cluster of differentiation 22 (CD22) expression percentage and fluorescent intensity on lymphoblasts of 30 patients with R/R B-ALL treated with anti-CD22 immunoconjugate drug Inotuzumab Ozogamicin (INO) and analyzed the impact of both parameters on patient outcome. Most patients (24/30, 80%) had a high leukemic blast CD22-positivity defined as ≥90%. We did not observe a benefit in terms of complete remission, overall survival (OS) and duration of response (DoR) for patients with CD22 ≥ 90% versus CD22 90%. Concerning CD22-FI quartile analysis we appreciated a trend for superior response rates in higher quartiles (Q

Recent Advancements in Hematology: Knowledge, Methods and Dissemination is a series of editorials which is published on a biannual basis by the editorial board of the journal Bloods [...]

The treatment of hairy cell leukemia (HCL) has considerably changed over years. Purine analogues, namely cladribine, now represent the treatment of choice. One hundred and eighty-four patients were followed between 1986 and 2018 and treated according to era-specific guidelines. Responses were classified by combining Consensus Resolution criteria and marrow immunohistochemistry. Patients were grouped according to the number of treatment lines they received. Patients treated first line responded in 86% of cases, with complete response (CR) in 44% of cases. Response rates remained high throughout the first four lines (84%, 81%, 79% for the second line onward, with CR in 38%, 37%, 15% of cases respectively). One hundred and twenty-two patients received cladribine as first line treatment, with a response rate of 86% and a CR rate of 54%. Among the 66 CR patients, 45 (68%) have never received further therapy: 11 patients are in continuous CR between 5 and 10 years after treatment, 14 between 10 and 20 years and three patients at more than 20 years. Median time-to-next treatment (TTNT) for frontline cladribine-treated patients was 8.2 years: partial responders had a significantly shorter median TTNT than CR patients (5.3 years vs median not reached at 25.8 years, p< 0.001). Patients with HCL require subsequent lines of therapy in more than 50% of cases. Purine analogues allow significant response rates when applied first line and upon retreatment. Some patients may enjoy long lasting treatment-free intervals after one course of cladribine.

No abstract available.

In multiple myeloma, novel treatments with proteasome inhibitors (PIs) and immunomodulatory agents (IMiDs) have prolonged survival but the disease remains incurable. At relapse, next-generation sequencing has shown occasional mutations of drug targets but has failed to identify unifying features that underlie chemotherapy resistance. We studied 42 patients refractory to both PIs and IMiDs. Whole-exome sequencing was performed in 40 patients, and RNA sequencing (RNA-seq) was performed in 27. We found more mutations than were reported at diagnosis and more subclonal mutations, which implies ongoing evolution of the genome of myeloma cells during treatment. The mutational landscape was different from that described in published studies on samples taken at diagnosis. The TP53 pathway was the most frequently inactivated (in 45% of patients). Conversely, point mutations of genes associated with resistance to IMiDs were rare and were always subclonal. Refractory patients were uniquely characterized by having a mutational signature linked to exposure to alkylating agents, whose role in chemotherapy resistance and disease progression remains to be elucidated. RNA-seq analysis showed that treatment or mutations had no influence on clustering, which was instead influenced by karyotypic events. We describe a cluster with both amp(1q) and del(13) characterized by CCND2 upregulation and also overexpression of MCL1, which represents a novel target for experimental treatments. Overall, high-risk features were found in 65% of patients. However, only amp(1q) predicted survival. Gene mutations of IMiD and PI targets are not a preferred mode of drug resistance in myeloma. Chemotherapy resistance of the bulk tumor population is likely attained through differential, yet converging evolution of subclones that are overall variable from patient to patient and within the same patient.

Background Interactions between multiple myeloma plasma cells (MMPC) and the multiple myeloma (MM) niche control cell proliferation, drug resistance, and disease spreading through various adhesion molecules and chemokine receptors. Among these, junctional adhesion molecule-A (JAM-A) mediates MMPC-endothelial interactions and propagates neovascularization. Here we addressed whether JAM-A signaling mediates MMPC invasive behavior orchestrating intra- and extramedullary MM dissemination. Methods We investigated JAM-A expression with flow cytometry and immunohistochemistry in 60 MM patient bone marrow (BM) aspirates and biopsies at different disease stages with and without extramedullary disease (EMD) manifestation. We compared these results with RNA-Seq data from 647 newly diagnosed MM (NDMM) patients collected in the MMRF CoMMpass study. Using bioinformatics, we investigated JAM-A-related pathways with hierarchical cluster analysis. Subsequently, we functionally validated these JAM-A-related pathways regarding epithelial-mesenchymal transition (EMT), invasion, and MM dissemination in vitro. Results The median OS differed significantly in subjects with elevated membrane JAM-A expression levels, dividing the patients in the EMD JAM-Ahigh group with a median OS of 84.1 months, whereas median OS in JAM-Alow patients was not reached, irrespective of the EMD status (log-rank=4.19, P=.04). Immunohistochemistry analysis of BM biopsies confirmed these findings. RNA-Seq analysis corroborated the prognostic impact of JAM-A (log-rank=3.8, P=.051). High-risk patients with EMD and JAM-A expression displayed a unique gene-expression signature. Additionally, we constructed a novel expression cluster subgroup model, revealing complex molecular disease patterns and associations between clinical traits and expression markers. Strikingly, MM patients clustered by JAM-A expression levels and EMD manifestation revealed properties of epithelial-mesenchymal-transition and induced focal adhesion pathways. Notably, functional knockdown of JAM-A in MMPC in vitro not only reduced cell viability but also diminished MMPC adhesion molecules and CD138 surface expression. Furthermore, mTOR/PI3K in vitro inhibition with BEZ235 significantly downregulated surface expression in JAM-Ahigh MM cells. Interestingly, when we inhibited mTOR/PI3K in JAM-Alow MM cells, we observed JAM-A induction. Finally, ensuing functional shRNA knockdown of JAM-A halted MM invasion (P Conclusions Collectively, these data reveal JAM-A-mediated signaling critical for EMT transition and invasive behavior. Based on these findings we propose JAM-A as a promising biomarker and novel theragnostic target in MM patients.

Background MM is a hematological malignancy always evolving from pre-malignant stages, with progressive increase of genomic complexity. MM is characterized by a large abundance of copy number alterations (CNA); many of them, regarded as “driver”, stack up progressively from early tumor stages, causing biological changes that give rise to tumor hallmarks and malignant phenotypes. The combined application of whole genome analysis and mathematical models allows to deeply describe these alterations and to infer their order of acquisition during oncogenesis from their clonality levels, assuming that clonal ones are more ancestral than subclonal. Aims: (1) To define the temporal order of acquisition of CNA, leading to the onset of symptomatic MM and (2) to define a scoring model able to stratify patients (pts) according to the ancestrality of the alterations observed in their genomic landscape. Methods Genomic data collected from a total of 1384 newly diagnosed MM pts were included in the study: SNPs array data were collected from 514 pts of our Institution (BO dataset); in 870 pts, WES data were downloaded from CoMMpass study. CN calls and clonality levels were harmonized by an analysis pipeline including ASCAT, GISTIC v2 and custom R scripts. Timing estimates were obtained with BradleyTerry2 package. Survival analysis were performed on R. Results A full call-set of CNAs was obtained by harmonizing BO and CoMMpass datasets. The clonality information was first extrapolated from the whole call-set, to define the temporal order of acquisition of non-primary CNAs. CNAs were then accurately ranked, by using the obtained timing estimates, characterized by a quite narrow confidence interval. Of interest, chr 1q gains and chr 13q losses were frequently clonal and ranked as ancestral events, whereas chr 17p losses were late occurring events. By weighting the CNAs carried by any given pts at diagnosis with their relative timing estimate in a combinatorial process, an Ancestrality Index (AI) was defined for each pts (median AI=3.4, IQR=1.7-6.0). The AI was found to be significantly associated with progression free (PFS) and overall survival (OS) (p3.4 (i.e. with a more “ancestral” profile) had a worse outcome as compared to the rest of pts (OS 40% vs 58%, PFS 42% vs 56%, at a median follow up of 92m and 34m, p Conclusions By means of whole genome analysis and dataset harmonizing, the temporal order of acquisition of MM CNAs has been confidently described. A score reflecting the disease ancestrality of MM pts at diagnosis was generated and associated to survival outcomes. Overall, these findings support the evidence that MM pts at diagnosis carrying an excess of ancestral alterations, expected to likely be drivers, are prone to have a dismal prognosis.

Introduction Multiple Myeloma (MM) is a genetically complex disease, characterized by the recurrence of several chromosomal aberrations, which impair the disease prognosis. The use of genome-wide technologies has recently highlighted the existence of Complex Chromosomal Events (CCEs), caused by distinct phenomenons: Chromothripsis (CT), caused by single-step genomic events, and Stepwise Events (SE), consequence of multiple, small and sequential genomic events, occurring throughout subsequent cell cycles. The prognostic impact of CT in MM has not yet been fully elucidated. Aims of our study were: (1) to detect CCEs in MM, with a focus on CT, by using an original and reliable bio-informatic algorithm, (2) to characterize the genetic and genomic context of CT and (3) to correlate the presence of CTwith pts prognosis. Methods A total of 488 newly diagnosed MM patients (pts) have been included in the study. Genomic data have been obtained by SNPs arrays on bone marrow (BM) aspirates CD138+ enriched cell fractions; data were analysed by Affymetrix’s programs and R-scripts. Results An original algorithm able to discriminate among the 2 different CCEs (CT and SE),was set up and tested, by implementing the most commonly reported guidelines for CCEs identification with knowledges on MM-specific highly heterogeneous genomic context. CCEs were detected in 174 pts (36% with at least one CCE): in particular, 46/174 pts (26%) carried CT. CT can affect any chromosome, yet showing significant associations with the following genomic regions: chr1p (p=8.37E-15), chr2q (p=4.27E-8), chr11q (p=6.99E-5) and chr22q (p=5.15E-7). Pts carrying CT were more likely to carry also IgH translocations associated to bad prognosis (p=0.002, HR 3.4) and TP53 deletions (p=1.16E-5, HR=6.26). The presence of any CT event conferred hazard ratio of 1.52 (p=0.019) and 1.68 (p=0.019) to pts’ progression-free (PFS) and overall survival (OS), respectively, independently from the presence of both TP53 deletion and translocation t(4;14), as evaluated in a multivariated model. An association between CT events and XBP1 gene deletion was observed; since XBP1 expression has been correlated to an effective proteasome inhibitor (PI) therapy response, CT events particularly impacted survival expectancies of PI-treated pts, whose PFS and OS were significanlty worse than those of other pts (p=0.0098 and =0.023, respecitvely). Finally, the same CT events acquired at diagnosis were observed in those 4/55 pts, whose BM aspirates were analysed also at relapse, thus suggesting that, once occurred, CT might have a driver role for disease progression. Conclusion Our results showed that CT impact MM pts prognosis, independently from the genomic region affected and the pts’ genomic backgroung. Acknowledgment AIRC_IG2014, RF-2016.

mRNA vaccines BNT162b2 and mRNA1273 are highly effective in preventing SARS-CoV-2 infection and mortality in healthy adults. However, their immunogenicity in immunocompromised Multiple Myeloma (MM) patients is less clear. We performed an observational prospective study of 96 MM patients (pts) treated at our centre, aimed at assessing the humoral and cell-mediated immune (CMI) response following the full immunization schedule. To this aim, we measured serum levels of neutralizing IgG anti Spike-protein (IgG anti S-RBD) at 1, 3, 6, 9 and 12 months after the 2 nd dose of vaccination, using the electrochemiluminescence (ECLIA) platform (Elecsys® Anti-sars-Cov-2 ECLIA assay) and evaluated CMI response in terms of pts with a SARS-CoV-2 specific IFNγ T cell response by IGRA (Interferon-Gamma Release Assays) test at 3 and 12 months after 2 nd dose. A concentration level of IgG anti S-RBD ≥0.80 U/ml was considered a seropositive result. Herein, we report preliminary data on the development of humoral response in 96 MM pts who reached the first study timepoint (1 month after 2 nd dose), compared to 54 health-care workers as controls. At vaccination, the median age of the 96 patients (51 males/45 females) was 66.5 (range 47-83) years. The median number of previous lines of therapy was 1 (range 1-11) and only 7 (7.3%) pts were not receiving active treatment. 44.8% (n=43) pts had relapse/refractory MM. Among 72 (75%) transplant-eligible pts, 63 patients had previously received autologous stem-cell transplantation (ASCT) with a median time between ASCT and vaccine of 31 (range 3-274) months. 70 (72.9%) pts had received immunomodulatory drugs (IMIDs) containing regimens, 30 (31.3%) proteasome inhibitors (PIs), 11 (11.5%) IMIDs + PIs, 32 (33.3%) anti-CD38 monoclonal antibodies (anti-CD38 moAbs). 33 (34.4%) pts were in lenalidomide (R) maintenance therapy. At vaccination, 67 (68.8%) pts were in VGPR or higher, 18 (18.7%) in PR and 11 (11.3%) in SD or PD. Immunoparesis (≥1 uninvolved Ig below lower level limit) was observed in 78 (88.6%) pts, of whom 59 (67.1%) showed a reduction of two Ig classes. All pts had completed the 2 planned doses of BNT162b2 (40.6%) or mRNA1273 (59.4%) vaccine 3 or 4 weeks apart, respectively. Control cohort (n=54; median age of 51 [range 40-66] years) received mRNA vaccine during the same period. People with previous SARS-CoV-2 infection (positive IgG anti S-RBD or anti-nucleocapsid N antibody titer before vaccines) were excluded from the analysis. At 1 month post 2 nd dose, (median 30 days, IQR 28-32) seropositive response rate to vaccination was 91.7% (n=88) for MM pts vs 100% for controls, p=0.05; the median IgG anti S-RBD titer was 435 (range 0.4-2500) vs 1040.5 U/ml (range 160-2500), respectively; p=0.008. No difference in the rate of seropositive response between those who received the 2 type of vaccines was found (p=0.09). Pts with response level ≥ CR had a median antibody (Ab) titer (1242 U/ml, range 0.4-2500) significantly higher than those with ≤CR (221.5 U/ml, range 0.4- 2500), p Pts receiving PI (median Ab titer 156; range 0.4- 2500) and anti-CD38 MoAbs (median titer 265 U/ml; 0.4- 2500) containing regimens had a lower Ab titer than all the other pts (p=0.003 and p A distribution analysis of the Ab titer revealed a significant correlation between better humoral response and hematological response ≥ CR (p Multivariate analysis confirmed ≥ CR [OR 2.54, 95% CI 93-756], being in first line treatment [OR 2.10, CI 22-722] and R maintenance therapy [OR 4.53, CI 484-1233] as independent predictors of better humoral response at 1 month after 2 nd vaccine dose. In conclusion, mRNA vaccines provided a high seropositivity rate in pts in active MM treatment, with a better humoral response in pts achieving CR, those who received ASCT and receiving R maintenance. Immunoparesis was confirmed to be an unfavourable factor for the development of humoral response, as well as treatment with anti-CD-38 moAbs. Disclosures Mancuso: Celgene: Honoraria; Takeda: Honoraria; Sanofi: Honoraria; Amgen: Honoraria; Janssen: Honoraria. Zamagni: Takeda: Honoraria; Amgen: Honoraria; Bristol-Myers-Squibb: Honoraria; Janssen: Honoraria. Pantani: Amgen: Honoraria; Janssen: Honoraria. Rocchi: Amgen: Honoraria; GalxoSmithKline: Honoraria; Janssen: Honoraria. Rizzello: Amgen: Honoraria; GlaxoSmithKline: Honoraria; Sanofi: Honoraria. Tacchetti: Amgen: Honoraria; BMS/Celgene: Honoraria; Janssen: Honoraria; Takeda: Honoraria; AbbVie: Honoraria; Sanofi: Honoraria; GlaxoSmithKline: Honoraria; Oncopeptides: Honoraria. Zinzani: JANSSEN-CILAG: Other: Advisory board, Speakers Bureau; MSD: Consultancy, Other: Advisory board, Speakers Bureau; SANDOZ: Other: Advisory board; TG Therapeutics: Other: Advisory board, Speakers Bureau; GILEAD: Other: Advisory board, Speakers Bureau; SERVIER: Other: Advisory board, Speakers Bureau; BMS: Other: Advisory board, Speakers Bureau; CELLTRION: Other: Advisory board, Speakers Bureau; TAKEDA: Other: Advisory board, Speakers Bureau; ROCHE: Other, Speakers Bureau; EUSAPHARMA: Consultancy, Other, Speakers Bureau; KYOWA KIRIN: Other, Speakers Bureau; Incyte: Other, Speakers Bureau; NOVARTIS: Consultancy, Other, Speakers Bureau; ADC Therap.: Other; Beigene: Other, Speakers Bureau; VERASTEM: Consultancy, Other: Advisory board, Speakers Bureau. Cavo: Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Accommodations, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Consultancy, Honoraria; Novartis: Honoraria; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; GlaxoSmithKline: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol-Myers Squib: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Hyperactivation of the Hedgehog (Hh) pathway, which controls refueling of multiple myeloma (MM) clones, might be critical to disease recurrence. Although several studies suggest the Hh pathway is activated in CD138- immature cells, differentiated CD138+ plasma cells might also be able to self-renew by producing themselves the Hh ligands. We studied the gene expression profiles of 126 newly diagnosed MM patients analyzed in both the CD138+ plasma cell fraction and CD138-CD19+ B-cell compartment. Results demonstrated that an Hh-gene signature was able to cluster patients in two subgroups characterized by the opposite Hh pathway expression in mature plasma cells and their precursors. Strikingly, patients characterized by Hh hyperactivation in plasma cells, but not in their B cells, displayed high genomic instability and an unfavorable outcome in terms of shorter progression-free survival (hazard ratio: 1.92; 95% confidence interval: 1.19-3.07) and overall survival (hazard ratio: 2.61; 95% confidence interval: 1.26-5.38). These results suggest that the mechanisms triggered by the Hh pathway ultimately led to identify a more indolent vs a more aggressive biological and clinical subtype of MM. Therefore, patient stratification according to their molecular background might help the fine-tuning of future clinical and therapeutic studies.

Background The introduction of novel agents into the therapeutic algorithm of Multiple Myeloma (MM) has led to remarkable improvements in the rate of Minimal Residual Disease (MRD) negative status. Sustained MRD negativity is a robust prognosticator and a driver of treatment strategies. Therefore, it is expected that MRD molecular tracking would become critical in the management of MM, and could be included in daily clinical practice. Aim To evaluate the performances of next generation sequencing (NGS), implemented as best practice in MM MRD daily evaluation. Methods A cohort of 166 newly diagnosed transplant-eligible and -ineligible MM pts were screened to define the ID clonotypes. MRD was firstly assessed at achievement of at least a very good partial response during maintenance, and thereafter once a year. In high-risk pts, MRD was also detected between 1° and 2° autologous stem-cell transplantation (ASCT). The ID clonotypes screening has been performed by NGS, using an assay covering IgH and Igk genes (Invivoscribe®). The MRD tracking has been done both by conventional ASO-qPCR and by NGS. Data were analyzed by Lymphotrack Dx and MRD software (Invivoscribe®). Results The ID clonotypes screening was successful in 158/166 pts (95%), even though a small proportion of pts resulted polyclonal (14/158). Overall, 63, 27 and 54 pts had IgH, Igk and IgH/k ID clonotypes, respectively, mainly restricted to the VH3 (47%) family genes. MRD assessment was performed by NGS in 124/144 pts (overall, 96 MRD samples for 64 pts monitored to date), with 10-5 sensitivity in most cases (75/96). 44 pts were assessed during maintenance and 23 achieved MRD-negativity. On the contrary, 20 pts were evaluated between 1° and 2° ASCT, resulting MRD-positive in all cases. Overall, few FU samples (13/96) were reported as “positive-not-quantifiable” (PNQ), since had residual disease levels of 10-7, much lower than the internal control. In a subset of 20 pts with trackable IgH/Igk sequences, pts-specific assays were designed, according to the EuroMRD guidelines. In these pts, MRD was tested both by ASO-qPCR (including a standard curve and healthy donor cells, to define the sensitivity and the specificity, respectively) and by NGS. Overall, ASO-qPCR allowed the tracking of a single MRD clone (with up to 10-4 sensitivity) in 12/20 pts (60%), whereas NGS was feasible in all of them, confirming the ASO-qPCR results, yet with higher sensitivity and >95% confidence. Moreover, in 2 cases, NGS allowed to disclose ASO-qPCR PNQ results due to nonspecific amplification, thus unveiling MRD negativity with 10-5 sensitivity. Conclusion NGS has been successfully implemented as best practice in the management of MM pts, showing the superiority of this method over ASO-qPCR conventional approach. The ID clonotype was defined in almost all pts included in the workflow, thus allowing their MRD molecular monitoring, according to the clinical requirements. Acknowledgment AIRC IG2018-22059

Background Multiple Myeloma (MM) is a plasma cell (PC) disorder characterized by the presence of multiple lytic lesions at the time of diagnosis. Recently, cell-free DNA (cfDNA) has proven to resume the heterogeneity of spatially distributed clones. However, the potential of cfDNA to track the evolutionary dynamics and the heterogeneity of MM, possibly anticipating the emergence of therapy resistant residual cells, remains to be confirmed. Aim of this study is to evaluate cfDNA at diagnosis and during follow-up in order to compare this approach with both bone marrow (BM) molecular and whole-body imaging residual disease assessment. Methods A total of 97 patients (pts) were screened at baseline and during follow-up with 18F-FDG PET/CT and NMR, and molecularly assessed by Ultra Low Pass-Whole Genome Sequencing (ULP-WGS). ULP-WGS was used to characterize both the neoplastic PC clone from BM (gDNA) and the cfDNA from peripheral blood. Data were analysed by ichorCNA and Clonality R packages. Results Overall, cfDNA tumour fraction (TF) at diagnosis was significantly lower as compared to gDNA TF [median (M) TF: 3.0%vs.74.4%, respectively]. Nevertheless, high cfDNA TF levels (49/97 pts = 50%, M cfDNA TF: 10%, range : 3.0-40.6%) correlated with high gDNA TF levels (M gDNA TF: 84%, range: 5.9-95.2%). Similarly, a significant correlation was shown between cfDNA TF and the BM plasma cells clone throughout disease progression, highlighting a parallel dynamics of tumour burden from SMM to MM to +3m post-induction (cfDNA TF vs. % CD138+/CD38+ BM cells: 1.5 vs 1.0; 3.0 vs. 2.3; 1.2 vs. 0.01, respectively, p: 0.008). Pts with high cfDNA TF were likely to have more sites of extramedullary disease (EMD) at PET-CT, a higher number of PET lesions and higher tumour metabolic activity, as compared to pts with low TF (EMD 8/49, 17% vs. 2/49, 3.4%; M n. PET lesions: 8 vs. 2; SUVmax: 12.9 vs. 3.9). Similarly, bone involvement as detected by MRI, was more evident in pts with high cfDNA TF (M n. focal lesions: 6 vs. 1). More interestingly, after 3 cycles of induction therapy, imaging and cfDNA TF dynamics were concordant: indeed, in those cases where FDG activity and focal lesions still persisted (4/10=40%: SUVmax 5.8; >2 PET lesions), cfDNA TF as well was still detectable (>1 TF).Finally, the comparison between cfDNA and BM genomic profiles showed an overall concordance of the copy number alterations (CNAs) landscape in most patients (83/97; 86.4%), whereas three patients (10/97; 10,3%) displayed a different genomic profile in cfDNA, as compared to BM. Conclusions although only few cases showed genomic evidence of spatial heterogeneity, in pts with high cfDNA TF, imaging data overall suggested a propensity to a metastatic spread of the disease. Future studies will be addressed to exploit the use of cfDNA in disease monitoring. Acknowledgements AIRC IG2018-22059.

Background: Multiple Myeloma (MM) is a rare and heterogeneous blood cancer of the plasma cells. Various new therapies have been introduced and are used in combination to combat the heterogeneity. Despite ongoing research and the development of innovative therapies, improvements for the fast progressing (high-risk) patients have been limited. Disease behavior and clinical outlook of patients that look very similar in the absence of clinical and cytogenetic high-risk features, vary considerably. Their fast progression could not have been foreseen at diagnosis as their initial features were uninformative. In order to identify high-risk patients for selective innovative treatment strategies in trials and clinical practice, it is important to have a conclusive assessment of the patient's risk profile at diagnosis. This assessment should include their Gene Expression Profile (GEP). Aim: To show that GEP is an important and indispensable contributor in selecting high-risk MM patients. Method: Six datasets were combined: MRC-IX (n=180), HOVON-87/NMSG-18 (n=148), EMN-02/HOVON-95 (n=249), GIMEMA-MMY-3006 (n=112), a Czech cohort (n=27 E-MTAB-1038) and the MMpredict non-trial cohort (n=89, [Chen YT. et al. CLML. 2019 19(10):e60-61]). Pooled, a total of n=805 MM patient samples were available including corresponding GEP data, iFISH, ISS annotation and Overall Survival (OS). Patients were risk classified in three strata as proposed by Kuiper R. et al. Blood. 2015 Oct 22;126(17):1996-2004: Low Risk (LR) as SKY92 standard risk + ISS I; Intermediate Risk (IR) as SKY92 standard risk + ISS II or III; and High Risk (HR) as SKY92 high risk. Subsequently, each stratum is further refined into: patients with high-risk iFISH t(4;14) and/or del(17p) (iFISH); and patients without these markers (non-iFISH). The Cox proportional Hazards model was applied to estimate survival. Results: The combination of SKY92+ISS identified three risk strata in the cohort: n=188 for LR (23%), n=448 for IR (56%) and n=169 for HR (21%). The OS of the HR stratum was significantly shorter than the LR stratum (hazard ratio=6.0, p Conclusion: Currently used risk stratification methods are sub-optimal and the use of these markers leave 53% of high-risk patients unidentified. This might impact the clinical strategy for that unidentified high-risk patient as a physician could have escalated their treatment. Furthermore, it might influence the conclusion on the effectiveness of investigational therapeutic treatment in clinical trials. Lastly, clinical trials focused on high-risk patients, will reach full inclusion much faster and obtain earlier read-outs as GEP, here SKY92, identifies additional and true fast progressing high-risk patients. SKY92 should therefore be added as risk stratification method for a holistic view on a patient's course of disease. Figure 1: Kaplan Meier plots for the three SKY92 + ISS strata: low risk (LR; figure 1B), intermediate risk (IR; figure 1C) and high risk (HR; Figure 1D) and their respective splits based on presence of iFISH markers t(4;14) and/or del(17)p or absence of both. Figure 1 Disclosures Van Vliet: SkylineDx: Current Employment, Current equity holder in private company. Chen:SkylineDx: Current Employment, Current equity holder in private company. Van Beers:SkylineDx: Ended employment in the past 24 months. Kuiper:SkylineDx: Current Employment, Current equity holder in private company. Valent:SkylineDx: Current Employment, Current equity holder in private company. Spaan:SkylineDx: Current Employment, Current equity holder in private company. Zamagni:BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Speakers Bureau; Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Other: Travel, Accommodations, Expenses, Speakers Bureau; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Speakers Bureau; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Speakers Bureau; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Cavo:Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Honoraria, Speakers Bureau; Karyopharm: Honoraria; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel accomodations, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel accomodations, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Oliva:Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees. Larocca:Takeda: Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees. Chng:Abbvie: Honoraria; Novartis: Honoraria; Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Amgen: Honoraria, Research Funding. Waage:Janssen: Consultancy, Honoraria, Speakers Bureau; Takeda: Consultancy; Shire: Honoraria. Sonneveld:Amgen: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; Skyline Dx: Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy.

Proteasome inhibitors (PIs) and immunomodulatory drugs (IMiDs), significantly enhanced the depth of response and prolonged the survival of Multiple Myeloma (MM) patients, although not all patients respond favourably to treatment. Optimization of treatment schedules and dosages of IMiDs and PIs might lead to improved treatment efficacy. In this study we aimed at exploring the optimal schedule of IMiDs and PIs in both in vitro models, including bone marrow (BM) microenvironment simulation, and an ex-vivo model using patient-derived BM samples. MM cells were exposed to IMiDs and PIs either simultaneously or sequentially. Using the median effect method of Chou Talalay, we evaluated the combination indices for simultaneous and sequential treatment schedules. We demonstrated schedule-dependent synergistic cytotoxicity for the combination of IMiDs and PIs and a maximal apoptosis was observed in IMiDs pre-exposure schedule. The superior activity of this schedule was maintained even in BM microenvironment models, and was further confirmed using patient-derived samples. Our data overall suggest that the administration of IMiDs before PIs can improve treatment efficacy. Clinical trials are needed to investigate the most effective schedule, which could be to start the administration of IMiDs before PIs to increase cells killing.

There has been a fast progress in clinical use of antibody-based immunotherapy, given the superior efficacy commonly achieved in clinic and the limited toxicity. However, personalization of treatment remains of major importance, both to achieve better clinical performance for monotherapy and to identify the best combinations on a patient-by-patient basis. Predicting patient's response is complex due to the need to characterize both tumor response and immunologic mechanisms possibly activated by the therapy, including antibody dependent cellular cytotoxicity (ADCC). We present the Inter-Cell Networking Profiling (ICNP), a novel analytical method enabling a comprehensive and precise characterization of the modulatory effect of immunotherapies on immune-tumor cell interactions. ICNP works on the Open Microwell (OMW) microfluidic system which recreates 20,000 unique cell clusters from ex-vivo patient samples and exposes them to anticancer drugs. We validated the ICNP using multiple myeloma (MM) patient samples to characterize the efficacy of Daratumumab, an anti-CD38 antibody (Ab). Bone marrow samples in EDTA were collected from 11 MM patients. 8 samples were processed by Ficoll-Paque, preserving the original composition of effector (E) and target (T) cells, i.e. NK and plasma cells respectively. 3 samples were processed to obtain co-cultures of WBC depleted of plasma cells (which include NK cells) and U-266 MM cell line. NK and plasma cells were stained with anti-CD16/CD56 and anti-CD138 fluorescently-labeled Abs, respectively. Propidium Iodide (PI) was used as death marker. A statistical model was created to project the optimal experimental setup (E:T ratio, cell concentration) to maximize the co-localization of E/T cells in the 20,000 microwells of the OMW platform. After seeding, cells were incubated with Daratumumab 10µg/mL or no drug and analyzed through fluorescence time lapse microscopy for up to 12 hours. ICNP analysis first separates microwells with both E/T cells in close proximity from those not featuring both cell types (Fig 1A). Then, anti-CD38 efficacy is evaluated in microwells with E/T co-localization, thus implementing a miniaturized ADCC assay (Fig 1B). At the same time, spontaneous NK activity is measured in microwells with E/T co-localization and no drug, while direct effect of the drug on target cells can be measured in microwells with T but not E cells. We first validated our statistical model of co-localization in microwells against the actual number of wells with E/T co-localization (correlation R2: 0.79-0.97, n=5). Then, we characterized the immune composition of 8 MM patients samples with the OMW, finding that E/T cell fractions were in the ranges 5-21% (E) and 1-28% (T). Interestingly, according to our statistical model, co-localization occurs in at least 1% of microwells for all the 8 samples, making ICNP applicable with good statistical significance in the OMW system on ex-vivo clinical samples without any pre-enrichment. Finally, ICNP was evaluated on 4 cases (3 obtained by mixing patient's WBC with U-266 MM cell line and 1 complete MM patient sample). We measured the effect of anti-CD38 Ab using i) the standard approach, considering all microwells regardless of the co-presence of E and T; ii) ICNP approach, considering only microwells featuring E/T co-localization. Results show that drug effect is much evident with ICNP in all the 4 cases with an average increase in target cell death of 40%, indicating a higher sensitivity of this approach than the averaged analysis (Fig 1C, right). Importantly, in one case, the standard analysis did not identify significant differences between anti-CD38 treated and control cells, that could instead be observed with ICNP (p ICNP proved to enable a comprehensive profiling of the immune system by evaluating in one test the immune composition and the fitness of immune cells, both native and drug-treated. These results open the opportunity to develop functional precision medicine approaches for predicting patient's response to drugs with immune-mediated mechanisms of action. AB and RR equally contributed Figure 1 Disclosures Bettelli: CellPly.S.r.l.: Employment. Ruggiano:Cellply S.r.l.: Employment. Bocchi:CellPly S.r.l.: Employment. Rocchi:CellPly.S.r.l.: Employment. Faenza:CellPly S.r.l.: Employment. Zamagni:Janssen: Honoraria, Other: Advisory board, Speakers Bureau; Amgen: Honoraria, Other: Advisory board, Speakers Bureau; BMS: Honoraria, Other: Advisory Board, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; Sanofi: Honoraria, Other: Advisory Board, Speakers Bureau; Celgene Corporation: Honoraria, Other: Advisory board, Speakers Bureau. Bettelli:CellPly S.r.l.: Employment. Rambelli:CellPly S.r.l.: Employment. Guadagnuolo:CellPly S.r.l.: Employment. Pecorari:CellPly S.r.l.: Employment. Giulianelli:CellPly S.r.l.: Employment. Pisani:CellPly S.r.l.: Employment. Biscarini:CellPly S.r.l.: Employment. Cavo:amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Guerrieri:CellPly S.r.l.: Equity Ownership. Bocchi:CellPly S.r.l.: Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

Context Post-HSCT relapse of B-cell ALL is associated with a dismal outcome. IO allows, in the setting of R/R B-ALL patients, high response rates, but with limited duration. Objective To report the outcome of 8 B-ALL adult patients, relapsed after allogeneic HSCT, treated with IO and DLI. Design Retrospective analysis (first patient treated in April 2015, last patient in October 2019). Setting Multicenter (Italian centers). Patients or other participants Five Ph-negative and 3 Ph-positive B-ALL adult patients, with BM disease (6 morphological relapse and 2 MRD-positivity) were treated; 2 patients had additionally extramedullary (EM) disease. Three patients were in salvage 1, 5 patients in salvage ≥ 2; 50% of the patients had previously received Blinatumomab. Median time from transplant to relapse and from relapse to IO was 11 (range 2-21) and 2.5 (range 0-65) months, respectively. Interventions Patients received a median of 3 (range 2-6) IO courses. Four patients received IO and DLI in an alternate schedule and 4 patients sequentially after IO; a median of 3 (range 2-4) DLI at escalating dose was administered (1st dose ranging from 1 × 104/kg CD3+ to 5 × 106/kg CD3+; following doses from 1 × 105 to 5 × 107/kg CD3+). Main outcome measures CR and MRD rate, EM response, DFS, OS, toxicity. MRD was evaluated with BCR-ABL fusion transcript or V(D)J IgH/TCR disease-specific rearrangement on BM. DFS and OS were calculated from start of IO. Toxicity was graded according to CTCAE version. 4.03. Results All patients achieved CR after 1st IO cycle. Six of 8 patients obtained MRD negativity after 2nd IO cycle (4 of 6 patients after 1st cycle). Both PET+ patients achieved PET-negativity. With a median follow-up of 23.5 (range 3-58) months, 6 of 8 (75%) patients are alive. Four of 8 (50%) patients relapsed, of which 2 with CNS localization. Median DFS is 12 months (range 3-58) and median OS is 23.5 (3-58) months. Four out of 8 patients experienced G4 thrombocytopenia. Two patients experienced grade 1 GvHD and no VOD were reported. Conclusions IO and DLI are a safe combination in the post-HSCT setting that may ameliorate the dismal prognosis of this patient subset.

Background Several new drugs are approved for treatment of patients with multiple myeloma (MM), but no validated biomarkers are available for the prediction of a clinical outcome. We aimed to establish whether pretreatment blood and bone marrow plasma concentrations of major cytokines and angiogenic factors (CAFs) of patients from a phase 3 trial of a MM treatment could have a prognostic and predictive value in terms of response to therapy and progression-free and overall survival and whether these patients could be stratified for their prognosis. Methods Blood and bone marrow plasma levels of Ang-2, FGF-2, HGF, VEGF, PDGF-β, IL-8, TNF-α, TIMP-1, and TIMP-2 were determined at diagnosis in MM patients enrolled in the GIMEMA MM0305 randomized controlled trial by an enzyme-linked immunosorbent assay (ELISA). These levels were correlated both reciprocally and with the type of therapy and patients’ characteristics and with a group of non-MM patients as controls. Results No significant differences were detected between the blood and bone marrow plasma levels of angiogenic cytokines. A cutoff for each CAF was established. The therapeutic response of patients with blood plasma levels of CAFs lower than the cutoff was better than the response of those with higher levels in terms of percentage of responding patients and quality of response. Conclusion FGF-2, HGF, VEGF, and PDGF-β plasma levels at diagnosis have predictive significance for response to treatment. The stratification of patients based on the levels of CAFs at diagnosis and their variations after therapy is useful to characterize different risk groups concerning outcome and response to therapy. Trial registration Clinical trial information can be found at the following link: NCT01063179 Electronic supplementary material The online version of this article (10.1186/s13045-018-0691-4) contains supplementary material, which is available to authorized users.

Multiple myeloma (MM) is often associated with renal insufficiency (RI) which adversely influences the prognosis. Several studies demonstrated that bortezomib can improve both renal function and outcome. We prospectively evaluated 21 newly diagnosed MM patients with severe renal impairment secondary to tubular-interstitial damage, most of them due to myeloma kidney, who were primarily treated with bortezomib-based therapy combined with high cut-off hemodialysis (HCOD). The median serum creatinine level at baseline was 6.44 mg dL(-1) and calculated median estimated glomerular filtration rate (eGFR), according to Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equation, was 8 mL/min/1.73 m(2) . Serum free light chain (sFLC) median concentration was 6,040 mg L(-1) . Post induction and best stringent complete response rates were 19 and 38%, respectively. Responses were fast, occurring within a median of 1.4 months. The combination of bortezomib and HCOD led to a prompt and remarkable (>90%) decrease in sFLC levels. Sixteen patients (76%) became dialysis independent within a median of 32 days. With a median follow up of 17.2 months, the 3-year PFS and OS were 76 and 67%, respectively. No early deaths were observed. This study demonstrates that incorporation of bortezomib into induction therapy combined with HCOD is a highly effective strategy in rescuing renal function and improving outcomes in patients with MM and RI.

Precise assessment of response to therapy is of high importance in every phase of multiple myeloma (MM). In addition to the well-established role of monoclonal protein for clinical monitoring, several methods of minimal residual disease evaluation, both inside and outside the bone marrow (BM), are to date available. Next generation flow cytometry and sequencing are probably the best approaches at the BM level, being highly sensitive and uniformly applied. FDG PET/CT is the best imaging technique for evaluating and monitoring response to therapy outside the BM. Functional whole-body MRI techniques (DCE and DWI) seem promising for response evaluation and need further studies. Standardization of most of these techniques is in progress.

Thal-dex (TD) is an effective therapy for advanced MM. We evaluated TD as salvage treatment of MM patients at first relapse. Thal was given at a daily dose of 100 or 200 mg until progression. Dex was administered 160 mg/month. One hundred patients were enrolled. First line therapy included ASCT (72%) and conventional CHT (28%). Fifty-nine percent received a fixed thal dose of 100 mg/day. The most frequent adverse events were constipation (42%), peripheral neuropathy (58%, 5% grade 3), bradycardia (20%), skin rash (11%), and VTE (7%). Discontinuation of thal due to adverse events was recorded in eight patients. On ITT, 46% of patients achieved at least a PR. Median DOR was 28 months, median time to next therapy was 15.5 months. Median OS, TTP, and PFS were 43, 22, and 21 months, respectively. TTP and PFS were significantly longer for patients with at least PR to TD. TD was an effective salvage treatment for MM patients at first relapse, as demonstrated by durable disease control and prolonged OS. TD was well tolerated, as reflected by the long stay on treatment without disease progression (median 25 months) and a low discontinuation rate due to toxicity (8%).

A subanalysis of the GIMEMA-MMY-3006 trial was performed to characterize treatment-emergent peripheral neuropathy (PN) in patients randomized to thalidomide-dexamethasone (TD) or bortezomib-TD (VTD) before and after double autologous transplantation (ASCT) for multiple myeloma (MM). A total of 236 patients randomized to VTD and 238 to TD were stratified according to the emergence of grade ≥2 PN. Gene expression profiles (GEP) of CD138+ plasma cells were analyzed in 120 VTD-treated patients. The incidence of grade ≥2 PN was 35% in the VTD arm and 10% in the TD arm (P

In Multiple myeloma (MM) no treatment has a curative potential and even complete response to novel agents such as proteasome inhibitors (PIs) and immunomodulatory agents (IMiDs) are followed by relapse over time. Next generation sequencing (NGS) has showed how MM at diagnosis is defined by several somatic mutations, but only few drivers, even fewer "druggable" mutations, and many found at a subclonal level. At relapse, targeted studies have shown occasional mutations in drug target genes but the genomic and transcriptomic determinants of chemoresistance in MM remains elusive. We selected 42 MM patients refractory to both lenalidomide and PIs. Whole exome sequencing was performed in 40 of them, and RNAseq in 27. Clinical annotation was available for all patients. Standard analysis pipelines where applied to analyze mutations, copy number alterations (CNAs), mutational signatures, gene expression and expressed mutations. Patients received a median of 3 lines of treatment, with median overall survival of 14.6 months from sampling. We found a median of 77.5 mutations per patient, which is more than what reported at diagnosis (Bolli et al, Nature Communications 2014;5:2997). 100% of samples showed evidence of subclonality, and 37% of them exhibited a higher number of subclonal than clonal variants. Therefore, even at this advanced stage the MM genome is evolving and is composed of different subclones that may display different chemosensitivity. The mutational landscape was also different. TP53 mutations were the second most common after KRAS (20% and 17.5%, respectively). Interestingly TP53 mutations all clustered in patients receiving bortezomib as the last line of treatment. Only 2 patients showed a CRBN mutation, both subclonal. Combining mutations and CNA analysis, the TP53 pathway was the most frequently inactivated (45% of patients). Altogether, mutations or deletions of genes in the CRBN E3 ubiquitin ligase complex were found in 32.5% of patients, while proteasomal subunit genes were infrequently hit. Refractory cases were also uniquely characterized by a novel signature linked to exposure to alkylating agents, whose activity was more pronounced after high-dose melphalan suggesting a mutagenic effect of the drug on residual cells at the time of transplant. Whether this has any pathogenetic role on the disease course remains to be elucidated. RNAseq analysis did not show any influence of treatment or mutational data on the clustering of samples, which was mainly influenced by karyotypic events. The main cluster was composed by non-hyperdiploid patients with both amp(1q) and del(13): these showed CCND2 and MCL1 upregulation, the latter representing a marker of venetoclax resistance and novel target of experimental treatments. Only 26.3% of mutations were expressed, and this correlated with the clonality level of the mutation. However, most mutations in driver genes were expressed, with the notable exception of those causing nonsense mediated decay. Overall, classical high-risk features or CRBN pathway mutations were found in 65% of the cohort. However, only amp(1q) predicted survival in our cohort. The lack of prognostic value of high-risk lesions is likely explained by a higher prevalence of such features in double-refractory stages. Our data suggest that gene mutation is not a preferred mode of evolution of drug resistance in MM. Chemoresistance of the bulk tumor population is likely attained though differential, yet converging evolution of different subclones that are overall highly variable from patient to patient and within the same patient. Disclosures Kastritis: Prothena: Honoraria; Genesis: Honoraria; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria; Pfizer: Honoraria. Dimopoulos:Sanofi Oncology: Research Funding. Cavo:bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Corradini:Janssen: Honoraria, Other: Travel Costs; Takeda: Honoraria, Other: Travel Costs; Jazz Pharmaceutics: Honoraria; Gilead: Honoraria, Other: Travel Costs; Daiichi Sankyo: Honoraria; Celgene: Honoraria, Other: Travel Costs; Amgen: Honoraria; AbbVie: Consultancy, Honoraria, Other: Travel Costs; KiowaKirin: Honoraria; Kite: Honoraria; BMS: Other: Travel Costs; Sanofi: Honoraria; Servier: Honoraria; Roche: Honoraria; Novartis: Honoraria, Other: Travel Costs. Bolli:Celgene: Honoraria; Novartis: Honoraria; Gilead: Other: travel expenses.

Introduction: The role of serum free light chain (sFLC) assay for monitoring immunoglobulin (Ig) secretory multiple myeloma (Ig-MM) remains an area of debate. IMWG guidelines (Durie et al. Leukemia 2006) recommend the use of electrophoresis (EP) and immunofixation (IF) for definitions of response and progressive disease (PD), while the measurement of sFLC is required only to fulfill criteria for stringent complete response. Aims: We aimed at evaluating the prognostic impact of sFLC levels during monitoring of Ig-MM. Methods: We analyzed all consecutive Ig-MM patients (pts) who received at our Centre a first line novel agent-based therapy between October 2006 and December 2018, and for whom sFLC data by BN II nephelometer, along with serum and urine EP plus IF, were available at diagnosis and every 3-4 months until the last contact date. Criteria for response and PD were those established by the IMWG. IMWG criteria for PD in oligo/non-secretory MM were used to identify an increase in sFLC levels. sFLC escape (sFLCe) was defined as an increase in sFLC, without any IMWG criteria of PD. To evaluate the prognostic role of rising sFLC, sFLCe was considered as an event for outcomes after relapse. Second time to progression/sFLCe (2nd TTPe) was the time from the date of first PD or sFLCe to that of second PD or sFLCe, while OS after progression/sFLCe (OS after Pe) was calculated from first PD or sFLCe to the date of death. Results: A total of 339 pts were identified. At baseline, 311 (92%) pts had an abnormal sFLC ratio (sFLCR) and 231 (68%) a sFLC measurable disease defined by an abnormal sFLCR and involved sFLC ≥100 mg/L. First-line treatments included proteasome-inhibitors (PI) (42%), immunomodulators (IMiDs) (13%), or both these agents (45%). Autotransplant was performed in 48% of pts. Overall, 148 (44%) pts achieved a complete response (CR) and 198 (60%) achieved (or maintained) a normal sFLCR. With a median follow-up of 54.1 (IQR 25.0-83.7) months (mos), median PFS and OS were 35.9 and 97.9 mos. The presence at baseline of a sFLC measurable disease was associated with worse PFS (median 31.5 vs 45.6 mos, HR=1.58, p=0.004) and OS (64.5% vs 83.3% at 54 mos, HR=1.98, p=0.003), while sFLCR normalization predicted for extended PFS (median 45.3 vs 16.8 mos, HR=0.21, p Conclusions: Our results highlight the prognostic value of sFLC during monitoring of Ig-MM, and support the inclusion of the sFLC assay along with EP and IF for defining response and progression. Disclosures Tacchetti: Oncopeptides: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau; BMS: Honoraria; Amgen: Honoraria, Speakers Bureau; Janssen: Honoraria; Takeda: Honoraria, Speakers Bureau. Zamagni:Sanofi: Honoraria, Other: Advisory Board, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; Amgen: Honoraria, Other: Advisory board, Speakers Bureau; BMS: Honoraria, Other: Advisory Board, Speakers Bureau; Celgene Corporation: Honoraria, Other: Advisory board, Speakers Bureau; Janssen: Honoraria, Other: Advisory board, Speakers Bureau. Pantani:Takeda: Honoraria; BMS: Honoraria; Janssen: Honoraria; Celgene: Honoraria; Amgen: Honoraria. Mancuso:Amgen: Honoraria; Janssen: Honoraria; Takeda: Honoraria; Celgene: Honoraria, Speakers Bureau. Zinzani:CELLTRION: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SANDOZ: Membership on an entity's Board of Directors or advisory committees; IMMUNE DESIGN: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; CELGENE: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; PORTOLA: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ROCHE: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; EUSAPHARMA: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; KYOWA KIRIN: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SANOFI: Consultancy; SERVIER: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; JANSSEN-CILAG: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; GILEAD: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; VERASTEM: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Cavo:bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau.

Introduction The differentiation status plasticity of Multiple Myeloma (MM) plasma cells (PCs) is an adaptive strategy that might confer a specific fitness to tumour cells, enabling their interaction with an evolving microenvironment. Therefore, proliferation rates of MM clones are not constant, and the immunophenotypic profile of the most skilled MM PCs might be the expression of specific genetic and genomic programs, that emerge under the therapeutic pressure and promote tumour development. However, the genomic background that supports any diverse plasma cell differentiation phenotypes has not yet been inferred. Aim To correlate the genetic and genomic background with the immunophenotypic profile of MM clones at diagnosis, in order to stratify patients (pts) according to a Maturation Index, and ultimately to evaluate the impact of this stratification on the disease outcome. Patients and Methods 117 newly diagnosed MM (NDMM) pts, mostly treated up-front with a proteasome inhibitor (PI) -based treatment, were included in the study. For each pts, both neoplastic PCs and CD19+ B cells compartments were characterized by 8-color multi-parameter flow cytometry analysis, combining CD138-PE, CD38-PE-Cy7, CD56-APC-Cy7, CD20-APC, CD19-FITC, CD27-APC, CD45-PerCp, CD28-APC, CD117-FITC, CD28-APC, CD81-APC, IgK-APC and IgL-FITC. In a subgroup of pts, both a SNP array profile for copy number alterations (CNAs) and a 25-genes targeted mutational panel were assessed in CD138+ PCs. A custom ddPCR assay was also employed to evaluate through a 10-Hh gene signature the self-renewal status of PCs. Results In order to define a Maturation Index, pts were evaluated at different levels of heterogeneity for: a) differential expression of CD19/CD81 markers; b) level of chromosomal instability (CIN) and point mutations; d) self-renewal status. Based on the co-expression of CD19 and CD81 markers, pts were stratified in 3 different subgroups, recapitulating a progressive PC maturation process: the most immature, which included pts with CD19+/CD81+ PCs (18/117 = 15%), the intermediate, including CD19-/CD81+ PCs (42/117 = 36%) and the most mature, including CD19-/CD81- PCs (57/117 = 49%). The advanced PC differentiation status characterizing this latter subgroup was further confirmed by the high expression of CD28 and CD44, and the reduced expression of CD20, CD27 and CD45, commonly associated with less mature stages of the disease (p CIN was defined according both to the total CNAs count and to the number of chromosomes' breakpoints (BPs). Pts with an advanced differentiation status displayed a higher number of total CNAs and BPs (median tot. CNAs = 550 vs. 105, and median BPs nr. = 18.5 vs. 8 in CD19-81- and CD19+81+ pts, respectively, p Finally, a more mature PC clone was significantly related to a higher prevalence of unfavourable features at baseline (e.g. ≥ 3 PET lesions, ≥ 100 k/l ratio, ISS III disease stage p Conclusions A Maturation Index defined NDMM pts with an advanced differentiation status both at immunophenotypic and molecular level, finding lastly associated with a prevalence of poor prognostic features. Chromosomal instability, together with cellular phenotypic plasticity, represents an important, yet poorly defined, mechanism by which MM clones accelerate their own evolution and survival. Acknowledgements: AIRC_IG2014-15839, RF-2016-02362532. Disclosures Mancuso: Celgene: Honoraria, Speakers Bureau; Amgen: Honoraria; Takeda: Honoraria; Janssen: Honoraria. Zamagni:Sanofi: Honoraria, Other: Advisory Board, Speakers Bureau; Celgene Corporation: Honoraria, Other: Advisory board, Speakers Bureau; Janssen: Honoraria, Other: Advisory board, Speakers Bureau; Amgen: Honoraria, Other: Advisory board, Speakers Bureau; BMS: Honoraria, Other: Advisory Board, Speakers Bureau; Takeda: Honoraria, Speakers Bureau. Tacchetti:Oncopeptides: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; BMS: Honoraria; Celgene: Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau; Janssen: Honoraria. Zinzani:CELGENE: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; PORTOLA: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ROCHE: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; GILEAD: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; JANSSEN-CILAG: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SERVIER: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SANDOZ: Membership on an entity's Board of Directors or advisory committees; IMMUNE DESIGN: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; EUSAPHARMA: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; KYOWA KIRIN: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SANOFI: Consultancy; MSD: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; CELLTRION: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; VERASTEM: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Cavo:janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

The treatment of hairy cell leukemia (HCL) has deeply changed over years. Purine analogs, namely cladribine (2CdA) now represent the treatment of choice. The BRAF V600E mutation is now regarded as the pathogenic event. One hundred and eighty-four patients were followed between 1986 and 2018 and treated according to era-specific guidelines. This is the largest monocentric series reported. Responses were classified by combining Consensus Resolution criteria and marrow immunohistochemistry. Patients were grouped according to the number of treatment lines they received (table). Ten patients treated with frontline 2CdA and in complete response (CR) for at least 5 years were tested for the presence of the BRAF V600E mutation in peripheral blood by droplet digital PCR as a molecular marker for active disease. Patients treated first line responded in 86% of cases, with 44% CR. Response rates remained high throughout the first 4 lines (84%, 81%, 79% for the second line onward, with CR in 38%, 37%, 15% of cases respectively), although decreasing progressively with the number of treatments received. One hundred and twenty-two patients received 2CdA as first line treatment, with a response rate of 86% and a CR rate of 54%. Among the 66 CR patients, 45 (68%) have never received further therapy: 11 patients are in continuous CR between 5 and 10 years after treatment, 14 between 10 and 20 years and 3 patients at more than 20 years. Median time-to-next treatment (TTNT) for patients after receiving 2CdA was 8.2 years: partial responders had a significantly shorter median TTNT than CR patients (5.3 years versus median not reached at 25.8 years, p=0.0001) (figure). Seven patients in CR for more than 5 years after front line 2CdA were BRAF V6500E negative in peripheral blood. One of these displayed disease recurrence and required further treatment roughly 2 years later. Three patients were positive for the BRAF V600E mutation at 6.5, 8.4 and 13.7 years after treatment and developed an overt disease relapse between 4 months and 2 years. Patients with HCL require subsequent lines of therapy in more than 50% of cases. Purine analogs allow significant response rates when applied first line and upon retreatment. Some patients may enjoy long lasting responses after one course of 2CdA and display no evidence of BRAF V600E mutation in peripheral blood. A PCR-based evaluation of the allelic burden in peripheral blood may provide information regarding disease activity over time. Figure Disclosures Cavo: Celgene, Janssen, Amgen, BMS, Abbvie, Takeda: Honoraria; Janssen, Celgene: Other: Travel Accommodations; Janssen, Celgene: Speakers Bureau; Janssen, Celgene, Amgen, Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees. Zinzani:TG Therapeutics: Honoraria, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eusapharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Multiple Myeloma (MM) maintenance therapy is a low intensive, prolonged treatment, commonly administered to newly diagnosed patients (pts) at the end of fixed-time, front-line regimens. Lenalidomide (LEN) is considered the best available maintenance option for MM able to prolong pts survival. However, the actual benefits or disadvantages of a LEN-based continuous maintenance and its potential role as selective pressure able to induce genomic changes are still unclear. The identification of specific therapy-driven modifications has been so far prevented by the scarce number of homogeneously-treated cohorts of pts with paired samples (diagnosis, D and relapse, R). In this study we estimated the role of LEN maintenance therapy in eliciting genomic changes in a cohort of MM pts homogeneously up-front treated with PI-based regimens. Whole genome Copy Number Aberrations (CNAs) landscape was obtained by SNPs array in 54 pts whose BM-CD138+ were collected both at D and at first R. Pts had an high-risk (HR) disease, as defined both by the presence of HR cytogenetic aberration at baseline in 81% of pts and by the 29 m median TTP. RawCopy 1.10 was used for the segmentation of SNPs array signals; samples' purity was adjusted by using manually reviewed ASCAT solutions. A custom gene-level CN calling approach was set up, to match every gene's CN value at D and R, thus generating genomic evolutive patterns based on changes of these values. Finally, high-risk genomic loci were computed using GISTIC 2.0_v7 to derive focal regions with oncogene and/or tumor suppressor genes relevant for MM biology. After induction therapy, 31/54 pts were treated with HD chemotherapy followed by either single or double ASCT; LEN maintenance therapy was then offered both to 20/31 auto-transplanted and to 6/23 not auto-transplanted pts. Three main evolutive trajectories (linear L, drift D, and branching B) were defined according to the CN changes' direction, reflecting a putative positive, negative, or both positive and negative selective pressure, respectively. A fourth, stable (S) trajectory was also observed, characterized by the absence of CN changes between D and R. Overall, 29, 15 and 10 pts relapsed with B/D, L and S pattern, respectively; at R, all LEN-treated pts quantitively and qualitatively changed their sub-clonal architecture: a B/D evolutive pattern characterized 70% of pts. By contrast, genome remained mostly stable in 61% of not-treated pts. We then focused on CN changes of specific chromosomal regions and/or genomic loci, whose prognostic role has been already established in MM (i.e. CN losses of TP53 on chr17p, RB1 on chr13q, CYLD on chr16q, CDKN2C and FAM46C on chr1p; CN gain of CKS1B on chr1q). When present at D these CNAs tended to persist throughout the disease course regardless of whether pts received or not maintenance. The emersion of any of these CNAs at R was widely observed both in pts receiving or not maintenance, whereas a negative selective pressure over them was more likely to occur in pts receiving maintenance, as compared to the others (50% vs 11% of B/D trajectories in LEN-treated vs not-treated pts, respectively). Strikingly, in LEN-treated pts, the extension of both TTP and OS was favored by the extinction and/or negative selection of the HR CNAs (B/D patterns), and shortened by their stability or positive selection (L/S patterns) (median TTP 46 vs 32 m HR=3,6 CI 1,2-10,6, p=0.01; median OS 111 vs 63 m HR 5,7 CI 1,1-32,4, p=0.04 in B/D vs L/S pts, respectively). On the contrary, the absence of maintenance selective pressure seemed to affect neither the evolution trajectory, nor the clinical course of not-treated pts (fig 1). The extinction of sub-clones carrying HR lesions in pts receiving maintenance therapy is likely to be associated to the negative selection exerted by the therapy itself. This might explain the extended survival of pts receiving maintenance and relapsing with B/D evolution patterns, as compared to that of pts whose genomic landscape either tended to remain stable or let the prevalent emersion of HR genomic features. On the contrary, the sub-clonal architecture of pts not receiving maintenance seemed to randomly evolve, due to the absence of a specific therapy-related selective pressure. Overall, information on the genomic changes occurring throughout the disease course might be relevant for the recognition of pts most benefitting from a continuous therapy. Thanks to AIRC_IG2014-15839, RF-2016-02362532 Disclosures Zamagni: Takeda: Honoraria, Speakers Bureau; Sanofi: Honoraria, Other: Advisory Board, Speakers Bureau; Janssen: Honoraria, Other: Advisory board, Speakers Bureau; Amgen: Honoraria, Other: Advisory board, Speakers Bureau; BMS: Honoraria, Other: Advisory Board, Speakers Bureau; Celgene Corporation: Honoraria, Other: Advisory board, Speakers Bureau. Tacchetti:BMS: Honoraria; Takeda: Honoraria, Speakers Bureau; Janssen: Honoraria; Oncopeptides: Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau. Mancuso:Celgene: Honoraria, Speakers Bureau; Janssen: Honoraria; Takeda: Honoraria; Amgen: Honoraria. Petrucci:Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Liberati:Incyte: Consultancy; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Bristol & Mayer: Honoraria; Janssen: Honoraria; Celgene: Honoraria. Rossi:Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; Mundipharma: Honoraria; BMS: Honoraria; Sandoz: Honoraria. Boccadoro:Bristol-Myers Squibb: Honoraria, Research Funding; Mundipharma: Research Funding; Sanofi: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; AbbVie: Honoraria. Cavo:amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

Multiple myeloma (MM) plasma cell (MMPC) interactions with the microenvironment control MMPC growth, survival, drug-resistance and intra- and extramedullary dissemination. Dissemination of MMPCs through bone marrow niches and in extra-medullary sites is an active process of invasion involving bone marrow endothelial cells, multiple adhesion molecules and chemokine receptors. Since enhanced angiogenesis characterizes MM, we investigated whether junctional adhesion molecule-A (JAM-A) mediated interactions between MM bone marrow endothelial cells (MMECs) and MMPCs impact disease progression. To this end, we analyzed JAM-A expression levels in MMECs of 312 MM patients in two independent cohorts with flow cytometry, namely 111 newly diagnosed (NDMM) and 201 relapsed/refractory (RRMM) and compared them to 36 monoclonal gammopathy of undetermined significance (MGUS) and healthy subjects. To corroborate our data and investigate at a gene-expression level the prognostic value of deregulated genes (FDR Surface protein expression of JAM-A on MMECs predicted poor overall survival (OS) in NDMM (not reached (NR) vs. 78 months univariate hazards ratio-HR=9.14, 95% CI 2.8-29.76, P Ensuing functional shRNA knockdown of JAM-A reduced MM invasion (P Collectively, our findings pinpoint JAM-A as a key player propagating a vicious cycle of MMECs and MMPCs interaction; the expression of JAM-A and the related adhesion pathways can prognostically stratify patients in the late disease stages impacting two main MM progression processes: angiogenesis and extra-medullary dissemination. Therefore, we propose JAM-A as a promising MM biomarker and novel therapeutic target in advanced disease. Disclosures Klapper: Roche, Takeda, Amgen, Regeneron: Honoraria, Research Funding. Rosenwald:MorphoSys: Consultancy. Cavo:celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

We retrospectively investigated the role of serial serum-free light chain (sFLC) evaluations in 150 multiple myeloma (MM) patients treated with first-line bortezomib-based regimens. Baseline sFLC ratio (sFLCR) identified three groups of patients - normal, lightly abnormal (

Despite significant improvement in outcomes have been observed for multiple myeloma (MM) patients over the past 10-15years, mainly due to the introduction of novel agents targeting the tumor clone and the bone marrow microenvironment, treatment of refractory and/or relapsed (RR) disease remains a challenge, particularly for patients who have failed prior bortezomib- and lenalidomide-based therapies. More recently, new drugs with different mechanisms of action, including second generation proteasome inhibitors, third generation immunomodulatory drugs, histone deacetylase inhibitors and monoclonal antibodies, have been developed and are under investigation, further increasing treatment options for RRMM patients. Overall, novel agent-based triplet combinations demonstrated superior response rates and prolonged disease control when compared with two-drug regimens in several randomized clinical trials, without adding any relevant additional toxicity. Salvage triplet therapies are likely to play a key role in overcoming drug-resistance and hold promise to further improve long-term outcomes of RRMM patients.

The aim of the present study was to compare thalidomide-dexamethasone (Thal-Dex) and vincristine-doxorubicin-dexamethasone (VAD) as primary therapy in preparation for autologous peripheral blood stem-cell (PBSC) transplantation for multiple myeloma (MM). For this purpose, we performed a retrospective matched case-control analysis of 200 patients who entered 2 consecutive studies from 1996 to 2004 and received Thal-Dex (n = 100) or VAD (n = 100) administered for 4 months before collection of PBSCs and autologous transplantation. Matching criteria included age, clinical stage, and serum β2-microglobulin levels. In comparison with VAD, Thal-Dex resulted in a significantly higher response rate (52% versus 76%, respectively; P < .001) and effected more profound reduction in myeloma cell mass of both immunoglobulin G (IgG; P = .02) and IgA (P = .03) type. More frequent toxicities included nonfatal deep vein thrombosis with Thal-Dex (15%) and granulocytopenia with VAD (12%). In each of the 2 treatment groups, 91% of patients proceeded to PBSC mobilization. The median number of collected CD34+ cells was 7.85 × 106/kg in the Thal-Dex group and 10.5 × 106/kg in the control group. Thal-Dex may be considered an effective and relatively well-tolerated oral alternative to the more complex VAD regimen as front-line therapy for MM patients who are candidates for subsequent autologous transplantation.

Abstract 805FN2 Background. Achievement of CR is generally associated with improved clinical outcomes for patients (pts) with MM and represents a primary endpoint of current clinical trials. The GIMEMA Italian Myeloma Network designed a phase 3 study to demonstrate that the triplet VTD regimen was superior over a doublet such as thalidomide-dexamethasone (TD) as induction therapy prior to double ASCT for newly diagnosed MM. On an intention-to-treat basis, the rate of complete or near complete response (CR/nCR) was 31% for the 236 pts on VTD induction therapy, while it was 11% (p Methods. For this purpose, in a molecular substudy to the main clinical study we assessed the ability of gene expression profile (GEP) to predict attainment of CR/nCR in 122 pts enrolled in the VTD arm of the study. Their characteristics at baseline, including cytogenetic abnormalities, were comparable with those of the whole population of 236 pts. Highly purified CD138+ plasma cells were obtained at diagnosis from each of these pts and were profiled for gene expression using the Affymetrix U133 Plus2.0 platform. In order to build a low-dimensional signature with optimal performance, genomic data were analyzed with an original algorithm that exploits quadratic discriminant analysis with a bottom-up approach that builds N-gene signatures starting from two-dimensional signatures. Gene models were applied to test datasets to predict achievement of either CR/nCR or less than nCR, and classification performances were validated by a leave-one-out crossvalidation procedure. Results. Thirty four pts out of the 122 (28%) who were included in the present analysis achieved a CR/nCR, while the remaining 88 patients failed this objective. The molecular approach described above allowed to identify several gene signatures among which we choose a 163-gene signature that provided a predictive capability of 79% sensitivity, 87% specificity, 71% positive predictive value (PPV) and 92% negative predictive value (NPV). These expression values were used in an unsupervised hierarchical clustering to stratify the population of 122 profilated pts into 3 well defined subgroups. Seventy nine pts were included in subgroup A, while the remaining 43 pts were included in either subgroup B (n=22) or subgroup C (n=21). Notably, 19 out the 34 CR/nCR pts (56%) clustered in subgroup B, whereas the remaining 15 pts were randomly distributed within subgroup A. Analysis of demographic and disease characteristics of the pts belonging to the 3 major subgroups, revealed that in subgroup B the frequencies of pts carrying del(13q) (78%) or del(17p) (22%) or with an IgA isotype (54%) were significantly higher in comparison with the corresponding values found in subgroup A (47%, 4%, and 10%, respectively) and subgroup C (38%, 10%, and 5%, respectively). In order to obtain a more feasible set of genes predictive of CR/nCR, several smaller signatures originating from the 163-gene signature were further analyzed by means of the same algorithm described above. The best predictive capability was obtained with a 41-gene signature that provided 88% sensitivity, 97% specificity, 91% PPV and 95% NPV. A GeneGo ® network analysis of genes included in the signatures showed that the most relevant network nodes included tumour suppressor genes (FBXW7 and MAD), genes involved in inflammatory response (TREM1 and TLR4) and genes involved in B cell development (IKZF1, IL10 and NFAM1). Genes included in the signatures do not gather in specific chromosomes, thus confirming the absence of bias on selection of signatures genes, potentially due to prevalence of MM typical chromosomal aberrations. Conclusions. GEP analysis of a subgroup of pts who received VTD induction therapy allowed to provide a 41-gene signature that was able to predict attainment of CR/nCR and, conversely, failure to achieve at least nCR in 91% and 95% of cases, respectively. These favorable results might represent a first step towards the possible application of a tailored therapy based on the single patient's genetic background. Supported by: Fondazione Del Monte di Bologna e Ravenna, Ateneo RFO grants (M.C.) BolognAIL. Disclosures: Bringhen: Celgene: Honoraria; Janssen-Cilag: Honoraria; Novartis: Honoraria; Merck Sharp & Dhome: Membership on an entity's Board of Directors or advisory committees. Offidani:Janssen: Honoraria; Celgene: Honoraria.