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Background: Belantamab mafodotin (belamaf) has shown promising antimyeloma activity in relapsed or refractory multiple myeloma (RRMM) as a single agent. It was hypothesized that its multimodal activity may be enhanced by programmed cell death protein 1 pathway inhibition and activation of T cell–mediated antitumor responses. This study investigated the efficacy and safety of belamaf with pembrolizumab in patients with RRMM. Methods: DREAMM‐4 (NCT03848845) was an open‐label, single‐arm, phase 1/2 study divided into dose‐escalation (part 1) and dose‐expansion (part 2) phases. Patients were ≥18 years old with ≥3 prior lines of therapy including a proteasome inhibitor, an immunomodulatory drug, and an anti‐CD38 agent. Patients received belamaf (2.5 or 3.4 mg/kg, part 1; 2.5 mg/kg, part 2) and 200 mg pembrolizumab for ≤35 cycles. Results: Of 41 enrolled patients, 34 (n = 6 part 1, n = 28 part 2) who received 2.5 mg/kg belamaf plus pembrolizumab were included in this final analysis. Sixteen patients (47%) achieved an overall response. Minimal residual disease negativity was achieved in three of 10 patients who had very good partial response or better. Five of eight patients who had prior anti–B‐cell maturation antigen therapy achieved partial response or better, including two who had B‐cell maturation antigen–refractory disease. Common grade ≥3 adverse events were keratopathy (38%) and thrombocytopenia (29%). Despite belamaf‐related ocular events, quality‐of‐life measures remained stable over time. No new safety signals were observed. Conclusions: The results of DREAMM‐4 demonstrated clinical activity and a favorable safety profile of belamaf plus pembrolizumab in patients with RRMM. This trial is registered at www.ClinicalTrials.gov as NCT03848845. [ABSTRACT FROM AUTHOR]

Objectives: Treatment intensification (including consolidative high‐dose chemotherapy with autologous stem cell transplantation [HDT‐ASCT]) significantly improved outcome in primary central nervous system lymphoma (PCNSL) patients. Methods: We conducted a multicenter, retrospective analysis of newly diagnosed PCNSL patients, treated with intensified treatment regimens. The following scores were evaluated in terms of overall survival (OS) and progression‐free survival (PFS): Memorial Sloan‐Kettering Cancer Center (MSKCC), International Extranodal Lymphoma Study Group (IELSG), and three‐factor (3F) prognostic score. Further, all scores were comparatively investigated for model quality and concordance. Results: Altogether, 174 PCNSL patients were included. One hundred and five patients (60.3%) underwent HDT‐ASCT. Two‐year OS and 2‐year PFS for the entire population were 73.3% and 48.5%, respectively. The MSKCC (p =.003) and 3F score (p <.001), but not the IELSG score (p =.06), had the discriminatory power to identify different risk groups for OS. In regard to concordance, the 3F score (C‐index [0.71]) outperformed both the MSKCC (C‐index [0.64]) and IELSG (C‐index [0.53]) score. Moreover, the superiority of the 3F score was shown for PFS, successfully stratifying patients in three risk groups, which also resulted in the highest C‐index (0.66). Conclusion: The comparative analysis of established PCNSL risk scores affirm the clinical utility of the 3F score stratifying the widest prognostic spectrum among PCNSL patients treated with intensified treatment approaches. [ABSTRACT FROM AUTHOR]

FLA-IDA salvage chemotherapy combined with a seven-day course of venetoclax (FLAVIDA) in patients with relapsed/refractory acute leukaemia Eighty-one patients were identified that fulfilled the selection criteria of the FLAVIDA patients and were compared to the FLAVIDA patients included in this analysis (detailed information about the dosing scheme are provided in the Supplementary materials). Cumulative incidence of blood count recovery amongst responding patients in the FLAVIDA cohort (red line) and patients in the FLA-IDA control cohort (blue line). (C) Relapse-free survival of the nine patients in the FLAVIDA cohort and of the 32 patients in the FLA-IDA control cohort who achieved CR/CRi after one cycle of chemotherapy. [Extracted from the article]

Summary: Myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN) and chronic myelomonocytic leukaemia (CMML) can progress to secondary acute myeloid leukaemia (sAML). We compared the outcome of 4214 sAML patients who received allogeneic haematopoietic stem cell transplantation (allo‐HSCT) from an unrelated (62%) or human leucocyte antigen (HLA)‐identical sibling donor (38%) according the underlying disease: MDS (n = 3541), CMML (n = 251) or MPN (n = 422). After a median follow up of 46·5 months, the estimated 3‐year progression‐free (PFS) and overall survival (OS) for the entire group was 36% (34–37%) and 41% (40–43%), respectively. The cumulative incidence of relapse and non‐relapse mortality (NRM) was 37% (35–39%) and 27% (26–29%), respectively. In a multivariable analysis for OS, besides age (P < 0·001), unrelated donor (P = 0·011), cytomegalovirus ± constellation (P = 0·007), Karnofsky index ≤ 80 (P < 0·001), remission status (P < 0·001), peripheral blood as stem cell source (P = 0·009), sAML from MPN (P = 0·003) remained a significant factor in comparison to sAML from MDS, while worse outcome of sAML from CMML did not reach statistical significance (P = 0·06). This large registry study demonstrates a major impact of the underlying disease on outcome of sAML after allo‐HSCT. [ABSTRACT FROM AUTHOR]

Upon antigen-specific or allogeneic activation, T cells sharply increase their metabolic activity to cope with augmented needs for proliferation and effector functions. Therefore, enzymes involved in energy metabolism constitute attractive targets to modulate the activity of pathogenic effector T cells in the setting of graft-versus-host-disease (GVHD). Here, we show that T cells deficient for acetyl-CoA carboxylase 1 (TACC1) are dramatically less pathogenic than wild-type (WT) T cells in a lethal C57BL/6 into BALB/c model of acute GVHD and permitted sustained survival of recipient mice. In line with this clinical observation, higher frequencies of GVHD-suppressing Foxp3+ regulatory T (Treg) cells were detected in the colon of TACC T-cell recipients. In vitro, T-cell stimulation with allogeneic DCs induced higher proportions of Treg cells but also led to diminished proliferation of TACC1 T cells compared to WT T cells. Furthermore, TACC1 T cells activated by allogeneic DCs showed impaired glycolysis and lipid synthesis. Thus, targeting de novo fatty acid synthesis via acetyl-CoA carboxylase inhibition may be a promising new strategy to prevent GVHD. [ABSTRACT FROM AUTHOR]

Dominant tolerance to self-antigen requires the presence of sufficient numbers of CD4+Foxp3+ Treg cells with matching antigen specificity. However, the size and role of TCR repertoire diversity for antigen-specific immuno-regulation through Treg cells is not clear. Here, we developed and applied a novel high-throughput (HT) TCR sequencing approach to analyze the TCR repertoire of Treg cells and revealed the importance of high diversity for Treg-cell homeostasis and function. We found that highly polyclonal Treg cells from WT mice vigorously expanded after adoptive transfer into non-lymphopenic TCR-transgenic recipients with low Treg-cell diversity. In that system, we identified specific Treg-cell TCR preferences in distinct anatomic locations such as the mesenteric LN indicating that Treg cells continuously compete for MHC class-II-presented self-, food-, or flora-antigen. Functionally, we showed that high TCR diversity was required for optimal suppressive function of Treg cells in experimental acute graft versus host disease (GvHD). In conclusion, we suggest that efficient immuno-regulation by Treg cells requires high TCR diversity. Thereby, continuous competition of peripheral Treg cells for limited self-antigen shapes an organ-optimized, yet highly diverse, local TCR repertoire. [ABSTRACT FROM AUTHOR]

BACKGROUND: Delayed donor red blood cell chimerism (DRCC), pure red blood cell aplasia (PRCA), and autoimmune hemolytic anemia (AIHA) are poorly documented complications after hematopoietic cell transplantation (HCT). The clinical variable “prolonged isolated red blood cell transfusion requirement” (PRTR) was evaluated as a trigger for an extended diagnostic workup. STUDY DESIGN AND METHODS: PRTR was defined as the need for red blood cell (RBC) transfusions beyond Day 60 after HCT. We analyzed 487 patients transplanted between 2000 and 2006. Median age was 37 years (range, 0-70 years). Peripheral blood stem cells (n = 344), marrow (n = 138), and cord blood (n = 5) from 278 unrelated and 209 family donors were used. RESULTS: Univariate analysis identified age (incidence of 18.3% among elderly patients, 10.5% in adults, and 2.0% among children [p = 0.002]), ABO incompatibility (16.4% after major incompatible, 2.9% after minor incompatible, and 9.4% after ABO-compatible transplantations [p = 0.003]), conditioning (15.2% after reduced-intensity regimens vs. 7.3% after myeloablative conditioning; p = 0.006), donor type (13.2% after HLA-matched unrelated, 13.6% after mismatched unrelated, 5.7% after matched related, and 0.0% after mismatched related grafts; p = 0.026), and acute graft-versus-host disease (aGVHD; 7.1% with aGVHD vs. 12.5% without aGVHD; p = 0.046) as predisposing factors. In multivariate analysis minor ABO incompatibility (odds ratio [OR] = 0.2, p = 0.01), younger age (OR = 0.1, p = 0.02), and matched related HCT (OR = 0.4, p = 0.02) remained independent protective factors. CONCLUSIONS: PRTR could serve as a trigger for a standardized screening for DRCC, PRCA, and AIHA after HCT. [ABSTRACT FROM AUTHOR]

Induced antigen-specific Foxp3 T cells (iTreg) are being discussed as a promising alternative to polyclonal natural Foxp3 T cells (nTreg) for cell-based therapies, particularly to achieve transplantation tolerance. Using Foxp3eGFP-reporter mice, we here establish an efficient protocol to induce and expand alloantigen-specific iTreg from Foxp3CD4 T cells with cluster-disrupted DC. These iTreg were mainly CD62L and showed efficient suppressive activity in vitro. However, in contrast to nTreg, adoptively transferred iTreg entirely failed to prevent lethal graft versus host disease (GVHD). Within irradiated recipients, the majority of adoptively transferred Foxp3 iTreg, but not Foxp3 nTreg quickly reverted to Foxp3CD4 T cells. We therefore suggest that therapeutic approaches to treat GVHD should rely on nTreg, whereas the use of de novo alloantigen-induced iTreg should be handled with caution since the stability of the regulatory phenotype of the iTreg could be of major concern. [ABSTRACT FROM AUTHOR]