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Abstract: In newly diagnosed transplant-ineligible patients with myeloma, daratumumab has improved outcomes when added to the standard-of-care regimens. In a randomized trial, we tested whether similar improvements would be observed when daratumumab was added to the bortezomib, cyclophosphamide, and dexamethasone (VCD) regimen. Transplant-ineligible patients with untreated myeloma were randomized to receive VCD or VCD plus daratumumab (VCDD). A total of 121 patients were randomized: 57 in the VCD arm and 64 in the VCDD arm. Baseline characteristics were balanced between the 2 arms. The median progression-free survival (PFS) was 16.8 months (95% confidence interval [CI], 15.3-21.7) and 25.8 months (95% CI, 19.9-33.5) in the VCD and VCDD arms, respectively (hazard ratio, 0.67; log-rank test P = .066). In a preplanned analysis, it was demonstrated that the daratumumab-containing arm showed a significant improvement in PFS from 18 months onward, based on estimates at fixed time points after randomization. The proportions of patients who were progression-free at the following time points were: 18 months, 48% vs 68% (P = .0002); 24 months, 36% vs 52% (P = .0001); and 30 months, 27% vs 41% (P < .0001) in the VCD and VCDD arms, respectively. The best overall response and very good partial response rate were significantly higher in the daratumumab arm compared with the VCD and VCDD arms, respectively (65% vs 86%, P = .007; and 28% vs 52%, P = .009). Seventy-two percent of the VCDD patients completed the 9 cycles of induction therapy with no grade 3 or 4 peripheral neuropathy adverse events. This study supports VCDD as an option for the initial treatment of transplant-ineligible patients with myeloma. This trial was registered at the Australian New Zealand Clinical Trials Registry (ACTRN12617000202369)., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Frailty is most prevalent among elderly multiple myeloma (MM) patients, and frail patients have a higher risk of poor outcomes due to reduced performance status or comorbidities. This post hoc analysis assessed efficacy and safety of carfilzomib combinations in frail patients with relapsed and/or refractory MM from the phase 3 ASPIRE (carfilzomib [27 mg/m2]-lenalidomide-dexamethasone [KRd27] vs lenalidomide-dexamethasone [Rd]), ENDEAVOR (carfilzomib [56 mg/m2]-dexamethasone [Kd56] vs bortezomib-dexamethasone [Vd]), and ARROW (once-weekly carfilzomib [70 mg/m2]-dexamethasone [Kd70] vs carfilzomib [27 mg/m2]-dexamethasone [Kd27]) studies. A frailty algorithm incorporating age, Charlson comorbidity index, and performance status classified patients as fit, intermediate, or frail. Results are presented for frail patients (ASPIRE, n = 196; ENDEAVOR, n = 330; ARROW, n = 141). In ASPIRE, median progression-free survival (PFS) (hazard ratio; 95% confidence interval) was 24.1 (KRd27) vs 15.9 months (Rd) (0.78; 0.54-1.12); median overall survival (OS) was 36.4 vs 26.2 months (0.79; 0.57-1.08). In ENDEAVOR, median PFS was 18.7 (Kd56) vs 6.6 months (Vd) (0.50; 0.36-0.68); median OS was 33.6 vs 21.8 months (0.75; 0.56-1.00). In ARROW, median PFS was 10.3 (once-weekly Kd70) vs 6.6 months (twice-weekly Kd27) (0.76; 0.49-1.16). In all 3 studies, rates of grade ≥3 treatment-emergent adverse events were consistent with those observed in the primary studies. The ASPIRE, ENDEAVOR, and ARROW primary analyses demonstrated favorable benefit-risk profiles with carfilzomib-containing regimens compared with controls. Across clinically relevant subgroups, including those by frailty status, consistent efficacy and safety were observed with KRd27, Kd56, and weekly Kd70, and treatment with these regimens should not be restricted by frailty status., (© 2020 by The American Society of Hematology.)

CD8+CD57+ terminal effector T (TTE) cells are a component of marrow-infiltrating lymphocytes and may contribute to the altered immune responses in multiple myeloma (MM) patients. We analyzed TTE cells in the bone marrow (BM) and peripheral blood (PB) of age-matched controls and patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering MM (SMM), and newly diagnosed (ND) MM using flow cytometry, mass cytometry, and FlowSOM clustering. TTE cells are heterogeneous in all subjects, with BM containing both CD69- and CD69+ subsets, while only CD69- cells are found in PB. Within the BM-TTE compartment, CD69- and CD69+ cells are found in comparable proportions in controls, while CD69- cells are dominant in MGUS and SMM and predominantly either CD69- or CD69+ cells in NDMM. A positive relationship between CD69+TTE and CD69-TTE cells is observed in the BM of controls, lost in MGUS, and converted to an inverse relationship in NDMM. CD69-TTE cells include multiple oligoclonal expansions of T-cell receptor/Vβ families shared between BM and PB of NDMM. Oligoclonal expanded CD69-TTE cells from the PB include myeloma-reactive cells capable of killing autologous CD38hi plasma cells in vitro, involving degranulation and high expression of perforin and granzyme. In contrast to CD69-TTE cells, oligoclonal expansions are not evident within CD69+TTE cells, which possess low perforin and granzyme expression and high inhibitory checkpoint expression and resemble T resident memory cells. Both CD69-TTE and CD69+TTE cells from the BM of NDMM produce large amounts of the inflammatory cytokines interferon-γ and tumor necrosis factor α. The balance between CD69- and CD69+ cells within the BM-TTE compartment may regulate immune responses in NDMM and contribute to the clinical heterogeneity of the disease., (© 2020 by The American Society of Hematology.)

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) significantly reduces the rate of relapse in acute myeloid leukemia (AML) but comes at the cost of significant treatment-related mortality. Despite the reduction in relapse overall, it remains common, especially in high-risk groups. The outcomes for patients who relapse after transplant remains very poor. A large proportion of the morbidity that prevents most patients from accessing allo-HSCT is due to toxic nonspecific conditioning agents that are required to remove recipient hematopoietic stem and progenitor cells (HSPCs), allowing for successful donor engraftment. CD300f is expressed evenly across HSPC subtypes. CD300f has transcription and protein expression equivalent to CD33 on AML. We have developed an anti-CD300f antibody that efficiently internalizes into target cells. We have generated a highly potent anti-CD300f antibody-drug conjugate (ADC) with a pyrrolobenzodiazepine warhead that selectively depletes AML cell lines and colony forming units in vitro. The ADC synergizes with fludarabine, making it a natural combination to use in a minimal toxicity conditioning regimen. Our ADC prolongs the survival of mice engrafted with human cell lines and depletes primary human AML engrafted with a single injection. In a humanized mouse model, a single injection of the ADC depletes CD34+ HSPCs and CD34+CD38-CD90+ hematopoietic stem cells. This work establishes an anti-CD300f ADC as an attractive potential therapeutic that, if validated in transplant models using a larger cohort of primary AML samples, will reduce relapse rate and toxicity for patients with AML undergoing allo-HSCT., (© 2020 by The American Society of Hematology.)