The monoclonal antibody daratumumab can induce antibody-dependent cellular cytotoxicity (ADCC) via CD16 expressed by natural killer (NK) cells. Prior studies have shown that the number of NK cells decreased after initiation of daratumumab treatment. We used flow cytometry to evaluate the expression of immune checkpoint receptors on NK cells from patients with newly diagnosed multiple myeloma (NDMM) compared to myeloma patients progressing during treatment with daratumumab (DRMM). In accordance with prior studies, we found that the percentage of NK cells was significantly lower in the DRMM group compared to the NDMM group. In addition, the percentage of the cytotoxic CD56dim NK cell subset was lower in the DRMM group, and a lower portion of these NK cells expressed CD16, the receptor mediating ADCC. There was no difference in the expression of the inhibitory receptor PD-1, but the NK cells from DRMM patients expressed an exhausted-associated phenotype with a lower expression of the stimulatory receptor DNAM-1 and a higher expression of the inhibitory receptor TIGIT. Dysfunctional NK cells have been observed in other patients progressing on daratumumab. Our data show that patients progressing on DARA-containing regimens display NK cells with an inhibitory-skewed phenotype. Whether this reflects a driver, biomarker, or consequence of resistance requires further functional and longitudinal investigation.

In previous analyses of MAIA, daratumumab plus lenalidomide/dexamethasone (D-Rd) significantly improved progression-free survival and overall survival (OS) versus lenalidomide/dexamethasone (Rd) in transplant-ineligible newly diagnosed multiple myeloma (NDMM). We report results on long-term OS and subsequent antimyeloma therapies from the MAIA final analysis. A protocol amendment (July 20, 2021) led to a long-term extension of MAIA, during which patients were followed for OS. A total of 737 patients were randomized to D-Rd (n = 368) or Rd (n = 369). At a median follow-up of 89.3 months (range, 0.0-102.2; interquartile range, 85.3-93.0), median OS was 90.3 months (95% confidence interval [CI], 80.8-not estimable [NE]) with D-Rd versus 64.1 months (56.0-70.8) with Rd (hazard ratio [HR], 0.67; 95% CI, 0.55-0.82); estimated 7-year OS rates were 53.1% (95% CI, 47.8-58.2) and 39.3% (34.1-44.5), respectively. Median time to subsequent antimyeloma treatment was not reached (95% CI, 84.1-NE) for D-Rd versus 42.4 months (33.5-50.6) for Rd (HR, 0.51; 95% CI, 0.41-0.63; P < 0.0001). Death due to adverse events occurred in 84 patients (D-Rd, n = 44/364 [12%]; Rd, n = 40/365 [11%]). With >7 years of follow-up, D-Rd demonstrated a new benchmark for median OS (7.5 years) in transplant-ineligible NDMM, further supporting frontline D-Rd use to maximize survival.

Abstract Both the phase 3 MAIA and ALCYONE studies demonstrated significant survival benefit with the addition of daratumumab to standard-of-care Rd (Revlimid [lenalidomide] and dexamethasone; D-Rd) or to VMP (Velcade [bortezomib], melphalan, and prednisone; D-VMP), respectively, vs Rd or VMP alone in transplant-ineligible newly diagnosed multiple myeloma (NDMM). Patients with NDMM are highly susceptible to infection; therefore, gaining a greater understanding of infection incidence may help to mitigate future risk. We conducted a pooled analysis of infection incidence, timing, and management strategies from MAIA and ALCYONE. The median (range) age of the pooled population was 72 (40-93) years. Incidence was higher with D-Rd/D-VMP vs Rd/VMP for grade 3/4 (36.9% vs 22.4%) and grade 5 (3.0% vs 1.5%) infections; however, exposure-adjusted incidence rates were generally comparable between groups. Any-grade infections led to the discontinuation of study treatment in ∼2% of patients across treatment groups. Of the timing intervals explored, the highest incidence of grade 3/4 infection occurred within the first 6-month interval of study treatment initiation in both groups. Median time to the first onset of grade 3/4 infections (per Kaplan-Meier estimates) was 83.3 months and not estimable in the D-Rd/D-VMP and Rd/VMP groups, respectively. Although the rates of D-Rd/D-VMP treatment discontinuation due to infection remained low in MAIA and ALCYONE, clinicians should remain vigilant about infections throughout treatment and follow local guidelines and International Myeloma Working Group recommendations to minimize the risk of infection. These trials were registered at www.ClinicalTrials.gov as NCT02252172 (MAIA) and NCT02195479 (ALCYONE).

Daratumumab (DARA) is a human monoclonal antibody for the treatment of multiple myeloma (MM), an incurable hematologic malignancy characterised by the accumulation of malignant plasma cells, located in the bone marrow (BM). We previously reported that peripheral blood plasma (PB) extracellular vesicles (EVs), isolated from 57 MM patients treated with DARA contain elevated CD55, CD59 and CD147 relative to healthy PB EVs, and elevated PDL1 was associated with patient response to DARA. The aim of this study was to identify additional proteins altered in these patients in order to generate predictive MM EV protein signatures. Flow cytometry analysis revealed that CD31, CD36 and CD44 were significantly elevated in MM PB EVs relative to healthy PB EVs, while CD8 and LAT1 were significantly decreased. CD38, LAT1 and PDL1 were significantly higher in PB EVs of patients with a long-term response to DARA. Multivariate ROC curves revealed a diagnostic signature (MM panel) with a sensitivity 86.4% and specificity 91.6%, and a predictive signature (Response panel) with a sensitivity 80% and specificity 91.2%. In conclusion we identified two EV signatures that may have potential as a non-invasive liquid biopsy to complement or replace invasive BM sampling for monitoring patient response to DARA.

Objectives: This final post hoc analysis evaluated patient-reported outcomes from the Phase 3 MAIA study of daratumumab, lenalidomide, and dexamethasone (D-Rd) versus lenalidomide and dexamethasone (Rd) after median 64.5-month follow-up in transplant-ineligible patients with newly diagnosed multiple myeloma (NDMM), including patient subgroups. Methods: Key scales from the EORTC QLQ-C30 (global health status [GHS], physical functioning, pain, and fatigue) were assessed. Scores were evaluated every 3 months for 1 year, then every 6 months until disease progression. Results: The intent-to-treat population (n = 737) included 46.3% frail, 35.4% 70 to < 75 years old, and 43.6% >= 75 years old. D-Rd-treated patients showed improvements from baseline that were sustained over 5 years in the intent-to-treat population and across subgroups by age, frailty, and bone lesions. Greater proportions of patients treated with D-Rd versus Rd achieved minimally important changes for improvement at cycle 36 (year similar to 3) in GHS (odds ratio, 1.84 [95% CI, 1.16-2.91]), physical functioning (1.93 [1.18-3.14]), pain (1.41 [0.90-2.22]), and fatigue (2.00 [1.24-3.23]). Greater proportions of patients with bone lesions improved with D-Rd versus Rd on GHS and physical functioning. Conclusions: In transplant-ineligible patients with NDMM, D-Rd improved health-related quality of life over a 5-year period versus Rd.

In the MAIA study, daratumumab plus lenalidomide and dexamethasone (D-Rd) improved progression-free survival (PFS) and overall survival (OS) versus lenalidomide and dexamethasone (Rd) alone in transplant-ineligible patients with newly diagnosed multiple myeloma (NDMM). We report updated efficacy and safety from MAIA (median follow-up, 64.5 months), including a subgroup analysis by patient age (<70, ≥70 to <75, ≥75, and ≥80 years). Overall, 737 transplant-ineligible patients with NDMM were randomized 1:1 to D-Rd or Rd. The primary endpoint, PFS, was improved with D-Rd versus Rd (median, 61.9 vs 34.4 months; hazard ratio [HR], 0.55; 95% confidence interval [CI], 0.45–0.67; P < 0.0001). Median OS was not reached in the D-Rd group versus 65.5 months in the Rd group (HR, 0.66; 95% CI, 0.53–0.83; P = 0.0003); estimated 60-month OS rates were 66.6% and 53.6%, respectively. D-Rd achieved higher rates of complete response or better (≥CR; 51.1% vs 30.1%), minimal residual disease (MRD) negativity (32.1% vs 11.1%), and sustained MRD negativity (≥18 months: 16.8% vs 3.3%) versus Rd (all P < 0.0001). D-Rd demonstrated clinically meaningful efficacy benefits across age groups. No new safety concerns were observed. Updated results (median follow-up, >5 years) continue to support frontline use of D-Rd in transplant-ineligible patients with NDMM.

Daratumumab-based regimens demonstrate clinical efficacy in relapsed/refractory multiple myeloma (RRMM). As more patients receive frontline daratumumab-based therapy, evaluation of daratumumab retreatment is needed. In the phase 2 LYNX study (ClinicalTrials.gov Identifier: NCT03871829), 88 patients with RRMM who received 1-3 prior lines of therapy, one of which contained daratumumab, were randomized to receive subcutaneous daratumumab plus carfilzomib/dexamethasone (D-Kd; n = 44) or carfilzomib/dexamethasone (Kd; n = 44). The primary endpoint was the very good partial response or better (≥VGPR) rate. At the interim futility analysis, no significant differences in ≥ VGPR rates were found between treatment groups; therefore, the null hypothesis of no treatment difference was accepted, leading to study termination. At the final analysis, 45.5% of D-Kd patients and 40.9% of Kd patients achieved ≥ VGPR (odds ratio, 1.2 [90% CI, 0.59-2.46]; p = 0.6757). No new safety concerns were identified. Future studies are needed to optimize daratumumab-based regimens for patients with RRMM who have prior daratumumab exposure.

In the MAIA study (median follow-up, 56.2 months), daratumumab plus lenalidomide and dexamethasone (D-Rd) significantly improved progression-free survival (PFS) and overall survival versus lenalidomide and dexamethasone (Rd) alone in transplant-ineligible newly diagnosed multiple myeloma (NDMM). In this post hoc analysis of clinically important subgroups in MAIA (median follow-up, 64.5 months), transplant-ineligible patients with NDMM were randomized 1:1 to D-Rd or Rd. The primary endpoint was PFS; secondary endpoints included overall response rate (ORR) and measurable residual disease (MRD)–negativity rate (10–5). PFS favored D-Rd versus Rd in most subgroups, including patients aged ≥75 years (HR, 0.59; 95 www.clinicaltrials.gov as NCT02252172.

Introduction Patients (pts) with multiple myeloma (MM) eventually become refractory to current treatments. There is an unmet need for new therapies with durable efficacy, favorable safety, and simplified dosing schedules. ABBV-383 is a unique BCMA x CD3 bispecific antibody T-cell engager comprising bivalent high-avidity BCMA binding domains, a low-affinity CD3-binding domain designed to minimize cytokine release and the risk for cytokine release syndrome (CRS), and a silenced Fc tail for extended half-life enabling dosing convenience. In an ongoing first-in-human (FIH) study (NCT03933735) in heavily pretreated pts with relapsed or refractory (RR) MM, ABBV-383 monotherapy (60 mg Q4W) resulted in deep and durable responses. Introduction of a modified dexamethasone (Dex) premedication (premed) schedule in cycle (C) 1 lowered incidence and severity of CRS (43% overall; 5% grade ≥2) vs pts treated with low Dex (71% overall; 20% grade ≥2) (JCO 2024;42[suppl 16]:7531). We now report results of Arm A of the open-label, phase 1b study (NCT05650632) evaluating 1 step-up dose (SUD) of ABBV-383 as a strategy to mitigate the risk of severe CRS and further assess ABBV-383 activity in pts with RRMM. Methods This study is enrolling pts with RRMM, ECOG performance status ≤2, and documented evidence of progression during or after the last treatment. Pts must have received ≥3 prior lines of therapy, including a proteasome inhibitor, an immunomodulatory drug, and an anti-CD38 monoclonal antibody. Arm A consists of a dose-optimization (DO) and a dose-expansion (DE) part. During DO, pts received a single SUD of intravenous ABBV-383 (2/4 mg) on C1 day (D) 1, followed by the target dose of 60 mg on D4. In the DE, based on DO findings, pts received the recommended ABBV-383 SUD on C1D1, followed by 60 mg on D4. The modified premed schedule that lowered incidence and severity of CRS in the FIH study was also introduced prior to target dose on C1D4. After C1, pts received 60 mg ABBV-383 Q4W on D1 of each cycle for DO and DE until disease progression, withdrawal, or discontinuation. Primary endpoint was grade ≥2 CRS events during C1. Other endpoints included any grade CRS events, treatment-emergent adverse events (TEAEs), immune pharmacodynamics, and clinical activity. Results As of April 2024, 70 pts were enrolled in Arm A: 47 in DO (2 mg SUD, n=26; 4 mg SUD, n=21) and 23 in DE. Median age was 69 years (range: 40-84), 59% were male, and 76% were triple-class refractory. Median prior lines of therapy was 4 (range: 3-10). Median follow-up time (months [mo]) was 6.5, 7.5, and 2.8 for 2 mg DO, 4 mg DO, and DE, respectively. Any grade CRS was reported in 10 (39%) and 11 (52%) pts during DO at 2 and 4 mg SUD; CRS grade ≥2 occurred in 3 (12%) pts in the 2 mg SUD and in 6 (29%) pts in the 4 mg SUD, leading to selection of 2 mg SUD for DE. In the DE, 7 (30%) pts experienced CRS; 1 (4%) pt experienced grade 2 CRS, there were no grade ≥3 events, and only 2 (9%) pts received tocilizumab to treat CRS. Overall, median time to CRS onset and resolution was 14.7 and 9 hours, respectively; no pts had CRS after C1. Immune effector cell-associated neurotoxicity syndrome occurred in 7 (10%) pts (grade 1: 4%; grade 2: 6%; grade 3: 4%). Most common TEAEs were CRS (40%), neutropenia (37%), diarrhea (29%), anemia (24%), and fatigue (20%); most common grade 3/4 TEAEs were neutropenia (31%), anemia (19%), thrombocytopenia (13%), and leukopenia (11%). Grade 5 TEAEs occurred in 5 pts; 1 event was deemed possibly related to ABBV-383 (COVID-19 pneumonia). In the efficacy-evaluable population (n=68), the objective response rate was 62% (95% CI: 49.2, 73.3); 35 (52%) pts had a VGPR or better. Median time to response was 1.1 mo (range: 1-4) and median duration of follow-up was 5.8 mo (range: 1-12). Response rates are expected to improve with longer follow-up. Maximum reduction in peak levels of CRS-related cytokines, including IL-6, were observed in DE compared with DO and 60 mg Q4W without SUD (FIH study). Peak activation and proliferation of CD8 T cells was comparable with ABBV-383 in DO, DE, and 60 mg Q4W-treated pts. Conclusions Introduction of 1 SUD of 2 mg on D1 followed by full dose of 60 mg on D4 in C1 combined with modification to the Dex premed schedule reduced the incidence and severity of CRS in pts with RRMM, further optimizing the safety profile of ABBV-383. Preliminary efficacy data show early and high response rates, consistent with outcomes from other ABBV-383 studies.

The advent of BCL-2 inhibitor-based time-limited therapies has currently replaced chemoimmunotherapy as one standard of care in chronic lymphocytic leukemia (CLL). Despite many differences in efficacy and safety profile, both treatment approaches achieve similarly high rates of undetectable measurable residual disease (U-MRD).1, 2 U-MRD has been shown to correlate with progression-free survival (PFS) and even with overall survival (OS) within the MURANO trial,3 as well as in the CLL14 trial.4 Currently, U-MRD is accepted by the European Medicines Agency (EMA) as intermediate endpoint within clinical trials.5 The iwCLL 2018 response criteria require a bone marrow (BM) aspirate and trephine biopsy for confirmation of complete remission, with immunohistochemistry (IHC) recommended as a tool to differentiate between CLL cells versus benign T- and B-cell infiltrates.6 While the prognostic value of measurable residual disease (MRD) in CLL has been extensively studied before,7-11 the role of BM assessments by IHC on trephine biopsies has not yet been evaluated. As both BM aspirations and trephine biopsies are collected using an invasive procedure, their added valued remained a matter of debate. Therefore, prognostic value of BM IHC and flow cytometry-based BM MRD assessments is analyzed herein. Moreover, we investigated whether or not sensitive MRD assessments in the peripheral blood (PB) might be able to completely replace the need for BM assessments. Finally, the impact of central versus local pathology investigations are evaluated. Patient data were derived from the prospective, randomized CLL10 trial of the GCLLSG, in which chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab (FCR) or bendamustine and rituximab (BR) was administered. BM aspiration and biopsy were performed at final staging 2 months (+28 days) after end of therapy. Central assessment of BM trephine biopsy material for IHC was performed by the hematopathology department in Kiel in conjunction with the prior local pathology. To this end, pathologists aim to identify lymphoid cells with a CLL phenotype in aggregates of lymphoid cells according to the current WHO classification12 by superimposing B-cell distribution pattern detected by CD20, CD19, or CD79a with the staining for CD5 and CD23 on separate slides. B-cell markers were stained according to standard protocols on an automated stainer. MRD was assessed in the central laboratory in Kiel by four-color flow cytometry at a threshold of 10−4 as previously described.13, 14 We compared the impact of MRD and IHC using Kaplan–Meier landmark analyses of PFS and OS from the time point of sample assessment with log-rank tests and Cox proportional hazards regression modeling. Independent prognostic baseline factors for PFS were identified by multivariable analyses using Cox proportional hazards regression modeling with backward and forward selection. All statistical tests were two-sided and p values were descriptive without adjustments for multiple testing. The significance level was set at 0.05. Out of 561 patients who were enrolled in the CLL10 trial, 310 patients (55.3%) underwent BM examinations by IHC. Of these, samples from 209 patients (67.4%) were centrally evaluated. FCR was administered in 120 (57.4%) of the 209 patients with centrally assessed IHC and 89 patients (42.6%) were treated with BR. For further patient characteristics see Table 1. Centrally evaluable samples for BM MRD were available in 168 of 209 patients (80.4%). Out of these 168 samples, seven samples (4.2%) tested IHC positive (+) with BM U-MRD, 77 samples (45.8%) tested IHC negative (−) with BM U-MRD, 53 samples (31.5%) were IHC+ with BM detectable MRD (D-MRD), and 31 (18.5%) had discordantly IHC−/BM D-MRD. Patients with BM U-MRD had an estimated 3-year PFS rate from landmark of 100% if simultaneously IHC+ and an estimated 3-year PFS rate from landmark of 92.9% if IHC− (log-rank p = 0.202). Thus, IHC does not seem to contribute to identification of low-risk disease once BM U-MRD is known. In BM D-MRD patients, simultaneous IHC+ showed an estimated 3-year PFS rate from landmark of 31.7%, compared to concordant IHC− with an estimated 3-year PFS rate from landmark of 59.8% (HR = 2.062, 95% confidence interval [CI]: 1.155–3.683, p = 0.014). Detecting CLL by IHC in BM D-MRD patients might contribute to identify patients suffering from persistent high-level disease with a poor PFS (Figure 1A). However, very high-risk disease might be identified in the BM and PB with similar accuracy using an additional cut-off at an MRD threshold of 10−2.7 The estimated 3-year OS-rate from landmark was 100.0% for patients with IHC+/BM U-MRD, whereas patients with IHC−/BM U-MRD had an estimated 3-year OS-rate from landmark of 97.3% (log-rank p = 0.537). For patients with IHC+/BM D-MRD, the estimated 3-year OS-rate from landmark was 94.1% versus 100.0% in patients with IHC−/BM D-MRD (HR = 0.368; 95% CI: 0.108–1.258, p = 0.111) (Figure 1A). Analyzing patients with U-MRD in the PB, the estimated 3-year PFS rate was 51.3% for 33 IHC+ patients, compared to 101 patients with IHC− who had an estimated 3-year PFS rate of 83.3% (HR = 2.646, 95% CI: 1.488–4.705, p < 0.001). For 29 patients with IHC+ and PB D-MRD, the estimated 3-year PFS rate was 30.7% compared to 55.6% in nine patients with IHC−/PB D-MRD (HR = 2.035, 95% CI: 0.772–5.368, p = 0.151) (Figure 1B). The estimated 3-year OS-rate was 100.0% for patients with IHC+/PB U-MRD and 98.0% for patients with IHC−/PB U-MRD (HR = 0.668, 95% CI: 0.146–3.050, p = 0.602). Patients with IHC+/PB D-MRD had an estimated 3-year OS-rate from landmark of 89.1% and patients with IHC−/PB D-MRD of 100.0% (HR = 0.364, 95% CI: 0.073–1.807, p = 0.216) (Figure 1B). Next, we investigated whether PB MRD assessments could completely replace both BM investigations, thus obviating the need for this invasive procedure. In univariable analysis, treatment arm, BM infiltration by IHC and MRD in PB and BM, as well as del(11q) status, IGHV mutational status, and serum thymidine kinase at baseline, were identified as prognostic factors for PFS. When considering all these variables in the multivariable analysis, flow MRD in the BM as well as IGHV mutational status were suggested as independent prognostic factors for PFS. We conclude that for better prognostication a flow-based MRD assessment of a BM aspirate remains necessary. Once BM MRD is known, there seems to be no added value of a trephine biopsy, which might be omitted. When excluding MRD from multivariable analysis, treatment arm, IGHV mutational status, and BM infiltration by IHC were identified as independent prognostic factors. Thus, if no MRD assessments are available, a BM examination seems to contribute to prognostication. Multivariable analysis for OS was not performed as BM infiltration by IHC was not significantly associated with landmark OS in univariable analyses. Within the total population of 310 patients with both locally and centrally assessed IHC, we found that IHC+, evaluated as a single parameter, was associated with shorter PFS as the estimated 3-year PFS rate from landmark was 39.3% versus 77.5% in IHC− (HR = 2.671, 95% CI: 1.942–3.674, p < 0.001). We thereafter evaluated the prognostic value of IHC when assessed in local versus central laboratories. Interestingly, IHC− patients with IHC evaluated in a local laboratory (estimated 3-year PFS-rate 68.0%) carried a poorer prognosis compared to patients with IHC tested in the central laboratory (estimated 3-year PFS-rate 82.2%, HR = 1.756, 95% CI: 1.108–2.782, p = 0.017). This finding suggests a better specificity of the reference laboratory for IHC− results. The estimated 3-year PFS-rate from landmark for patients with IHC+ was 33.3% for local versus 42.5% for the central laboratory (HR = 1.160, 95% CI: 0.733–1.834; p = 0.527) (Figure 1C). The difference between local and central laboratory in IHC− samples might be explained by the fact that there was no common standard when evaluating the local samples. Thus, whenever a trephine biopsy is taken, an assessment in a reference pathology laboratory is advisable. When investigating OS from landmark time point of sample assessment according to BM infiltration by IHC and local versus central laboratory, no significant differences were detected. This might be explained by effective subsequent treatments. The estimated 3-year OS-rate from landmark for patients with IHC− was 93.5% if assessed by local laboratory and 98.5% by central laboratory (HR = 1.983, 95% CI: 0.943–4.170, p = 0.071). The estimated 3-year OS-rate from landmark for patients with IHC+ was 82.6% for local laboratory and 93.1% for central laboratory (HR = 2.114, 95% CI: 0.793–5.639, p = 0.135) (Figure 1C). In summary, we could confirm that MRD seems to be a valid prognostic parameter for PFS for time-limited therapies, although these data comprise only chemoimmunotherapies and should be reevaluated for targeted agents if data on both, MRD and IHC, are available. This is consistent with a pooled analysis of phase 3 trials based on chemoimmunotherapy combinations (CLL8, CLL10, CLL11), which has also shown a significant relationship between MRD in the PB and PFS.11 Within this patient population of the CLL10 trial, no statistically relevant difference in OS could be shown. IHC was confirmed as an independent prognostic marker in multivariable analysis for PFS when flow cytometry-based MRD was excluded. Although both methods, flow MRD as well as IHC, add valuable information on depth of response, the results of the multivariable analyses indicate that flow MRD in BM provides the prognostic information needed and patients may be spared an additional biopsy. If a biopsy is performed, we recommend to evaluate the histology centrally to improve the prognostic value of the assessment. Open Access funding enabled and organized by Projekt DEAL. Nadine Kutsch, Sandra Robrecht, Sebastian Böttcher, Wolfram Klapper, Barbara Eichhorst conceived and designed the analysis. Nadine Kutsch, Anna Fink, Elisabeth Lange, Rudolf Weide, Michael G. Kiehl, Martin Sökler, Rudolf Schlag, Ursula Vehling-Kaiser, Georg Köchling, Christoph Plöger, Michael Gregor, Torben Plesner, Michael R. Clausen, Marco Herling, Kirsten Fischer, Hartmut Döhner, Clemens-Martin Wendtner, Michael Hallek, Barbara Eichhorst collected the data. Ilske Oschlies, Matthias Ritgen, Karl-Anton Kreuzer, Stephan Stilgenbauer, Sebastian Böttcher, Wolfram Klapper contributed data or analysis tools. Sandra Robrecht performed the statistical analysis. Nadine Kutsch wrote the first draft of the paper. All authors contributed to manuscript revision, read, and approved the submitted version. Nadine Kutsch: Honoraria: AbbVie, AstraZeneca, BMS, Kite/Gilead; Research support: AstraZeneca, Gilead. travel grants: AbbVie, AstraZeneca, Beigene, Celgene, Janssen. Sandra Robrecht: Honoraria: AstraZeneca. Anna Fink: Research funding: AstraZeneca and Celgene, Travel grants: AbbVie. Elisabeth Lange: no COIs. Rudolf Weide: Personal fees from AstraZeneca, BeiGene, Biotest, CSL Behring, Daiichi Sankyo, Eisai, Gilead, Hexal, Incyte, Medac, Menarini-Stemline, Pierre Fabre, Roche, SeaGen, Sobi, and Takeda. Our institution has received research funding from Amgen, Biotest, Celgene, CSL Behring, Daiichi Sankyo, Eisai, GSK, Hexal, Lilly, Medac, Mundipharma, Octapharma, Sobi, and Takeda. Michael G. Kiehl: no COIs. Martin Sökler: no COIs. Rudolf Schlag: no COIs. Ursula Vehling-Kaiser: no COIs. Georg Köchling: no COIs. Christoph Plöger: no COIs. Michael Gregor: no COIs. Torben Plesner: advisory board: Celgene/BMS. Michael R. Clausen: no COIs. Ilske Oschlies: no COIs. Matthias Ritgen: grants from F. Hoffman-La Roche; and personal fees from F. Hoffmann-La Roche and AbbVie. Marco Herling: no COIs. Kirsten Fischer: Advisory Board: AbbVie, Roche, AstaZeneca, Honoraria: Roche, AstraZeneca, Travel Support: Roche. Hartmut Döhner: Advisory role with honoraria for AbbVie, AstraZeneca, Gilead, Janssen, Jazz, Pfizer, Servier, Stemline, Syndax; clinical research funding (to institution) from AbbVie, Astellas, Bristol Myers Squibb, Celgene, Jazz Pharmaceuticals, Kronos Bio, Servier. Clemens-Martin Wendtner: Research grants, advisory boards and travel grants by Hoffmann-La Roche, Janssen-Cilag, AstraZeneca, AbbVie, BeiGene and GSK. Karl-Anton Kreuzer: consultant or advisory board member, honoraria and research support by AbbVie, Amgen, F. Hoffmann-LaRoche, Gilead, Janssen-Cilag and Mundipharma. Stephan Stilgenbauer: Advisory board, honoraria, research support, travel support, speaker fees, trial participation: AbbVie, Amgen, AstraZeneca, BeiGene, BMS, Celgene, Gilead, GSK, Hoffmann-La Roche, Janssen, Lilly, Novartis, Sunesis. Michael Hallek: Consultant or advisory board member, honoraria, and research support by AbbVie, Amgen, Celgene, F. Hoffmann-LaRoche, Gilead, Janssen-Cilag and Mundipharma. Sebastian Böttcher: research funding from Janssen and AbbVie; and honoraria from Roche, Janssen, AbbVie, Novartis, Becton Dickinson, AstraZeneca, and Sanofi. Wolfram Klapper: Research grants from Roche, Amgen, Janssen, InCyte Regeneraon, Takeda and advisory role (Roche) paid to my institution. All without relevance for the current manuscript. Barbara Eichhorst: Consultant or advisory board member, research support or travel support by AbbVie, AstraZeneca, Celgene, F. Hoffmann-LaRoche, Gilead, Janssen-Cilag. The authors declare no sources of funding. The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

Multiple myeloma (MM) is a haematological malignancy with abnormal proliferation of plasma cells in the bone marrow (BM), and MM patients with highly proliferative plasma cells have reduced overall survival. Circular RNAs (circRNAs) are endogenous, non-coding molecules that are promising biomarkers in cancer. Here, we present the largest study of circRNAs in MM to date and explore the prognostic potential of circRNAs and the link between proliferation and circRNA expression in MM. We performed deep total RNA sequencing (RNA-seq) on two cohorts: one cohort consisting of 45 whole BM MM patient samples and 13 healthy controls (HCs), and another cohort consisting of 43 CD138-purified plasma cell MM patient samples. We found that circRNAs are globally upregulated in the whole BM of MM patients compared to HCs. In whole BM, low proliferation and high circRNA levels were associated with a poor prognosis, while in purified plasma cells, low proliferation and high circRNA levels were associated with a favourable prognosis. Individual circRNAs from purified plasma cells were found to be significantly associated with MM patient outcomes and provide additional prognostic value to the proliferative indexes. Together, our findings emphasise the potential of circRNAs as prognostic biomarkers in MM.

Transfer of surface membrane from UM9 cells to monocytes.

Background Venetoclax (VEN) is an oral BCL-2 inhibitor that is effective for the treatment of multiple myeloma (MM) with t(11;14), expressing high levels of BCL-2. In a previous phase 1 study, VEN was given to 66 patients [30 with t(11;14)] with relapsed and refractory MM (RRMM) at 300, 600, 900 or 1200 mg in dose-escalation cohorts and 1200 mg in the expansion cohort, without reaching a maximum tolerated dose; the overall response rate (ORR) in t(11;14) positive patients was 40% (Kumar et al. 2017). Later, in a phase 1-2 study, 800 mg VEN with 40/20 mg weekly dexamethasone (DEX) was explored in 51 patients with RRMM and t(11;14) with an overall response rate (ORR) of 48-60% (Kaufman et al. 2021). Here, we report the interim results of an ongoing, Danish, investigator-initiated, open label, phase 2 study which is testing the safety and efficacy of low-dose VEN-DEX in RRMM. Methods Patients with RRMM, at least one prior line of therapy and t(11;14) were included in the study between 1 st July 2020 and data cutoff in 31 st July 2022. VEN was administered orally, once daily at a dose of 400 mg. DEX was administered orally, once weekly at a dose of 20 mg. Treatment continued until progressive disease or unacceptable toxicity. After discontinuation of treatment, patients were followed for 24 months. The primary endpoint of the study was ORR, key secondary endpoints were progression-free survival (PFS) and overall survival (OS). Grade three or higher adverse events (AE) were recorded. Results Patient characteristics At the time of data cutoff in July 2023, twenty-six patients were included in the study. The median (IQR) age was 74 (63-82) years. The median time from diagnosis was 4 (1-7) years. The median (IQR) number of prior lines of therapy was 3 (2-5). 46% of patients were males. At screening, 56% had anemia, 7% had renal failure, 15% had hypercalcemia according to the CRAB criteria. Performance status was 0 in 40% and 1-2 in 60% of patients. 47% of patients had ISS I, 19% had ISS II, 33% had ISS III. Besides t(11;14), present in all patients, 7% of patients had high-risk cytogenetic abnormalities, defined as the presence of t(4;14), t(14;16) or del(17p). 55% of patients had been treated with high dose melphalan and autologous stem cell transplantation, 92% had been exposed to an IMiD, 96% to a proteasome inhibitor, 70% to daratumumab. 29% were triple class-refractory, 15% were penta-drug refractory. Safety One patient had a grade 4 ventricular ulcer, besides this there were no grade 4 or 5 AEs. The most frequent grade 3 AE was infection, detected in 9 (35%) patients. Of these, there were 3 cases of pneumonia, 3 cases of COVID-19, 1 case of influenza, 1 case of gastroenteritis, and 1 case of fever of unknown focus. Other grade 3 AEs related to venetoclax were dehydration in 2 patients, thrombocytopenia in 1 patient, and nausea in 1 patient. The dose of venetoclax was reduced in 3 patients, to 200 mg daily in each case. Efficacy Ten of 25 evaluable patients had partial response or better, resulting in an ORR of 40% (Figure 1A). Four percent of patients achieved stringent complete response, 16% very good partial response and 20% partial response. In subgroup analysis, worse responses were observed in patients with creatinine >177 µmol/L (n=2), high-risk cytogenetics (n=2), triple-class refractory (n=7) and penta-drug refractory (n=3) disease. In responding patients, the median duration of response (DOR) was not reached. The estimated percentage of patients still responding to therapy was 74% after one year and 55% after two years. The median (95% CI) PFS in the intention-to treat population was 5.5 (3.7; not available) months (Figure 1B). Median OS was not reached. The estimated percentage of patients still alive was 90% after one year. Conclusion: Based on this interim analysis, low-dose VEN-DEX in patients with RRMM and t(11;14) has a convenient safety profile and an efficacy comparable to previously tested VEN and VEN-DEX regimens with higher VEN doses. Updated results will be presented at the meeting.

Introduction: The MAIA study (NCT02252172) evaluated D-Rd versus Rd alone in transplant-ineligible pts with NDMM. At a median follow-up of 56.2 months, D-Rd significantly improved progression-free survival (PFS) and overall survival versus Rd (Facon T, Lancet Oncol 2021). Here, we present an analysis of clinically important subgroups in MAIA, including pts aged ≥75 years, pts with International Staging System (ISS) stage III disease, pts with renal insufficiency (defined as baseline creatinine clearance [CrCl] ≤60 mL/min), pts with extramedullary plasmacytomas at baseline, and pts with high cytogenetic risk (defined as having ≥1 of the following high-risk cytogenetic abnormalities: t[4;14], t[14;16], del17p [per IMWG recommendations]). Methods: In MAIA, pts with NDMM who were ineligible for high-dose chemotherapy and autologous stem-cell transplant were randomized 1:1 to receive D-Rd or Rd. All pts received 28-day cycles of oral Rd (R: 25 mg [10 mg recommended if CrCl was 30-50 mL/min] on Days 1-21; d: 40 mg [20 mg if aged >75 years or body-mass index <18.5 kg/m2] on Days 1, 8, 15, 22). Pts in the D-Rd arm received intravenous daratumumab (16 mg/kg QW in Cycles 1-2, Q2W in Cycles 3-6, and Q4W thereafter). Pts in both arms were treated until disease progression or unacceptable toxicity. The primary endpoint was PFS, and key secondary endpoints included overall response rate (ORR) and minimal residual disease (MRD)-negativity rate (10-5 sensitivity). Results: 737 pts were randomized (D-Rd, n=368; Rd, n=369); most subgroups had a similar number of pts per treatment arm: age ≥75 years (n=160; n=161); ISS stage III (n=107; n=110); renal insufficiency (n=162; n=142); extramedullary plasmacytomas (n=15; n=9); and high cytogenetic risk (n=48; n=44). After a 64.5-month median follow-up, PFS (Figure A) and ORR (Figure B) generally favored D-Rd versus Rd across subgroups. MRD-negativity rates were higher with D-Rd versus Rd for pts aged ≥75 years (26.9% vs 9.9%; P<0.0001), pts with ISS stage III disease (27.1% vs 10.9%; P=0.0030), pts with renal insufficiency (29.6% vs 7.7%; P<0.0001), pts with extramedullary plasmacytomas (33.3% vs 0%; P=0.1181), and pts with high cytogenetic risk (25.0% vs 2.3%; P=0.0019). Sustained (≥6 months and ≥12 months) MRD-negativity rates were higher with D-Rd versus Rd across subgroups: age ≥75 years (≥6 months, 15.6% vs 5.0%; ≥12 months, 13.8% vs 3.1%), ISS stage III disease (≥6 months, 17.8% vs 3.6%; ≥12 months, 15.9% vs 2.7%), renal insufficiency (≥6 months, 21.0% vs 1.4%; ≥12 months, 18.5% vs 1.4%), extramedullary plasmacytomas (≥6 months, 26.7% vs 0%; ≥12 months, 13.3% vs 0%), and high cytogenetic risk (≥6 months, 12.5% vs 0%; ≥12 months, 12.5% vs 0%). In an analysis of safety among pts aged ≥75 years, grade 3/4 treatment-emergent adverse events (TEAEs) occurred in 95.5% of D-Rd pts and 95.0% of Rd pts; the most common (≥20%; D-Rd/Rd) were neutropenia (62.4%/41.5%), lymphopenia (21.0%/12.6%), anemia (20.4%/25.2%), and pneumonia (20.4%/14.5%). Serious TEAEs occurred in 80.9% and 79.2% of D-Rd and Rd pts, respectively. TEAEs led to study treatment discontinuation in 15.3% of D-Rd pts and 27.7% of Rd pts. TEAEs with an outcome of death occurred in 11.5% of D-Rd pts and 13.2% Rd pts. Conclusions: In this subgroup analysis of MAIA, D-Rd improved PFS, ORR, and MRD-negativity rates versus Rd across clinically important subgroups, including pts aged ≥75 years, pts with ISS stage III disease, pts with renal insufficiency, pts with extramedullary plasmacytomas, and pts with high cytogenetic risk. In pts aged ≥75 years, the rates of grade 3/4 and serious TEAEs were similar with D-Rd and Rd, with a lower rate of discontinuation due to TEAEs for D-Rd versus Rd. Results for these clinically important subgroups provide confidence in using D-Rd across all pt types, supporting D-Rd as a standard of care for transplant-ineligible pts with NDMM. Results for additional cytogenetic risk subgroups that include pts with gain and/or amp 1q21 will be presented at the meeting. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Introduction: Daratumumab (DARA) is a human IgGκ monoclonal antibody targeting CD38 with a direct on-tumor and immunomodulatory mechanism of action. DARA is approved in combination with standard of care in patients (pts) with newly diagnosed multiple myeloma (NDMM) and as monotherapy and in combination with standard of care for pts with relapsed/refractory multiple myeloma. In the randomized, phase 3 MAIA study (NCT02252172), DARA plus lenalidomide and dexamethasone (D-Rd) versus lenalidomide and dexamethasone (Rd) alone was evaluated in transplant-ineligible pts with NDMM. In the primary analysis of MAIA (median follow-up, 28.0 months), D-Rd significantly improved progression-free survival (PFS) versus Rd alone (Facon T, N Engl J Med 2019). Additionally, D-Rd significantly prolonged PFS versus Rd for pts aged ≥75 years (median, not reached [NR] vs 31.9 months; hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.44-0.92; P = 0.0146; Usmani SZ, ASCO 2019). In an analysis of overall survival (OS; median follow-up, 56.2 months), D-Rd showed a significant reduction in the risk of death versus Rd alone (HR, 0.68; 95% CI, 0.53-0.86; P = 0.0013; Facon T, Lancet Oncol 2021). Here, we present a subgroup analysis of MAIA pts aged <75 years, <70 years, and ≥70 to <75 years. Methods: Pts with NDMM ineligible for high-dose chemotherapy with autologous stem cell transplant were randomized 1:1 to receive D-Rd or Rd alone. All pts received 28-day cycles of lenalidomide (R: 25 mg orally on Days 1-21) and dexamethasone (d: 40 mg orally on Days 1, 8, 15, and 22) with or without DARA (16 mg/kg intravenously once weekly in Cycles 1-2, once every 2 weeks in Cycles 3-6, and once every 4 weeks thereafter) until disease progression or unacceptable toxicity. The primary endpoint was PFS. Key secondary endpoints included overall response rate (ORR), OS, and minimal residual disease (MRD)-negativity rate (10-5 sensitivity, clonoSEQ® version 2.0). Results: Of 737 randomized pts (D-Rd, n = 368; Rd, n = 369), 416 (56%) pts were aged <75 years (D-Rd, n = 208; Rd, n = 208), 155 (21%) pts were aged <70 years (D-Rd, n = 78; Rd, n = 77), and 261 (35%) pts were aged ≥70 to <75 years (D-Rd, n = 130; Rd, n = 131). At a median follow-up of 64.5 months, PFS was improved for pts receiving D-Rd versus Rd who were aged <75 years (median, NR vs 37.5 months; HR, 0.52; 95% CI, 0.39-0.68; P <0.0001; Figure A), <70 years (median, NR vs 39.2 months; HR, 0.35; 95% CI, 0.21-0.56; P <0.0001), and ≥70 to <75 years (median, 61.9 vs 37.5 months; HR, 0.64; 95% CI, 0.45-0.89; P = 0.0079; Figure B). The estimated 60-month PFS rates were higher for pts receiving D-Rd versus Rd across all subgroups: <75 years (57.4% vs 33.6%), <70 years (67.2% vs 28.7%), and ≥70 to <75 years (51.6% vs 36.6%). OS was also improved for pts receiving D-Rd versus Rd who were aged <75 years (HR, 0.59; 95% CI, 0.43-0.83; P = 0.0017), <70 years (HR, 0.50; 95% CI, 0.27-0.90; P = 0.0179), and ≥70 to <75 years (HR, 0.64; 95% CI, 0.43-0.96; P = 0.0274). The estimated 60-month OS rates were higher for pts receiving D-Rd versus Rd across all subgroups: <75 years (73.9% vs 58.8%), <70 years (79.9% vs 61.7%), and ≥70 to <75 years (70.3% vs 57.0%). The ORR was higher for D-Rd versus Rd in pts aged <75 years (95.2% vs 81.7%; P <0.0001), <70 years (93.6% vs 80.5%; P = 0.0156), and ≥70 to <75 years (96.2% vs 82.4%; P = 0.0004). Increased rates of MRD negativity (10-5) were observed with D-Rd versus Rd in pts aged <75 years (36.1% vs 12.0%; odds ratio [OR], 4.13; 95% CI, 2.49-6.84; P <0.0001), <70 years (35.9% vs 11.7%; OR, 4.23; 95% CI, 1.84-9.75; P = 0.0006), and ≥70 to <75 years (36.2% vs 12.2%; OR, 4.07; 95% CI, 2.16-7.67; P <0.0001). Conclusions: At a median follow-up of 64.5 months, D-Rd improved efficacy versus Rd alone in subgroups of pts aged <75, <70, and ≥70 to <75 years. D-Rd demonstrated clinically meaningful benefit across all endpoints, including PFS, OS, ORR, and MRD negativity. These results, along with those presented previously (Usmani SZ, ASCO 2019), support the frontline use of DARA-based combination regimens in pts aged <75 years and ≥75 years with transplant-ineligible NDMM. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Daratumumab-mediated CD38 reduction of MM cells in the presence of PBMCs as shown by Western blot analysis.

Topic: 13. Myeloma and other monoclonal gammopathies - Biology & Translational Research Background: CD38 monoclonal antibodies (mAb) have become part of backbone regimens for the treatment of multiple myeloma (MM). GEN3014 (HexaBody-CD38) is a next-generation CD38 mAb, carrying an E430G mutation in its Fc domain. This mutation facilitates IgG hexamer formation upon binding to CD38 on the cell membrane, leading to enhanced binding of complement and highly efficient complement-dependent cytotoxicity (CDC). In cell lines and primary MM patient samples, GEN3014 showed CDC-mediated tumor cell killing that was more efficient than daratumumab. In MM patients dosed with GEN3014, reduction in peripheral complement factor C2 and total complement lytic activity was observed at all evaluable doses (0.2-24 mg/kg). Complement parameters rapidly returned to baseline after dosing, indicating that GEN3014 did not exhaust complement (Spencer et al. ASH2022). Aims: To confirm the potent CDC activity of GEN3014, complement consumption was evaluated in GEN3014 or daratumumab treated samples in (A) preclinical studies under complement limiting conditions and (B) in patient samples from the current GEN3014 study vs. data previously reported from MMY2002. Methods: In vitro CDC assays were performed using variable concentrations of normal human serum (NHS), as a source of complement, and titrations with C2 under limiting complement conditions. Levels of complement factor C2 and complement lytic activity (CH50) were determined in the plasma or serum of patients dosed with GEN3014 during the dose escalation phase of the first-in-human, phase 1/2 trial of GEN3014 in patients with relapsed or refractory (RR)MM (NCT04824794). Results: At lower complement levels, maximal CDC-mediated tumor cell kill in vitro by GEN3014 and daratumumab was reduced, while the antibody concentration to reach the half maximal effect (EC50) was not affected. This indicates that a suboptimal CD38 mAb concentration does not augment the rate-limiting effect of complement. At all complement levels, GEN3014 showed higher CDC compared to daratumumab (Figure 1), indicating that GEN3014 more efficiently uses complement to induce tumor cell kill, also at lower complement levels. Adding C2 to low serum levels (partially) restored the CDC activity of GEN3014, indicating that C2 is a limiting factor for CDC under these conditions. In patients dosed with 8 or 16 mg/kg GEN3014, decreased complement factor C2 (mean peak change from baseline -51.0%, [range = 0 to -78.3%] n=11) and decreased complement lytic activity (CH50) (mean peak change from baseline -35.9% [range =0 to -91.6%] n=10) were observed. Peak decreases were observed within the first 48 hours after initial dosing with GEN3014. The observed decrease in C2 level for subjects treated with GEN3014 was more prominent than reported for daratumumab (mean 25% reduction from baseline at C1D2) (Nijhof et al 2016), which is in line with increased CDC activity of GEN3014 appreciated in vitro. Summary/Conclusion: GEN3014 showed potent CDC activity in vitro, with higher maximal kill compared to daratumumab, also under suboptimal complement conditions. GEN3014 induced a stronger decline of complement levels in patients compared to historical data of daratumumab, supporting its potential to induce enhanced CDC in patients. These findings support the ongoing phase 1/2 trial in patients with RRMM (NCT04824794) evaluating the safety and efficacy of GEN3014, which includes a head-to-head comparison with daratumumab.Figure 1 GEN3014 and daratumumab induced CDC under suboptimal complement conditions. CDC activity of GEN3014, daratumumab and an isotype control at a dose of 10 µg/mL and a dose range of normal human serum on SU-DHL-4 cells. The average percentage tumor cell kill from three independent experiment ± SD are shown. Keywords: CD38, Multiple myeloma, Complement

Loss of CD38 from the MM cell membrane is associated with reduced CDC and ADCC

WHAT IS THIS SUMMARY ABOUT? This is a summary of a clinical trial called MAIA. The trial tested 2 combinations of cancer drugs (daratumumab plus lenalidomide and dexamethasone compared with lenalidomide and dexamethasone) in people with newly diagnosed multiple myeloma. None of the participants who took part in the study had been treated before or were eligible to receive stem-cell transplants. HOW WAS THE STUDY IN THIS SUMMARY CONDUCTED? A total of 737 participants took part. Half of the participants took daratumumab plus lenalidomide and dexamethasone, while the other half of the participants took only lenalidomide and dexamethasone. Once participants started taking the drugs, the cancer was monitored for improvement (response to treatment), worsening (disease progression), or no change. Participants' blood and urine were tested for myeloma protein to measure response to the treatment. Participants were also monitored for side effects. WHAT WERE THE RESULTS OF THE STUDY? After approximately 56 months of follow-up, more participants who took daratumumab plus lenalidomide and dexamethasone were alive and had decreased myeloma protein levels (indicating improvement of cancer) than participants who took only lenalidomide and dexamethasone. The most common side effects were abnormally low white and red blood cell counts and increased lung infections. WHAT DO THE RESULTS OF THE STUDY MEAN? In the MAIA study, participants with multiple myeloma who took daratumumab plus lenalidomide and dexamethasone lived longer and had decreased myeloma protein levels than participants who took only lenalidomide and dexamethasone, indicating survival could be more likely with daratumumab added. Clinical Trial Registration: NCT02252172 (Phase 3 MAIA study).