Kapoor, Prashant

Background: SAR442257 (SAR'257) is a trispecific antibody that targets CD38, CD3 and CD28. Simultaneous CD3 and CD28 binding triggers T cell co-signaling, and additional CD38 recognition directs the T cells to CD38+ cancer cells such as multiple myeloma (MM) and non-Hodgkin lymphoma (NHL). This is a first-in-human phase 1 study investigating the safety, efficacy, pharmacokinetic (PK) and pharmacodynamic (PD) profile of SAR'257 in patients (pts) with refractory and relapsed (rr) MM and rrNHL. Methods: This is a multicenter, international, open-label, dose-escalation study (NCT04401020) of SAR'257 in pts with rrMM refractory to standard-of-care (SOC) options, including anti-CD38 monoclonal antibodies, and in pts rrNHL without any SOC options. SAR'257 was administered intravenously with lead-in doses (Day 1−5) in the first week, followed by twice weekly (BIW) or once weekly (QW) dosing; 11 target dose levels (TDLs) in pts with rrMM (9 TDLs: 0.06-11 µg/kg BIW; 2 TDLs: 18-27 µg/kg QW), and 2 TDLs in pts with rrNHL (2 µg/kg BIW and 4 µg/kg QW). Results: As of February 19, 2024, 47 pts (rrMM, n=40; rrNHL, n=7) received SAR'257. The median ages (years) were 64 (rrMM; range: 40−84) and 70 (rrNHL; range: 18−75). The median number of prior lines was 5 (range: 3−12) for rrMM and 5 (range: 2−7) for rrNHL cohort. In rrMM cohort, all (100%) pts had prior exposure to an anti-CD38 monoclonal antibody (MAb) and were refractory to anti-CD38 and in rrNHL cohort all were anti-CD38 naïve. The median time from last anti-CD38 dose was 2.7 (range: 1−65) months for rrMM cohort. Safety analysis revealed that 68% (n=32) pts had treatment-emergent adverse events (TEAEs; 26 pts in rrMM and 6 pts in rrNHL); 21.3% pts (n=10) Grade (G) ≥3 TEAEs (7 in rrMM and 3 in rrNHL). Cytokine release syndrome (CRS) was the most common TEAE, occurring in 52.5% of rrMM pts across all TDLs (n=21; G≥3 in 1 pt from 11 µg/kg BIW TDL) and in 57.1% of rrNHL pts (n=4; no G≥3) at the two TDLs tested. Repetitive CRS episodes (>1 episode) were more frequent at higher TDLs. Infusion-related reactions (IRRs; any G) were observed in 22.5% pts with rrMM (n=9; no G≥3) and in 28.5% pts with rrNHL (n=2; G≥3 in 1 pt). Epstein-Barr virus (EBV) infection/reactivation was reported in 17.5% (n=7; G≥3 in 4 pts) and 28.6% (n=2; no G≥3) pts with rrMM and rrNHL respectively. Further, 15% (n=6, G≥3 in 2 pts) from rrMM and 14.3% (n=1; G2 CMV reactivation) pts from rrNHL cohort reported cytomegalovirus (CMV) infection/reactivation. One case of immune effector cell-associated neurotoxicity syndrome (ICANS) was reported (G4) in the rrNHL cohort. Four dose-limiting toxicities (DLTs) were observed in the rrMM cohort [1 at 4 µg/kg BIW (G3 hepatotoxicity); 1 at 11 µg/kg BIW (G5 CRS−EBV reactivation; and 2 at 27 µg/kg QW (G3 CMV infection reactivation and G3 febrile neutropenia in same pt)]. Three DLTs were observed in the rrNHL cohort (2 at 2 µg/kg BIW [G4 neutropenia and G4 thrombocytopenia; same pt] and 1 at 4 µg/kg QW [ICANS G4]). For pts with rrMM, the maximum plasma concentration of SAR'257 reached within or above the theoretical efficacious range (0.1−1nM; extrapolated from ex vivo models), starting at 8 µg/kg BIW and 18 µg/kg QW in the first treatment cycle. As of July 08, 2024, the overall response rate (ORR), defined as partial response (PR) or better, was 5% (n=2) in the rrMM cohort: 1 pt exhibited stringent complete response (duration of response [DOR]=8.1 months, on-going) and 1 showed a complete response (CR) at 27 µg/kg QW TDL. In rrNHL cohort, the ORR was 14.3%, 1 pt achieved PR (DOR=7.1 months) at 2 µg/kg BIW TDL. The disease control rate (stable disease or better for >8 weeks) was 60% (n=24) and 28.6% (n=2) in the rrMM and rrNHL cohorts respectively. For both cohorts exploratory biomarker analysis revealed that: (1) SAR'257 treatment activated peripheral blood T cells and reduced regulatory T cell numbers and CD4/CD8 ratio; (2) CD38 expression on plasma cells positively corelated with time since the last anti-CD38 MAb dose; (3) Among the pts experiencing CRS, the peak values of cytokines (Interleukin (IL)-6, IL-8, and C-reactive protein) were significantly higher during the first cycle in comparison to subsequent cycles. Conclusion: This Phase 1 study of SAR'257 showed an anti-tumor response in a small number of pts from the rrMM and rrNHL cohorts. Due to safety concerns, in particular high rates of EBV and CMV reactivation and recurrent episodes of CRS in the higher dose levels, the study was terminated during dose escalation.

Introduction: Anti-BCMA CAR-T therapies like idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel) have revolutionized RRMM treatment. However, the 6-8-week manufacturing period often leads to disease progression and/or death in up to 25% of patients (pts), necessitating effective bridging strategies. Talquetamab (talq), a bispecific antibody targeting GPRC5D, is approved for RRMM pts with four prior lines of therapy and offers rapid disease debulking without impacting BCMA. This study assesses the safety and efficacy of a short course of talq as a bridging therapy for pts receiving cilta-cel or ide-cel. Methods: This multicenter retrospective study involved 14 US academic medical centers within the US Multiple Myeloma Immunotherapy Consortium. We included pts with RRMM who underwent leukapheresis and received talq bridging therapy with the intent to proceed to commercial cilta-cel or ide-cel. We assessed the safety, feasibility, and efficacy of talq bridging therapy. Safety outcomes included cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), talq-related unique toxicities, and delayed neurotoxicity (NT). Efficacy outcomes included response rates to talq and CAR-T therapies. Results: Between June 2023 and May 2024, 77 pts received talq bridging therapy after apheresis with the intention to proceed to CAR-T. The median age was 66 years (range, 58-73); 14% were Black and 10% Hispanic. Poor prognostic features, including high-risk cytogenetics, were present in 45%, extramedullary disease (EMD) in 43%, and 72.7% were triple-class refractory. The median number of prior lines of therapy was 5 (range 3-11) and 10 pts (13%) had prior BCMA targeted therapy. Out of 77 pts, 10 pts were pending CAR-T infusion at the time of last follow up; 6 pts could not receive CAR-T infusion due to manufacturing failures. Of the remaining 61 patients who underwent successful CAR-T manufacturing, 58 (95%) pts were successfully infused with CAR-T therapy following talq bridging. Three (5%) pts died due to disease progression prior to CAR-T infusion. Talq was given 0.8 mg/kg biweekly in 59 (76%) pts and the median time on talq was 22 days (IQR: 10-41 days). Following talq bridging, none of the pts had grade >=3 CRS and 2 (2.5%) had grade 3 ICANS. Skin toxicities occurred in 32 (41%), nail toxicities in 19 (25%), and oral toxicities in 43 (56%) pts mainly grade 1. Most oral, skin, and taste changes resolved at the last follow-up (60%). Response to talq was evaluable in 72 out of 77 patients. An overall response was noted in 45/72 (62%) pts including unconfirmed CR in 14, VGPR in 10 and PR in 21 pts. There was no association of AEs and response to talq with high-risk cytogenetics, EMD and high baseline ferritin levels. Out of the 58 patients who went on to receive CAR-T therapy following talq bridging (45 cilta-cel and 13 ide-cel), 38 (65%) experienced CRS, with grade 3 CRS noted in 2 (3%) pts. ICANS occurred in 5 (8.6%) pts, with 1 (1.7%) grade 3 ICANS. Only 1 pt had delayed NT (facial nerve palsy) at the last follow up. No treatment related deaths were observed. Of these 58 pts, response was evaluable in 40 pts and a response at day +30 was noted in 39/40 (97.5%) pts (14 in CR, 10 in VGPR, 15 in PR). The median follow-up from CAR-T was 61 days (28-113). For the 58 pts who received CAR-T, the median time from the last talq dose to CAR-T infusion was 25 days (IQR: 19-36), and to lymphodepletion was 24 days (IQR: 18-33). There was no difference in the CAR-T related AEs by the duration of Talq washout (>4 weeks vs. =< 4 weeks). Conclusions: Talquetamab is an excellent bridging option before BCMA-targeted CAR-T therapy, showing high response rates even with short-term use and enabling most pts to receive CAR-T. Most oral, skin, and taste changes resolved post CAR-T. These findings underscore the effectiveness of a short course of talq bridging to maintain disease control and improve outcomes post CAR-T. Updated data with longer follow-up will be presented at the meeting.

Summary In 2014, the International Myeloma Working Group (IMWG) updated the criteria for diagnosing myeloma and added three additional criteria to the traditional Calcium elevation, Renal impairment, Anemia, Bone disease (CRAB) criteria, called the Sixty % marrow plama cells, Light chain ratio >60, Mri demonstates lytic lesions (SLiM) criteria (clonal bone marrow plasma cells ≥60%, involved to uninvolved free light chain ratio (FLCr) ≥100 and >1 focal lesion on magnetic resonance imaging (MRI)). We report on the outcomes of 30 patients who underwent autologous stem cell transplantation (ASCT) where therapy was initiated solely based on SLiM criteria and compared them to a matched cohort of 60 patients whose myeloma‐defining event was CRAB. The SLiM cohort had a shorter median time to neutrophil (15 vs. 16 days, p = 0.049) and platelet (15 vs. 17 days, p = 0.0004) engraftment. The 36‐month overall survival (OS) was 100% in the SLiM group and 93.27% in the control group (95% CI 83.06%–97.42%), with a trend towards longer OS in the SLiM cohort ( p = 0.065). The 36‐month progression‐free survival (PFS) was 91.61% in the SLiM (95% CI 69.93%–97.87%) and 65.95% in the control group (95% CI 52.31%–76.53%). There was no difference in the PFS between the cohorts ( p = 0.414). ASCT is efficacious and safe in MM patients transplanted only due to SLIM criteria. Early intervention in this asymptomatic cohort did not appear to result in deeper responses or better PFS compared to outcomes in symptomatic patients.

Abstract As patients with relapsed/refractory multiple myeloma (RRMM) continue to live longer, they might get exposed to most available drugs and drug classes during the disease course. For such late line RRMM or among patients without access to novel therapies, retreatment with a drug that the disease had previously been refractory to might be one option. In this retrospective study, we describe 315 patients with RRMM at our institution who were retreated with a drug that the disease had been previously refractory to. We found an overall response rate of 56.2% and a median progression-free survival (PFS) of 11 months with retreatment. Patients with a longer time on initial therapy with the index drug (>28.4 months) had a superior PFS with retreatment (median PFS, 16.9 vs 8.1 months; P < .001). Similarly, patients with a longer time gap between the initial line of therapy with index drug and retreatment with index drug (>46.1 months) had better PFS with retreatment (28.2 vs 8.9 months; P = .016). In conclusion, retreatment with a previously refractory drug is a viable therapeutic option for RRMM, with the most significant benefit derived in disease demonstrating sensitivity to initial drug exposure and among those with a longer gap between initial drug exposure and retreatment.

Waldenström macroglobulinaemia (WM) is a unique, cluster of differentiation (CD) 20+ B‐cell malignancy, with a characteristic immunoglobulin M‐secreting lymphoplasmacytic bone marrow infiltrate that is bolstered by a highly supportive microenvironment, including upregulated programmed death 1 expression. However, the impact of checkpoint inhibition in WM is unclear. Commentary on: Kothari et al. PembroWM: A phase II trial to investigate the safety and efficacy of rituximab and pembrolizumab in relapsed/refractory Waldenström's macroglobulinaemia. Br J Haematol 2024; 205: 2273‐2281 .

Waldenström macroglobulinemia (WM) is a B-cell lymphoma characterized by the presence of bone marrow lymphoplasmacytic infiltration and circulating monoclonal immunoglobulin M protein. The clinical presentation of WM is variable, ranging from gradually progressive cytopenias, organomegaly, fatigue, B symptoms, and peripheral neuropathy to the more emergent presentation with symptomatic hyperviscosity, cryoglobulinemia, hemolytic anemia–associated symptoms, acquired von Willebrand disease or acquired hemophilia–associated bleeding. Approximately 1 in 5 patients with WM are asymptomatic at diagnosis and classified as having smoldering WM, not requiring WM-directed therapy. Although WM typically has an indolent, relapsing-remitting course, the outcomes are heterogeneous. The prognosis of patients with WM is known to be impacted by certain clinical and laboratory features at initial presentation, with advanced age, elevated serum lactate dehydrogenase, and low serum albumin unfavorably affecting the outcome. Although complications such as histologic transformation or light and/or heavy chain (AL/ALH) amyloidosis are infrequent, their occurrence adversely influences the disease course. The International Prognostic Staging System for WM (IPSS-WM) is a validated model, often used in clinical practice, but needs to be reexamined in the current era. The discovery of the recurrent MYD88 L265P gain-of-function point mutation and the subclonal CXCR4 mutations has helped improve our understanding of the WM biology, and the prognostic impact of these mutations is under evaluation, with somewhat inconsistent findings thus far across studies. This review discusses the clinical presentation, diagnostic criteria, and prognostic markers of WM.

AbstractObjectivesCluster of differentiation 38 (CD38) is a key target on multiple myeloma (MM) cells. This multi‐centre, Phase 1, single‐agent study (NCT04000282) investigated SAR442085, a novel fragment crystallisable (Fc)‐modified anti‐CD38 monoclonal antibody (mAb), with enhanced affinity towards Fc‐gamma receptor on effector cells in patients with relapsed and/or refractory (RR) MM.MethodsThis study comprised two parts: Part‐A (dose‐escalation involving anti‐CD38 mAb pre‐treated and naïve patients) and Part‐B (dose expansion). Primary endpoints were maximum tolerated dose and recommended Phase 2 dose (RP2D).ResultsThirty‐seven heavily pre‐treated patients were treated in Part A. Part‐B (dose‐expansion) was not studied. Seven dose‐limiting toxicities were reported at DL3, DL5, DL6, and DL7. RP2D was determined to be 5–7·5 mg/kg. Most common treatment‐emergent adverse events were infusion‐related reactions in 70·3% (26/37) patients. Grade ≥3 thrombocytopenia was reported in 48·6% (18/37). Overall response rate was 70% in anti‐CD38 mAb naïve and 4% in anti‐CD38 pre‐treated patients, with a median progression‐free survival of 7·62 (95%CI: 2·858; not calculable) months and 2·79 (95%CI: 1·150; 4·172) months and, respectively.ConclusionsThe efficacy of SAR442085 was promising in anti‐CD38 mAb naïve patients but did not extend to the larger cohort of anti‐CD38 mAb pre‐treated patients. This observation, along with transient high‐grade thrombocytopenia, could potentially limit its clinical use.

Abstract Currently, the role of DNA methylation in the immunoglobulin M (IgM) monoclonal gammopathy disease spectrum remains poorly understood. In the present study, a multiomics prospective analysis was conducted integrating DNA methylation, RNA sequencing (RNA-seq), and whole-exome sequencing data in 34 subjects (23 with Waldenström macroglobulinemia [WM], 6 with IgM monoclonal gammopathy of undetermined significance [MGUS], and 5 normal controls). Analysis was focused on defining differences between IgM gammopathies (WM/IgM-MGUS) compared with controls, and specifically between WM and IgM-MGUS. Between groups, genome-wide DNA methylation analysis demonstrated a significant number of differentially methylated regions that were annotated according to genomic region. Next, integration of RNA-seq data was performed to identify potentially epigenetically deregulated pathways. We found that pathways involved in cell cycle, metabolism, cytokine/immune signaling, cytoskeleton, tumor microenvironment, and intracellular signaling were differentially activated and potentially epigenetically regulated. Importantly, there was a positive enrichment of the CXCR4 signaling pathway along with several interleukin (interleukin 6 [IL-6], IL-8, and IL-15) signaling pathways in WM compared with IgM-MGUS. Further assessment of known tumor suppressor genes and oncogenes uncovered differential promoter methylation of several targets with concordant change in gene expression, including CCND1 and CD79B. Overall, this report defines how aberrant DNA methylation in IgM gammopathies may play a critical role in the epigenetic control of oncogenesis and key cellular functions.