A Phase 1b Study of Step-up Dosing with ABBV-383, a B-Cell Maturation Antigen (BCMA) x CD3 Bispecific Antibody, in Patients with Relapsed or Refractory Multiple Myeloma
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.
Optimizing multiple Myeloma clinical trials: research direction, addressing limitations, and strategies for improvement
Abstract Background Smoldering multiple myeloma (SMM), an asymptomatic precursor of multiple myeloma (MM), carries a variable risk of progression to MM. There is little consensus on the efficacy or optimal timing of treatment in SMM. We systematically reviewed the landscape of all clinical trials in SMM. We compared the efficacy of treatment regimens studied in SMM to results from these regimens when used in newly diagnosed multiple myeloma (NDMM), to determine whether the data suggest deeper responses in SMM versus NDMM. Methods All prospective interventional clinical trials for SMM, including published studies, meeting abstracts, and unpublished trials listed on ClinicalTrials.gov up to April 1, 2023, were identified. Trial-related variables were captured, including treatment strategy and efficacy results. Relevant clinical endpoints were defined as overall survival (OS) and quality of life. Results Among 45 SMM trials identified, 38 (84.4%) assessed active myeloma drugs, while 7 (15.6%) studied bone-modifying agents alone. Of 18 randomized trials in SMM, only one (5.6%) had a primary endpoint of OS; the most common primary endpoint was progression-free survival (n = 7, 38.9%). Among 32 SMM trials with available results, 9 (28.1%) met their prespecified primary endpoint, of which 5 were single-arm studies. Six treatment regimens were tested in both SMM and NDMM; 5 regimens yielded a lower rate of very good partial response rate or better (≥VGPR) in SMM compared to the corresponding NDMM trial (32% vs 63%, 43% vs 53%, 40% vs 63%, 86% vs 89%, 92% vs 95%, and 94% vs 87%, respectively). Conclusion In this systematic review of all prospective interventional clinical trials in SMM, we found significant variability in trial design, including randomization status, primary endpoints, and types of intervention used. Despite the statistical limitations, comparison of treatment regimens revealed no compelling evidence that the treatment is more effective when introduced early in SMM compared to NDMM.
Still high risk? A review of translocation t(14;16) in multiple myeloma
American Journal of Hematology | June 14, 2024 | Volume: 99 | Issue: 10 | Pages: 1979-1987
AbstractMultiple myeloma (MM) is a heterogeneous and complex disease, both in mutational biology as well as in the clinical presentation of patients. While tailored and biomarker‐targeted therapy remains the direct goal for patient‐centric management, existing therapies in MM remain largely uniform. Translocation t(14;16) is a rare primary genetic event found in less than 5% of patients with newly diagnosed MM. Here, we present an overview of the biology of t(14;16), epidemiology, clinical presentation, prognostic impact, and discuss the future clinical and therapeutic strategies for targeting this rare yet high‐risk group in MM to optimize patient outcomes.
Gain1q in Myeloma Randomized Clinical Trials- How Is It Reported and How Does It Impact Outcomes: A Systematic Review
Introduction: Extra copies of chromosome 1q21 (+1q: gain=3 copies, amp=4 or more copies) have been associated with worse outcomes for patients with multiple myeloma (MM). We performed a systematic review to evaluate current reporting of +1q, efficacy of existing regimens for +1q, and prognostic implications of +1q in MM randomized controlled trials (RCTs). Methods: We searched three databases for MM RCTs. Our inclusion criteria were all published MM RCTs from 2012-2022. Each MM RCT was analyzed for reported data on +1q. The following features specific to +1q were collected: +1q reported or not as a high-risk cytogenetic alteration, definition of gain1q with respect to percentage of cells with abnormality detected, documentation of distinction between Gain1q and Amp1q in analysis, prevalence of +1q in enrolled population, outcomes of patients [Overall Survival (OS) and Progression Free Survival (PFS)] in patients with +1q in the experimental versus control arm and in patients with and without +1q. Results: A total of 124 trials were included. Among these trials, 28 (23%) studies reported data on +1q, including 26 studies that reported data in the primary manuscript and two studies that reported in separate publication. These trials reported a total of 2692 patients with +1q which represented 25% of all the patients enrolled. Out of 28 trials, three trials (11%) specified the criteria for categorizing patients as +1q (example in IKEMA and IFM-99: the presence of at least three copies in at least 30% of analyzed plasma cells was required). Only four trials (14%) reported survival data on gain and amp separately and the remaining 24 (86%) studies reported for gain or did not specify gain vs amp. Amongst the trials that reported +1q, 22 (79%) considered this to be a high-risk cytogenetic abnormality. Amongst trials that met primary endpoint showing improvement in PFS and clearly reported on +1q, the following drugs also improved PFS for those with +1q (when comparing hazard ratio (HR) for intervention versus control arm in the +1q subgroup): lenalidomide (len) maintenance in Myeloma XI, selinexor in BOSTON, and isatuximab in IKEMA and ICARIA. Several trials met their endpoint and showed improvement in PFS in the +1q cohort in same direction as overall study results but had confidence intervals for +1q subgroup that crossed 1. These included addition of carfilzomib in Myeloma XI, addition of carfilzomib vs bortezomib to len and dex for +1q (but not in Amp1q) in ENDURANCE, addition of elotuzumab to pomalidomide and dex, and bortezomib-based treatment before and after autologous stem cell transplantation (auto-SCT) vs no bortezomib (Table 2). Seven studies reported HR for patients with +1q in the trial (across both arms) compared to those without. In six studies (all studies other than SWOG1211), worse outcomes were seen with respect to OS and PFS for those with +1q versus without (Table 2). Important interventions for which subgroup analysis of +1q was not presented in trial results, and hence conclusions about the efficacy of the drugs specifically for patients with +1q cannot be ascertained included pomalidomide and ixazomib. Although subgroup analysis of various daratumumab trials has shown improvement for high-risk MM, the effect on gain1q was not isolated. Two recent contemporary trials that isolated effect of auto-SCT (DETERMINATION and IFM-2009) did not report +1q. However, in FORTE Trial, adverse prognostic implications of +1q were not seen in the arm receiving carfilzomib, len, dex and auto-SCT, indicating a possible role of carfilzomib and auto-SCT in ameliorating the adverse prognostic implications of +1q. Although len maintenance improved PFS after auto-SCT as maintenance in Myeloma XI overall for those with +1q, it did not appear to improve PFS for patients with isolated +1q (with no other concurrent genetic abnormalities). Conclusion: This systematic review of MM RCTs finds considerable heterogeneity in the reporting of +1q abnormalities in the literature, and +1q to be inconsistently classified as a poor prognostic factor in subgroup analysis of randomized myeloma trials. Most interventions that have shown to be successful in randomized trials and have clearly reported on the +1q subgroup have shown concordant direction of results and benefit of the applied intervention in the +1q subgroup. A more standardized approach to reporting of this abnormality is needed.
Comparison of the Efficacy in Clinical Trials Versus Effectiveness in the Real-World of Treatments for Multiple Myeloma: A Population-Based Cohort Study
Introduction: Improvements in outcomes of patients with multiple myeloma (MM) depend on the use of regimens approved based on results from large phase III randomized controlled trials (RCTs) demonstrating their efficacy. However, many real-world (RW) patients would not have met the stringent RCTs inclusion criteria. Therefore, the effectiveness of these drugs in the RW setting is unknown. Understanding this efficacy-effectiveness gap is important to contextualize the expected outcomes in the current RW setting. Therefore, we conducted a retrospective population-based study to compare the efficacy versus effectiveness of registration RCTs with RW patients using standard of care (SoC) MM regimens for the primary outcomes of 1) progression free survival [PFS]; 2) overall survival [OS] and 3) serious adverse events (AEs). Methods: RW data was obtained from the Institute for Clinical Evaluative Sciences, an administrative database capturing all health records in the publicly funded health care system in Ontario, Canada. Adult patients treated between Jan 2007 to Dec 2020 with SoC regimens were included. Only regimens with corresponding registrational phase III RCTs which led to the public reimbursement in Ontario were included (lenalidomide/dex [Rd] and bortezomib/Rd [VRd] for newly diagnosed transplant ineligible patients, and relapsed MM (RRMM) regimens included carfilzomib/Rd [KRd], carfilzomib/dex [Kd], daratumumab/Rd [DRd], daratumumab/bortezomib/dex [DVd], pomalidomide/dex [Pd]). In the RW cohort, PFS was defined as the time from initiation of index regimen to death, initiation of subsequent MM treatment, or last follow-up, and patients remaining on the index regimen as last follow up were censored. Kaplan-Meier curves from pivotal phase 3 RCTs were manually digitized to provide individual patient-level estimates of PFS and OS. Meta-analyses were performed to compare the gap of PFS and OS outcomes of RW versus RCT patients, and effect estimates were summarized using hazard ratios (HR). The frequency of serious AE data was abstracted from published RCTs. Given that serious AEs in RCTs would have resulted in hospitalization, hospital admission during treatment with the index regimen was used as a surrogate for serious AEs in the RW cohort. Differences in RW and RCT safety outcomes were reported descriptively. Results & Discussion: A total of 3951 RW MM patients, treated with 7 standard of care MM regimens, were included. Baseline characteristics of patients in the RW and RCT cohorts are shown in table 1. Overall, patients in the RW cohort were older than in the RCTs. For relapsed regimens, there was a longer time between MM diagnosis and start of the regimen in the real-world versus RCT. With regards to the efficacy-effectiveness gap, MM patients treated in routine practise in the RW had a worse PFS despite overestimated of RW PFS compared to highly selected RCT patients for 6 of the 7 MM regimens evaluated, with a pooled HR of 1.44 (95% CI 1.34-1.54) in the meta-analysis (Figure 1A). Similarly, RW patients had a worse OS compared to RCT patients treated with 6 of the 7 regimens, with a pooled HR of 1.75 (95% ci 1.63-1.88) in the meta-analysis (Figure 1B). RRMM patients in the RW had higher rates of prior lenalidomide exposure compared to RCT patients. The only regimen which showed a trend towards performing better in the RW as compared to RCTs was Pd. The reason for this is likely multifactorial but perhaps patients included in the MM-003 RCT may have had more refractory MM (given the higher prior immunomodulatory drug exposure and longer time from diagnosis to treatment among Pd RCT patient) compared to RW patients in this study. With regards to safety, the percentage of patients with inpatient hospitalization during treatment in the real-world cohort and reported serious AEs in RCT were comparable (VRD 57% vs not reported [NR]; Rd 64% vs NR; Kd 57% vs 59%; KRd 53% vs 60%; DVd 36% vs NR; DRd 46% vs 49%; Pd 59% vs 61%). Conclusion: This is one the largest population-level studies highlighting the significant efficacy-effectiveness gap between registrational RCTs and RW usage of these regimens, with RW patients experiencing 44% worse PFS and 75% worse OS compared to RCT patients. Our data emphasize the importance of ongoing evaluation of RW data to contextualize effectiveness and toxicity of selected regimens in the clinic, and better inform both clinicians and patients for shared treatment decision making.
Real-World Treatment Patterns and Clinical Outcomes Among Triple-Class Exposed and B-Cell Maturation Antigen (BCMA) Exposed Multiple Myeloma Patients
Introduction: Despite the development of advanced treatment options, multiple myeloma (MM) remains an incurable disease. Most MM patients relapse and require further treatments. B-cell maturation antigen (BCMA) targeted immunotherapy is a novel MM therapy class that is now available to heavily pre-treated relapse/refractory MM (R/R MM) patients, who were triple class exposed (TCE) to proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), and anti-CD38 monoclonal antibodies. As BCMA therapies continue to be further utilized and become an integral part of MM treatment, the proportion of TCE patients who are also BCMA exposed (TCE+BCMA exposed) is expected to grow. However, the clinical outcomes of TCE+BCMA exposed RRMM patients have not been previously assessed. The objective of this study was to evaluate the real-world outcomes of TCE+BCMA exposed MM patients who started a subsequent LOT, describing their characteristics, treatment patterns, and clinical outcomes. Subgroups of penta-drug exposed (at least two PIs, at least two IMiDs, and at least one anti-CD38) patients, as well as White and African American patients were also evaluated as penta-drug exposure status and race were known to impact clinical outcomes. Methods: Adult patients with MM who were TCE+BCMA exposed and started a subsequent LOT starting from July 03, 2019 (when additional new treatment options became available) were selected from the Komodo Healthcare Map (a US claims dataset) and were followed until the earliest of death, last claim, or end of study period (December 31, 2022). Index date was defined as the start date of the subsequent LOT following TCE and BCMA exposure. Descriptive statistics were provided for patient characteristics and treatment patterns. Clinical outcomes including time to treatment discontinuation or death (TTD) and time to next treatment or death (TTNT) were estimated using the Kaplan-Meier method. Results: A total of 344 TCE+BCMA exposed patients, who received the next LOT were included in the study, including 152 (44.2%) patients who were penta-drug exposed before index, 57 (16.6%) African American, and 185 (53.8%) White patients. Key baseline demographic characteristics and treatment history for the overall group and the three subgroups are listed in Table 1. The mean (SD) and median number of prior LOTs for the overall group before index date were 5.7 (1.7) and 6.0, respectively. The most prevalent prior treatments before the index date for the overall group were daratumumab (99.1%), belantamab mafadotin (91.9%), pomalidomide (84.3%), carfilzomib (83.1 %), bortezomib (76.2%) and lenalidomide (72.1%). Excluding corticosteroids, the most frequently used index treatments (i.e., treatment used post TCE+BCMA exposure) were carfilzomib- (21.9%), bortezomib- (20.8%), pomalidomide- (18.3%), and belantamab mafadotin- (18.3%) based regimens. The median (95% confidence interval [CI]) TTD was 3.7 (3.3, 4.4) months, and the median (95% CI) TTNT was 6.4 (5.5, 7.6) months. TTD and TTNT estimates for the three subgroups are listed in Table 2. Conclusions: To our knowledge, this is the first real-world study of treatment patterns and outcomes for TCE+BCMA exposed MM patients who started a subsequent LOT. The findings showed that this group of heavily pretreated MM patients were often retreated with the same therapies or therapies in the same classes, as they have limited effective treatment options. TCE+BCMA exposed patients exhibited poor clinical outcomes, as demonstrated by the rapid treatment discontinuation and moving on to the next treatment shortly after initial treatment. Many patients were already penta-drug exposed, and they appear to have worse clinical outcomes than the overall patient group. A shorter TTD was observed, and a trend for shorter TTNT was observed among African American patients than White patients. The findings highlight the continued need for effective treatments for heavily treated MM patients and particularly those with poor outcomes.
Impact of bortezomib‐based versus lenalidomide maintenance therapy on outcomes of patients with high‐risk multiple myeloma
Cancer | April 6, 2023 | Volume: 129 | Issue: 14 | Pages: 2179-2191
AbstractBackgroundLenalidomide maintenance after autologous stem cell transplant (ASCT) in multiple myeloma (MM) results in superior progression‐free survival and overall survival. However, patients with high‐risk multiple myeloma (HRMM) do not derive the same survival benefit from lenalidomide maintenance compared with standard‐risk patients. The authors sought to determine the outcomes of bortezomib‐based maintenance compared with lenalidomide maintenance in patients with HRMM undergoing ASCT.MethodsIn total, the authors identified 503 patients with HRMM who were undergoing ASCT within 12 months of diagnosis from January 2013 to December 2018 after receiving triplet novel‐agent induction in the Center for International Blood and Marrow Transplant Research database. HRMM was defined as deletion 17p, t(14;16), t(4;14), t(14;20), or chromosome 1q gain.ResultsThree hundred fifty‐seven patients (67%) received lenalidomide alone, and 146 (33%) received bortezomib‐based maintenance (with bortezomib alone in 58%). Patients in the bortezomib‐based maintenance group were more likely to harbor two or more high‐risk abnormalities and International Staging System stage III disease (30% vs. 22%; p = .01) compared with the lenalidomide group (24% vs. 15%; p < .01). Patients who were receiving lenalidomide maintenance had superior progression‐free survival at 2 years compared with those who were receiving either bortezomib monotherapy or combination therapy (75% vs. 63%; p = .009). Overall survival at 2 years was also superior in the lenalidomide group (93% vs. 84%; p = .001).ConclusionsNo superior outcomes were observed in patients with HRMM who received bortezomib monotherapy or (to a lesser extent) in those who received bortezomib in combination as maintenance compared with lenalidomide alone. Until prospective data from randomized clinical trials are available, post‐transplant therapy should be tailored to each patient with consideration for treating patients in clinical trials that target novel therapeutic strategies for HRMM, and lenalidomide should remain a cornerstone of treatment.
Impact of second primary malignancy post–autologous transplantation on outcomes of multiple myeloma: a CIBMTR analysis
Abstract The overall survival (OS) has improved significantly in multiple myeloma (MM) over the last decade with the use of proteasome inhibitor and immunomodulatory drug-based combinations, followed by high-dose melphalan and autologous hematopoietic stem cell transplantation (auto-HSCT) and subsequent maintenance therapies in eligible newly diagnosed patients. However, clinical trials using auto-HSCT followed by lenalidomide maintenance have shown an increased risk of second primary malignancies (SPM), including second hematological malignancies (SHM). We evaluated the impact of SPM and SHM on progression-free survival (PFS) and OS in patients with MM after auto-HSCT using CIBMTR registry data. Adult patients with MM who underwent first auto-HSCT in the United States with melphalan conditioning regimen from 2011 to 2018 and received maintenance therapy were included (n = 3948). At a median follow-up of 37 months, 175 (4%) patients developed SPM, including 112 (64%) solid, 36 (20%) myeloid, 24 (14%) SHM, not otherwise specified, and 3 (2%) lymphoid malignancies. Multivariate analysis demonstrated that SPM and SHM were associated with an inferior PFS (hazard ratio [HR] 2.62, P < .001 and HR 5.01, P < .001, respectively) and OS (HR 3.85, P < .001 and HR 8.13, P < .001, respectively). In patients who developed SPM and SHM, MM remained the most frequent primary cause of death (42% vs 30% and 53% vs 18%, respectively). We conclude the development of SPM and SHM leads to a poor survival in patients with MM and is an important survivorship challenge. Given the median survival for MM continues to improve, continued vigilance is needed to assess the risks of SPM and SHM with maintenance therapy post–auto-HSCT.
Prognostic Value of Translocation 11;14 in Patients with Relapsed/Refractory Myeloma Receiving Anti-CD38 Therapy