Impact of Ultra High-risk Genetics on Real-world Outcomes of Transplant-eligible Multiple Myeloma Patients

Early Chimeric Antigen Receptor T Cell Expansion Is Associated with Prolonged Progression-Free Survival for Patients with Relapsed/Refractory Multiple Myeloma Treated with Ide-Cel: A Retrospective Monocentric Study

The outcomes of patients with relapsed and refractory multiple myeloma (RRMM) previously treated with the 3 main classes of myeloma therapy-immunomodulatory drugs, proteasome inhibitors, and anti-CD38 antibodies-remain poor. Recently, based on the phase II pivotal KarMMa trial showing prolonged overall survival (OS) and progression-free survival (PFS) in heavily treated patients, idecabtagene vicleucel (ide-cel), a B cell maturation antigen (BCMA)-directed chimeric antigen receptor (CAR) T cell therapy (CAR-T) product, was approved in the United States for the treatment of RRMM. In France, since June 2021, an early access program has authorized the use of ide-cel in the setting of RRMM (defined as progressive myeloma after at least 3 previous regimens, including the 3 main antimyeloma therapies). We report the first French experience through this early access program in a retrospective study of 24 consecutive patients treated with ide-cel at our institution. The patients were evaluated according to International Myeloma Working Group criteria and by positron emission tomography computed tomography (PET-CT) at 1, 3, 6, 9, and 12 months after ide-cel infusion. Most patients had adverse cytogenetic abnormalities, and RRMM with triple-refractory drugs were seen in 79%. Bridging therapy was required for 19 of 24 patients. Before CAR-T cell infusion, lymphodepletion with fludarabine and cyclophosphamide was systematically performed. The median follow-up was 15.2 months. At 3 months after ide-cel infusion, 92% of patients achieved at least a partial response, and 50% achieved a complete response or better (≥CR). At 6 months, 70% of patients had a persistent ≥CR. At 3 and 6 months, bone marrow minimal residual disease (10-6 level) was undetectable in 79% and 75% of patients, respectively. At 6 months, CR as assessed by PET-CT was achieved in 15 of 20 patients (75%). The median PFS was 14.8 months, and median OS was not reached. Notably, an expansion of circulating CAR-T cells to >180/mm3 after infusion was strongly associated with prolonged PFS. Additionally, the level of soluble BCMA measured before infusion was identified as a prognostic factor for PFS, likely correlated to the tumor burden. Grade 1-2 cytokine release syndrome (CRS) occurred in 22 of 24 patients (92%). Only 1 patient (4%) experienced grade ≥3 CRS. The occurrence of neurologic toxicity was infrequent (12.5%) and reversible in all cases. Hematologic toxicity was relatively common, and secondary hypogammaglobulinemia occurred in most patients. Infections (mostly viral) were frequent but most often nonsevere. This study echoes the promising results of the KarMMa trial and identifies possible prognostic indicators in RRMM patients treated with ide-cel, potentially refining treatment strategies and improving outcomes in this challenging context.

Approach to High-Risk Multiple Myeloma

Improving the outcome of high-risk myeloma (HRMM) is a key therapeutic aim for the next decade. To achieve this aim, it is necessary to understand in detail the genetic drivers underlying this clinical behavior and to target its biology therapeutically. Advances have already been made, with a focus on consensus guidance and the application of novel immunotherapeutic approaches. Cases of HRMM are likely to have impaired prognosis even with novel strategies. However, if disease eradication and minimal disease states are achieved, then cure may be possible.

Outcomes of Autologous Stem Cell Transplantation in Patients with Ultra-High-Risk Multiple Myeloma

Multiple myeloma (MM) patients with high-risk cytogenetic abnormalities have inferior survival outcomes and are underrepresented in clinical trials. There is scarce data on MM patients with more than one high-risk cytogenetic aberration (ie, ultra- high-risk MM). This study was conducted to evaluate outcomes of newly diagnosed MM patients with ultra-high-risk MM who underwent autologous hematopoietic stem cell transplantation (autoHCT). We conducted a retrospective single-center chart review analysis of adult patients with ultra-high-risk MM who underwent autoHCT between 2008 and 2018 at MD Anderson Cancer Center. High-risk cytogenetics were defined as del(17p), t(4;14), t(14;16), or 1q21 gain or amplification (1q+) by fluorescence in situ hybridization. Primary endpoints were progression-free survival (PFS) and overall survival (OS). Seventy-nine patients with two or more high-risk cytogenetic abnormalities were included in our analysis. The median age of 61 years (range, 33.5 to 76.5 years), and 57% were female. Sixty-seven patients had two high-risk cytogenetic abnormalities, and 12 patients had three high-risk cytogenetic abnormalities. The most common combinations of high-risk abnormalities were [1q+, t(4:14)] (n = 25; 32%) and [1q+, del17p] (n = 21; 27%). The majority of patients received either bortezomib, lenalidomide, and dexamethasone (48%) or carfilzomib, lenalidomide, and dexamethasone (16%) as induction therapy. Prior to autoHCT, 52 patients (66%) achieved a very good partial response or better (≥VGPR), whereas 23 patients (29%) achieved minimal residual disease (MRD)-negative ≥VGPR. Fifty-six patients (71%) received post-transplantation maintenance therapy. Thirty-six patients (46%) achieved MRD-negative ≥VGPR at day +100 after autoHCT, and 40 patients (51%) did so at best post-transplantation response. With a median follow-up in surviving patients of 38.3 months (range, 11.9 to 104.8 months), the median PFS and OS in the entire cohort were 22.9 months and 71.5 months, respectively. For the subset of patients with three HR abnormalities, the median PFS was 15.6 months and median OS was 28.0 months. In multivariate analysis, achieving MRD-negative ≥VGPR prior to autoHCT was associated with improved PFS (hazard ratio [HR], .42; P = .045), whereas male sex (HR, .15; P = .009) and achieving MRD-negative ≥VGPR post-autoHCT (HR, .27; P = .026) were associated with improved OS. In conclusion, patients with ultra-high-risk MM have a median PFS of <24 months with the current standard of care that includes consolidation with autoHCT. These patients may benefit from earlier use of newer treatment modalities, such as chimeric antigen receptor T cell therapy and bispecific antibodies.

Definers and drivers of functional high-risk multiple myeloma: insights from genomic, transcriptomic, and immune profiling

Traditional prognostic models for newly diagnosed patients with multiple myeloma (MM), including International Staging System criteria and number of high-risk chromosomal abnormalities, are based on disease characteristics at diagnosis. However, the identification of patients at risk of more rapidly progressive MM is inherently a dynamic assessment. In a subset of patients with MM, adverse disease biology only becomes evident after the failure of first-line therapy. We define this entity as functional high-risk MM (FHRMM), encompassing relapse within 18 months of treatment initiation and/or within 12 months of frontline autologous stem cell transplantation. FHRMM is not adequately captured by traditional prognostic models, and there is a need for better understanding of mechanisms or risk factors for early relapse or progression. In this review, we explore potential definitions of FHRMM before delving into its underlying drivers based on genetic, transcriptomic, and immune cell profiling studies. Emerging data suggest that specific features of both myeloma cells and immune cells can enable the FHRMM phenotype. We conclude our review by discussing ongoing and future studies that seek to identify and intervene upon patients with FHRMM preemptively.

The role of staging in multiple myeloma

INTRODUCTION

The importance of cancer staging is determined by how accurately it can predict prognosis, and how useful it is for treatment decisions. Compared to other malignancies, multiple myeloma (MM) staging proved more challenging because of unreliable prognostic factors and wide-ranging life expectancy. As traditional MM staging continues to evolve, it requires reassessment of its prognostic and predictive value.

AREAS COVERED

The studies that included prognostic and predictive value of MM stages from 1975 through 2023 were selected for this review using PubMed, MEDLINE platforms. The history and evolution of MM staging are revisited, including its role in predicting survival, treatment planning and potential practical implications for the future. The role of MM staging for oncological practice and patient counseling is discussed.

EXPERT OPINION

The utility of the traditional MM staging remains unsatisfactory because it lacks a strong connection with the disease biology, prognosis or treatment planning. Additionally, it demonstrates a modest value for patient counseling because individual prognosis is subject to under- or overestimation, and the median survival or survival rates are difficult concepts to grasp. Although the role of MM stages may change in the future, the current research upholds the notion that MM staging benefits more medical research and clinical trials than oncological practice.