KarMMa-RW: comparison of idecabtagene vicleucel with real-world outcomes in relapsed and refractory multiple myeloma

Management of bone disease with concurrent chimeric antigen receptor T-cell therapy for multiple myeloma

In the intricate landscape of multiple myeloma, a hematologic malignancy of plasma cells, bone disease presents a pivotal and often debilitating complication. The emergence of Chimeric Antigen Receptor T-cell (CAR-T) therapy has marked a pivotal shift in the therapeutic landscape, offering novel avenues for the management of MM, particularly for those with relapsed or refractory disease. This innovative treatment modality not only targets malignant cells with precision but also influences the bone microenvironment, presenting both challenges and opportunities in patient care. In this comprehensive review, we aim to examine the multifaceted aspects of bone disease in patients with multiple myeloma and concurrent CAR-T therapy, highlighting its clinical ramifications and the latest advancements in diagnostic modalities and therapeutic interventions. The article aims to synthesize current understanding of the interplay between myeloma cells, CAR-T cells, and the bone microenvironment in the context of current treatment strategies in this challenging and unique patient population.

Challenges and Lessons Learned in Autologous Chimeric Antigen Receptor T-Cell Therapy Development from a Statistical Perspective

Chimeric antigen receptor (CAR) T-cell therapy is a human gene therapy product where T cells from a patient are genetically modified to enable them to recognize desired target antigen(s) more effectively. In recent years, promising antitumor activity has been seen with autologous CAR T cells. Since 2017, six CAR T-cell therapies for the treatment of hematological malignancies have been approved by the Food and Drug Administration (FDA). Despite the rapid progress of CAR T-cell therapies, considerable statistical challenges still exist for this category of products across all phases of clinical development that need to be addressed. These include (but not limited to) dose finding strategy, implementation of the estimand framework, use of real-world data in contextualizing single-arm CAR T trials, analysis of safety data and long-term follow-up studies. This paper is the first step in summarizing and addressing these statistical hurdles based on the development of the six approved CAR T-cell products.

Implementing Multilevel Network Meta-Regression for Time-To-Event Outcomes: A Case Study in Relapsed Refractory Multiple Myeloma

OBJECTIVES

Multilevel network meta-regression (ML-NMR) leverages individual patient data (IPD) and aggregate data from a network of randomized controlled trials (RCTs) to assess the comparative efficacy of multiple treatments, while adjusting for between-study differences. We provide an overview of ML-NMR for time-to-event outcomes and apply it to an illustrative case study, including example R code.

METHODS

The case study evaluated the comparative efficacy of idecabtagene vicleucel (ide-cel), selinexor+dexamethasone (Sd), belantamab mafodotin (BM), and conventional care (CC) for patients with triple-class exposed relapsed/refractory multiple myeloma in terms of overall survival. Single-arm clinical trials and real-world data were naively combined to create an aggregate data artificial RCT (aRCT) (MAMMOTH-CC versus DREAMM-2-BM versus STORM-2-Sd) and an IPD aRCT (KarMMa-ide-cel versus KarMMa-RW-CC). With some assumptions, we incorporated continuous covariates with skewed distributions, reported as median and range. The ML-NMR models adjusted for number of prior lines, triple-class refractory status, and age and were compared using the leave-one-out information criterion. We summarized predicted hazard ratios and survival (95% credible intervals) in the IPD aRCT population.

RESULTS

The Weibull ML-NMR model had the lowest leave-one-out information criterion. Ide-cel was more efficacious than Sd, BM, and CC in terms of overall survival. Effect modifiers had minimal impact on the model, and only triple-class refractory was a prognostic factor.

CONCLUSIONS

We demonstrate an application of ML-NMR for time-to-event outcomes and introduce code that can be used to aid implementation. Given its benefits, we encourage practitioners to utilize ML-NMR when population adjustment is necessary for comparisons of multiple treatments.

Review of CAR T-Cell Therapy in Multiple Myeloma: A Canadian Perspective

Multiple myeloma (MM) is an incurable plasma cell malignancy. In the context of the current standard of care therapies in Canada, outcomes among patients with relapsed/refractory multiple myeloma (RRMM), particularly those with triple-class (or more) refractory disease remain poor. Immunotherapies have significantly changed the treatment landscape of MM. Since 2021, two BCMA-targeting CAR T-cell therapy products have been approved for RRMM-namely Idecabtagene vicleucel (Ide-cel) (ABECMA®) and Ciltacabtagene autoleucel (Cilta-cel) (CARVYKTI®), both of which are available in the US and Europe. Although they have shown unprecedented efficacy in RRMM, their clinical and logistical limitations must be acknowledged. MM CAR T-cell therapy is likely to be approved in Canada soon. Therefore, it is timely that we review the latest evidence for commercially available CAR T-cell therapy in multiple myeloma, with a focus on its relevance and impact in the Canadian setting. There will be challenges to access and strategies must be in place to ensure equitable care for all Canadians with MM. Alongside haematologists working in the immune effector cell therapy programs, providers in the community will also play a role in the ongoing monitoring and management of long-term side effects including opportunistic infections and late neurotoxicity.

Multiple myeloma: signaling pathways and targeted therapy

Multiple myeloma (MM) is the second most common hematological malignancy of plasma cells, characterized by osteolytic bone lesions, anemia, hypercalcemia, renal failure, and the accumulation of malignant plasma cells. The pathogenesis of MM involves the interaction between MM cells and the bone marrow microenvironment through soluble cytokines and cell adhesion molecules, which activate various signaling pathways such as PI3K/AKT/mTOR, RAS/MAPK, JAK/STAT, Wnt/β-catenin, and NF-κB pathways. Aberrant activation of these pathways contributes to the proliferation, survival, migration, and drug resistance of myeloma cells, making them attractive targets for therapeutic intervention. Currently, approved drugs targeting these signaling pathways in MM are limited, with many inhibitors and inducers still in preclinical or clinical research stages. Therapeutic options for MM include non-targeted drugs like alkylating agents, corticosteroids, immunomodulatory drugs, proteasome inhibitors, and histone deacetylase inhibitors. Additionally, targeted drugs such as monoclonal antibodies, chimeric antigen receptor T cells, bispecific T-cell engagers, and bispecific antibodies are being used in MM treatment. Despite significant advancements in MM treatment, the disease remains incurable, emphasizing the need for the development of novel or combined targeted therapies based on emerging theoretical knowledge, technologies, and platforms. In this review, we highlight the key role of signaling pathways in the malignant progression and treatment of MM, exploring advances in targeted therapy and potential treatments to offer further insights for improving MM management and outcomes.

T-cell exhaustion in multiple myeloma

INTRODUCTION

Chimeric Antigen Receptor (CAR) T-cells and Bispecific Antibodies (BsAb) are the leading platforms for redirecting the immune system against cells expressing the specific antigen, revolutionizing the treatment of hematological malignancies, including multiple myeloma (MM). In MM, drug-resistant relapses are the main therapy-limiting factor and the leading cause of why the disease is still considered incurable. T-cell-engaging therapies hold promise in improving the treatment of MM. However, the effectiveness of these treatments may be hindered by T-cell fitness. T-cell exhaustion is a condition of a gradual decline in effector function, reduced cytokine secretion, and increased expression of inhibitory receptors due to chronic antigen stimulation.

AREAS COVERED

This review examines findings about T-cell exhaustion in MM in the context of T-cell redirecting BsAbs and CAR-T treatment.

EXPERT OPINION

The fitness of T-cells has become an important factor in the development of T-cell redirecting therapies. The way T-cell exhaustion relates to these therapies could affect the further development of CAR and BsAbs technologies, as well as the strategies used for clinical use. Therefore, this review aims to explore the current understanding of T-cell exhaustion in MM and its relationship to these therapies.

Unscheduled health care interactions in patients with multiple myeloma receiving T-cell redirection therapies

ABSTRACT

Outcomes for patients with relapsed/refractory multiple myeloma (R/RMM) have dramatically improved after the development and now growing utilization of B-cell maturation antigen-targeted chimeric antigen receptor (CAR) T-cell therapy and bispecific antibody (BsAb) therapy. However, health care utilization as a quality-of-life metric in these growing populations has not been thoroughly evaluated. We performed a retrospective cohort study evaluating the frequency and cause of unscheduled health care interactions (UHIs) among patients with R/RMM responding to B-cell maturation antigen-targeted BsAb and CAR T-cell therapies (N = 46). This included the analysis of remote UHIs including calls to physicians' offices and messages sent through an online patient portal. Our results showed that nearly all patients with R/RMM (89%) receiving these therapies required a UHI during the first 125 days of treatment, with a mean of 3.7 UHIs per patient. Patients with R/RMM responding to BsAbs were significantly more likely to remotely contact their physicians' offices (1.8-fold increase; P = .038) or visit an urgent care center (more than threefold increase; P = .012) than patients with R/RMM responding to CAR T-cell therapies. This was largely due to increased reports of mild upper respiratory tract infections in BsAb patients. Our results underscore the need to develop preemptive management strategies for commonly reported symptoms that patients with R/RMM experience while receiving CAR T-cell or BsAb therapies. This preemptive management may significantly reduce unnecessary health care utilization in this vulnerable patient population.

Assessment of algorithms for identifying patients with triple-class refractory multiple myeloma using real-world data

Objective: Patients with triple-class refractory (TCR) multiple myeloma (MM) have limited treatment options and poor prognoses. This high unmet need has prompted the development of new therapies allowing for improved outcomes for these patients. Recently, new targeted therapies for the treatment of patients with relapsed or refractory MM have been approved based on single-arm clinical trial results. Real-world (RW) data enable a better understanding of the effectiveness of new therapies in clinical practice and provide external controls for single-arm studies. However, using RW data to identify patients with TCR MM is challenging and subject to limitations. Methods: In this retrospective cohort study of an analysis of the COTA electronic health record (EHR) database, we used four algorithms to define refractory status and created four groups of patients with TCR MM initiating post-TCR therapy. Each algorithm relied on slightly different criteria to identify TCR patients, but all were based on the International Myeloma Working Group (IMWG)-derived and/or healthcare provider (HCP)-reported progressions within the database. Results: A total of 3815 patients with newly diagnosed MM met the eligibility criteria for this study. The choice of the algorithm did not impact the characteristics of identified patients with TCR MM (Algorithm 1 [n = 404], Algorithm 2 [n = 123], Algorithm 3 [n = 404], and Algorithm 4 [n = 375]), including their demographic and disease characteristics, MM treatment history, or treatment patterns received after becoming TCR. However, identifying TCR MM using a combination of IMWG-derived and HCP-reported progressions allowed up to a 70% increase in the size of the identified group of patients compared with using only IMWG-derived progressions. Conclusion: In RW settings, progressions from both IMWG-derived data and physician reports may be used to identify patients with TCR MM.

Accelerating drug development at Bristol Myers Squibb through innovation

This paper focuses on the use of novel technologies and innovative trial designs to accelerate evidence generation and increase pharmaceutical Research and Development (R&D) productivity, at Bristol Myers Squibb. We summarize learnings with case examples, on how we prepared and continuously evolved to address the increasing cost, complexities, and external pressures in drug development, to bring innovative medicines to patients much faster. These learnings were based on review of internal efforts toward accelerating R&D focusing on four key areas: adopting innovative trial designs, optimizing trial designs, leveraging external control data, and implementing novel methods using artificial intelligence and machine learning.

BCMA-targeting chimeric antigen receptor T cell therapy for relapsed and/or refractory multiple myeloma

Recently, many new therapies have improved the outcomes of patients with relapsed and/or refractory multiple myeloma (RRMM). Nevertheless, recurrence is still unavoidable, and better treatment choices for RRMM are urgently needed. The clinical success of Chimera antigen receptor (CAR) T cell therapy in many hematological diseases, including leukemia and lymphoma, has drawn considerable attention to RRMM. As CAR T cell therapy continues to mature and challenge traditional therapies, it is gradually changing the treatment paradigm for MM patients. The B cell maturation antigen (BCMA), expressed in malignant plasma cells but not normal ones, is an ideal target for MM treatment, due to its high expression. The US Food and Drug Administration (FDA) and European Medicines Agency (EMA) has approved two BCMA-targeting CAR T cell products, idecabtagene vicleucel (Ide-cel) and ciltacabtagene autoleucel (Cilta-cel), for use in RRMM. In this review, we focus on data from RRMM patients involved in clinical trials of Ide-cel and Cilta-cel and discuss the present situation and future direction of CAR T cell therapy for this condition.

Characterization and Outcomes of Spanish Patients With Relapsed/Refractory Multiple Myeloma Included in the LocoMMotion Study

BACKGROUND

Despite advances in treatments for multiple myeloma (MM), most patients relapse and become refractory to standard drug classes including immunomodulatory drugs (IMiDs), proteasome inhibitors (PIs), and anti-CD38 antibodies. The LocoMMotion study showed poor clinical outcomes in triple-class exposed patients with relapsed/refractory MM (RRMM) treated with real-world clinical practice (RWCP) therapy. Here, we report efficacy outcomes for Spanish patients receiving RWCP treatments in the LocoMMotion study compared with the full cohort.

PATIENTS AND METHODS

The prospective, noninterventional, multinational LocoMMotion study (NCT04035226) enrolled 248 patients who had received ≥ 3 prior lines of therapy (LOT), including a PI, an IMiD, and an anti-CD38 antibody, with disease progression during or after their last LOT. The primary endpoint was overall response rate (ORR). Secondary endpoints included progression-free survival (PFS) and overall survival (OS).

RESULTS

Spanish patients (n = 24) had received a median of 4 prior LOT (range, 2-7). At 29.2 months median follow-up, patients had received 14 different treatment regimens used in RWCP during the study. Efficacy outcomes were consistent between the Spanish cohort and overall study population. The ORR was 29.2% (95% CI, 12.6%-51.1%). Median PFS and OS were 4.6 months (95% CI, 1.2-6.3) and 11.6 months (95% CI, 6.4-24.5), respectively.

CONCLUSION

Spanish patients from the LocoMMotion study demonstrated poor outcomes in response to RWCP treatments consistent with those of the overall study population, highlighting the need for access to new and effective therapies for patients with RRMM in Spain and globally.

Chimeric Antigen Receptor T Cells in the Treatment of Multiple Myeloma

Chimeric antigen receptor T cells (CARTs) represent another powerful way to leverage the immune system to fight malignancy. Indeed, in multiple myeloma, the high response rate and duration of response to B cell maturation antigen-targeted therapies in later lines of disease has led to 2 Food and Drug Administration (FDA) drug approvals and opened the door to the development of this drug class. This review aims to provide an update on the 2 FDA-approved products, summarize the data for the most promising next-generation multiple myeloma CARTs, and outline current challenges in the field and potential solutions.

Ex Vivo Efficacy of SAR442257 Anti-CD38 Trispecific T-cell Engager in Multiple Myeloma Relapsed After Daratumumab and BCMA-targeted Therapies

T cell-engaging antibodies (TCEs) are showing promising efficacy in relapsed/refractory multiple myeloma, even in patients that relapsed after B-cell maturation antigen (BCMA)-targeted therapy. Patients with multiple myeloma may have compromised T-cell health unaccounted for by preclinical models. Here, we use Myeloma Drug Sensitivity Testing (My-DST) for ex vivo measurement of anti-multiple myeloma cytotoxicity for the trispecific CD38/CD28xCD3 TCE SAR442257 through activation of the patients' own endogenous T cells to inform clinical development of the compound in multiple myeloma. My-DST incubates primary mononuclear cells in humanized media for 48 hours followed by flow cytometry for multiple myeloma cell viability with or without drug treatment. SAR442257 was tested on 34 samples from patients with multiple myeloma across disease settings. Potential biomarkers, T-cell dependence, and degranulation were assessed. SAR442257 was effective at low dose in My-DST cultures. High ex vivo response rates were observed in primary aspirates taken from patients with multiple myeloma at diagnosis, with modestly reduced response in multiple myeloma recently treated with anti-CD38 mAbs. SAR442257 was highly effective in patients relapsing after BCMA therapy. The CD38/CD28xCD3 trispecific format was substantially more effective than a conventional bispecific CD38/CD3 antibody format and CD38 mAbs. Anti-multiple myeloma cell cytotoxicity was dependent on the presence of endogenous T cells. Surface CD38 expression was the strongest biomarker of TCE response. My-DST is capable of measuring T cell-dependent killing using the multiple myeloma patient's own bone marrow-derived T cells. SAR442257 shows promise for multiple myeloma and may be best suited for patients declared resistant to both CD38 mAbs and BCMA-targeted therapy.

SIGNIFICANCE

This study introduces the use of My-DST to measure and characterize sensitivity to anti-CD38 T-cell engager SAR442257 in primary samples using matched endogenous T cells. Preclinical testing in samples from patients with diverse treatment history supports further testing in post-chimeric antigen receptor T-cell multiple myeloma.

Elranatamab efficacy in MagnetisMM-3 compared with real-world control arms in triple-class refractory multiple myeloma

Elranatamab efficacy in the single-arm, registrational MagnetisMM-3 trial (NCT04649359) was compared with that of physician's choice of treatment (PCT) for triple-class refractory multiple myeloma. MagnestisMM-3 eligibility criteria were applied to two USA-based oncology electronic health record databases, COTA and Flatiron Health (FH), to identify cohorts for this study (NCT05932290). Applied statistical techniques accounted for cohort imbalances. MagnetisMM-3 (BCMA-naive; n = 123) outcomes were compared with those from COTA (n = 239) and FH (n = 152). Elranatamab was associated with a significantly higher objective response rate (risk ratios, 1.88-2.25), significantly longer progression-free survival (hazard ratios [HRs], 0.37-0.57), and, across most analyses, significantly longer overall survival (HRs, 0.46-0.66) versus PCT. BCMA-naive patients who were treated with elranatamab exhibited significantly better outcomes than patients treated in real-world clinical practice.

Challenges and strategies associated with CAR-T cell therapy in blood malignancies

Cellular immunotherapy, particularly CAR-T cells, has shown potential in the improvement of outcomes in patients with refractory and recurrent malignancies of the blood. However, achieving sustainable long-term complete remission for blood cancer remains a challenge, with resistance and relapse being expected outcomes for many patients. Although many studies have attempted to clarify the mechanisms of CAR-T cell therapy failure, the mechanism remains unclear. In this article, we discuss and describe the current state of knowledge regarding these factors, which include elements that influence the CAR-T cell, cancer cells as a whole, and the microenvironment surrounding the tumor. In addition, we propose prospective approaches to overcome these obstacles in an effort to decrease recurrence rates and extend patient survival subsequent to CAR-T cell therapy.

CAR-T cell manufacturing: Major process parameters and next-generation strategies

Chimeric antigen receptor (CAR)-T cell therapies have demonstrated strong curative potential and become a critical component in the array of B-cell malignancy treatments. Successful deployment of CAR-T cell therapies to treat hematologic and solid cancers, as well as other indications such as autoimmune diseases, is dependent on effective CAR-T cell manufacturing that impacts not only product safety and efficacy but also overall accessibility to patients in need. In this review, we discuss the major process parameters of autologous CAR-T cell manufacturing, as well as regulatory considerations and ongoing developments that will enable the next generation of CAR-T cell therapies.

Racial and ethnic differences in clinical outcomes among patients with multiple myeloma treated with CAR T-cell therapy

ABSTRACT

Idecabtagene vicleucel (ide-cel) was the first chimeric antigen receptor T-cell therapy to gain US Food and Drug Administration approval for patients with relapsed/refractory multiple myeloma (RRMM). The clinical outcomes of standard of care (SOC) ide-cel in racially and ethnically diverse populations have been understudied. This study pooled data from 207 patients with RRMM (28% patients of racial and ethnic minority groups) treated with SOC ide-cel across 11 institutions to examine racial and ethnic differences in the incidence of toxicities and adverse events, response to ide-cel, and survival. This study included 22 (11%) Hispanic, 36 (17%) non-Hispanic Black, and 149 (72%) non-Hispanic White patients with RRMM. Compared with Hispanic and non-Hispanic White patients, non-Hispanic Black patients had higher median levels of C-reactive protein (1.0, 0.8, and 3.5 mg/dL, respectively; P = .02) and baseline ferritin (362.0 vs 307.0 vs 680.5, respectively; P = .08) and were more likely to develop cytokine release syndrome (77%, 85%, and 97%, respectively; P = .04). Although best overall response rate was lower among Hispanic patients (59%) than among non-Hispanic Black (86%) and White patients (86%; P = .01), there were no racial and ethnic differences in progression-free or overall survival. We provide, to our knowledge, the first and largest investigation of clinical outcomes of SOC ide-cel by race and ethnicity. Despite differences in safety and response to ide-cel, our findings encourage the use of ide-cel in all patients with RRMM. These findings should be confirmed in larger samples of diverse patients with RRMM, with longer follow-up time.

Essentials of CAR-T Therapy and Associated Microbial Challenges in Long Run Immunotherapy

Chimeric antigen receptor (CAR)-T cell therapy has shown potential in improving outcomes for individuals with hematological malignancies. However, achieving long-term full remission for blood cancer remains challenging due to severe life-threatening toxicities such as limited anti-tumor efficacy, antigen escape, trafficking restrictions, and limited tumor invasion. Furthermore, the interactions between CAR-T cells and their host tumor microenvironments have a significant impact on CAR-T function. To overcome these considerable hurdles, fresh methodologies and approaches are needed to produce more powerful CAR-T cells with greater anti-tumor activity and less toxicity. Despite advances in CAR-T research, microbial resistance remains a significant obstacle. In this review, we discuss and describe the basics of CAR-T structures, generations, challenges, and potential risks of infections in CAR-T cell therapy.

Cost-Effectiveness of Anti-BCMA Chimeric Antigen Receptor T Cell Therapy in Relapsed/Refractory Multiple Myeloma

Despite its promising outcomes, anti-BCMA chimeric antigen receptor T cell therapy (CAR-T) is the most expensive myeloma treatment developed to date, and its cost-effectiveness is an important issue. This study aimed to assess the cost-effectiveness of anti-BCMA CAR-T compared to standard antimyeloma therapy in patients with relapsed/refractory multiple myeloma. The model included myeloma patients in Japan and the United States who have received ≥3 prior lines of antimyeloma therapy, including immunomodulatory drugs, proteasome inhibitors, and anti-CD38 monoclonal antibodies. A Markov model was constructed to compare the CAR-T strategy, in which patients receive either idecabtagene vicleucel (ide-cel) or ciltacabtagene autoleucel (cilta-cel) followed by 3 lines of multiagent chemotherapy after relapse, and the no CAR-T strategy, in which patients receive only chemotherapy. Data from the LocoMMotion, KarMMa, and CARTITUDE-1 trials were extracted. Several assumptions were made regarding long-term progression-free survival (PFS) with CAR-T. Extensive scenario analyses were made regarding regimens for no CAR-T strategies. The outcome was an incremental cost-effectiveness ratio (ICER) with willingness-to-pay thresholds of ¥7,500,000 in Japan and $150,000 in the United States. When a 5-year PFS of 40% with cilta-cel was assumed, the ICER of the CAR-T strategy versus the no CAR-T strategy was ¥7,603,823 per QALY in Japan and $112,191 per QALY in the United States over a 10-year time horizon. When a 5-year PFS of 15% with ide-cel was assumed, the ICER was ¥20,388,711 per QALY in Japan and $261,678 per QALY in the United States over a 10-year time horizon. The results were highly dependent on the PFS assumption with CAR-T and were robust to changes in most other parameters and scenarios. Although anti-BCMA CAR-T can be cost-effective even under current pricing, a high long-term PFS is necessary.

Current use of CAR T cells to treat multiple myeloma

Anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T-cell therapies currently approved by the US Food and Drug Administration (FDA) have dramatically improved clinical outcomes for patients with heavily pretreated multiple myeloma who have disease refractory to conventional proteasome inhibitors, immunomodulatory drugs, and anti-CD38 monoclonal antibodies. However, despite this progress, multiple myeloma remains an incurable hematologic malignancy. In this review, we discuss practical considerations for currently FDA approved CAR T-cell therapies, including newer data evaluating those agents in earlier lines of therapy. We also discuss considerations for patients following relapse from anti-BCMA CAR T-cell therapy, which currently represents an unmet clinical need.

Allogeneic Stem Cell Transplantation in Multiple Myeloma: Risk Factors and Outcomes in the Era of New Therapeutic Options-A Single-Center Experience

BACKGROUND

Despite major treatment advances, multiple myeloma remains incurable. The outcome of patients who are refractory to immunomodulatory agents, proteasome inhibitors, and anti-CD38 monoclonal antibodies is poor, and improved treatment strategies for this difficult-to-treat patient population are an unmet medical need.

METHODS

This retrospective, unicentric analysis included 38 patients with relapsed/refractory multiple myeloma or plasma cell leukemia who underwent allogeneic stem cell transplantation (allo-HSCT) between 2013 and 2022. Survival outcomes, relapse incidence, and non-relapse mortality were calculated according to remission status, date of allo-HSCT, cytogenetic risk status, timing, and number of previous autologous HSCTs.

RESULTS

The median PFS was 13.6 months (95% CI, 7.7-30.4) and the median OS was 51.4 months (95% CI, 23.5-NA) in the overall cohort. The cumulative incidence of relapse at 3 years was 57%, and non-relapse mortality was 16%. The median PFS and OS were significantly longer in patients with very good partial remission (VGPR) or better compared to patients with less than VGPR at the time of allo-HSCT (mPFS 29.7 months (95% CI, 13.7-NA) vs. 6.5 months (95% CI, 2.6-17.0); p = 0.009 and mOS not reached vs. 18.6 months (95% CI, 7.0-NA); p = 0.006).

CONCLUSION

For selected patients, allo-HSCT may result in favorable overall survival, in part by providing an appropriate hemato-immunological basis for subsequent therapies.

Beyond BCMA, why GPRC5D could be the right way: treatment strategies with immunotherapy at relapse after anti-BCMA agents

Multiple Myeloma remains incurable, and there is a need for therapies with novel mechanisms of action. Recently, B cell maturation antigen targeted therapy has demonstrated deep and durable responses in a largely treated population. However, the relapse rate of myeloma patients after anti-BCMA treatment strategies is increasing worldwide, and one of the most challenging issues for them is to choose the best therapy sequencing. After anti-BCMA treatment, retreatment with anti-BCMA drugs remains an option, but new targets are emerging strongly. One of them is G protein-coupled receptor, class C group 5 member D (GPRC5D), that due to the very promising data from the use of chimeric antigen receptor T-cells (CAR-T) and bispecific antibodies (BsAb) seems to be the ideal candidate in the relay of myeloma treatment at relapse. In this literature review, we discuss data from treatment with the new drugs at relapse after anti-BCMA therapies, observing an undeniable benefit from the use of drugs directed against GPRC5D.

Evolution of Pharmacological Treatments and Associated Costs for Multiple Myeloma in the Public Healthcare System of Catalonia: A Retrospective Observational Study

(1) Background: Our understanding of and treatment for multiple myeloma (MM) has advanced significantly, and new pharmacological treatments have promising benefits but high price tags. This study analyzes prescription patterns and pharmaceutical expenditure for MM treatments in Catalonia's public healthcare system over eight years. (2) Methods: A retrospective observational study examined MM treatment data from 2015 to 2022 in Catalonia, using healthcare registries from the Catalan Health Service to collect information on patients, medicines used, and treatment costs. (3) Results: A total of 4556 MM patients received treatment, with a rising trend in the number of treated patients each year from 902 in 2015 to 1899 in 2022. The mean age was 68.9 years, and patients were almost evenly distributed by gender (51.5% male). Most patients were treated with bortezomib (3338 patients), lenalidomide (2952), and/or daratumumab (1093). Most drugs showed increased utilization annually, most significantly for lenalidomide and daratumumab. The total pharmacological treatment cost throughout the entire study period was EUR 321,811,249, with lenalidomide leading with the highest total cost (EUR 157,236,784), and daratumumab exhibiting the highest increase in annual expenditure. (5) Conclusions: The study reveals a progressive increase in the number of MM patients treated and rising pharmaceutical costs. Lenalidomide and daratumumab incurred the highest costs. The findings highlight MM treatment's economic impact and the need to monitor prescription patterns and expenditures to optimize healthcare resources and decision making. Understanding these trends can guide resource allocation effectively.

Multiple Myeloma in 2023 Ways: From Trials to Real Life

Multiple myeloma is a chronic hematologic malignancy that obstinately tends to relapse. Basic research has made giant strides in better characterizing the molecular mechanisms of the disease. The results have led to the manufacturing of new, revolutionary drugs which have been widely tested in clinical trials. These drugs have been approved and are now part of the therapeutic armamentarium. As a consequence, it is essential to combine what we know from clinical trials with real-world data in order to improve therapeutic strategies. Starting with this premise, our review aims to describe the currently employed regimens in multiple myeloma and compare clinical trials with real-life experiences. We also intend to put a spotlight on promising therapies such as T-cell engagers and chimeric antigen receptor T-cells (CAR-T) which are proving to be effective in changing the course of advanced-stage disease.

Chimeric Antigen Receptor T Cells: Immunotherapy for the Treatment of Leukemia, Lymphoma, and Myeloma

In immunotherapy with T cells genetically modified to express chimeric antigen receptors (CAR), autologous lymphocytes are extracted from the patient, genetically modified to obtain CAR-T cells, and reintroduced into the patient to attack cancer cells. The success of this therapy has been achieved in the area of CD19-positive leukemias and lymphomas, being approved for the treatment of non-Hodgkin's lymphomas, acute lymphoblastic leukemia, and multiple myeloma. CARs are proteins that combine antibody specificity with T-cell cytotoxicity. The most common toxicities associated with therapy were not predicted by preclinical testing and include cytokine release syndrome, neurotoxicity, and cytopenias. These toxicities are usually reversible. One of the main challenges facing the field is the high economic cost that therapy entails, so the search for ways to reduce this cost must be a priority. In addition, other challenges to overcome include the situation that not all patients are supplied with the product and the existence of long waiting times for the start of therapy. The aim of this review is to present the development of the structure of CAR-T cells, the therapies approved to date, the toxicity associated with them, and the advantages and limitations that they present as immunotherapy.

Idecabtagene Vicleucel Is Well Tolerated and Effective in Relapsed/Refractory Myeloma Patients with Prior Allogeneic Stem Cell Transplantation

BCMA-specific chimeric-antigen receptor (CAR-) T cell therapy has led to high response rates and durable remissions in patients with relapsed refractory multiple myeloma. However, little data are available for patients after prior allogeneic stem cell transplantation (allo-SCT) in whom T cells are chimeric. In this study, we aimed to assess the safety and efficacy of patient-derived donor CAR-T therapy in myeloma patients with prior allo-SCT, particularly with regard to graft-versus-host disease (GVHD). We report a comprehensive clinical analysis of 3 patients who had previously undergone allo-SCT for high-risk myeloma and were treated with idecabtagene vicleucel (ide-cel) at our institution. Ide-cel was well tolerated, with no clinically relevant immune effector cell-associated neurotoxicity syndrome or cytokine release syndrome observed in any patient. Importantly, no new GVHD was observed, even though all patients had a history of GVHD. All patients responded to treatment with at least a very good partial remission. Two patients relapsed within 6 months, and 1 patient was still in stringent complete remission at the time of this report. Our findings demonstrate that treatment with ide-cel is feasible, very well tolerated, and effective in patients with relapsed/refractory multiple myeloma after prior allo-SCT.

Patient-Reported Outcomes among Multiple Myeloma Patients Treated with Standard of Care Idecabtagene Vicleucel

Idecabtagene vicleucel (ide-cel) was the first FDA-approved chimeric antigen receptor T-cell therapy for relapsed/refractory multiple myeloma (RRMM) patients. This was the first study to evaluate patient-reported outcomes (PROs) among RRMM patients receiving ide-cel in standard of care (SOC). We prospectively assessed health-related quality of life (HRQOL) and symptoms from pre-infusion (baseline) through day (D)90 post-infusion. Baseline PRO associations with patient characteristics, mean PRO changes, and time to stable change were evaluated with t-tests, linear mixed-effects models, and Kaplan-Meier analyses, respectively. Within-person change scores and minimally important difference thresholds determined clinical and meaningful significance. Participants (n = 42) were a median of 66 years old (range: 43-81). At baseline, extramedullary disease was associated with worse physical well-being (p = 0.008), global pain (p < 0.001), performance status (p = 0.002), and overall symptom burden (p < 0.001). Fatigue (p < 0.001) and functional well-being (p = 0.003) worsened by D7 before returning to baseline levels. Overall HRQOL (p = 0.008) and physical well-being (p < 0.001) improved by D60. Most participants reported PRO improvement (10-57%) or maintenance (23-69%) by D90. The median time it took to stabile deterioration in functional well-being was 14 days. The median time it took to stabile improvement in physical and emotional well-being was 60 days. Overall, RRMM patients reported improvements or maintenance of HRQOL and symptom burden after SOC ide-cel.

Idecabtagene vicleucel for relapsed and refractory multiple myeloma: post hoc 18-month follow-up of a phase 1 trial

Idecabtagene vicleucel (ide-cel) is a B-cell-maturation antigen (BCMA)-directed chimeric antigen receptor T cell therapy. We performed a post hoc analysis of a single-arm phase 1 multicenter study in relapsed/refractory multiple myeloma (CRB-401) (n = 62; median follow-up, 18.1 months). The primary endpoint was safety outcomes, and secondary endpoints included overall response rate (ORR), complete response (CR) and very good partial response (VGPR). The study met its primary endpoint with low rates of grade 3/grade 4 cytokine release syndrome (6.5%) and neurotoxicity (1.6%). ORR was 75.8%; 64.5% achieved VGPR or better and 38.7% achieved CR or stringent CR. Among exploratory endpoints, median duration of response, progression-free survival (PFS) and overall survival were 10.3, 8.8 and 34.2 months, respectively, and ide-cel expansion in blood and bone marrow correlated with clinical efficacy and postinfusion reduction of soluble BCMA. Patients with PFS ≥ 18 months had more naive and less exhausted T cells in apheresis material and improved functional T cell phenotype in the drug product compared with those with less durable responses. These results confirm ide-cel safety, tolerability and efficacy and describe T cell qualities that correlate with durable response. Clinicaltrials.gov identifier : NCT02658929 .

Considerations for pooling real-world data as a comparator cohort to a single arm trial: a simulation study on assessment of heterogeneity

BACKGROUND

Novel precision medicine therapeutics target increasingly granular, genomically-defined populations. Rare sub-groups make it challenging to study within a clinical trial or single real-world data (RWD) source; therefore, pooling from disparate sources of RWD may be required for feasibility. Heterogeneity assessment for pooled data is particularly complex when contrasting a pooled real-world comparator cohort (rwCC) with a single-arm clinical trial (SAT), because the individual comparisons are not independent as all compare a rwCC to the same SAT. Our objective was to develop a methodological framework for pooling RWD focused on the rwCC use case, and simulate novel approaches of heterogeneity assessment, especially for small datasets.

METHODS

We present a framework with the following steps: pre-specification, assessment of dataset eligibility, and outcome analyses (including assessment of outcome heterogeneity). We then simulated heterogeneity assessments for a binary response outcome in a SAT compared to two rwCCs, using standard methods for meta-analysis, and an Adjusted Cochran's Q test, and directly comparing the individual participant data (IPD) from the rwCCs.

RESULTS

We found identical power to detect a true difference for the adjusted Cochran's Q test and the IPD method, with both approaches superior to a standard Cochran's Q test. When assessing the impact of heterogeneity in the null scenario of no difference between the SAT and rwCCs, a lack of statistical power led to Type 1 error inflation. Similarly, in the alternative scenario of a true difference between SAT and rwCCs, we found substantial Type 2 error, with underpowered heterogeneity testing leading to underestimation of the treatment effect.

CONCLUSIONS

We developed a methodological framework for pooling RWD sources in the context of designing a rwCC for a SAT. When testing for heterogeneity during this process, the adjusted Cochran's Q test matches the statistical power of IPD heterogeneity testing. Limitations of quantitative heterogeneity testing in protecting against Type 1 or Type 2 error indicate these tests are best used descriptively, and after careful selection of datasets based on clinical/data considerations. We hope these findings will facilitate the rigorous pooling of RWD to unlock insights to benefit oncology patients.

Phase 1 study of CART-ddBCMA for the treatment of subjects with relapsed and refractory multiple myeloma

Relapsed and refractory multiple myeloma (RRMM) is a plasma cell neoplasm defined by progressively refractory disease necessitating chronic and increasingly intensive therapy. Despite recent advances, limited treatment options exist for RRMM. This single-arm, open label phase 1 study aimed to evaluate the safety of novel B-cell maturation antigen (BCMA)-targeting chimeric antigen receptor (CAR) T construct that leverages a completely synthetic antigen-binding domain (CART-ddBCMA), which was specifically engineered to reduce immunogenicity and improve CAR cell surface stability. Thirteen patients ≥18 years with RRMM who received at least 3 prior regimens of systemic therapy were enrolled in the study. Patients received a single dose of 100 × 106 CART-ddBCMA (DL1) or 300 × 106 CART-ddBCMA (DL2) following standard lymphodepleting chemotherapy. The primary endpoints of the study were to evaluate the incidence of treatment emergent adverse events, including dose-limiting toxicities, and establish a recommended phase 2 dose. Results showed that CART-ddBCMA was well tolerated and demonstrated a favorable toxicity profile. Only 1 case of grade ≥3 cytokine release syndrome and 1 case of immune effector cell-associated neurotoxicity were reported; both were at DL2 and were manageable with standard treatment. No atypical neurological toxicities and Parkinson disease-like movement disorders were observed. The maximum tolerated dose was not reached. All infused patients responded to CART-ddBCMA, and 9/12 (75%) patients achieved complete response/stringent complete response. Responses deepened over time, and at the time of last data-cut (median follow-up 56 weeks), 8/9 (89%) evaluable patients achieved minimal residual disease negativity. In conclusion, the findings demonstrate the safety of CART-ddBCMA cells and document durable responses to CART-ddBCMA in patients with RRMM. This trial was registered at www.clinicaltrials.gov as #NCT04155749.

Phase 2 results of idecabtagene vicleucel (ide-cel, bb2121) in Japanese patients with relapsed and refractory multiple myeloma

BACKGROUND

In the phase 2 KarMMa trial, patients with relapsed/refractory multiple myeloma (RRMM) achieved deep and durable responses with idecabtagene vicleucel (ide-cel), a B-cell maturation antigen-directed chimeric antigen receptor (CAR) T cell therapy. Here we report a sub-analysis of the Japanese cohort of KarMMa.

METHODS

Adult patients with RRMM who had received  ≥ 3 prior treatment regimens, including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 antibody, and had disease refractory to last treatment received ide-cel at a target dose of 450 × 10⁶ CAR positive T cells.

RESULTS

Nine patients were treated with ide-cel. The overall response rate was 89% (median follow-up, 12.9 months). The best overall response was stringent complete response in 5 patients (56%), very good partial response in 3 (33%), and stable disease in 1. Median duration of response was not reached. All patients experienced grade ≤ 2 cytokine release syndrome and one patient experienced grade 2 neurotoxicity, but all resolved. Two patients died, one each from plasma cell myeloma and general health deterioration.

CONCLUSION

Ide-cel yielded deep, durable responses with a tolerable and predictable safety profile in Japanese patients with RRMM. These results are similar to those of the non-Japanese population in KarMMa.

Recent Advances in the Use of Chimeric Antigen Receptor-Expressing T-Cell Therapies for Treatment of Multiple Myeloma

INTRODUCTION

Chimeric antigen receptor T cell (CAR-T) therapies have revolutionized the treatment paradigm for heavily pretreated B-cell malignancies such as large B-cell lymphoma. There is a major unmet need for effective treatments for heavily pretreated relapsed/refractory multiple myeloma (RRMM), for which many CAR-T therapies are under active clinical investigation. Goal of the review: This review provides an overview of recently updated clinical trial data and indirect treatment comparison analyses regarding two clinically advanced CAR-T therapies, idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel).

DISCUSSION

Recently presented data after prolonged follow-up periods for ide-cel (KarMMa) and cilta-cel (CARTITUDE-1) have demonstrated that both therapies have the potential to elicit responses in individuals with heavily pretreated RRMM. Indirect treatment comparisons between cilta-cel and ide-cel suggest cilta-cel is associated with deeper and more durable responses than ide-cel in triple class-exposed RRMM; however, these types of comparisons have limitations and direct head-to-head trials are needed to confirm these findings. Additional indirect treatment comparisons conducted separately for ide-cel and cilta-cel have demonstrated that these CAR-T therapies hold promise for substantial clinical benefit relative to currently available treatments for RRMM. Further considerations, including safety profiles and real-world treatment considerations, are also discussed.

CONCLUSION

Data collected to date support CAR-T therapies holding substantial promise for patients with heavily pretreated RRMM relative to other currently available therapies. Additional real-world data will help provide further insights into the comparative efficacy and safety profiles of these treatments in RRMM as these treatments become more widely available.

Cost-effectiveness of idecabtagene vicleucel compared with conventional care in triple-class exposed relapsed/refractory multiple myeloma patients in Canada and France

BACKGROUND

The chimeric antigen receptor (CAR) T-cell therapy idecabtagene vicleucel (ide-cel) is approved for the treatment of adult patients with relapsed/refractory multiple myeloma (RRMM) who have already received an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 antibody and have progressed on their last therapy. The objective of this study was to assess the cost-effectiveness of ide-cel versus conventional care in Canada and France.

METHODS

A partitioned survival model was used to estimate the cost-effectiveness of ide-cel (target dose 450 × 10⁶ CAR T cells) in its approved indication in terms of life-years (LYs), quality-adjusted LYs (QALYs), and costs. Patient-level data from the KarMMa Phase II clinical trial (clinicaltrials.gov NCT03361748) and KarMMa-RW study were used to inform the model; overall and progression-free survival were extrapolated using standard parametric functions after the observed periods. The model adopted Canadian and French societal perspectives over a lifetime horizon. Costs, utilities, discounting (Canada: 1.5%, France: 2.5%), and general population mortality were country-specific.

RESULTS

The base case demonstrated that ide-cel was associated with more additional LYs (+2.64 and +2.51) and QALYs (+2.31 and +2.54) than conventional care at incremental costs of CAN$588,490 and €392,251 in Canada and France, respectively. The resulting incremental cost-effectiveness ratio (ICER) for ide-cel was $255,245 per QALY in Canada, and €154,593 per QALY in France.

CONCLUSION

Ide-cel was associated with significant survival improvements in terms of both LYs and QALYs in patients with progressive triple-class-exposed RRMM. The ICER for ide-cel was similar to that of other approved and reimbursed RRMM therapies.

Fitness and frailty in myeloma

As the aging population grows, so too does the number of well-tolerated antimyeloma therapies. Physicians will see an increasing volume of patients for subsequent lines of therapy, which could now extend this relationship for over a decade. For younger patients, treatment choices are infrequently impacted by concerns of fitness, but instead about effecting the deepest, most durable response. Older adults, in contrast, are more likely to experience under- than overtreatment, and therefore more objective (and ideally straightforward) ways to evaluate their fitness and ability to tolerate therapy will increasingly assist in decision-making. Post hoc analyses categorizing the fitness of trial patients in the modern treatment era globally demonstrate that even in highly selected populations, those that are recategorized as less fit or frail are consistently at higher risk of inferior outcomes and increased toxicities. Real-world data are comparatively lacking but do demonstrate that most patients with myeloma are not representative of those enrolled on clinical trials, generally more heavily burdened by comorbidities and more likely to be categorized as "less than fit." Simultaneously, the number of therapeutic options open to patients in the relapsed setting continues to grow, now including T-cell engagers and cellular therapies, with their unique toxicity profiles. The aim of this review is to summarize the available data, highlight some of the approaches possible to easily assess fitness and how results might inform treatment selection, and illustrate ways that patients' condition can be optimized rather than lead to exclusion from the more complex therapies newly available.

Current updates on generations, approvals, and clinical trials of CAR T-cell therapy

Chimeric antigen receptor (CAR) T-cell therapy is a novel, customized immunotherapy that is considered a 'living' and self-replicating drug to treat cancer, sometimes resulting in a complete cure. CAR T-cells are manufactured through genetic engineering of T-cells by equipping them with CARs to detect and target antigen-expressing cancer cells. CAR is designed to have an ectodomain extracellularly, a transmembrane domain spanning the cell membrane, and an endodomain intracellularly. Since its first discovery, the CAR structure has evolved greatly, from the first generation to the fifth generation, to offer new therapeutic alternatives for cancer patients. This treatment has achieved long-term and curative therapeutic efficacy in multiple blood malignancies that nowadays profoundly change the treatment landscape of lymphoma, leukemia, and multiple myeloma. But CART-cell therapy is associated with several hurdles, such as limited therapeutic efficacy, little effect on solid tumors, adverse effects, expensive cost, and feasibility issues, hindering its broader implications.

Ciltacabtagene autoleucel: The second anti-BCMA CAR T-cell therapeutic armamentarium of relapsed or refractory multiple myeloma

Ciltacabtagene autoleucel (also known as cilta-cel) is a chimeric antigen receptor (CAR) T-cell therapy that targets B-cell maturation antigen (BCMA) on the surface of cancer cells in B cell malignancies, such as multiple myeloma (MM). It is a second-generation CAR that is outfitted with an ectodomain comprising two BCMA-binding single chain variable fragment (ScFv) domains, a transmembrane domain, and an endodomain possessing CD3ζ and 4-1BB. Cilta-cel is an autologous, gene-edited CAR T-cell that is prepared by collecting and modifying the recipient’s T-cells to create a patient personalized treatment in the laboratory to be infused back. This CAR T-cell product exceptionally entails CARs with two BCMA-targeting single-domain antibodies that detect two epitopes of BCMA expressed on the malignant cells of MM. Cilta-cel is the current addition to the treatment armamentarium of relapsed or refractory (r/r) MM after its approval by the FDA on February 28, 2022, based on the results of the Phase 1b/2 CARTITUDE-1 study. It was the second approved anti-BCMA CAR T-cell product after idecabtagene vicleucel (ide-cel) to treat myeloma patients. It induces early, deep, and long-lasting responses with a tolerable safety profile in r/r MM. Cilta-cel-treated myeloma patients may potentially experience adverse effects ranging from mild to life-threatening, but they are mostly manageable toxicities. Besides, it has a consistent safety profile upon a longer follow-up of patients. Cilta-cel generally outperforms ide cel in terms of efficacy in MM, but shows comparable adverse events. This review highlights the current updates on cilta-cel efficacy, adverse events, comparison with ide-cel, and its future direction in the treatment of MM.

CAR T-Cell Therapy for Patients with Multiple Myeloma: Current Evidence and Challenges

The therapeutic landscape of multiple myeloma (MM) has benefited from an emergence of novel therapies over the last decade. By inducing T-cell kill of target cancer cells, chimeric antigen receptor (CAR) T-cell therapies have improved outcomes of patients with hematologic malignancies. B-cell maturation antigen (BCMA) is the current target antigen of choice for most CAR T-cell products under investigation for MM. However, their shortcomings deal with logistical and clinical challenges, including limited availability, manufacturing times, and toxicities. This article provides an overview of recently developed and investigational CAR T-cell therapies for MM, highlighting current evidence and challenges.

Early cytopenias and infections after standard of care idecabtagene vicleucel in relapsed or refractory multiple myeloma

Idecabtagene vicleucel (ide-cel) was FDA-approved in March 2021 for the treatment of relapsed/refractory multiple myeloma after 4 lines of therapy. On the KarMMa trial, grade ≥ 3 cytopenias and infections were common. We sought to characterize cytopenias and infections within 100 days after ide-cel in the standard-of-care (SOC) setting. This multi-center retrospective study included 52 patients who received SOC ide-cel; 47 reached day-90 follow-up. Data were censored at day 100. Grade ≥ 3 cytopenia was present among 65% of patients at day 30 and 40% of patients at day 90. Granulocyte colony stimulating factor (G-CSF) was administered to 88%, packed red blood cell transfusions to 63%, platelet transfusions to 42%, thrombopoietin (TPO) agonists to 21%, intravenous immunoglobulin to 13%, and CD34+ stem cell boosts to 8%. At day 100, 19% and 13% of patients had ongoing use of TPO agonists and G-CSF, respectively. Infections occurred in 54% of patients and were grade ≥ 3 in 23%. Earlier infections in the first 30 days were typically bacterial (68%) and severe (50%). Later infections between days 31 and 100 were 50% bacterial and 42% viral; only 13% were grade ≥ 3. On univariate analysis, high pre-CAR-T marrow myeloma burden (≥ 50%), circulating plasma cells at pre-lymphodepletion (LD), and grade ≥ 3 anemia at pre-LD were associated with grade ≥ 3 cytopenia at both days 30 and 90. Longer time from last bridging treatment to LD was the only significant risk factor for infection.

Chimeric anti-GPC3 sFv-CD3ε receptor-modified T cells with IL7 co-expression for the treatment of solid tumors

Chimeric antigen receptor (CAR) T cells targeting glypican-3 (GPC3) demonstrated early signs of therapeutic efficacy to hepatocellular carcinoma patients with a risk of cytokine release syndrome (CRS). Several adoptive cell therapies (ACTs) with T cells using the natural T cell receptor (TCR) signaling induced more efficient antitumor function and reduced cytokine production relative to CARs in solid tumors. To improve the efficacy and safety of GPC3-targeted ACTs, T cells were modified with anti-GPC3 single-chain fragment variable(sFv) linked to CD3ε, which could be incorporated into the entire TCR/CD3 complex to form chimeric sFv-CD3ε receptor (sFv-ε). sFv-ε T cells showed competitive antitumor activity and lower cytokine release compared to 28ζ or BBζ CAR T cells, which may be ascribed to moderately less activated Ca²⁺-calcineurin-NFAT signaling pathway. We further generated murine sFv-ε T cells with interleukin-7 co-expression (7sFv-ε) to promote T cell survival and to mobilize the endogenous immune system. In immunocompetent mouse models, 7sFv-ε T cells showed superior persistence, antitumor efficacy, and immunological memory while preserving the low production of cytokines associated with CRS compared to conventional sFv-ε T cells. These results indicate that GPC3-specific 7sFv-ε T cells could serve as a promising therapeutic strategy for solid tumors.

Patient selection for CAR T or BiTE therapy in multiple myeloma: Which treatment for each patient?

Multiple myeloma (MM) is a plasma cell malignancy that affects an increasing number of patients worldwide. Despite all the efforts to understand its pathogenesis and develop new treatment modalities, MM remains an incurable disease. Novel immunotherapies, such as CAR T cell therapy (CAR) and bispecific T cell engagers (BiTE), are intensively targeting different surface antigens, such as BMCA, SLAMF7 (CS1), GPRC5D, FCRH5 or CD38. However, stem cell transplantation is still indispensable in transplant-eligible patients. Studies suggest that the early use of immunotherapy may improve outcomes significantly. In this review, we summarize the currently available clinical literature on CAR and BiTE in MM. Furthermore, we will compare these two T cell-based immunotherapies and discuss potential therapeutic approaches to promote development of new clinical trials, using T cell-based immunotherapies, even as bridging therapies to a transplant.

Moving Toward a Cure for Myeloma

Historically, multiple myeloma has been considered an incurable disease, mainly because of its recurrence after transient control. However, the landscape of multiple myeloma therapeutics has significantly changed over the last 2 decades, with disease remissions lasting much longer. The advent of modern-day induction regimens, usage of high-dose melphalan followed by autologous stem cell transplantation, and well-tolerated maintenance regimens has resulted in deeper and durable responses, with less frequent disease recurrences, and patients are living much longer. Moreover, the conventional testing for response assessments in multiple myeloma was developed at least 60 years earlier, and there was a clear need for more sensitive diagnostics to test measurable residual disease at deeper levels. Next-generation sequencing and next-generation flow cytometry are highly sensitive techniques that were refined over the last decade and have a sensitivity of 10^-5 to 10^-6 (1 cell per 100,000/1 million). More recently, immunotherapy strategies-including the cellular therapies-have allowed us to expand our ability to achieve and maintain measurable residual disease negativity even in the refractory setting. These advances have brought us much closer to a cure for multiple myeloma; clearly, it has become more realistically achievable, challenging the dogma of multiple myeloma as an incurable disease.

BCMA-targeted therapies for multiple myeloma: strategies to maximise efficacy and minimize adverse events

INTRODUCTION

Immunotherapies targeting B cell maturation antigen (BCMA) in multiple myeloma are transitioning through trials and entering the clinic, and will likely become a core pillar in myeloma therapeutics. These agents demonstrate unprecedented activity in multiply relapsed patients, but - notwithstanding the short follow-up times - their survival curves do not appear to demonstrate a plateau, and the treatments inevitably bring with them a range of toxicities that might be associated with tolerability issues.

AREAS COVERED

We will briefly lay out the current therapeutic landscape in multiple myeloma, before introducing BCMA and explaining its significance. We will address in turn the three key classes of anti-BCMA immunotherapies: antibody-drug conjugates, bispecific antibodies and chimeric antigen receptor T cells. We describe the mechanisms of action of these classes and review the evidence supporting their efficacy and toxicities. We then bring all three therapies into one discussion that explores how to mitigate toxicities and overcome myeloma's ability to resist these potent treatments.

EXPERT OPINION

Finally, we take the discussion back to the clinic, and consider how we might deploy anti-BCMA therapies most effectively for our patients. We consider the sequencing of treatment, and what further evidence is needed to more fully inform our therapy decisions.

Indirect treatment comparison of idecabtagene vicleucel versus conventional care in triple-class exposed multiple myeloma

Aim: To compare the efficacy of idecabtagene vicleucel (ide-cel, bb2121) versus conventional care (CC) in triple-class exposed relapsed and refractory multiple myeloma (RRMM) patients. Patients & methods: A matching-adjusted indirect comparison was conducted using individual patient-level data from the pivotal, phase II, single-arm KarMMa trial (NCT03361748) and aggregate-level data from MAMMOTH, the largest independent observational study of CC in heavily pretreated RRMM patients. Results: Ide-cel improved overall response rate (odds ratio: 5.30; 95% CI: 2.96-9.51), progression-free survival (hazard ratio: 0.50; 95% CI: 0.36-0.70) and overall survival (hazard ratio: 0.37; 95% CI: 0.25-0.56) versus CC. Conclusion: These results suggest ide-cel offers improvements in clinical outcomes relative to CC in this heavily pretreated RRMM population.

The Implementation of TNFRSF Co-Stimulatory Domains in CAR-T Cells for Optimal Functional Activity

The Tumor Necrosis Factor Receptor Superfamily (TNFRSF) is a large and important immunoregulatory family that provides crucial co-stimulatory signals to many if not all immune effector cells. Each co-stimulatory TNFRSF member has a distinct expression profile and a unique functional impact on various types of cells and at different stages of the immune response. Correspondingly, exploiting TNFRSF-mediated signaling for cancer immunotherapy has been a major field of interest, with various therapeutic TNFRSF-exploiting anti-cancer approaches such as 4-1BB and CD27 agonistic antibodies being evaluated (pre)clinically. A further application of TNFRSF signaling is the incorporation of the intracellular co-stimulatory domain of a TNFRSF into so-called Chimeric Antigen Receptor (CAR) constructs for CAR-T cell therapy, the most prominent example of which is the 4-1BB co-stimulatory domain included in the clinically approved product Kymriah. In fact, CAR-T cell function can be clearly influenced by the unique co-stimulatory features of members of the TNFRSF. Here, we review a select group of TNFRSF members (4-1BB, OX40, CD27, CD40, HVEM, and GITR) that have gained prominence as co-stimulatory domains in CAR-T cell therapy and illustrate the unique features that each confers to CAR-T cells.

Overview of approved CAR-T therapies, ongoing clinical trials, and its impact on clinical practice

In recent years, we have seen rapid expansion of chimeric antigen receptor T-cell (CAR-T) therapies in multiple malignancies. CAR-T therapy has profoundly altered the treatment landscape of non-Hodgkin lymphoma, B-cell acute lymphoblastic leukemia, and multiple myeloma. Currently available CD19 and B-cell maturation antigen-directed CAR-T therapies have shown high overall response rate and durable remissions in patients who have failed standard therapies. Multiple studies are underway exploring the role of CAR-T-cell therapy as earlier line of treatment. In high-grade B-cell lymphoma, CD19 CAR-T therapy may replace autologous hematopoietic cell transplantation as second line therapy in near future. CAR-T-cell therapy targeting novel tumor-associated antigens will help expand utility of this treatment modality in other hematological malignancies. It may also help overcome limitations of currently approved CAR-T-cell therapies. In this review, we have provided an overview of currently approved CAR-T therapies and upcoming clinical trials which may potentially impact the clinical practice.