Indirect Treatment Comparisons of Mosunetuzumab With Third- and Later-Line Treatments for Relapsed/Refractory Follicular Lymphoma

Matching-adjusted indirect comparison of efficacy and safety of lisocabtagene maraleucel and mosunetuzumab for the treatment of third-line or later relapsed or refractory follicular lymphoma

BACKGROUND

The treatment landscape for relapsed or refractory (R/R) follicular lymphoma (FL) has changed with the introduction of anti-CD19 chimeric antigen receptor T-cell therapies, including lisocabtagene maraleucel (liso-cel) and CD20 × CD3 bispecific T-cell-engaging monoclonal antibodies such as mosunetuzumab. Liso-cel and mosunetuzumab have demonstrated positive benefit-risk profiles for third-line or later (3L+) treatment of patients with R/R FL and are approved treatments for these patients. In the absence of a prospective, randomized study, we conducted an unanchored matching-adjusted indirect comparison (MAIC) to assess the efficacy and safety of liso-cel and mosunetuzumab for 3L+ treatment in patients with R/R FL.

METHODS

Unanchored MAICs were performed to estimate relative treatment effects between TRANSCEND FL (NCT04245839) and GO29781 (NCT02500407). For TRANSCEND FL, the leukapheresis set (N = 114) was used for primary comparisons of the following efficacy endpoints: objective response rate (ORR), complete response (CR) rate, duration of response (DOR), and progression-free survival (PFS). The treated set (N = 107) was used for comparisons of the following safety endpoints: cytokine release syndrome (CRS), neurological events (NE), serious infections, and use of corticosteroids or tocilizumab for CRS. Sensitivity analyses were conducted for efficacy using the TRANSCEND FL treated efficacy set (N = 101).

RESULTS

After adjustment, liso-cel was associated with higher ORR (odds ratio [OR] = 3.78, 95% confidence interval [CI] 1.48‒9.67]) and CR rate (OR = 6.46, 95% CI 2.85‒14.65), and improved DOR (hazard ratio [HR] = 0.45, 95% CI 0.26‒0.77) and PFS (HR = 0.28, 95% CI 0.16‒0.49) compared with mosunetuzumab. Results remained consistent across sensitivity analyses. Liso-cel had a lower incidence of grade ≥ 3 CRS (OR = 0.45, 95% CI 0.04‒5.13), grade 3‒4 serious infections (OR = 0.35, 95% CI 0.12‒1.03), and corticosteroid use for CRS management (OR = 0.14, 95% CI 0.03‒0.65); however, liso-cel exhibited higher incidence of any-grade CRS (OR = 1.86, 95% CI 1.01‒3.43), any-grade NEs (OR = 2.16, 95% CI 0.72‒6.44), and tocilizumab use for CRS management (OR = 2.27, 95% CI 0.86‒5.99).

CONCLUSIONS

Findings highlight a potential positive benefit-risk profile of liso-cel over mosunetuzumab as a 3L+ treatment for R/R FL.

Building the future management of follicular lymphoma with T-cell-redirecting strategies

ABSTRACT

Follicular lymphoma (FL) usually requires multiple lines of therapy, and disease control remains largely insufficient with conventional chemoimmunotherapy. Several T-cell-redirecting strategies recently approved in the relapsed/refractory setting have the potential to improve outcomes and change the treatment algorithm in FL. This review focuses on the role of chimeric antigen receptor T cells and bispecific antibodies in FL, paying special attention to sequencing approaches and future directions.

Lisocabtagene maraleucel in follicular lymphoma: the phase 2 TRANSCEND FL study

An unmet need exists for patients with relapsed/refractory (R/R) follicular lymphoma (FL) and high-risk disease features, such as progression of disease within 24 months (POD24) from first-line immunochemotherapy or disease refractory to both CD20-targeting agent and alkylator (double refractory), due to no established standard of care and poor outcomes. Chimeric antigen receptor (CAR) T cell therapy is an option in R/R FL after two or more lines of prior systemic therapy, but there is no consensus on its optimal timing in the disease course of FL, and there are no data in second-line (2L) treatment of patients with high-risk features. Lisocabtagene maraleucel (liso-cel) is an autologous, CD19-directed, 4-1BB CAR T cell product. The phase 2 TRANSCEND FL study evaluated liso-cel in patients with R/R FL, including 2L patients who all had POD24 from diagnosis after treatment with anti-CD20 antibody and alkylator ≤6 months of FL diagnosis and/or met modified Groupe d'Etude des Lymphomes Folliculaires criteria. Primary/key secondary endpoints were independent review committee-assessed overall response rate (ORR)/complete response (CR) rate. At data cutoff, 130 patients had received liso-cel (median follow-up, 18.9 months). Primary/key secondary endpoints were met. In third-line or later FL (n = 101), ORR was 97% (95% confidence interval (CI): 91.6‒99.4), and CR rate was 94% (95% CI: 87.5‒97.8). In 2L FL (n = 23), ORR was 96% (95% CI: 78.1‒99.9); all responders achieved CR. Cytokine release syndrome occurred in 58% of patients (grade ≥3, 1%); neurological events occurred in 15% of patients (grade ≥3, 2%). Liso-cel demonstrated efficacy and safety in patients with R/R FL, including high-risk 2L FL. ClinicalTrials.gov identifier: NCT04245839 .

Cost-effectiveness of treating relapsed or refractory 3L+ follicular lymphoma with axicabtagene ciloleucel vs mosunetuzumab in the United States

Introduction

Novel therapies for 3L+ relapsed/refractory (r/r) follicular lymphoma (FL) have been approved recently by the US Food and Drug Administration including anti-CD19 CAR-T therapies such as axicabtagene ciloleucel (axi-cel) and CD20 × CD3 T-cell-engaging bispecific monoclonal antibodies such as mosunetuzumab (mosun). The objective of this study was to assess the cost-effectiveness of axi-cel compared to mosun in 3L+ r/r FL patients from a US third-party payer perspective.

Methods

A three-state (progression-free, progressed disease, and death) partitioned-survival model was used to compare two treatments over a lifetime horizon in a hypothetical cohort of US adults (age ≥18) receiving 3L+ treatment for r/r FL. ZUMA-5 and GO29781 trial data were used to inform progression-free survival (PFS) and overall survival (OS). Mosun survival was modeled via hazard ratios (HRs) applied to axi-cel survival curves. The PFS HR value was estimated via a matching-adjusted indirect comparison (MAIC) based on mosun pseudo-individual patient data and adjusted axi-cel data to account for trial populations differences. One-way sensitivity analysis (OWSA) and probabilistic sensitivity analyses (PSA) were conducted. Scenario analyses included: 1) the mosun HRs were applied to the weighted (adjusted) ZUMA-5 24-month data to most exactly reflect the MAIC, 2) mosun HR values were applied to axi-cel 48-month follow-up data, and 3) recent axi-cel health state utility values in diffuse large B-cell lymphoma patients.

Results

The analysis estimated increases of 1.82 LY and 1.89 QALY for axi-cel compared to mosun. PFS for axi-cel patients was 6.42 LY vs. 1.60 LY for mosun. Increase of $257,113 in the progression-free state was driven by one-time axi-cel treatment costs. Total incremental costs for axi-cel were $204,377, resulting in an ICER of $108,307/QALY gained. The OWSA led to ICERs ranging from $240,255 to $75,624, with all but two parameters falling below $150,000/QALY. In the PSA, axi-cel had an 64% probability of being cost-effective across 5,000 iterations using a $150,000 willingness-to-pay threshold. Scenarios one and two resulted in ICERs of $105,353 and $102,695, respectively.

Discussion

This study finds that axi-cel is cost-effective compared to mosun at the commonly cited $150,000/QALY US willingness-to-pay threshold, with robust results across a range of sensitivity analyses accounting for parameter uncertainty.

A Comparison of 3-Year Follow-up of ZUMA-5 (Axicabtagene Ciloleucel) With SCHOLAR-5 in Relapsed/Refractory Follicular Lymphoma

In the pivotal ZUMA-5 trial, axicabtagene ciloleucel (axi-cel; an autologous anti-CD19 chimeric antigen receptor T-cell therapy) demonstrated high rates of durable response in relapsed/refractory follicular lymphoma patients. SCHOLAR-5 is an external control cohort designed to act as a comparator to ZUMA-5. Here, we present an updated comparative analysis of ZUMA-5 and SCHOLAR-5, using the 36-month follow-up data and the intent-to-treat population of ZUMA-5. Using propensity-score methods, 127 patients in ZUMA-5 were compared to 129 patients in SCHOLAR-5. At this extended follow-up, axi-cel continues to demonstrate clinically meaningful benefits in survival compared to historically available treatments in this population.

[T-cell recruiting immunotherapies in B-cell lymphoma - the future backbone for all therapy lines?]

The introduction of immunologically targeted therapies has represented a significant advancement in the treatment of B-cell lymphomas, particularly aggressive B-cell lymphoma. CD19 CAR-T cells such as Axicabtagen-Ciloleucel (Axi-cel) and Lisocabtagen Maraleucel (Liso-cel) have been approved since 2022 and 2023, respectively, for second-line therapy of Diffuse Large B-Cell Lymphomas (DLBCL), when there is primary refractory disease or relapse within 12 months after the end of first-line therapy. These therapies result in a significant improvement in progression-free survival compared to the previous standard therapy (salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation). Especially in elderly patients or patients with underlying medical conditions, CAR-T cell therapies like Axi-cel and Liso-cel demonstrate acceptable tolerability and high efficacy.Furthermore, bispecific T-cell-engaging antibodies ("bispecifics") such as Glofitamab, Epcoritamab, and Mosunetuzumab also represent promising treatment options for patients with relapsed disease after failure of second- or later line therapy and show efficacy even in a subset of patients relapsing after CD19 CAR-T cells. However, randomized study results for these substances are not yet available. They are expected to be used in earlier lines of therapy in the future, especially in combination with standard chemotherapy regimens. Common side effects of bispecific antibody therapies are cytokine release syndrome (CRS) and immune-mediated cytopenias, whereas immune-cell associated neurotoxicity syndrome (ICANS) is relatively rare compared to CD19 CAR T cells. In summary, bispecifics represent a novel, highly effective immunotherapy for the treatment of lymphomas with a very favourable toxicity profile.