Bispecific Antibodies Demonstrate Favorable Real-World Outcomes for R/R Follicular Lymphoma

Key Takeaways:

• Patients with relapsed or refractory (R/R) follicular lymphoma (FL) who were treated with either mosunetuzumab or epcoritamab achieved an overall response rate (ORR) of 87% and a complete response rate (CRR) of 72%.
• At 1-year and 18-month follow-ups, the progression-free survival (PFS) rates were 72% and 56%, respectively. The overall survival (OS) rates were 94% and 92%, respectively.
• Adverse events were low, with 34% of patients experiencing cytokine release syndrome (CRS) and 3% experiencing immune effector cell-associated neurotoxicity syndrome (ICANS).

Despite success in clinical trials, little research has been done to evaluate the real-world outcomes of mosunetuzumab and epcoritamab on R/R FL.

This study assessed the efficacy and safety outcomes of bispecific antibodies on patients with R/R FL who were treated in the Collaborative United States Bispecifics Consortium (CUBIC). The study observed 99 patients treated with either mosunetuzumab or epcoritamab between February 2023 and September 2025 across 8 CUBIC centers.

The Efficacy and Safety Outcomes of Mosunetuzumab and Epcoritamab

Although 99 patients were included in the study, 96 had complete response data. Among these 96 patients, the ORR was 87%, and the CRR was 72%. The median time to achieve the best response was 2.9 months.

The PFS rate after 1 year was 72% and 56% after 18 months. The OS rates at 1 year and 18 months were 94% and 92%, respectively.

Among the 96 patients with complete data, CRS occurred in 34% of patients, with none of the events achieving a level higher than grade 2. ICANS occurred in 3% of patients, all of which were grade 1 events.

The study’s authors summarized their findings by saying, “Bispecific antibodies for R/R FL demonstrated high response rates, favorable survival outcomes, lower rates of cytokine release syndrome...and ICANS rates comparable to those observed in pivotal clinical trials, supporting their use across heterogeneous populations, including very elderly patients.”

Reference

Allen J, Shah R, Feng L, et al. Real-world outcomes of bispecific antibodies in relapsed/refractory (R/R) follicular lymphoma (FL). J Clin Oncol. 2026;44(16):7010. doi:10.1200/JCO.2026.44.16_suppl.7010