FDA Accepts sBLA for Mosunetuzumab Plus Polatuzumab vedotin in R/R LBCL
- The FDA has accepted an sBLA for the subcutaneous formulation of mosunetuzumab plus polatuzumab vedotin in adult patients with relapsed/refractory LBCL, including DLBCL, after at least 1 prior line of systemic therapy.
- In the phase 3 SUNMO study, the combination produced a significant PFS benefit vs R-GemOx (HR, 0.41; 95% CI, 0.28-0.60).
- The FDA is expected to make a decision on the regimen’s approval by February 9, 2027.
How was SUNMO designed?
SUNMO enrolled patients with relapsed/refractory LBCL who had received at least 1 prior line of therapy and were ineligible for autologous stem cell transplantation.2 The study included patients with DLBCL not otherwise specified, transformed follicular lymphoma, high-grade B-cell lymphoma, and grade 3 follicular lymphoma. Patients were stratified by number of prior lines of therapy (1 vs 2 or more) and relapsed vs refractory disease.
Eligible patients were randomly assigned 2:1 to receive subcutaneous mosunetuzumab for 8 cycles plus intravenous (IV) polatuzumab vedotin for 6 cycles via 21-day treatment cycles or to the chemotherapy arm. In the chemotherapy arm, patients received 8 cycles of IV rituximab, gemcitabine, and oxaliplatin every 14 to 21 days.
The primary end points were PFS and overall response rate (ORR), both by IRC assessment. Overall survival (OS) was a key secondary end point; safety was also assessed as a secondary end point.
What were the additional efficacy and safety data?
The ORR in the investigational arm was 70.3% (95% CI, 61.9%-77.8%) vs 40.0% (95% CI, 28.5%-52.4%) in the chemotherapy arm. The respective complete response (CR) rates were 51.4% (95% CI, 42.8%-60.0%) and 24.3% (95% CI, 14.8%-36.0%). The median duration of response (DOR) was 18.8 months (95% CI,11.5-not evaluable [NE]) vs 6.0 months (95% CI, 3.7-23.9), respectively. The respective 2-year DOR rates were 47.9% (95% CI, 37.0%-58.8%) and 15.4% (95% CI, 0.0%-39.8%). The median durations of CR were not reached and 18.3 months (95% CI, 3.9-NE), respectively; the respective 2-year duration of CR rates were 62.5% (95% CI, 50.1%-74.9%) and 22.0% (95% CI, 0.0%-56.2%).
The safety profile of mosunetuzumab plus polatuzumab vedotin was consistent with the known profiles of the individual agents. In the investigational arm (n = 135), any-grade cytokine release syndrome (CRS) was reported in 25.9% of patients, consisting of grade 1 (21.5%), 2 (3.7%), and 3 (0.7%) CRS events. Serious CRS occurred in 5.2% of patients. The median time to onset of first instance of CRS was 3 days (range, 1-6), and the median duration of CRS was also 3 days (range, 1-11).
"Navigating relapsed or refractory LBCL can be challenging, particularly for patients who do not live near a major academic center,” Meghan Gutierrez, CEO of the Lymphoma Research Foundation, said in the news release.1 "The potential new [mosunetuzumab and polatuzumab vedotin] combination may address this critical access issue by offering treatment options closer to where a patient lives. It fills a gap in care for people who can't afford to travel far distances or for long periods of time for treatment."
References
- FDA accepts supplemental biologics license application for Roche’s Lunsumio and Polivy combination for people with relapsed or refractory large B-cell lymphoma. News release. Roche. June 17, 2026. Accessed June 18, 2026. https://www.roche.com/media/releases/med-cor-2026-06-18
- Kim W, Westin J, Maruyama D, et al. Mosunetuzumab plus polatuzumab vedotin (mosun-pola) versus rituximab, gemcitabine and oxaliplatin (R-GemOx) in patients with relapsed/refractory large B-cell lymphoma (R/R LBCL): updated efficacy and safety from the phase 3 SUNMO study including in second-line (2L) versus third-line plus (3L+) patient subgroups. J Clin Oncol. 2026;44(suppl 16):7007. doi:10.1200/JCO.2026.44.16_suppl.7007