Mosunetuzumab + Polatuzumab Promising Trial Results for R/R LBCL

Posted: Mar 06, 2025

Treatment Advances

How effective is the bispecific antibody mosunetuzumab (Lunsumio, Genentech) when combined with the antibody-drug conjugate polatuzumab vedotin (Polivy, Genentech) for people with relapsed/refractory large B-cell lymphoma (LBCL)?

Comparing this treatment combination against the current LBCL standard of rituximab (Rituxan, Genentech) with polatuzumab supports improving standard care with more effective options.

At the 2024 ASH conference, Julio Chavez, MD, MS, from Moffitt Cancer Center, presented results from a phase 2 clinical trial on this promising combination. Listen to Dr. Chavez’s interview or read the research summary below to learn more.

Polatuzumab + Mosunetuzumab or Rituximab Results

The study is ongoing; however, so far, 80 people with relapsed/refractory LBCL have received polatuzumab with either mosunetuzumab or rituximab in eight 21-day treatment cycles.

Mosunetuzumab was given as an injection, while polatuzumab and rituximab were administered through IV infusions. Patients had the option to receive treatment in an outpatient setting, allowing them to go home afterward without needing an overnight hospital stay.

	Patients who received mosunetuzumab + polatuzumab	Patients who received rituximab + polatuzumab
Overall response rate (percentage of patients who experienced a partial or full reduction of cancer cells following treatment)	78%	50%
Complete response rate (percentage of patients in which cancer was not detected by testing after treatment)	58%	35%
Average duration of response (how long remission lasted since achieving a response)	Not reached, meaning on average, patients were still in remission at the 18-month check-in after responding to treatment	10.1 months
Average overall survival (amount of time patients were alive since the start of treatment)	Not reached, meaning on average, patients were alive at the check-in point of 18 months since starting treatment	Not reached, meaning on average, patients were alive at the check-in point of 18 months since starting treatment
Common side effects experienced by ≥30% of patients	Injection-site reaction (55%), diarrhea (48%), fatigue (35%), and constipation (30%)	Nausea (36%), diarrhea (33%), and fatigue (33%)
Percentage of patients who experienced serious side effects	33% of patients, most commonly neutropenia	26% of patients, most commonly neutropenia

If you have concerns regarding how side effects can be managed with supportive care, please speak with your LBCL specialist.

Key Takeaways

A fixed-duration treatment of mosunetuzumab and polatuzumab, given in an outpatient setting, has shown greater effectiveness than rituximab and polatuzumab for people with relapsed/refractory large B-cell lymphoma (R/R LBCL), leading to higher response rates, longer remission, and manageable side effects.

This combination is currently being evaluated in phase 3 of the SUNMO study, and we look forward to further research as it continues to show promise as an effective treatment option for those in need of additional therapies.

Continue learning from experts about how bispecific antibodies are changing the LBCL treatment landscape

Watch Bispecific Antibodies for LBCL Event Recording

Sources: