Mosunetuzumab Yields Clinically Beneficial Outcomes for Patients With Follicular Lymphoma Treated With 3 or More Lines of Therapy

Findings from Real-World Data Comparison

Findings from a real-world data comparison published in Leukemia & Lymphoma indicated that CD20-CD3 bispecific antibody mosunetuzumab monotherapy demonstrated clinically beneficial outcomes as a chemotherapy-free option among patients with follicular lymphoma treated with 3 or more lines (3 L+) of systemic therapy. 

Sarah F McGough, PhD, Genentech Inc, San Francisco, California, and coauthors stated, “Many patients with FL will require multiple lines of therapies, with generally increasing refractoriness and decreasing duration of response to each.” They added that despite the breakthroughs of treatment in this space, “major barriers to treatment remain.” 

A single-arm phase 2 trial found that mosunetuzumab showed high complete response rates and tolerable safety among this patient population. In this comparison of clinical outcomes, the study authors aimed to evaluate the results of the single-arm trial in a real-world context by comparing outcomes among 2 cohorts.

A total of 158 evaluable patients with 3 L+ FL from a United States electronic health records database and 90 patients from the mosunetuzumab single-arm trial were included in this comparison. The primary end point was the proportion of patients with a complete response, and the secondary end points included overall response rate, duration of response, progression-free survival, and overall survival. 

Results indicated that the overall response rate was 80% in the mosunetuzumab cohort versus 75% in the real-world data cohort. The complete response rate was 60% in the mosunetuzumab cohort versus 33% in the real-world data cohort. Overall survival was significantly longer in the mosunetuzumab cohort versus the real-world data cohort. Progression-free survival and time to the next treatment were similar between the cohorts. 

As end points were reached, Dr McGough and coauthors concluded, “These findings, as well as other attributes, such as a manageable safety profile; novel, chemotherapy-free, CD20-targeted T-cell engaging mechanism of action; and fixed duration, outpatient, and off-the-shelf administration suggest that mosunetuzumab could be a promising treatment option for the 3 L + FL population.” 

Source: 

McGough SF, Shamas N, Wang J, et al. Comparative effectiveness between mosunetuzumab monotherapy clinical trial and real-world data in relapsed/refractory follicular lymphoma in third or subsequent lines of systemic therapy. Leuk & Lymph. Published online: December 25, 2023. doi: 10.1080/10428194.2023.2262066