Dual Treatment Shows Promising Efficacy in Untreated Follicular Lymphoma

Mosunetuzumab combined with lenalidomide showed a manageable safety profile and promising efficacy in patients with untreated follicular lymphoma, according to a phase Ib/II trial presented at the 65th American Society of Hematology Annual Meeting & Exposition.

The trial, led by Franck Morschhauser, MD, PhD, of the University of Lille in France, studied a fixed-duration regimen of mosunetuzumab plus lenalidomide throughout 12 cycles. A total of 37 patients received 5 mg of subcutaneous mosunetuzumab on day one, and a target dose of 45 mg on days eight and 15 of cycle one and day one of cycles two to 12. Meanwhile, patients received 20 mg of oral lenalidomide on days one to 32 of cycles two to 12.

All patients reported at least one treatment-emergent adverse event (TEAE), with 26 patients experiencing TEAEs related to mosunetuzumab and 29 experiencing TEAEs related to lenalidomide. Two patients discontinued treatment: one due to uveitis, and one due to tumor flare. Sixteen (43.2%) patients experienced at least one grade 3–4 TEAE, most commonly neutropenia. Cytokine release syndrome was observed in 20 (54.1%) patients.

Of 27 efficacy-evaluable patients, 22 (81.5%) reached a complete metabolic response, and two (7.4%) reached a partial metabolic response.

Blood sample analysis showed increased CD69 and sustained human leukocyte antigen (HLA)-DR expression in CD8 T-cells, modulation of CD8 subsets favoring central and effector memory phenotypes, sustained activity of natural killer cells, and minimal effects on CD4 T-cells.

“This fixed-duration, chemotherapy-free [mosunetuzumab plus lenalidomide] regimen offers a convenient means for outpatient [subcutaneous] administration,” the researchers concluded. “Advancing [this regimen] into the first-line setting offers potential benefits in chemotherapy-naïve [patients].”

Reference

Morschhauser F, Patel K, Bobillo S, et al. Preliminary findings of a phase Ib/II trial indicate manageable safety and promising efficacy for mosunetuzumab in combination with lenalidomide (M+Len) in previously untreated (1L) follicular lymphoma (FL). Abstract #605. Presented at the 65th ASH Annual Meeting & Exposition; December 9-12, 2023; San Diego, California.