Dr Patel on Choosing Between Mosunetuzumab and Epcoritamab in Follicular Lymphoma

"Both [mosunetuzumab and epcoritamab] are overall well tolerated in terms of efficacy, though, is there really a difference [between these agents]? We just don't have enough information to answer that.”

Vivek G Patel, MD, an assistant professor of medicine in the Division of Hematology Oncology at Vanderbilt University Medical Center, discussed the clinical similarities and differences between mosunetuzumab-axgb (Lunsumio) and epcoritamab-bysp (Epkinly) for the treatment of patients with follicular lymphoma.

When selecting the appropriate bispecific antibody for patients with follicular lymphoma, is important to discern whether there are meaningful differences between available products, Patel stated. In follicular lymphoma, 2 bispecific antibodies—mosunetuzumab and epcoritamab—have demonstrated efficacy and are FDA approved in the third-line or later setting, Patel stated. Although both agents operate via similar mechanisms—engaging T cells to target and kill B cells—the structural designs differ between these antibodies, Patel stated. Despite the similar functions between these agents, the molecular configurations, or motifs, of these bispecific antibodies are not identical, Patel stated.

When comparing mosunetuzumab with epcoritamab, there are currently insufficient data to clearly define the effects of these structural differences on clinical outcomes, Patel stated. Notably, in large B-cell lymphoma, mosunetuzumab did not demonstrate the same level of efficacy as epcoritamab, which has limited the utility of mosunetuzumab in that population, Patel stated. However, mosunetuzumab appears to align particularly well with the biology of follicular lymphoma, offering substantial efficacy and a favorable adverse effect profile, Patel stated.

In terms of tolerability, the 2 agents have similar safety profiles, and are both associated with low rates of high-grade cytokine release syndrome and rare occurrences of immune effector cell–associated neurotoxicity syndrome, particularly that of higher grade, Patel stated. Overall, both agents are generally well tolerated, Patel stated. Regarding comparative efficacy between the 2, data remain inconclusive, and no definitive determination can yet be made, Patel concluded.