Regeneron's filing is backed by data from the Phase I/II LINKER-MM1 trial showing an objective response rate of 71% among patients who got the recommended 200mg dose of linvoseltamab, including 46% who had a complete response or better. After a minimum of 24 weeks of therapy, those who achieved a very good partial response or better shifted from every two-week to every four-week dosing. All patients treated with the 200mg dose experienced an adverse event (AE), including 85% who with a Grade ≥3 AE. The most common AE was cytokine release syndrome (CRS), which was reported at 46%, with the vast majority deemed to be Grade 1 or 2 cases. Promising, but indistinguishable agents?
Key opinion leaders (KOLs) interviewed for a FirstWord report agreed that early data for linvoseltamab as well as for ABBV-383 appear promising, although there seems to be little to distinguish either of these agents from each other or from Tecvayli and Elrexfio. They suggested ABBV-383, which is in Phase I testing for fourth-line MM, could hold an advantage over linvoseltamab due to a less frequent dosing schedule and subcutaneous delivery, compared with the need for intravenous infusions with Regeneron's drug. European regulators have also recently accepted linvoseltamab for review. The clinical development programme for the drug includes the confirmatory Phase III trial LINKER-MM3 trial in patients with relapse/refractory MM. The study is currently enrolling and is expected to read out in 2032. Regeneron is also testing it for earlier use, including in a Phase I/II trial in the first-line setting, a Phase II trial in high-risk smoldering MM and a Phase II trial in monoclonal gammopathy of undetermined significance. Planning for a Phase I study of linvoseltamab plus one of Regeneron's CD38xCD28 costimulatory bispecifics is also in the works.