05:40 PM EDT, 05/22/2025 (MT Newswires) -- Regeneron Pharmaceuticals ( REGN ) said late Thursday its initial phase 1b trials data of linvoseltamab in combination with carfilzomib or bortezomib to treat refractory multiple myeloma showed a 90% objective response rate after a 15-month follow-up.

Almost 76% of patients achieved a complete response, the company said.

Adverse events were recorded in over 50% of the patients, while grade 3 adverse events included neutropenia, cytokine release syndrome, diarrhea, and thrombocytopenia. Infections developed in 91% of patients, and serious adverse events occurred in 83%.

The company will present trial data at the American Society of Clinical Oncology 2025 Annual Meeting on June 2.

Shares were down 2% in after-hours trading.