RedirecTT-1: Talquetamab + teclistamab for extramedullary MM

Phase II results from the RedirecTT-1 (NCT04586426) study of talquetamab (an anti-G protein-coupled receptor family C group 5 member D agent) plus teclistamab (an anti–B-cell maturation antigen) in patients with drug-resistant, true extramedullary multiple myeloma (MM) (N = 90) were recently published in The New England Journal of Medicine by Kumar et al. The primary endpoint was overall response rate (ORR); secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety. 

Key data: The ORR was 79% (95% confidence interval [CI], 69–87), with 54% of patients achieving a complete response (CR) or better (95% CI, 44–65). Among responders, 64% had a DoR ≥12 months. Median PFS was 15.4 months; median OS was not reached, with 12-month OS of 74% (95% CI, 63–83). Grade 3 or 4 adverse events (AEs) occurred in 76% of patients. Five deaths were considered treatment related. 

Key learning: Dual targeting with talquetamab plus teclistamab demonstrated clinically meaningful efficacy in patients with true extramedullary MM, a high-risk population with historically poor outcomes, though the incidence of severe AEs was high.