Favorable response to daratumumab combination therapy in patients with multiple myeloma with an immature phenotype: a...

This study aimed to investigate the relationship between myeloma cell maturity, clinical profiles, and treatment outcomes in patients with multiple myeloma (MM).

The J-CHARGE-MM database includes data from 1200 MM patients diagnosed between January 2011 and January 2023. Immunophenotyping by flow cytometry using antibodies against CD38, CD49e, and MPC-1 was used to evaluate myeloma cell maturity.

Out of 969 patients evaluable for myeloma cell maturity, 115 were classified as mature type, 626 as intermediate type, and 228 as immature type. Patients with the immature type were more likely to have the IgG type and 1q21 gain/amplification. Treatment response and outcome analysis showed that patients with the immature type had lower response rates and worse time to next treatment (TTNT) with bortezomib-based therapy compared to those with the mature or intermediate type. Lenalidomide-based therapy partially mitigated the adverse impact of the immature type. However, daratumumab combination therapy showed higher response rates and better TTNT, which was almost equivalent between the mature/intermediate and immature types.

Stratifying patients with MM based on myeloma cell maturity provides meaningful information for choosing the best treatment strategy and improving patient outcomes.