Just scratching the surface: novel treatment approaches for multiple myeloma targeting cell membrane proteins

Area of Science:

• Immunology
• Oncology
• Pharmacology

Background:

• Understanding the roles of innate and adaptive immunity in multiple myeloma (MM) oncogenesis has spurred novel immune-based therapies.
• B cell maturation antigen (BCMA), G protein-coupled receptor family C group 5 member D (GPRC5D), and Fc receptor-like protein 5 (FcRL5) are key cell-surface targets on MM plasma cells.
• These targets have demonstrated significant activity in heavily pretreated, relapsed/refractory MM patients.

Purpose of the Study:

• To review current and clinically developing immunotherapeutic strategies targeting BCMA, GPRC5D, and FcRL5 in MM.
• To discuss the mechanisms of acquired resistance to these immunotherapies.
• To explore strategies for overcoming resistance and improving patient outcomes.

Main Methods:

• Literature review of available and investigational immunotherapies for MM.
• Analysis of mechanisms underlying resistance to BCMA, GPRC5D, and FcRL5-targeted therapies.
• Discussion of potential strategies to enhance therapeutic efficacy and overcome resistance.

Main Results:

• Since 2020, approved therapies include antibody-drug conjugates, bispecific T cell engagers, and CAR T cells targeting BCMA or GPRC5D.
• These therapies show promising activity in relapsed/refractory MM but are not universally effective.
• Acquired resistance to current immunotherapies is a significant clinical challenge.

Conclusions:

• Targeting BCMA, GPRC5D, and FcRL5 represents a significant advancement in MM immunotherapy.
• Understanding and overcoming resistance mechanisms are crucial for improving long-term patient responses.
• Further research into novel strategies is needed to enhance the efficacy of these promising treatments.