Comprehensive Summary of Talquetamab Monotherapy and Combination Therapy in Relapsed or Refractory Multiple Myeloma

Introduction to Talquetamab and Its Clinical Context

Multiple myeloma (MM) is a malignant plasma cell disorder characterized by clonal proliferation of abnormal plasma cells primarily in the bone marrow. Patients with true extramedullary myeloma (plasmacytomas outside the bone marrow) represent a subset with poor prognosis and a high risk of relapse or disease progression due to drug resistance and sanctuary site involvement. Treatment options historically have been limited and often ineffective in this setting.

Talquetamab is a bispecific antibody that targets G protein-coupled receptor family C group 5 member D (GPRC5D) on myeloma cells and CD3 on T cells, directing T-cell mediated killing of myeloma cells. This therapy has emerged as a promising option in heavily pretreated, relapsed or refractory multiple myeloma (RRMM) patients, including those naïve or previously exposed to T-cell redirection (TCR) therapies. Teclistamab is a bispecific antibody targeting B-cell maturation antigen (BCMA) and CD3, which has been combined with talquetamab for dual targeting of extramedullary disease. Below is a detailed summary of two key clinical studies evaluating talquetamab, both as monotherapy and in combination with teclistamab.