On July 30, the FDA approved an injectable form of daratumumab combined with bortezomib, lenalidomide, and dexamethasone for transplant-eligible multiple myeloma patients. On September 20, isatuximab was approved for use with the same three drugs for patients ineligible for a stem cell transplant. Both drugs target the CD38 protein, prevalent in myeloma cells.
Daratumumab for Transplant-Eligible Patients
The approval for daratumumab was based on the PERSEUS trial, involving 709 patients. Results showed that 84% of patients in the daratumumab group were alive without cancer progression after nearly 4 years, compared to 68% in the standard treatment group. Additionally, 75% of daratumumab-treated patients achieved minimal residual disease (MRD) negativity, a significant improvement over the standard therapy group.
Isatuximab for Transplant-Ineligible Patients
Isatuximab's approval stemmed from the IMROZ trial, with 443 participants. After nearly 5 years, 63% of the isatuximab group were alive without cancer progression, versus 45% in the standard treatment group. More than 55% of isatuximab-treated patients achieved MRD negativity, compared to fewer than 41% in the standard therapy group.
The Importance of MRD Negativity
MRD negativity has emerged as a crucial indicator of treatment effectiveness, offering a more sensitive assessment than traditional methods. Achieving MRD negativity is associated with improved progression-free and overall survival.
Questions About Four-Drug Therapy
Despite the promising results, questions remain about the optimal duration of maintenance therapy and the best use of CD38-targeted therapies. Ongoing research aims to address these uncertainties, with NCI sponsoring several trials to explore these questions further.
These FDA approvals represent significant advancements in the treatment of multiple myeloma, offering new hope for patients with this challenging disease.
