Patients with relapsed or refractory multiple myeloma (RRMM) who received daratumumab in addition to standard therapy in the CASTOR and POLLUX Phase III trials had higher rates of MRD negativity than patients who received standard therapy alone. MRD negativity was also more prolonged in the daratumumab-treated patients and was associated with longer progression-free survival.
These findings from an exploratory analysis published in April in the Journal of Clinical Oncology “represent the largest set of MRD data prospectively collected among patients with RRMM,” write lead author Hervé Avet-Loiseau, MD, of the University Cancer Institute in Toulouse, France, and his colleagues.
MRD assessment using next-generation sequencing, at a sensitivity threshold of 10-5, was a prespecified secondary endpoint in both the CASTOR and POLLUX trials, which enrolled, respectively, 498 and 569 patients with RRMM who had received one or more prior lines of therapy. Sustained MRD negativity was defined as the maintenance of MRD negativity in bone marrow confirmed at least 6 or 12 months apart.
“Our data represent the largest data set analyzed to date, but other studies have highlighted the role of sustained MRD negativity in MM and its association with survival outcomes,” the authors write. “Taken together, these findings support the utility of sustained MRD assessment in MM.”
- Avet-Loiseau H, San-Miguel J, Casneuf T, et al. Evaluation of Sustained Minimal Residual Disease Negativity With Daratumumab-Combination Regimens in Relapsed and/or Refractory Multiple Myeloma: Analysis of POLLUX and CASTOR. J Clin Oncol. 2021;39(10):1139-1149. doi:10.1200/JCO.20.01814