Dr Jamroziak on Daratumumab vs Observation in Multiple Myeloma With MRD Reappearance

“The hazard ratio [for EFS] was 0.20 [in favor of] daratumumab [vs observation], so there was an 80% reduction in the risk of significant paraprotein relapse or clinical relapse.”

Krzysztof Jamroziak, PhD, hematology specialist in the Department of Hematology, Transplantology, and Internal Medicine, as well as the acting deputy head, Department of General Hematology, at the Medical University of Warsaw, discussed findings from the phase 2 PREDATOR-MRD trial (NCT03697655).

PREDATOR-MRD was a multicenter, open-label study that examined pre-emptive treatment with daratumumab (Darzalex) vs observation in patients with multiple myeloma who completed 1 or 2 prior lines of therapy and achieved a complete response with minimal residual disease (MRD) negativity after their most recent treatment. The primary end point was event-free survival (EFS), Jamroziak noted.

Twelve patients were each randomly assigned to receive daratumumab or observation, Jamroziak said. Patient characteristics were generally well balanced between the 2 arms, he added.

At a median follow-up of 17.9 months (range, 2.6-33.3), findings from the interim analysis of PREDATOR-MRD presented during the 2025 EHA Congress demonstrated that 3 patients in the daratumumab arm experienced significant paraprotein relapse or clinical relapse compared with 9 patients in the observation arm, Jamroziak explained. Additionally, the median EFS in the investigational arm was not reached (NR; 95% CI, NR-NR) compared with 9.5 months (95% CI, 5.0-NR) in the observation arm; the hazard ratio for EFS was 0.20 (95% CI, 0.05-0.76; P = .0097), Jamroziak emphasized.

Jamroziak noted that the MRD negativity rate on day 1 of cycle 3 represented a key exploratory end point of PREDATOR-MRD.

In terms of safety, the most common hematologic adverse effects (AEs) in the investigational arm consisted of anemia (8.3%), lymphopenia (8.3%), and neutropenia (8.3%); none of these toxicities were reported in the control arm. Any-grade non-hematologic AEs occurred at rates of 66.7% and 33.3% in the investigational and control arms, respectively. Fifty percent of patients in the daratumumab arm experienced any-grade upper respiratory tract infection. Common any-grade AEs in both arms included urinary tract infection (16.7% vs 8.3%), other infections (25.0% vs 25.0%), and musculoskeletal pain (41.7% vs 8.3%).