Daratumumab was granted accelerated approval for the treatment of multiple myeloma (MM) in patients who have received ≥3 prior lines of therapy or who are refractory to both a proteasome inhibitor and an immunomodulatory agent.

Chari and colleagues sought to collect safety and patient-reported outcomes data through a multicenter, open-label, early-access treatment protocol. Eligible patients were those who would have fulfilled entry criteria for the MMY2002 trial, which served as the basis for daratumumab approval. The 348 patients enrolled in the study received daratumumab, 16 mg/kg weekly for 8 weeks, then every 2 weeks for 16 weeks, and then every 4 weeks until disease progression or unacceptable toxicity. Fifty-two percent of the patients transitioned to commercial daratumumab after it was approved. Thirty-seven percent discontinued due to progressive disease.

More than half of the patients experienced grade 1-2 infusion-related reactions, which occurred primarily during the first infusion. Fifty percent of patients reported treatment-emergent grade >3 adverse events, the most common being thrombocytopenia (15%) and anemia (14%). Thirty-five percent had serious adverse events, the most common being pneumonia and hypercalcemia (2.9%). Twelve percent of serious adverse events were drug-related as assessed by the investigators. Health-related quality-of-life scales were maintained, with a median change from baseline of 0 on the EQ-5D-5L and EORTC QLQ-C30 health preference scales after 1 and 2 cycles and at last assessment. The EQ-5D-5L visual analog scale showed a median increase from baseline of 1 and 2 units after 1 and 2 cycles, respectively.

These data confirm the safety of daratumumab in the patient population for whom it was approved. Patients were able to maintain their health-related quality of life during a median duration of 2 months of therapy.

Chari J, et al. ASH 2016. Abstract 2133.