Real-world Duration of Use and Dosing Frequency of Daratumumab in Patients With Multiple Myeloma in the United States

Abstract

Daratumumab (DARA) is an anti-CD38 monoclonal antibody approved as a combination therapy for newly diagnosed multiple myeloma (MM) and as monotherapy and combination therapy for relapsed or refractory MM cases. We assessed the length of DARA use across lines of therapy and the probabilities of treatment discontinuation in patients with MM in the real-world. We used the deidentified Clinformatics Data Mart database from Optum to identify patients with MM (n=2124) who received DARA-containing treatment between November 1, 2015 and March 31, 2021 in the United States. Patients were excluded if they had received a stem cell transplant. The duration of DARA use was defined as the time interval between the first initiation and discontinuation of DARA as a time-to-event outcome using the Kaplan-Meier method. A gap of more than 60 days between 2 consequent DARA claim dates was defined as DARA discontinuation. The median duration of continuous DARA use was 16.6 months. By 24 months, 33.1% of patients remained on DARA treatment. In a subgroup analysis of patients with 12 months or more continuous insurance coverage (n=1246), the median length of DARA use was 24.7 months; by 24 months, 51.8% remained on DARA treatment. The dose adherence ratios (observed DARA doses relative to the label) were close to 1.0, particularly among patients with longer follow-up, indicating that real-world DARA dosing frequency was similar to that on the approved label. In summary, this real-world analysis reported that the median duration of continuous DARA use is 16.6 months, with high dosing adherence in patients who have MM.