Transition from Intravenous to Subcutaneous Daratumumab Formulation in Clinical Practice.

INTRODUCTION: Daratumumab is an anti-CD38 monoclonal antibody widely used for treating patients with newly diagnosed or relapsed/refractory multiple myeloma. The subcutaneous formulation of daratumumab was developed with the purpose of minimizing the treatment burden (to patients and health care system) associated with intravenous daratumumab. Given its recent approval, there is a knowledge gap regarding the best practices that should be instituted for safe administration of subcutaneous daratumumab. METHODS: A retrospective chart review was performed from August 2020 until November 2020 to identify patients either switched to or treated upfront (daratumumab naive) with any subcutaneous daratumumab-based treatment regimen. All patients received appropriate premedications per institutional standards of care. The study end points were to report real-world data regarding administration-related reaction rates (at or following discharge from infusion center), as well as compare their incidence rates to those noted in the COLUMBA study (historical cohort). RESULTS: The study included 58 patients, of whom 38% (n = 22) were daratumumab naive. The majority (84%, n = 49) received subcutaneous daratumumab in combination with various antimyeloma regimens. There were no cases of administration-related reactions at infusion center or after discharge irrespective of previous exposure to intravenous daratumumab. None of the patients included herein required rescue home medications or visited the emergency department within 24 to 48 hours after subcutaneous daratumumab administration. These translated into a significant difference in incidence of administration-related reactions compared with historical cohort (0% vs. 13%, P = .003). CONCLUSION: Subcutaneous daratumumab was extremely well tolerated and could be safely administered without need for monitoring or rescue home medications.