Evaluation of administration-related reactions with subcutaneous daratumumab with and without premedication

Daratumumab-hyaluronidase-fihj (Dara-SQ) is frequently used in the treatment of plasma cell disorders and is associated with improved outcomes. Dara-SQ was shown to be non-inferior to intravenous daratumumab (Dara-IV) in efficacy, safety, and associated with fewer administration-related reactions (ARRs). Despite the lower ARR risk with Dara-SQ, package labeling still recommends indefinite premedication. In this study, we investigated the safety of premedication discontinuation after one cycle of Dara-SQ.

This pre-post interventional quality improvement study included all patients aged 18 years and older diagnosed with multiple myeloma or light chain (AL) amyloidosis who received at least one dose of Dara-SQ. Patients in Arm 1 received Dara-SQ per package labeling, while patients in Arm 2 had premedication omitted (excluding dexamethasone) after cycle 1. The primary endpoint was the incidence of ARR after cycle 1. Overall ARR rate and therapy time saved were also evaluated.

A total of 102 patients (63 in Arm 1 and 39 in Arm 2) were included. There were zero reactions in either arm after cycle 1 across 1479 Dara-SQ doses administered over a 30-month period with or without premedication omission. The overall ARR rate was 2.9% (3/102), which all occurred prior to premedication omission. Therapy timed saved from premedication omission was 194 hours in a 6-month period, equating to approximately $140 000 USD.

ARRs to Dara-SQ were rare, mild, and occurred during cycle 1 prior to premedication omission. Omission of noncorticosteroid premedication is safe, feasible, and carries substantial time and cost savings for patients and infusion centers.