Comparison of Non-sedating and Sedating Histamine H1-receptor Antagonist Premedication for Preventing Subcutaneous Daratumumab-associated Infusion-related Reactions: A Multicenter Retrospective Observational Study.

Sedating antihistamines (sAH) are widely used as premedication to prevent infusion-related reactions (IRRs). Subcutaneous daratumumab (DARA-SC) is administered in a shorter time than its intravenous form. Therefore, sedation caused by sAH after DARA-SC administration may also pose a concern. We investigated the efficacy and safety of sAH and non-sedating antihistamines (nsAH) premedication. This multicenter, retrospective, observational study was conducted from six hospitals in Japan. Data from the electronic medical records of consecutive patients with multiple myeloma who received DARA-SC injection between 19 May 2021 and 31 December 2022 was analyzed. The incidence of IRR and drowsiness was investigated as efficacy and safety endpoints, respectively. Differences in incidence between patients treated with nsAH and those treated with sAH were compared. Thirty-one patients in the nsAH group and 130 patients in the sAH group were evaluated. All patients in the nsAH group were treated with levocetirizine, while patients in the sAH group were treated with dexchlorpheniramine or diphenhydramine. The incidence of IRRs was 0% (0/31) in the nsAH group and 1.5% (2/130) in the sAH group. The incidence of drowsiness was 6.5% (2/31) in the nsAH group and 7.7% (10/130) in the sAH group. These differences were not statistically significant. This study showed that levocetirizine is not obviously inferior in efficacy and safety relative to sAH in preventing IRRs and drowsiness. Therefore, levocetirizine can be considered as a substitute for patients for whom the use of sAH is not acceptable.