Daratumumab infusion reaction rates pre- and post-addition of montelukast to pre-medications.

Daratumumab, a CD38-directed monoclonal antibody indicated for multiple myeloma treatment in adult patients, is associated with a high incidence of infusion-related reactions (IRRs). Due to CD38 receptor presence in the lungs, many reactions present similarly to asthma or allergic rhinitis. Montelukast, a leukotriene receptor antagonist, has been hypothesized to reduce daratumumab IRRs due to its efficacy in treating allergic rhinitis and asthma and the presence of leukotriene receptors in the lungs. Recently published data reported daratumumab can be safely administered via rapid rate protocol that reduces infusion time from 195 min to 90 min after completion of two doses. This retrospective, observational cohort study examined 73 patients who received daratumumab in the outpatient setting between December 2015 and April 2020. Patients were included if they were 18 years or older, had an International Classification of Disease (ICD)-10 diagnosis code for multiple myeloma, and received daratumumab intravenously. The primary outcome was a comparison of IRRs between those who did and did not receive montelukast. Secondary outcomes included IRR symptoms, rescue medications utilized for IRRs, and rapid rate administration outcomes. Montelukast use was associated with a lower rate of IRRs (44.4% vs. 65.2%, p = 0.044). Pulmonary IRR symptoms were more common in those who did not receive montelukast. Rapid rate administration of daratumumab did not lead to any IRRs. Adding montelukast as a pre-medication for daratumumab infusions led to a reduction in IRRs, and rapid rate administration was found to be safe after completion of two full doses of daratumumab.