P180 | ACCELERATED INFUSION OF ISATUXIMAB: SINGLE-CENTER REAL-WORLD EVIDENCE SUPPORTING A 30-MINUTE ADMINISTRATION.

Background: Isatuximab (Isa) is an anti-CD38 monoclonal antibody currently approved for relapsed/refractory multiple myeloma (RRMM), in combination with either carfilzomib-dexamethasone (Isa-Kd) after 1 prior line of therapy (LOT) or pomalidomide-dexamethasone (Isa-Pd) after 2 prior LOTs. Infusion-related reactions (IRRs) represent the most common adverse events (AEs), occurring in ~40% of patients (pts), mostly grade (G) 1–2 (ICARIA and IKEMA trials), thus specific premedication is recommended. According to the summary of product characteristics, in the absence of IRRs, infusion rate progressively increases up to 200 mL/h (total duration of 75 minutes, mins) by the 3rd administration. However, a phase 1b study recently assessed the feasibility of faster infusion with promising results (Ocio EM et al, Hemasphere, 2024). Aims and methods: We present a retrospective single-center study aimed at assessing feasibility, safety, and time-saving benefit of 30-mins Isa infusion (Isa30). In this respect, from May 2024, pts having received ≥3 Isa doses were switched to Isa30, with standard premedication. Results: Eighteen RRMM pts with a median of 1 prior LOTs (range: 1–3) were enrolled (11 males, 7 females). Sixteen pts (89%) received Isa-Kd and 2 (11%) Isa-Pd. The median age at first Isa30 was 70 years (range 43-80). Relevant comorbidities included allergic reactions (10/18, 56%), cardiovascular (9/18,50%), and infectious diseases (3/18, 17%). Pts had received a median of 11.5 cycles (range 0–32) and 27 infusions (range 3–65) at standard rates before switching to Isa30. Three pts (17%) had experienced IRRs, all G1-G2, during the 1st standard-rate infusion. Following the switch to Isa30, a total of 279 infusions were administered with no IRRs observed. Other AEs were reported in 14/18 pts (78%), primarily hematologic and cardiovascular (mainly hypertension in those receiving carfilzomib), and were consistent with expected profiles. Importantly, the accelerated infusion strategy resulted in a cumulative time saving of ~209 hours across all pts, with a median of ~12 hours (range 5-17) saved per patient. Conclusions: Our experience suggests that Isa can be safely administered over 30 mins starting from the 4th infusion, without an increased risk for IRRs. Overall, this approach offers meaningful clinical and organizational advantage by significantly reducing chair time and improving treatment efficiency.