11156 Background: Rapid Drug Desensitization (RDD) as The Castells protocol is based on progressively increasing concentrations and infusion rates of the drug under close monitoring, inducing temporary drug tolerance. To assess the role of Rapid Drug Desensitization (RDD) to treat cancer patient with infusion-related allergic reactions (IRRs) we planned an observational trial in 2021. Methods: From 2021 to 2025 all patients experiencing IRRs at the Rimini Oncology Unit, after an allergological evaluation, were treated according to the Castells desensitization protocol. We analyzed the safety of this apporach as well as the treatment discontiunation rate. The IRR severity was classified (grade 1-3) using the Brown classification from 2004. Results: A total of 155 patients were treated with RDD. Among drugs administered using a desensitization protocol, drugs administered with the RDD were paclitaxel (38.06%), oxaliplatin (25.80%), docetaxel (14.10%), and carboplatin (12.9%), irinotecan (1.94%), etoposide (1.94%), liposomal doxorubicin (1.29%), trastuzumab (1.29%), atezolizumab (0.65%), cetuximab (0.65%), cyclophosphamide (0.65%), and cisplatin (0.65%). Grade 3 reactions occurred in 1.29% of patients during RDD, while grade 2 and grade 1 reactions were observed in 3.87% and 2.58%, respectively. No deaths associated with desensitization treatment occurred. The IRRs were managed with treatment interruption and administration of steroids and antihistamines. Notably, 3.22% of patients experienced an allergic reaction during RDD but were able to complete treatment. In total 132 patients completed the planned treatment (85.2%) using the RDD approach. Among those who discontinued, 7 patients (4.5%) stopped due to allergic reactions during the first desensitization cycle. The remaining treatment discontinuations were due to clinical deterioration, patient decision or transfer to another institution (1.9% each), progressive disease (3.9%), or other causes (0.7%). We summarized the characteristics in the table. Conclusions: The RDD protocol is safe and permits to maintain the original schedule in the most part of cancer patients that present a major allergic reaction during chemotherapy. Further trials are probably needed to better define the role of RDD and the drugs primarily candidate to the desensitization protocol. Number of patients % of the total (155 patients) Treatment completed 132 85.2% Discontinuation for infusional reaction 7 4.5% Discontinuation for clinical deterioration 3 1.9% Discontinuation for patient decision 3 1.9% Discontinuation for progressive disease 6 3.9% Discontinuation for transfer to another institution 3 1.9% Discontinuation for other causes 1 0.7%
Palmieri et al. (Wed,) studied this question.