- D3.547 - Clinical Outcomes and Safety of Drug Desensitization in Chemotherapy-Induced Hypersensitivity

Antineoplastic drugs are the third leading cause of drug-induced anaphylaxis. Rapid drug desensitization enables patients who develop chemotherapy-induced hypersensitivity reactions to continue receiving first-line anticancer therapy. This study evaluated the clinical characteristics, diagnostic work-up, and outcomes of patients with severe chemotherapy-induced hypersensitivity reactions managed at our tertiary care center.

We conducted a retrospective descriptive study of patients referred from the Clinical Oncology Department in 2024 who experienced hypersensitivity reactions and underwent rapid drug desensitization. Collected data included demographic characteristics, tumor type, chemotherapy line, and desensitization cycle. A standardized three-bag, 13-step desensitization protocol was used, with premedication including montelukast, aspirin, cetirizine, and methylprednisolone.

A total of 68 patients underwent desensitization; 46 (67%) were male, with a median age of 61.5 years. The most frequent tumor types were colorectal (44%), breast (18%), and gynecological cancers (18%), and 65% of patients had stage IV disease. Hypersensitivity reactions occurred most commonly with oxaliplatin (52%), liposomal doxorubicin (16%), and paclitaxel (10%), typically after the second treatment cycle. All taxane-related reactions occurred within the first two cycles, whereas 92% of platinum-related reactions occurred at later cycles. Baseline serum tryptase levels exceeded 11 ng/mL in three patients. According to Brown’s classification, reactions were grade 1 in 31%, grade 2 in 40%, and grade 3 in 29% of cases. During follow-up, 17 patients (25%) experienced disease progression. Median progression-free survival was 7 months, and median overall survival was 32 months.

Platinum derivatives and taxanes were the primary agents associated with hypersensitivity reactions. Taxanes tended to trigger reactions early, whereas platinum agents were associated with later-onset reactions. Rapid drug desensitization proved to be a safe and effective strategy, enabling continuation of first-line chemotherapy with favorable survival outcomes. The implementation of standardized desensitization protocols should be encouraged in patients with chemotherapy-induced hypersensitivity reactions.