PURPOSE Desensitization is a safe alternative for patients with hypersensitivity reactions (HSRs) to platinum-based chemotherapeutic agents and widely used in real practice by employing stepwise administration of multiple serial dilutions of the culprit drugs. However, its labor-intensive nature has required a simpler protocol that is easier to prepare and perform.

METHODS We performed an observational study of patients with platinum HSR who underwent a new non-dilution one-bag desensitization protocol. Premedication consisted of Montelukast as well as H1 and H2 blockers. The outcomes and safety profiles of a new protocol were assessed.

RESULTS A total of 36 patients were recruited (oxaliplatin 23, carboplatin 9, and cisplatin 4) and the most common grade of HSR presented was grade 2 (61.1%), followed by grade 3 (25%), and grade 1 (13.9%). Of 175 desensitization procedures, all cases were successfully completed in re-administration of culprit chemotherapeutic platinum agents; 146 (83.4%) had no breakthrough reactions (BTRs) while 29 (16.6%) did. Most BTRs were mild reactions (grade 1, 51.7%) or moderate reactions (grade 2, 44.8%) of Brown's Scale. Although there was one case of asymptomatic mild hypotension (grade 3, 3.5%), categorized as severe reaction, dyspnea, desaturation, and anaphylaxis did not occur. The proportion of severe HSRs was significantly lower than that of initial HSRs (3.5% vs. 25%, P = 0.0167).

CONCLUSIONS The new non-dilution desensitization protocol was safe and effective for re-administration of culprit platinum agents in patients with a history of HSRs. Therefore, this new protocol can be used as an alternative to existing protocols using multiple serial dilutions.