(233) Tolerability and Safety of a 3-step or 12-step Chemotherapy Desensitization Protocol

Poster Abstract: Background/Rationale: Chemotherapy desensitization protocols provide a way to continue preferred regimens in patients who experience hypersensitivity reactions, but questions remain regarding the optimal protocol, efficacy based on drug, and how to manage future infusions for patients with breakthrough reactions. Our institution has protocols for a 3-step and 12-step desensitization based on the drug and severity of initial reaction along with protocol modification strategies in the setting of breakthrough reactions.



Objective: The primary objective was the rate of completed chemotherapy desensitization. Secondary objectives included number of desensitization infusions completed per patient, rate of breakthrough reactions, and severity of breakthrough reactions.



Methods: A retrospective chart review was conducted evaluating patients who received chemotherapy desensitization infusions, as a 3-step or 12-step desensitization, between 2011 and 2023 at the University of Kansas Health Systems. Statistical analysis was performed using descriptive statistics.



Results: The analysis included 153 patients. 130 patients (82.8%) received a 12-step desensitization infusion, and 27 (17.2%) patients received a 3-step desensitization infusion. Chemotherapy desensitization was successfully completed in 97.8% of infusions (N=741/758). Agents included carboplatin (N=41, 27.2%), paclitaxel (N=40, 26.5%), docetaxel (N=28, 18.5%), oxaliplatin (N=28, 18.5%), cisplatin (N=5, 3.3%), liposomal doxorubicin (N=4, 2.6%), irinotecan (N=3, 2.0%), methotrexate (N=2, 1.3%), and cabazitaxel (N=1, 0.6%).

The median number of desensitization infusions completed per patient was 4.9 (range 0-52). During initial desensitization, 37 patients (24.2%) reacted, and 16 patients (10.2%) were not able to complete the full infusion. 9 patients (6%) discontinued treatment due to breakthrough reactions.

Mild to moderate breakthrough reactions occurred in 34 patients (22.2%), and severe breakthrough reactions occurred in 3 patients (1.9%). Only 1 patient (0.6%) required epinephrine. Of patients that reacted, 28 (75.7%) attempted subsequent infusions with protocol modifications, and of those only 1 was not able to tolerate a future desensitization. There were no patient deaths related to desensitization.



Conclusion: This study demonstrates that patients tolerated a 3-step or 12-step desensitization protocol and were able to continue therapy. Severe breakthrough reactions were rare demonstrating safety of this treatment strategy. In patients who experienced breakthrough reactions, modifications to future infusions were made to allow for successful subsequent desensitizations.

References (must also be included in final poster): Breslow RG, Caiado J, Castells MC. Acetylsalicylic acid and montelukast block mast cell mediator-related symptoms during rapid desensitization. Ann Allergy Asthma Immunol. 2009; 102: 155-160.

Caiado J, Bras R, Palino M, Costa L, Castells M. Rapid desensitization to antineoplastic drugs in an outpatient immunoallergy clinic. J Ann Allergy Asthma Immunol. 2020; 125: 325-333.

Castells MC, Tennant NM, Sloane DE, et al. Hypersensitivity reactions to chemotherapy: outcomes and safety of rapid desensitization in 413 cases. J Allergy Clin Immunol. 2008; 122(3): 574-580.

O’Malley DM, Vetter MH, Cohn DE, Khan A, Hays JL. Outpatient desensitization in selected patients with platinum hypersensitivity reactions. Gynecologic Oncology. 2017; 145: 603-610.