Successful desensitization protocol for hypersensitivity reaction probably caused by dabrafenib in a patient with metastatic melanoma

Successful Dabrafenib Desensitization Protocols in a Patient with Metastatic Melanoma

Dabrafenib and trametinib are two available molecules that have been approved for the treatment of metastatic melanoma with BRAF-V600E or V600K mutations. Their combined therapy has led to long-lasting survival benefits and substantially improved outcomes. Until now, only a few cases of severe hypersensitivity reactions to dabrafenib and vemurafenib have been reported, and even fewer desensitization protocols to these molecules have been documented. We report the case of a 71-year-old female patient with metastatic melanoma harboring a BRAF-V600E mutation undergoing targeted therapy with dabrafenib and trametinib. Two weeks after the initiation of the combined treatment, she developed a hypersensitivity reaction. The cause–effect relationship between dabrafenib and the hypersensitivity reaction was demonstrated twice, when symptoms recurred upon dabrafenib reintroduction. We started a rapid 3-day dabrafenib desensitization protocol, which was well tolerated. When the patient discontinued the drug administration, we decided on a longer protocol that included more steps and more days in order to prevent the occurrence of other hypersensitivity reactions. Our patient tolerated both rapid and slow-going schedules, the first one reaching the final dose within 3 days and the second one reaching the total daily dose within 14 days. Depending on the patient’s needs, the severity of the hypersensitivity reaction and the hospital’s availability, the doctor may choose either the rapid or slow-going desensitization protocol.

Preparations of exploration of immediate hypersensitivity to antineoplastic agents: An oncology pharmacy perspective

BACKGROUND

Cancer patients are being exposed to antineoplastic drugs more frequently and for longer periods, resulting in a higher risk of hypersensitivity reactions. The aim of this study was to assess the pharmaceutical time and direct cost of drug allergy explorations following immediate hypersensitivity reactions to antineoplastic agents.

METHODS

A micro-costing method was used to collect data on consumption of human and material resources for allergy exploration preparations. The monetisation was carried out on the basis of prices and hourly wage costs applied in 2018. The number and type of allergy explorations prepared by the pharmacy as well as nature of antineoplastic drugs tested, and the number of culprit drugs reintroductions were collected.

RESULTS

Almost 1.5 h is required to realise allergy tests for one patient including pharmacist time for prescription analysis and pharmacy technician's time for tests preparation. The mean manufacturing cost of these tests is estimated at €62.87 (€57.82-65.49) per culprit drug for one patient. Programming patients according to culprit drugs tested allows rationalising healthcare provider time and increasing efficiency. From January 2010 to December 2018, 277 patients were tested and 490 allergy explorations were performed, corresponding to more than 5000 preparations. Mostly, the culprit drug could be reintroduced (n = 383, 78.2%) allowing patients to receive the best possible treatment.

CONCLUSION

Management of hypersensitivity reactions is constantly progressing, as it contributes to improving patient care in oncology. This activity is time-consuming for the pharmacy team but allows patients with previous hypersensitivity reaction to continue effective treatment.