Successful desensitization protocol for hypersensitivity reaction caused by sunitinib in a patient with a gastrointestinal stromal tumor.

Sunitinib is an orally bioavailable small molecule that inhibits multiple receptor tyrosine kinases. Generalized hypersensitivity reactions (HSR) to sunitinib have not been described. A patient with a gastrointestinal stromal tumor (GIST) who developed a type I HSR to sunitinib and who was successfully treated by drug desensitization is reported. A 51-year-old man with metastatic GIST developed a type I HSR during sunitinib treatment. Four days after treatment initiation, the patient presented to the Emergency Department with acute generalized urticaria and facial and throat swelling. Sunitinib was restarted 1 week later, using a desensitization protocol in which 10 escalating reduced doses, beginning with 0.05 mg, were given following pre-medication with prednisone and promethazine. This protocol was well tolerated and allowed us to continue the treatment, obtaining partial remission of the liver metastasis that was followed by complete resection. Sunitinib was temporarily discontinued before the operation and renewed after surgery by repeating the same desensitization procedure. At the time of this report, sunitinib has been continued for 1 year without evidence of recurrent disease. Oral desensitization appears to be an option for patients with hypersensitivity type I to sunitinib and may permit its safe administration to patients who experience HSR to this life-prolonging medication.