To achieve optimal clinical outcomes with imatinib in GIST patients, it is crucial to maintain standard imatinib dose. Skin rash is a relatively common and sometimes severe adverse event of imatinib in GIST patients and may affect imatinib compliance. Our previous retrospective study suggested that severe skin rash induced by imatinib can be managed by systemic steroid without imatinib dose interruption or reduction. This phase II study was conducted to evaluate the efficacy and safety of systemic steroid in GIST patients with imatinib-associated severe skin rash.

Inclusion Criteria:

• Age 18 years or older, at the time of acquisition of informed consent
• Histologically confirmed metastatic and/or advanced (unresectable or recurrent) GIST with CD117(+), DOG-1(+), or mutation in KIT or PDGFRα gene
• Patients with metastatic and/or advanced (unresectable or recurrent) GISTs, receiving imatinib as adjuvant or neo adjuvant, palliative chemotherapy for pre-or post- operations
• imatinib-associated severe skin rash which was defined as grade 3 skin rash or grade 2 skin rash with pruritus over grade 2