Results of Multicenter Phase II Study With Imatinib Mesylate in Allogeneic Recipients With Steroid-Refractory Chronic GVHD

In this multicenter phase II study, we evaluated the safety and efficacy of imatinib in patients with steroid-resistant chronic graft-versus-host disease (cGVHD) and evaluated the quality of life (QOL) of the enrolled patients using the Short Form 36 (SF-36) health survey questionnaire. Thirty-six patients who were diagnosed with steroid-refractory cGVHD and treated with imatinib between March 2013 and February 2019 received 100 mg/day of imatinib for 2 weeks. Depending on the patient’s condition and investigator’s decision, the imatinib dose was allowed to be increased by 100 mg every 2 weeks up to 400 mg/day. Patients who achieved stable disease (SD), partial remission (PR), and complete remission (CR) at 3-month response evaluations continued imatinib for up to 6 months. The majority of the patients had multi-organ cGVHD, with skin (63.9%), lungs (44.4%), mouth (38.9%), and eyes (38.9%) as the most common sites. The overall response rate was 58.3%, including 3 and 18 patients with CR and PR, respectively, and an overall decline in National Institutes of Health (NIH) severity scores was observed at study completion in the absence of significant adverse effects. The overall response rates were 70.5%, 66.7%, 34.8%, and 25% in patients with gastrointestinal, liver, skin, and lung cGVHD, respectively. Factors representing emotional well-being were significantly improved based on the patient-reported QOL evaluation using SF-36. The effect of imatinib on steroid tapering, which was notable in responders, was also present in 50% of those who achieved SD without worsening cGVHD. Imatinib exhibited therapeutic efficacy in steroid-refractory and steroid-dependent cGVHD with tolerable toxicity. Clinical Trial Registration: KCT0006785.