Azacitidine for the treatment of steroid-refractory chronic graft-versus-host disease: the results of the phase II AZTEC clinical trial

Chronic graft-versus-host disease (cGvHD) is a major cause of non-relapse morbidity and mortality following allogeneic stem cell transplant. Over half of patients with moderate or severe cGvHD fail to respond adequately to first-line treatment with systemic steroids, and although a range of second-line options have been employed, a lack of prospective evidence means there is no standard of care. The AZTEC trial is a prospective, single-arm, phase II study investigating the safety and activity of azacitidine for the treatment of cGvHD in patients who are resistant to, or intolerant of, systemic steroid therapy. The co-primary outcomes were treatment tolerability, and activity measured as objective response according to modified National Institutes of Health criteria. Fourteen patients were recruited to the first stage of the trial, of whom seven completed the planned six cycles of azacitidine 36 mg/m2 days 1–5 per 28-day cycle. Azacitidine was tolerated by 13/14 patients, and 7/14 showed an objective response. Clinical responses were mirrored by improvements in patient-reported cGvHD symptoms and quality of life. AZTEC demonstrates that azacitidine is a safe and promising option for the treatment of cGvHD, and continued evaluation in the second stage of this phase II efficacy study is supported.