SAN DIEGO – An oral regimen of 420 mg ibrutinib achieved complete response in one-third of allogeneic stem cell recipients with chronic graft-vs.-host disease, David Miklos, MD, reported during a late-breaker session at the annual meeting of the American Society of Hematology.
Fully 79% of patients in this open-label phase II study were considered responders when first assessed, 71% of responses lasted at least 5 months, and patients whose disease involved multiple organs generally showed responses in at least two organs, said Dr. Miklos of Stanford (Calif.) University.
Ibrutinib is a first-in-class Bruton’s tyrosine kinase (BTK) inhibitor. Cardiotoxicities have been a concern with ibrutinib, but were not observed in this cohort of 42 patients whose graft-vs.-host disease had not benefited from frontline therapy, Dr. Miklos said during a video interview. However, 52% of patients in this study developed other serious adverse events that are typical with ibrutinib, including pneumonia, septic shock, and fever, he said.
Chronic graft-vs.-host disease is the most common morbidity after allogeneic transplant. This is an “orphan disease” – there are no approved therapies for patients for whom corticosteroids are ineffective, Dr. Miklos noted. Based on these results, investigators are planning a randomized, placebo-controlled, phase III study, he added.
Ibrutinib is jointly commercialized and developed by Janssen Biotech and by Pharmacyclics LLC, an Abbvie company. Dr. Miklos disclosed a consulting relationship, travel and expenses reimbursements, and research funding from Pharmacyclics.