“…Intriguingly, ibrutinib treatment beginning on day 28 after HSCT in mice with established cGVHD resulted in resolution of fibrosis, suggesting that treatment in the early phase of cGVHD can permit tissue repair and further suggesting that ongoing antibody deposition in cGVHD target organs may be required for a persistent fibrogenic process. Notably, for patients with debilitating cGVHD from fibrosis, therapies include supportive care, high-dose steroids, rapamycin, mycophenolate, imatinib, extracorporal photopheresis, IL-2, and lung transplant, all with incomplete efficacy and potentially serious complications (43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55). Although conclusions from rodent cGVHD must be validated in patients, our studies collectively indicate that a wide spectrum of cGVHD patients may benefit from ibrutinib therapy.…”