cGVHD is a life-threatening condition that can occur in patients after they have received a haematopoietic stem cell transplantation (HSCT) to treat certain blood or bone marrow cancer, when cells from the transplant attack healthy cells in a patient’s tissues. The condition is estimated to occur in 30-70 percent of all patients who receive HSCT.

"Patients with cGVHD who do not respond to other forms of therapy - typically corticosteroids to suppress their immune system - now have a treatment option specifically indicated to treat their condition," said Richard Pazdur, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Haematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research.

"This approval highlights how a known treatment for cancer is finding a new use in treating a serious and life-threatening condition that may occur in patients with blood cancer who receive a stem cell transplant."

Imbruvica (ibrutinib) is a first-in-class Bruton’s tyrosine kinase inhibitor already approved for certain indications across chronic lymphocytic leukaemia, Waldenström’s macroglobulinemia and marginal zone lymphoma, as well as mantle cell lymphoma under accelerated approval status.

In a clinical trial involving patients with cGVHD whose symptoms persisted despite standard treatment with corticosteroids, 67 percent of those treated with Imbruvica experienced an improvement in symptoms. In 48 percent of patients in the trial, the improvement of symptoms lasted for up to five months or longer.

Common side effects observed in trials include fatigue, bruising, diarrhoea, thrombocytopenia, muscle spasms, swelling and sores in the mouth, nausea, anaemia and pneumonia, while those more serious include haemorrhage, infections, cytopenias, irregular heartbeat, hypertension, new cancers (second primary malignancies) and metabolic abnormalities (tumour lysis syndrome).

"For most patients, the diagnosis of cGVHD comes after a long and already arduous battle with a blood-related disease," said David Miklos, associate Professor of Medicine, Stanford University, and lead investigator of the Imbruvica cGVHD clinical study.

"This approval provides physicians and the cGVHD patient community with a welcome new approach for patients who fail initial therapy, as data show treatment with Imbruvica resulted in encouraging and sustained clinical responses."