FDA Approves Rezurock for Chronic Graft-Versus-Host Disease After Two Prior Lines of Therapy

The kinase inhibitor Rezurock was well tolerated in patients with chronic graft-versus-host disease who received up to five lines of prior systemic therapy.

The Food and Drug Administration (FDA) has approved the kinase inhibitor Rezurock (belumosudil) for the treatment of adults and children aged 12 years and older with chronic graft-versus-host disease after receiving at least two prior lines of systemic therapy.

The treatment has been approved as a 200-milligram dose once daily, according to a release from Kadmon Holdings, the manufacturer of the drug.

“Rezurock represents a new treatment paradigm for thousands of (chronic graft-versus-host disease) patients, including those with difficult-to-treat manifestations like fibrosis,” Dr. Corey Cutler, associate professor of medicine at Harvard Medical School and medical director of the adult stem cell transplantation program at Dana-Farber Cancer Institute, said in the release. “Rezurock has shown robust and durable responses across the spectrum of (chronic graft-versus-host disease) and is safe and well tolerated, allowing patients to stay on therapy and achieve meaningful benefit from treatment.”

The approval of Rezurock, which was previously granted breakthrough therapy designation and priority review by the FDA, was based on findings from the ROCKstar trial. Researchers who conducted the trial assessed the safety and efficacy of Rezurock in 65 patients with chronic graft-versus-host disease who previously received two to five lines of systemic therapy, with a median of three prior lines of therapy.

With a 200-milligram dose of Rezurock, the overall response rate (patients with a partial or complete response to treatment) was 75% through the first day of the seventh cycle, with 6% of patients achieving a complete response (disappearance of all signs of cancer) and 69% of patients achieving a partial response (decrease in tumor size or extent of cancer in the body), according to the release. The median time to first response to the treatment was 1.8 months. Additionally, 62% of patients who responded to the treatment did not require administration of a new systemic therapy for at least 12 months after treatment response. The median duration of response to Rezurock was 1.9 months.

“Patients receiving Rezurock reported significant improvements in (chronic graft-versus-host disease) symptoms, showing that not only did treatment result in organ responses, but it also made people feel better,” said Dr. Stephanie Lee, professor at the Fred Hutchinson Cancer Research Center and the University of Washington School of Medicine, in the release. “This is so important for a chronic disease with a high symptom burden.”

Rezurock was well tolerated by patients in the trial, and side effects were consistent with those patients with advanced chronic graft-versus-host disease who received corticosteroids and/or other immunosuppressants, according to the release. The most common side effects, which occurred in at least 20% of patients in the trial, included weakness, infections, diarrhea, nausea, cough, shortness of breath, bleeding, swelling from excess fluid, musculoskeletal pain, abdominal pain, phosphate decreases (may lead to difficulty breathing, confusion, muscle weakness and muscle damage), headache, lymphocyte decreases (may indicate infection), gamma glutamyl transferase increases (potentially indicating liver injury) and high blood pressure, according to a release from the FDA.

Rezurock is expected to be available for use by patients in the United States by late August 2021, according to the release.

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