Kadmon Prepares FDA Filing for GVHD Drug Belumosudil Following Phase 3 Success

New York biotech Kadmon is on course to file for FDA approval of belumosudil for chronic graft versus host disease (GVHD) after it hit the mark in a pivotal trial. GVHD is a common and often fatal complication that can follow a bone marrow transplant, which occurs when the donated cells mount an immune response against the transplant recipient’s tissues and organs.

In the 132-patient ROCKstar study, almost three quarters of chronic GVHD patients treated with a daily oral dose of belumosudil (KD025) saw an improvement in symptoms that lasted for at least six months. The patients had chronic GVHD symptoms despite prior treatment with at least two lines of systemic therapy.

Current treatment options include steroids and immunosuppressant drugs like cyclosporine, as well as newer therapies like Johnson & Johnson’s Imbruvica (ibrutinib) and Incyte’s Jakafi (ruxolitinib) that are used for the acute stages of GVHD. Belumosudil, a Rho-associated protein kinase-2 (ROCK2) inhibitor, reduces immune mediators like IL-17 and IL-23 and would be a first-in-class therapy for GVHD if approved by the FDA.

In the ROCKstar trial, a 200mg dose of belumosudil given once-daily achieved an overall response rate of 73% of patients, similar to the 74% rate seen in a group taking it at 200mg twice-daily. The response rate has climbed from an interim analysis reported earlier this year, with almost half (49%) of responders maintaining the effect on symptoms for at least 20 weeks.

The FDA has agreed to review belumosudil under its Real-Time Oncology Review (RTOR) pilot programme, aiming to speed up access to promising new cancer drugs while ensuring they are safe and effective. Belumosudil has both breakthrough and orphan drug designations for chronic GVHD and is also being studied in a mid-stage trial for diffuse cutaneous systemic sclerosis, a subtype of systemic scleroderma.