Chronic graft versus host disease (cGvHD) is a complication that can occur in about 50% of patients following allogeneic stem cell transplant. Most cases are mild to moderate, but about 10-15 % of patients develop symptoms that are more severe with significant morbidity and mortality.
“In cGvHD, transplanted immune cells (graft) attack the patient's cells (host), leading to inflammation and fibrosis in multiple tissues, including skin, mouth, eye, joints, liver, lung, esophagus and gastrointestinal tract. Approximately 14,000 patients in the United States are living with cGvHD.”
Patients are typically systemically treated for this debilitating disease with corticosteroids and calcineurin inhibitors (such as cyclosporin and tacrolimus).
Belumosudil (Rezurock) Receives Breakthrough Therapy Designation
The news that the US Food and Drug Administration approved the compound belumosudil (future brand name: Rezurock) on July 16, 2021 and designated the drug as a Breakthrough Therapy, will therefore be welcomed by those patients with chronic GvHD. The drug is approved for “the treatment of adult and pediatric patients 12 years and older with cGvHD after failure of at least two prior lines of systemic therapy.” The compound is an oral drug that is the first in a new class of compounds targeting Rho-associated coiled-coil kinase 2 (ROCK2), a pathway that modulates the inflammatory response.
The drug’s developer, Kadmon, completed 2 Phase II clinical studies of about 65 patients each that were dosed either with 200 mg once a day or 200 mg taken twice a day.
The median time from cGvHD diagnosis was 25.3 months and 48% of patients had four or more organs involved. Patients had cycled through a median of 3 prior lines of systemic therapy and 78% were refractory to their last therapy.
In other words, this patient population was in serious need of a treatment alternative.
The results of these two studies can be summarized as follows:
- Overall Response Rates (ORR) of 74% with 200 mg once daily and 77% with 200 mg twice daily
- Responses were achieved across patient subgroups and complete responses were observed in all organ systems, including the lungs. Responses were durable, with a median duration of 54 weeks, which represents the total combined response periods for each patient.
- 44% of responders maintained their response for ≥1 year.
- There was a clinically meaningful improvement from baseline in the Lee Symptom Scale (LSS) score, a chronic GvHD symptom measurement, with belumosudil that was observed in 61% of patients.
- During treatment, 65% of patients were able to reduce their corticosteroid dose, with 21% of patients completely discontinuing corticosteroid therapy. Additionally, 22% of patients completely discontinued their calcineurin inhibitor therapy.
- Belumosudil was well-tolerated and adverse events have been consistent with those expected in patients with advanced cGvHD receiving corticosteroids and/or other immunosuppressants.
- Kadmon has announced that the drug will be commercially available by late August 2021. This is, unquestionably, good news for those living with this tough to treat/manage disease.
about the author
I am a patient diagnosed in 2014 with primary plasma cell leukemia (pPCL), a rare and aggressive variant of multiple myeloma and have been very fortunate to find successful treatment at the division of Cellular Therapy at the Duke University Cancer Institute. My wife, Vicki, and I have two adult children and two grandsons who are the ‘lights of our lives’. Successful treatment has allowed Vicki and I to do what we love best : traveling the world, albeit it with some extra precautions to keep infections away. My career in the pharmaceutical industry has given me insights that I am currently putting to use as an advocate to lower drug pricing, especially prices for anti-cancer drugs. I am a firm believer that staying mentally active, physically fit, compliant to our treatment regimen and taking an active interest in our disease are keys to successful treatment outcomes.