Belumosudil

For graft-versus-host disease (GVHD), a fatal complication after allogeneic hematopoietic stem cell transplantation, the advent of belumosudil has filled the clinical gap in second-line treatment. As the world's first and currently only approved ROCK2 kinase inhibitor, it targets and inhibits the ROCK2 signaling pathway, simultaneously regulates the phosphorylation levels of STAT3 and STAT5, reduces the secretion of pro-inflammatory cytokines and promotes the differentiation of regulatory T cells, ultimately achieving the reconstruction of immune balance. It is clinically mainly used for the treatment of chronic GVHD patients aged 12 years and above who have failed at least two prior lines of systemic therapy, and can also be used for acute GVHD patients with steroid resistance, providing a brand-new survival-benefiting option for this population that has long lacked effective treatment regimens.

The global market size of chronic GVHD drugs exceeded US$2.8 billion in 2023, and is expected to rise to US$6.3 billion in 2028 at a compound annual growth rate of 17.2%. Among them, ROCK inhibitors, as a category with a new mechanism of action, have a significantly higher growth rate than traditional immunosuppressants. In terms of competitive landscape, belumosudil is still the only GVHD therapeutic drug targeting this pathway that has been approved for marketing. In China, apart from the imported original drug, no generic drug has been approved for marketing yet. The 3 generic companies that have submitted applications are still in the bioequivalence trial stage, and the market has sufficient potential space.

The original developer of belumosudil is Kadmon Pharmaceuticals (later acquired by Sanofi), with the trade name Rezurock. Its core compound patent in the United States expires in 2038, and the compound patent in China expires in 2037. The approved dosage form of the original drug is tablet, with a specification of 200mg. It has been included in the FDA Orange Book Reference Listed Drug Catalog, and is also included in China's *Catalog of Reference Preparations for Chemical Drugs (39th Batch)*. In terms of domestic API registration, there is currently no domestic belumosudil API that has obtained the A-status registration number. The original preparation was approved by the NMPA for import and marketing in October 2023. (Data as of June 2025, please refer to the official CDE website for the latest information)

CATO can provide a full set of impurity reference standards for belumosudil, covering all key impurities in the synthesis and degradation processes. Most products are in stock. For in-stock products, orders placed before 16:00 will be shipped on the same day. All products fully meet the compliance requirements of multiple regulations such as the Chinese Pharmacopoeia and FDA, and can provide stable reference standard support for pharmaceutical enterprises in the links of API R&D, quality research and registration.