Deal with CStone Pharmaceuticals provides a route for investigational kinase drugs to reach cancer patients in China, Hong Kong, Macau, and Taiwan. 

Blueprint Medicines focuses on the development of highly selective therapies for the treatment of cancers and other diseases driven by the abnormal activation of kinases. The treatments are specially designed for genomically defined subsets of patients with unique genetic mutations that are most likely to respond to the treatments. 

In early June, the company signed a collaboration and license agreement with Chinese-based CStone Pharmaceuticals for the development and commercialization of its top three candidates - avapritinib, BLU-554 and BLU-667 - in Mainland China, Hong Kong, Macau and Taiwan, as monotherapies or combination therapies. 

Blueprint received an upfront payment of $40 million with up to $346 million in additional milestone payments. CStone will also pay to develop the drugs, although the two companies are sharing the costs for a clinical trial with BLU-554 as a combination treatment with CS1001, a clinical-stage anti-PD-L1 being developed by CStone as a first-line therapy for patients with hepatocellular carcinoma. 

All three of the drug candidates are kinase inhibitors that have demonstrated in early clinical trials to be effective in certain genomic-defined cancers. 

Avapritinib is a potent and selective inhibitor of PDGFRα D842V and KIT Exon 17 mutants, key drivers of metastatic and treatment-resistant gastrointestinal stromal tumors (GIST) and advanced systemic mastocytosis. BLU-554 targets the fibroblast growth factor receptor 4 (FGFR4), while sparing other members of the FGFR family and showing little to no inhibition of all other kinases. It is being developed for the treatment of advanced hepatocellular carcinoma, the most common form of liver cancer.

BLU-667 is an inhibitor designed to target rearranged during transfection (RET) fusions and is for the treatment of patients with non small-cell lung cancer. It was looked at quite favorably until better results were recently reported for Loxo’s new candidate LOXO-292.