CStone receives CTA approval in China to start Phase I trial for FGFR4 inhibitor BLU-554 (CS3008)

SUZHOU, China, Jan. 28, 2019 /PRNewswire/ -- CStone Pharmaceuticals (CStone) today announced that the National Medical Products Administration (NMPA) recently approved the clinical trial application (CTA) to start a Phase I clinical trial in China for BLU-554 (CS3008), an inhibitor of fibroblast growth factor receptor 4 (FGFR4) discovered by the company's partner Blueprint Medicines. CStone has exclusive rights to develop and commercialize BLU-554 in Mainland China, Hong Kong, Macau and Taiwan.

The trial is part of a global Phase I trial for BLU-554 in patients with advanced hepatocellular carcinoma (HCC) not previously treated with a tyrosine kinase inhibitor (TKI). The aim is to assess the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and preliminary efficacy of BLU-554 in this patient subset. CStone and Blueprint Medicines expect to enroll the first patient in the Phase I clinical trial in China soon.

HCC is the most common form of liver cancer. In China, HCC is the third most significant cause of cancer-related death, with approximately 466,000 new diagnoses and 422,000 deaths caused by the disease each year. It is estimated that approximately 30% of patients with HCC have tumors with aberrantly activated FGFR4 signaling. The majority of Chinese HCC patients (55%) are not diagnosed until the advanced stages of the disease. Currently, treatment options for advanced HCC patients remain limited.

BLU-554 is a potent and highly selective small-molecule inhibitor of FGFR4. Blueprint Medicines announced preliminary Phase I clinical data of BLU-554 at the European Society of Clinical Oncology (ESMO) 2017 Congress, as of a data cutoff date of August 18, 2017. In heavily pre-treated patients with FGFR4-driven HCC (n=38), the data showed an objective response in 6 patients (16%; 1 complete response and 1 partial response pending confirmation), while disease control was achieved by 26 patients (68%), and 18 patients (49%) had a reduced tumor burden. In 5 patients who had not previously received TKI therapy, preliminary evidence of prolonged disease control was observed. BLU-554 was well-tolerated and most adverse events reported by investigators were Grade 1 or 2.

Dr. Frank Jiang, CEO and chairman of CStone, commented: "Compared with current treatments, BLU-554 has produced encouraging data in terms of tolerability and disease control rates. We also plan to conduct a Phase I trial of BLU-554 in combination with CS1001 for the treatment of advanced HCC patients in China in the second half of 2019. Our hope is to make more effective treatment options available to HCC sufferers."

About BLU-554

BLU-554 is an oral, highly selective and irreversible inhibitor of FGFR4 developed by Blueprint Medicines, with a precise selectivity for FGFR4 that spares the paralog kinases FGFR1, FGFR2 and FGFR3. Blueprint Medicines is developing BLU-554 for the treatment of HCC caused by FGFR4 activation, estimated to account for approximately 30% of patients with HCC tumors. BLU-554 has been granted orphan drug status by the U.S. Food and Drug Administration.

In June 2018, CStone and Blueprint Medicines entered into a license and collaboration agreement in which Blueprint Medicines granted CStone exclusive rights to develop and commercialize BLU-554 in Greater China. Blueprint Medicines retains development and commercial rights for BLU-554 in the rest of the world.

About CStone

CStone Pharmaceuticals is a biopharma company focused on developing and commercializing innovative immuno-oncology and molecularly targeted drugs to address significant unmet medical needs for cancer patients in China and worldwide. Since company inception three years ago, CStone has assembled a world-class management team that has a full spectrum of complementary skillsets from preclinical research to clinical development and commercialization. Through a dual source of innovation, comprised of internal research and external partnership, the company has built a rich oncology pipeline of 14 drug candidates with significant mono- and combination-therapy potential and synergies, including 4 assets exclusively in-licensed from Agios and Blueprint Medicines. Among CStone's portfolio, 4 late-stage drug candidates are at or near registrational trial. CStone's business model has a clear focus on clinical development, while at the same time, the company is rapidly developing its commercial and manufacturing capabilities. The company is backed by prestigious VC and PE funds with record-breaking amounts of equity investment, raising a combined total of USD 412 million in two financing rounds to date. With an experienced team, a rich pipeline, a robust clinical development-driven business model, and substantial funding, CStone's vision is to become globally recognized as a leading biopharma company by bringing innovative and differentiated oncology therapies to cancer patients in China and worldwide.

For more information about CStone Pharmaceuticals, please visit: www.cstonepharma.com.

SOURCE CStone Pharmaceuticals