SHANGHAI, China – Chipscreen Biosciences Ltd., of Shenzhen, China, reported encouraging Phase II trial results for its Chidamide (formerly HBI-8000) in patients with relapsed or refractory peripheral T-cell lymphoma (PTCL) who had failed at least one prior systemic therapy.
Unlike currently available treatments which are delivered intravenously, Chidamide is an oral agent and is particularly effective against the most aggressive subtype of PTCL that's far more common in Chinese patients than Europeans or Americans.
The results are so promising, the China Food and Drug Administration (CFDA) granted the new drug application accelerated review.
Chidamide is an orally active benzamide type of class I-selective histone deacetylase (HDAC) inhibitor, an anticancer agent that modulates histone acetylation – an intracellular process that promotes epigenetic gene expression. Researchers hope HDAC reduces tumor-related gene expression to reduce tumor growth and metastasis. The HDAC inhibitors are particularly appealing as anticancer agents because they appear to reverse resistance to hormone receptor modulators.
Chidamide may follow the only other U.S. FDA-approved PTCL drugs – Folotyn (pralatrexate), marketed, respectively, by Summit, N.J.-based Celgene Corp. and by Spectrum Pharmaceuticals Inc.; and Istodax (romidepsin, Celgene).
Chidamide has unique properties that might give it an advantage, including oral administration. Both Folotyn and Istodax are administered intravenously. Plus, Chipscreen's CEO, Xian-Ping Lu, told BioWorld Today that the aggressive subtype occurs in about 20 percent of Chinese PTCL patients compared to 1 percent of European and American people. Improved efficacy for that subset is another plus for Chipscreen.
"I have great confidence this should be available to the patient" by the first quarter of 2014, Lu said.
Data supporting the CFDA's accelerated review status came from the CHIPDEL trial, an open-labeled, single-arm study that tested the safety and efficacy of Chidamide in 83 Chinese patients with relapsed or refractory PTCL.
The study reported exceptionally high objective response rates (ORR) of at least 27 percent in the treated patients. ORR as a primary endpoint for the trial was based on a prior agreement with the CFDA's Center for Drug Evaluation.
Lu said the safety data for Chidamide compare favorably with the safety data of competitor drugs, but full details will be released June 3 at the ASCO Annual Meeting in Chicago, during the Lymphoma and Plasma Cell Disorders Poster Discussion Session.
Currently, there are no other treatment options in China for patients with PTCL who relapse after first-line chemotherapy and will therefore be considered an orphan drug for registration purposes. For Chipscreen Biosciences that could mean an annual revenue of ¥150 million (US$24.5 million) from a single agent over the next three years.
He estimated 60,000 new patients each year in China are diagnosed with this PTCL.
Chipscreen Biosciences is currently also investigating Chidamide as a treatment option for non-small-cell lung cancer, and interim results for the Phase II double-blind trial are expected mid-2014. Chidamide has entered Phase II testing for breast cancer.
Huya Biosciences International LLC, of San Diego, holds exclusive development and commercialization rights to Chidamide worldwide outside of China, while Chipscreen maintains rights in China.
A key distinguishing driver behind Chipscreen Biosciences' drug development is a chemogenomics approach that matches small-molecule structures to disease targets and therapeutic functions.
In that approach, the company compares the molecular profiles of successful drugs, failed drugs and classical toxins in different model systems with the profiles of potential lead compounds.
Via that screening approach, Chipscreen also has a candidate drug, Chiglitazar, in Phase III trials for Type II diabetes and metabolic syndrome, and Chiauranib in Phase I testing for liver, ovarian, kidney and lung cancer, gastrointestinal stromal tumors and other solid cancers.