PTC Therapeutics, Inc. (PTC) announced the initiation of two clinical trials of the company's product candidate PTC299 in adult patients with solid tumor cancers and Kaposi Sarcoma, a HIV-related cancer. PTC299 is an orally delivered, investigational new drug that offers an innovative approach to anti-angiogenesis, limiting the formation of new blood vessels for tumors. Based on the pre-clinical and clinical studies to date, PTC299 has the potential to meet significant unmet medical need for patients with different types of cancer.

An open-label Phase 1b clinical trial will enroll up to 42 patients with locally advanced or metastatic solid tumors in order to evaluate the safety and efficacy of multiple doses of PTC299 alone and in combination with Taxotere(R) (docetaxel) chemotherapy. The primary objective of the study is to determine the maximum tolerated dose of PTC299. The trial will also assess the overall safety profile of the drug when administered alone and in combination with chemotherapy, evaluate its effect on the production of vascular endothelial growth factor (VEGF), its antitumor activity, and its pharmacokinetics. The study will be conducted at Memorial Sloan-Kettering Cancer Center in New York.

"As principal investigator of the Phase 1b clinical trial in advanced cancer, I am encouraged by promising preclinical and early clinical PTC299 data that suggest a distinctive approach to inhibition of tumor angiogenesis and an overall well tolerated safety profile," said Gary K. Schwartz, M.D., Chief, Melanoma and Sarcoma Service of the Memorial Sloan-Kettering Cancer Center. "PTC299 has the potential to address significant unmet medical need for patients with multiple tumor types."

In addition, a second open-label Phase 1/2 clinical trial will enroll up to 45 patients with Kaposi's sarcoma associated with human immunodeficiency virus (HIV) infection. Kaposi's sarcoma, a cancer that develops from the cells that line blood vessels, is the one of the most common HIV-related cancers. The primary objectives of the study are to determine the maximum tolerated dose of PTC299 and to evaluate the overall safety and efficacy profile of the drug as therapy for Kaposi's sarcoma. The study will be conducted by the AIDS Malignancy Consortium (AMC), a multicenter clinical trials group supported by the National Cancer Institute, part of the National Institutes of Health, and will be conducted at AMC sites in the U.S. The study will be led by Dr. Susan E. Krown, M.D., Member, Melanoma and Sarcoma Service, Memorial Sloan-Kettering Cancer Center, who chairs the AMC's Kaposi's Sarcoma Working Group.

"PTC299 offers a new approach to anti-VEGF therapy in cancer because it appears selective for pathological VEGF production and acts early in the VEGF pathway, upstream of currently available anti-angiogenic agents," said Langdon Miller, M.D., Chief Medical Officer of PTC Therapeutics. "We are committed to rapidly developing PTC299 for the treatment of cancer. These new trials broaden our existing efforts to characterize PTC299 activity and safety in multiple treatment settings."

PTC299 is a novel, orally administered small-molecule investigational drug that in preclinical models selectively blocked the pathological, or disease-related, production of the protein VEGF in tumors acting upstream of current therapies, while sparing physiological VEGF expression. VEGF plays a critical role in angiogenesis, or the formation of new blood vessels. Regulating the pathological production of VEGF is intended to inhibit the growth of a tumor by restricting its supply of oxygen and nutrients.

In previous Phase 1 clinical studies, PTC299 was generally well tolerated by healthy volunteers who received single or multiple doses, with no serious, dose-limiting or definitively drug-related adverse events reported. All clinical adverse events were mild (Grade 1) or moderate (Grade 2) in severity and did not require intervention. In addition, adverse events such as bleeding, hypertension and proteinuria were not observed.

About PTC299

PTC 299 is a novel, orally administered small-molecule compound that inhibits the production of the protein vascular endothelial growth factor (VEGF) in tumors. PTC discovered PTC299 through PTC's proprietary GEMS (Gene Expression Modulation by Small-Molecules) technology by targeting the post-transcriptional processes that regulate VEGF formation. Overexpression of VEGF plays a key role in the growth of many types of cancers. PTC299 inhibits VEGF production through a mechanism that is distinct from that of other VEGF inhibitors and has potential application in the treatment of multiple solid tumor types. For more information regarding PTC299 clinical trials, visit http://www.clinicaltrials.gov and search PTC299.

About PTC Therapeutics

PTC is a biopharmaceutical company focused on the discovery, development and commercialization of orally administered, proprietary, small-molecule drugs that target post-transcriptional control processes. Post-transcriptional control processes regulate the rate and timing of protein production and are of central importance to proper cellular function. PTC's internally-discovered pipeline addresses multiple therapeutic areas, including genetic disorders, oncology and infectious diseases. PTC has extensive knowledge of post-transcriptional control processes and has developed proprietary technologies that it applies in its drug discovery activities which have been the basis for collaborations with leading biopharmaceutical companies such as Genzyme, Pfizer, Celgene, CV Therapeutics and Schering-Plough. For more information, visit the company's Web site at http://www.ptcbio.com.

PTC Therapeutics, Inc.
http://www.ptcbio.com