PTC Therapeutics Presents Phase 1 Results Of Novel VEGF Inhibitor, PTC299

Armen Hareyan's picture

PTC Therapeutics presented data from its Phase 1 single- and multiple-dose studies in healthy volunteers evaluating PTC299, its novel VEGF inhibitor.

Data from these two safety and pharmacokinetic studies confirmed that PTC299 is well tolerated up to the maximum tested dose and, in the multiple-dose study, safely achieves the desired target plasma concentrations at all tested dose levels. PTC299 is a novel, orally bioavailable investigational drug discovered by PTC which selectively inhibits production of vascular endothelial growth factor (VEGF) in tumors.

"We are very encouraged by the results of these clinical studies which show that PTC299 is well tolerated at plasma concentrations associated with antiangiogenic and antitumor activity in preclinical models," statedLangdon Miller, M.D., Chief Medical Officer at PTC Therapeutics, Inc. "Furthermore, these Phase 1 data appear consistent with our preclinical results that suggest PTC299 selectively inhibits pathological tumor-associated VEGF production while not affecting physiological VEGF production. It is notable that we did not see adverse events such as bleeding, hypertension, or proteinuria that have been associated with other VEGF inhibitors. Given the very high unmet medical need in oncology, we are committed to rapidly advancing clinical trials of PTC299 in patients with cancer.

Data from these clinical trials were detailed in a poster entitled, "Phase 1 studies assessing the safety, PK, and VEGF-modulating effects of PTC299, a novel VEGF expression inhibitor" (Poster Number H9). The poster was presented on June 3rd at the Developmental Therapeutics: Molecular Therapeutics session of the 43rd Annual ASCO Meeting, being held from June 1-5, 2007, in Chicago, Illinois.


In the initial clinical study, 52 healthy volunteers received single doses up to 3 mg/kg of PTC299. In the subsequent multiple-dose study, 32 healthy volunteers received doses through 1.2 mg/kg/dose two times per day and 1.6 mg/kg/dose three times per day. Among these healthy volunteers, PTC299 was well tolerated, with no serious, dose-limiting, or definitively drug-related adverse events. All clinical adverse events were mild (Grade 1) or moderate (Grade 2) in severity and did not require any intervention. Pharmacokinetic data indicated dose-proportional increases in plasma exposures and the target trough plasma concentration was achieved and maintained at all dose levels in the multiple-dose study.

"The continued progress of PTC299 provides further validation of our novel GEMS technology which targets post-transcriptional control processes," commented Stuart W. Peltz, Ph.D., President and CEO of PTC Therapeutics, Inc. "PTC299 selectively inhibited tumor VEGF production and tumor growth in preclinical studies. With a new mechanism that acts upstream of available anti-angiogenic agents, PTC299 has demonstrated activity alone and in combination with hormonal, chemotherapeutic, and other antiangiogenic agents. These results position PTC299 as a potential therapy for a broad range of solid tumors."

PTC plans to initiate a Phase 1b/2 clinical trial in patients with advanced breast cancer during the second half of 2007. This trial will be funded in part through a three-year, $2.2 million grant from the Department of Defense (DoD), which was awarded to PTC last year to fund both the preclinical and clinical development of PTC299 in breast cancer.

The DoD Clinical Translational Research Award sponsors innovative preclinical and clinical/translational research that may result in substantial improvements over current approaches to breast cancer chemoprevention and therapy. As part of the Congressionally Directed Medical Research Programs, it administers funds for peer-reviewed research toward specific diseases and supports research that positively affects the health and well-being of Americans. For this grant (grant number W81XWH-06-1-0629), the U.S. Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick, MD 21702-5014 is the awarding and administering acquisitions office. The content of this press release does not necessarily reflect the position or the policy of the Government, and no official endorsement should be inferred.

PTC299 is a novel, orally administered small-molecule compound that inhibits the production of the protein vascular endothelial growth factor, or 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 other VEGF inhibitors and has potential application in the treatment of multiple solid tumor types. In September 2006, PTC announced that it had received a three- year, $2.2 million grant from the Department of Defense (DoD) to fund preclinical and translational clinical development of PTC299 as a potential treatment for breast cancer.

Gene Expression Modulation by Small-molecules (GEMS) is PTC's novel and proprietary screening technology for the identification of small-molecules that modulate post-transcriptional control mechanisms. Compounds identified through the GEMS technology target processes that act through the untranslated regions (UTRs) of messenger RNA (mRNA) molecules. GEMS was the basis for the discovery of PTC299 and is being used in multiple ongoing drug discovery programs.