Overview of Phase 1b/2 Trial: PTC299 for Treatment of Metastatic Breast Cancer

Breast cancer is a disabling and life-threatening disease for patients with advanced primary tumors or metastatic disease. In the past decade, the development of several compounds has demonstrated that treatment of metastatic breast cancer can be improved by offering more effective, less toxic, and more convenient options to patients. Nevertheless, we still lack effective treatments that ultimately abate or cure the disease, underscoring the real need for continuing efforts to develop new therapies and treatment options.
Tumor growth requires the formation of new blood vessels, called angiogenesis, which is important in breast cancer and other types of cancers. Many women with metastatic breast cancer produce high levels of a protein called vascular endothelial growth factor (VEGF), which allows the tumor to grow.

PTC has developed an orally administered investigational drug called PTC299, which is designed to decrease VEGF production. In studies using animal models of human cancer, including breast cancer, PTC299 has been shown to decrease tumor-derived VEGF production, leading to decreased tumor blood vessel production and strong reduction or inhibition of tumor progression.

Phase 1a clinical trials in healthy adult volunteers have evaluated the safety of PTC299 when given by mouth for up to 7 days. Results from these early clinical trials indicate that PTC299 is generally well tolerated at dose levels as high as, or higher than, those now being tested in patients with cancer.

PTC Therapeutics is now conducting a PTC299 Phase 1b/2 trial in adult women with metastatic breast cancer. This trial is ongoing at New York University Medical Center. Patients participating in this study take PTC299 by mouth twice a day. Each patient receives the drug in 6-week treatment cycles. Cycles of treatment are repeated for as long as the patient wishes to participate and is potentially benefiting from the drug in the course of the study. This study is testing different doses of PTC299 to further evaluate the activity and safety of the drug. Additionally, the study is monitoring whether PTC299 lowers levels of VEGF in the blood and whether the drug reduces the flow of blood to the tumors and, in turn, decreases tumor size.

To be considered for the trial, potential participants must:
• be female
• be at least 18 years old
• have metastatic breast cancer
• weigh between 88 and 220 pounds
• be able to perform daily activities without much help
• not be experiencing serious side effects from other medications
• have normal or near normal blood tests for liver, kidney, and bone marrow functions
• agree not to become pregnant while taking PTC299 and for at least 4 weeks after completing the study
• be willing and able to participate in study procedures
Other eligibility requirements will be explained at the trial site.

Additional details about this PTC299 clinical trial can be found at www.clinicaltrials.gov or by contacting Patient and Professional Advocacy at PTC Therapeutics (908-912-9256, PatientInfo@ptcbio.com ).