TBCRF Research Funding Helps Initiate Clinical Trial: New Targeted Therapy for Triple Negative Breast Cancer Patients
Triple negative breast cancer is a particularly aggressive type of breast cancer that gets its name from the fact that it lacks the receptors found in other types of breast cancer: estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). When present, these receptors function in stimulating the growth of the tumor, and consequently can be specifically targeted with often good treatment success: the more common ER and PR positive breast cancers are usually treated with hormone therapy drugs such as aromatase inhibitors or tamoxifen, while HER2 positive breast cancer is treated with trastuzumab.
Lacking these receptors, triple negative breast cancer is typically more difficult to treat and has a poorer prognosis. The search for some type of targeted therapy, therefore, is the focus of various researchers seeking alternative, more effective treatment options for women with this type of breast cancer.
The Breast Cancer Relief Foundation (TBCRF) recently awarded Dr. Brian Rowan, Ph.D., Associate Professor of Structural and Cellular Biology, at Tulane Cancer Center in New Orleans, LA with a $60,000 research grant to pursue this exact purpose. This grant is particularly important for Tulane, which reported that in the past year over 40% of their breast cancer diagnoses were of the triple negative type, a percentage that is much higher than the national average, which is typically between 10% and 17%.
This high number of triple negative breast cancer patients in their cancer center’s care impelled several medical researchers at Tulane to redirect their research efforts to study this type of breast cancer more closely. Recognizing the very high presence of a protein known as Src (sarcoma viral oncogene) in triple negative breast cancer tumors, Dr. Rowan and his team of scientists sought out a drug that would specifically target this protein, and they came to learn of the new experimental drug, KX-01, which was created by Kinex Pharmaceuticals.
Since no other laboratory anywhere was studying the use KX-01 for triple negative breast cancer, TBCRF was very proud to provide grant funding to Dr. Rowan and his team to pursue this very significant investigation. The results of their preclinical research were very encouraging: KX-01 was found to act as a Src inhibitor by binding directly to this protein in triple negative breast cancer cells; it significantly reduced tumor sizes; and it demonstrated low toxicity, which would indicate minimal side effects in actual treatment situations.
Their research also demonstrated an increased positive result when KX-01 was combined with traditional, broad-based chemotherapy agents such as paclitaxel and doxorubicin. This combination dramatically reduced tumor sizes during the same 36-day period.
Most exciting, however, was their observation that there was an added benefit when KX-01 was used in combination with hormone therapies traditionally used for ER and PR positive breast cancer. In the course of their experimentation, they made the very important discovery that KX-01 “turned on” the estrogen receptors in triple negative breast cancer cells. This change in the tumor cell created an environment in which the triple negative breast cancer could now be treated more effectively by using a combination of KX-01 and tamoxifen.
The impressive research of Dr. Rowan and his team on this combination appears to be a very promising new targeted therapy for this unique type of breast cancer that has, heretofore, had little success in targeted treatment. This past month, TBCRF staff toured Dr. Rowan’s lab and met with him and his team to hear firsthand of their results and where this research might lead. Dr. Rowan expressed his gratitude to TBCRF for the research grant which helped enable his preclinical study of KX-01, and he happily reported: “Data from these experiments has provided the critical rationale needed to initiate a clinical trial of KX-01 for triple negative breast cancer patients in New Orleans.” A “probe trial” with 43 patients will begin soon, and we are all very hopeful for the success of this new targeted treatment.
