PharmaGap Inc. has announced initial results from preclinical testing at the Ottawa Hospital Research Institute. Initial results from this study are positive and provide evidence that a peptide formulation of PharmaGap's lead cancer drug GAP-107B8 administered via the intraperitoneal route can reduce tumour burden (19%) and significantly suppress ascites formation (73%) relative to controls. The test was undertaken at OHRI in collaboration with Dr. Barbara Vanderhyden.
Dr. Vanderhyden, upon initial review of the data commented "The reduction in ascites volume is very interesting in its own right, because this is a notable cause of morbidity in women with ovarian cancer. There is currently no drug therapy that is effective against ovarian cancer-associated ascites accumulation. Paracentesis, the removal of abdominal ascites, is commonly used to alleviate symptoms and prolong survival of women with ovarian cancer. The presence of ascites in ovarian cancer has been reported to be an indicator of poor prognosis for survival and correlates with a significantly decreased 5-year survival rate (5% with ascites vs. 45% without ascites) among women with stage III or IV epithelial ovarian carcinoma."
The efficacy screening study was conducted over 2 weeks with twice daily dosing. With respect to this schedule the maximum tolerated dose as predetermined from a preliminary in-vivo study for each formulation (20 and 40 mg/Kg respectively) was administered.
In this study two formulations of GAP-107B8 peptides were tested in an established intraperitoneal xenograft model in immune-deficient mice and evaluated for tumour burden and accumulation of malignant ascites (excess fluid containing cancer cells in the abdominal cavity). The cell line selected for testing (OCC-1 human ovarian cancer) is of a phenotype characterized by the production of peritoneal ascites with growth of multiple small solid tumours.
Dr. Ken Sokoll, PharmaGap's Vice President of Clinical Development and Chief Operating officer stated "We are continuing the analysis of this data along with Dr. Vanderhyden's group and will provide additional details as they become apparent. This work has provided key information on preferred GAP-107B8 peptide formulations, relevant to our ongoing clinical development and peptide-based formulation program.”
Sokoll continued, "Future efficacy studies to be conducted in the ovarian cancer model will include more broad-based screenings with liposomal formulations in order to determine if these initial positive findings can be improved further and reproduced in other ascites-producing cell lines. It is noteworthy that ascites formation is not unique to ovarian cancer, and a high incidence has been reported in other cancer types, including endometrial, breast, colon, stomach and pancreatic cancers."