Inex Pharmaceuticals Phase II Trials at U.S. Cancer Center Show Onco TCS Reduces Tumours Of Advanced Lymphoma Patients.

VANCOUVER, British Columbia--(BUSINESS WIRE)--Nov. 5, 1998--INEX PHARMACEUTICALS(TSE:IEX.) (TSE:IEX.WT.A.) Inex Pharmaceuticals Corp. ("INEX", TSE: IEX) reported today that its anti-cancer drug Onco TCS has demonstrated the capacity to significantly reduce the size of tumours in patients with advanced-stage non-Hodgkin's lymphoma, a form of blood cancer, after standard chemotherapy treatments have failed.

Dr. Andreas Sarris, the lead investigator for the Phase II clinical trials underway at The University of Texas M.D. Anderson Cancer Center (UTMDACC) in Houston, says "the early results indicate that Onco TCS has promising activity and if this continues with the complete study, Onco TCS has the potential to become an important component in the first line of treatment of certain kinds of non-Hodgkins lymphoma (NHL)."

Dr. Sarris said that the overall response rate was 45 percent for the first 21 evaluable patients. In each of the patients who responded to Onco TCS treatment, the size of their tumours were reduced at least 50 percent. All trial participants were diagnosed to have either low or intermediate-grade NHL. Included in the response group were patients with B-cell and T-cell lymphomas as well as a patient with mantle cell lymphoma, which is a particularly serious form of B-cell NHL. In this study Onco TCS was well tolerated.

Onco TCS is based on the company's proprietary drug delivery technology called Transmembrane Carrier Systems (TCS). The active agent in Onco TCS is the chemotherapeutic vincristine. The administration of optimal doses of the free drug is often impossible due to severe toxicities. In pre-clinical studies, when the therapeutic agent is combined with the TCS, it is carried to disease sites and into diseased cells in higher concentration and for a longer duration than when it is administered without the TCS. The result of TCS encapsulation is more effective dosing with reduced toxicity. The free form of vincristine is part of several standard chemotherapy "cocktails" employed as first line treatment of non-Hodgkins lymphoma. In the M.D. Anderson trial, patients who had relapsed following these chemotherapy regimens were then treated with Onco TCS alone.

"The Phase II results provides clinical validation of the company's TCS drug delivery technology and the value the TCS could bring to other drugs," said Dr. James J. Miller, President and CEO of INEX. "These early clinical results from one of the most prestigious cancer centers in the world are consistent with the findings Inex has repeatedly demonstrated in pre-clinical studies."

All trial patients had relapsed following standard first line chemotherapies before they were enrolled in the Onco TCS trials. In some cases, patients had failed to respond after receiving up to four other treatment regimes including other experimental therapeutics before they were enrolled.

The Phase II trials at the M.D. Anderson Cancer Center will continue until 70 patients have been evaluated. INEX expects to receive results from this final phase of the Phase II trials during the Second Quarter of 1999. In addition, it has been proposed to expand the studies to include acute lymphocytic leukemia and Burkitt's lymphoma patients.

Lymphoma is a form of cancer that affects the blood and lymph tissues. Non-Hodgkin's lymphoma is the most common form of lymphoma, the sixth leading cause of cancer deaths and has the second fastest growing mortality rate in the United States. According to statistics from the National Cancer Institute, approximately 270,000 people are currently suffering from NHL in the United States alone. In 1997, there were 53,600 new cases of NHL in the United States and 5,300 new cases in Canada.

Vincristine was originally developed as a result of a Canadian-based research initiative and marketed by Eli Lilly and Company, the Indianapolis-based international pharmaceutical company. The drug was developed from extracts of the Vinca rosea plant, known as the Madagascar or common periwinkle, as was another cancer therapeutic, vinblastine. Vincristine has since gone off-patent, but in its generic form continues to be one of the most widely-used cancer therapeutics. INEX holds three issued U.S. patents and international patent applications that cover the combination of vincristine with INEX's TCS.

M. D. Anderson Cancer Center, located at the University of Texas at Houston, is one of the largest and most respected cancer centers in the United States. It is devoted exclusively to cancer patient care, research, education and prevention.

INEX is a Canadian biopharmaceutical company commercializing drugs that utilize the company's proprietary drug delivery systems to treat cancer and inflammatory diseases. The company is focused on gene-based drugs, such as antisense oligonucleotides, which regulate or block genes that produce an undesired disease-causing protein, and gene plasmids, which replace defective genes to achieve a therapeutic effect.