REDWOOD CITY, Calif., Dec. 27 /PRNewswire-FirstCall/ -- Threshold Pharmaceuticals, Inc. , today announced top-line results from the Phase 2 clinical trial of glufosfamide in combination with gemcitabine for the treatment of advanced pancreatic cancer. 21% of patients in the clinical trial had a partial response (including one unconfirmed partial response) and 36% of patients had stable disease. Glufosfamide was generally well tolerated in combination with gemcitabine with no new unexpected adverse events.
"We are pleased with these encouraging top-line results and look forward next year to additional six- and twelve-month survival data from this clinical trial," said Barry Selick, Ph.D., Threshold's chief executive officer. "We remain focused on our goal of bringing another treatment option to patients with pancreatic cancer."
Phase 2 Clinical Trial Results
In the Phase 2 clinical trial, 29 patients were treated, of which 28 patients with pancreatic adenocarcinoma previously untreated with chemotherapy were evaluated for response. Overall, 5 patients achieved a confirmed partial response and one other patient achieved an unconfirmed partial response. In addition, 10 patients experienced stable disease. Objective response was assessed radiologically after every two cycles of therapy. A partial response is characterized as a decrease in size by 30% of the sum of the longest diameters of target lesions, the absence of progression of all non-target lesions and no new lesions.
Preliminary analysis of the safety data in this Phase 2 glufosfamide and gemcitabine combination trial suggests the incidence of treatment-related nephrotoxicity may be slightly higher than what was observed in previous experience with either of these agents used individually.
This clinical trial remains ongoing. Final survival and safety results will be reported at the completion of the trial, estimated to occur by the end of the third quarter of 2007.
Phase 2 Clinical Trial Design
The Phase 2 clinical trial is evaluating patients with locally advanced and/or metastatic pancreatic adenocarcinoma previously untreated with chemotherapy. Patients receive the standard dose of gemcitabine plus glufosfamide. In addition to safety, the trial is investigating the efficacy of glufosfamide in combination with gemcitabine as determined by response rate, duration of response, progression-free survival, overall survival, six- and twelve-month survival and change in serum tumor marker levels (CA19-9). Patients in the trial receive the standard dose of gemcitabine (1000mg/m2) weekly for 3 of every 4 weeks and 4500mg/m2 of glufosfamide administered once every 4 weeks.
The trial is part of a Phase 1/2 clinical trial, whose Phase 1 results were reported in January 2006 at the ASCO GI Cancers Symposium. The primary objective of the Phase 1 portion of the trial was to evaluate safety and to determine the maximum tolerated dose (MTD) of glufosfamide when administered in combination with gemcitabine. The 19 patients in this portion of the trial received the standard dose of gemcitabine (1000mg/m2) weekly for 3 of every 4 weeks and one of four doses of glufosfamide (1500mg/m2, 2500mg/m2, 3500mg/m2 or 4500mg/m2) administered once every 4 weeks. The maximum tolerated dose was established at 4500mg/m2. No unanticipated adverse events based on previous experience with glufosfamide administered as a single agent were observed.
About Pancreatic Cancer
The American Cancer Society estimates that 33,730 patients will be diagnosed with pancreatic cancer in the United States in 2006, and approximately 32,300 patients will die from the disease. Only 15-20% of newly diagnosed patients are eligible for surgery, which is typically followed by radiation and chemotherapy. Patients with inoperable pancreatic cancer are treated with radiation and chemotherapy, or in the case of metastatic disease, chemotherapy alone as the advantages of radiation are reduced.
About Threshold Pharmaceuticals
Threshold is a biotechnology company focused on the discovery and development of small molecule therapeutics for the potential treatment of cancer. By selectively targeting abnormally-proliferating tumor cells, the Company's drug candidates are designed to be potentially more effective and less toxic to healthy tissues than conventional treatments. For additional information, please visit our website ( http://www.thresholdpharm.com/ ).
Forward-Looking Statements
Except for statements of historical fact, the statements in this press release are forward-looking statements, including statements regarding Threshold's product candidates, clinical trial progress and results, and potential therapeutic uses and benefits of our product candidates. These statements involve risks and uncertainties that can cause actual results to differ materially from those in such forward-looking statements. Potential risks and uncertainties include, but are not limited to, Threshold's ability to attract and retain employees, commence, enroll or complete its anticipated clinical trials, the time and expense required to conduct such clinical trials and analyze data, issues arising in the regulatory or manufacturing process and the results of such clinical trials (including product safety issues and efficacy results). Further information regarding these and other risks is included under the heading "Risk Factors" in Threshold's Quarterly Report on Form 10-Q, which was filed with the Securities Exchange Commission on November 9, 2006 and is available from the SEC's website ( http://www.sec.gov/ ) and on our website ( http://www.thresholdpharm.com/ ) under the heading "Investors." We undertake no duty to update any forward-looking statement made in this news release.
Contact:
Denise T. Powell
Sr. Director, Corporate Communications
Threshold Pharmaceuticals, Inc.
650-474-8206
