FDA Puts Clinical Hold On Telcyta Following ASCO Presentation
This article was originally published in The Pink Sheet Daily
Executive Summary
Telik plans to submit additional safety and other information to FDA and request a meeting with the agency “as soon as possible.”
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FDA asked Telik to stop dosing patients with its investigational cancer drug Telcyta (canfosfamide) after the firm reported disappointing trial results for the oncologic at the American Society of Clinical Oncology meeting in Chicago June 3. Telik announced the clinical hold June 4. "No new patients will be enrolled on Telcyta clinical trials and no patients currently being treated on the trials will receive additional treatment until the FDA releases the clinical hold," the Palo Alto, Calif., firm said. The company said it plans to submit additional detailed safety and other information to FDA and meet with the agency as soon as possible regarding the hold. Only the Assessment of Survival In Solid Tumors-5 trial had been open for enrollment, the company said, adding that "a small number" of patients had continued to receive treatment in previously-enrolled trials. At ASCO, Telik reported results from ASSIST-1 and ASSIST-2, which tested Telcyta as a monotherapy, and ASSIST-3, which compared it in combination with carboplatin to pegylated liposomal doxorubicin (Johnson & Johnson's Doxil ) in second-line treatment of advanced platinum refractory or resistant ovarian cancer. Though it failed to demonstrate an advantage for Telcyta, ASSIST-3 did offer clues for further studies. The primary endpoint of the study, objective response rate, may have been compromised because approximately 25 percent of patients were prematurely discontinued from the study for disease progression, Telik maintains. An independent radiologic review demonstrated "either stable disease or an objective response" for patients erroneously discontinued from their assigned study treatment, Telik Chief Medical officer Gail Brown said during a December conference call (1 (Also see "Telik Will Continue Developing Telcyta Despite Three Phase III Failures" - Pink Sheet, 2 Jan, 2007.)). Median progression-free survival, the secondary endpoint in ASSIST-3, was 3.5 months in both study arms. Still, investigators found statistically significant differences between the two arms in patients who had a drug-free period of six months or more from the date of last treatment with any therapy to the first study treatment. In that group, progression-free survival was 3.5 months on the PLD arm versus not yet reached on the Telcyta plus carboplatin arm. Median survival was 11.1 months on the PLD arm versus not yet reached on the Telcyta plus carboplatin arm. And, the objective response rate was 31.1 percent on the Telcyta plus carboplatin arm, compared with 10.5 percent on the PLD arm. "We are exploring the biology of platinum resistance and resensitization to identify optimal drug-free periods following platinum exposure," Brown said in a statement. Telcyta failed to achieve improvement in either overall survival or progression-free survival both in ASSIST-1, which evaluated it against Doxil and GlaxoSmithKline's Hycamtin (topotecan) as a third-line therapy for platinum resistant ovarian cancer, and in ASSIST-2, which compared it to AstraZeneca's Iressa (gefitinib) as a third-line therapy for advanced non-small cell lung cancer. Both studies were conducted under a special protocol assessment with FDA. The suspended ASSIST-5 is looking at Telcyta plus PLD versus PLD alone in second line therapy of platinum refractory or resistant ovarian cancer. - Shirley Haley ([email protected]) |