Shares of Telik Inc. went up Monday on news that the FDA had removed the partial hold on clinical trials for Telcyta (canfosfamide HCl, TLK286), its drug candidate that was put on the clinical shelf last June.

The FDA decision breathes new life into Telcyta, a new type of cancer cell-activated chemo drug designed to exploit the overexpression of glutathione S-transferase P1-1 found in many cancer cells. However, the company still faces an uphill clinical development challenge considering the poor study results unveiled already. While the removal of the hold allows the resumption of clinical testing, the company's terse press release gave no indication it that is forthcoming.

Telcyta was in development for treatment of advanced ovarian cancer and non-small-cell lung cancer until the FDA initiated the clinical hold after the presentation of data from multiple failed Phase III trials. The company first announced last December that the ASSIST-1, -2 and -3 Phase III trials had not met their primary endpoints, sending Telik's shares down 70 percent. (See BioWorld Today, Dec. 27, 2006.)

Then at the American Society of Clinical Oncology meeting in June, Telik released the details of those trials, sending the stock down another 21 percent. In the ASSIST-1 trial, which compared Telcyta as a monotherapy to either doxorubicin or topotecan in third-line ovarian cancer, median survival was 8.5 months with Telcyta compared to 13.6 months in the control group (p=0.0001). In the ASSIST-2 trial, which compared Telcyta as a monotherapy to Iressa (gefitinib, AstraZeneca plc) in third-line non-small-cell lung cancer, median survival was 4.6 months in the Telcyta arm and 6.1 months in the control arm. In the ASSIST-3 trial, which compared the combination of Telcyta and carboplatin to doxorubicin alone in second-line ovarian cancer, the primary endpoint of response rate was compromised due to premature discontinuations, but the secondary endpoint of median progression-free survival was 3.5 months for both groups. (See BioWorld Today, June 5, 2006.)

News of the hold sent shares of Telik (NASDAQ:TELK) up 14 percent, or 48 cents, on Monday to close at $3.94.