TLK 286 [
TELCYTA] is an antitumour agent in clinical development with Telik. It was developed through the application of Telik's proprietary TRAP chemogenomics technology.
TLK 286 works by targeting tumours that overexpress
glutathione S-transferase (GST) P1-1, an
enzyme that has been implicated in drug resistance and poor prognosis, and is elevated in solid tumours such as head and neck, breast, gastrointestinal, lung and ovarian tumours.
TLK 286 is activated by GST P1-1 and, subsequently, initiates apoptosis in targeted tumour cells. Telik owns worldwide rights to
TLK 286 and intends to commercialise it in the North American market. The company plans to select a collaborator in other territories with capabilities in manufacturing, sales and marketing. Telik was previously collaborating with Taiho, Japan, on development of
TLK 286, but this agreement appears to have been terminated. Telik announced in October 2002 that it had begun the first of a series of planned clinical trials of
TLK 286 in combination with
docetaxel in patients with
non-small cell lung cancer. A phase II trial was initiated in May 2001 in patients with
ovarian cancer. Two additional combination trials were initated in
ovarian cancer patients in December 2002. One of the trials will evaluate the combination of
TLK 286 with
Doxil in patients who have failed
platinum-based
chemotherapy. The second trial will evaluate
TLK 286 in combination with
carboplatin in patients who have recurrent,
platinum-sensitive
ovarian cancer. Telik held a successful phase III meeting with the US FDA to discuss plans for the first registration trial of
TLK 286, and in March 2003 it was announced that a phase III registration trial of
TLK 286 as monotherapy had been initiated in
platinum-refractory
ovarian cancer patients. The multinational trial has been designated the ASSIST-1 (Assessment of Survival in Solid Tumours-1) trial. Telik plans to enrol approximately 440 women who will be assigned to either
TLK 286 treatment or a control (
doxorubicin liposomal or
topotecan).