COUGAR BIOTECH RELEASES DATA ON PROSTATE CANCER DRUG

Cougar Biotechnology has announced positive Phase I data on the company's prostate cancer drug CB7630 (abiraterone acetate). In the trial, CB7630 was administered once daily to chemotherapy-naive patients with CRPC, who had progressive disease despite treatment with LHRH analogues and multiple other hormonal therapies including antiandrogens, diethylstilboestrol and dexamethasone.

The results from the trial showed that in the 14 patients tested, CB7630 was well-tolerated at doses as high as 2,000 mg/day with minimal toxicity. Moreover, no dose-limiting toxicity has been observed in the trial to date. Of the 12 patients that were evaluable for antitumor activity, eight patients (67 percent) experienced a confirmed decline in prostate specific antigen (PSA) levels of greater than 50 percent and six patients (50 percent) experienced PSA declines of greater than 90 percent. Of the five evaluable patients with measurable tumor lesions, treatment with CB7630 resulted in partial radiological responses (as measured by the RECIST criteria) in three (60 percent) patients. Individual patients treated with CB7630 also experienced radiographic regression of bone metastases and improvement in pain.

Circulating tumor cells (CTC) were detected in six of 14 patients, and changes in CTC counts were shown to correlate with changes in PSA. Ten (71 percent) of the 14 patients will continue on treatment with CB7630, with some patients having been on the drug for more than nine months.