* Says drug shows promise in prostate, ovarian cancer
* Co can now look for new partner for drug - analyst
* Shares rise 31 pct (Adds analyst comments, updates share movement)
Nov 18 (Reuters) - Cancer drug developer Exelixis Inc (EXEL.O) said interim data from two mid-stage trials of its lead experimental drug showed promise in patients with a type of prostate cancer and ovarian cancer, sending its shares up 31 percent.
On June 20, the company’s partner Bristol-Myers Squibb Co (BMY.N) had decided to return the rights and stop co-developing the drug, codenamed XL184, as the companies could not agree on an appropriate clinical program.
“With further clinical validation, we believe Exelixis can re-partner XL184 overseas for significant terms while retaining U.S. rights,” Piper Jaffray analyst Edward Tenthoff wrote in a note to clients.
Exelixis is also testing the drug in a late-stage trial in patients with a type of thyroid cancer. Tenthoff expects top-line data from the trial in early next year and first market approval by 2012.
In the first mid-stage study, the drug was tested in patients who had metastatic castration-resistant prostate cancer (CRPC) whose disease continues to grow despite standard chemotherapy.
Exelixis said 19 of 20 prostate cancer patients achieved either complete or partial resolution of lesions on bone scan by independent review.
“These data suggest that XL184 has a novel and differentiated clinical profile in CRPC, and will provide critical guidance in defining our high priority development activities for XL184 in 2011,” Chief Executive Michael Morrissey said in a statement.
In the other mid-stage study, where the drug was tested in patients with advanced ovarian cancer, tumor shrinkage was observed in 30 of 37 patients with measurable metastatic lesions, Exelixis said.
The San Francisco-based company has partnered with French drugmaker Sanofi-Aventis (SASY.PA) for two other mid-stage anti-cancer drug candidates.
The company’s shares, which have gained 22 percent since Bristol-Myers returned rights of the drug, were up $1.26 at $5.98 in afternoon trade on Nasdaq. They touched a high of $6.19 earlier.
About 7.8 million shares were traded till 1212 ET, more than seven times their normal volume. (Reporting by Anand Basu in Bangalore; Editing by Gopakumar Warrier, Unnikrishnan Nair)