Exelixis opens books on promising set of "cabo" cancer data

Exelixis ($EXEL) has pulled back the covers from a new set of promising mid-stage data for its lead cancer treatment, once referred to as XL184 but now dubbed "cabo." Investigators determined that 85 percent of the prostate cancer patients taking cabozantinib experienced complete or partial elimination of bone lesions at an interim point. And tumors shrank in two thirds of the patients whose cancer had metastasized to soft tissue.

The interim numbers--a full set of results should arrive this summer--were promising enough to boost the price of Exelixis' shares, which are now largely staked to the fate of this therapy. The South San Francisco-based developer restructured twice last year as it circled its wagons around its XL184 program. Once run by George Scangos (photo), now CEO of Biogen Idec, Exelixis is now helmed by Michael Morrissey, who makes no secret of his high hopes for this therapy.

"These interim data give us further confidence in our comprehensive development plan for cabozantinib in CRPC that includes three potential pivotal trials, the first focused on a composite endpoint that incorporates bone scan resolution and improvement in bone pain, and future trials evaluating overall survival and bone metastasis prevention in CRPC patients," said the CEO in a statement.

In the mid-stage study, researchers found that the bone lesions of 53 out of 62 evaluated patients had shrunk or been cleared. These lesions can cause fractures and intense pain for patients. The therapy was also linked to higher hemoglobin in anemic patients and a reduced need for powerful painkillers.

Bristol-Myers Squibb handed back the rights to cabozantinib last year after the two companies failed to agree on a development plan for the drug. The therapy is now involved in six separate studies for a variety of cancers, including one Phase III trial.

- here's the Exelixis press release
- get the story from Reuters