around its lead compounds in development late last year, and anointed XL184 as the top candidate that would drive its value in the future.
The drug is designed specifically to inhibit MET and VEGF receptor 2. It’s an interesting concept because it provides a dual mechanism to block molecular signaling pathways tumors use to grow and resist chemotherapy, and to form new blood vessels.
Interim results earlier this year from a mid-stage clinical trial showed the drug has at least some activity. The study looked at a high dose and low dose of the Exelixis drug in patients with relapsed forms of brain cancer (glioblastoma). Researchers found that 11 of 37 patients (30 percent) on the low dose, who hadn’t been treated before with an anti-VEGF therapy, had at least a partial response. The data, presented at the American Society of Clinical Oncology (ASCO), was “very competitive” with other treatments, Morrissey says.
Still, it wasn’t enough to light the fire of Bristol-Myers. The drug giant was basking in the glowing reviews it got at the same ASCO meeting for ipilimumab, an immune-based treatment for melanoma that has spread through the body. That drug was one of the stars of the show at ASCO, when Bristol-Myers showed in a study that patients lived a median time of about 10 months, compared with 6.4 months for those in a control group. After two years, about one out of four people who got the drug (23 percent) were alive, compared with one out of seven (14 percent) on the comparison treatment.
As ipilimumab became more of a high priority, Bristol and Exelixis found they couldn’t agree on the “scope, breadth and pace of the ongoing clinical development of XL184,″ according to a June statement. So Bristol walked away, leaving Exelixis with 100 percent ownership of the asset, and responsible for 100 percent of the development costs.
Exelixis’s board spent the summer thinking through
