Isis Pharmaceuticals Inc. has received a $15 million milestone payment from AstraZeneca PLC as a result of its prostate cancer drug entering phase 1 clinical trials. The news sent Isis (Nasdaq: ISIS) stock up 10 percent to close June 10 at $34.17 per share.

The company has received a steady trickle of milestone payments from various big pharma partner companies, including $3 million from GlaxoSmithKline PLC (NYSE: GSK) last month. To date, Isis has received more than $400 million from the sales and licensing of its intellectual property. It received $100 million up front from Massachusetts pharma giant Biogen Idec Inc. (Nasdaq: BIIB) last fall to develop drugs for neurological disorders.

Isis’ proprietary antisense technology changes the way genes function, silencing mutations or activating genes to compensate for an underlying genetic defect. The company has developed a massive patent portfolio since it was formed in 1989, and is one of the key stakeholders in the RNA therapies space.