Carlsbad-based Isis Pharmaceuticals Inc. will receive $7.5 million from Alnylam Pharmaceuticals Inc, in connection with a recently announced alliance between Alnylam and Genzyme Corp.

Genzyme, a Boston-based segment of French drugmaker Sanofi SA, is investing $700 million into Cambridge, Mass.-based Alnylam to acquire 12 percent of the company. In this deal, it is upping its stake in RNA interference technology with a focus on rare diseases — which is Isis’ specialty.

Isis has partnered with Alynylam for more than six years in the RNA interference — or RNAi –—space. 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.

Isis (Nasdaq: ISIS) to date has received more than $400 million from the sales and licensing of its intellectual property, including more than $50 million from collaborating with Alynylam, Isis Chief Operating Officer B. Lynne Parshall said in a statement.

Shares for Isis dropped 38 cents in day trading following the news, closing at $47.22 on Jan. 13. Stock for the company has risen dramatically in the past year — it is up 245 percent in the past year.