Alnylam Pharmaceuticals has acquired Merck’s subsidiary Sirna Therapeutics, comprising intellectual property and RNAi assets, including pre-clinical therapeutic candidates, chemistry, siRNA-conjugate and other delivery technologies.

Alnylam chief executive officer John Maraganore said: "We believe that the acquisition of Merck’s RNAi technologies and intellectual property will further our efforts to build a new class of medicines, advancing them to patients in need."

As part of the deal, Alnylam will pay Merck an upfront payment of $175m in cash and equity, including $25m cash/$150m in Alnylam common stock.

In addition, Merck is eligible to receive about $105m in developmental and sales milestone payments per product, as well as single-digit royalties, related with the progress of certain pre-clinical candidates discovered by Merck.

Merck is also eligible to get around $10m in milestone payments and single-digit royalties on Alnylam products covered by Sirna Therapeutics’ patent estate.

Merck Research Laboratories senior vice-president of Iain Dukes said: "We believe this agreement positions Sirna Therapeutics’ therapeutic RNAi assets with a company that has the focus and commitment necessary to harness their potential.

"This is consistent with our strategy to reduce emphasis on platform technologies and prioritize our R&D efforts to focus on product candidates capable of providing unambiguous promotable advantages to patients and payers."

The deal will see Merck transfer all technologies of Sirna Therapeutics into Alnylam’s platform for the delivery of RNAi therapeutics, which will include multiple granted patents and a range of chemistry, siRNA-conjugate and other delivery technologies for application to RNAi therapeutics.

In addition, the Sirna Therapeutics assets include certain pre-clinical candidates.

According to the companies, the deal is subject to customary closing conditions, including the requirements under the Hart Scott-Rodino Antitrust Improvements Act.

Image: The dicer protein from Giardia intestinalis, which catalyses the cleavage of dsRNA to siRNAs. Photo: courtesy of Opabinia regalis.