Sanofi and Alnylam have agreed to conclude the research and option phase of the companies' 2014 RNAi therapeutics alliance in rare genetic diseases. The material collaboration terms for patisiran, vutrisiran (ALN-TTRsc02) and fitusiran, as previously announced, will continue unchanged.

As part of this agreement, Alnylam will advance an additional investigational asset in an undisclosed rare genetic disease through the end of IND-enabling studies. Sanofi will be responsible for any potential further development or commercialization of such asset. If this product is approved, Alnylam will be eligible to receive tiered double-digit royalties on its global net sales.

"Our alliance with Alnylam has successfully brought one important medicine to patients with ATTR amyloidosis and it also has spawned a molecule that is in pivotal clinical trials for people with hemophilia," said John Reed, Global Head of Research and Development at Sanofi. "As we wrap up this phase of our program with Alnylam, we remain committed to advancing therapies for patients with rare diseases and rare blood disorders."

In addition, Alnylam and Sanofi have agreed to amend certain terms of the companies' equity agreement, with Sanofi obtaining a release of its lock-up of Alnylam stock holdings, subject to certain trading restrictions, amongst other provisions.