Ironwood Pharmaceuticals, Inc. has earned a $15 million development milestone payment from partner Astellas Pharma triggered by Astellas’ enrollment of the first patient in a Phase III trial of linaclotide in patients with irritable bowel syndrome with constipation (IBS-C) in Japan. Astellas expects to complete this trial in 2016.
 
The companies entered a licensing agreement in 2009 to develop and commercialize linaclotide in Japan for the treatment of IBS-C, chronic constipation and other gastrointestinal conditions. Ironwood received $30 million upfront and is eligible to receive an additional $30 million in development milestones, consisting of $15 million upon regulatory filing in Japan and $15 million upon approval. The agreement also provides for Ironwood to receive royalties on sales.
 
Also, Astellas plans to expand its development of linaclotide in Japan and is beginning a Phase II trial in adults with chronic constipation. If approved, the same royalty terms would apply.