Ensemble Therapeutics and Alexion Initiate Collaboration to Discover Macrocycle Drug Candidates Targeting Patients with Severe and Ultra-Rare Disorders

Ensemble Therapeutics, a biotechnology company developing Ensemblins™, a novel class of small molecule therapeutics with the potential to modulate targets typically addressed by biologics, today announced the initiation of a drug discovery collaboration with a subsidiary of Alexion Pharmaceuticals, Inc. (Nasdaq: ALXN), the global biopharmaceutical company focused on developing and commercializing life-transforming therapies for patients with life-threatening, ultra-rare disorders. The collaboration will deploy Ensemble’s proprietary drug discovery platforms for several undisclosed drug targets identified by Alexion to create highly innovative small molecule therapeutic candidates.

Under the terms of the collaboration, Ensemble will screen its Ensemblin™ collection of more than ten million macrocycles against several disease drug targets specified by Alexion, utilizing Ensemble’s extensive medicinal chemistry capabilities to discover new small molecule clinical candidates. Alexion will have the exclusive worldwide rights to develop and commercialize candidates arising from the collaboration. Other terms of the agreement were not disclosed; Ensemble will receive an upfront payment and research support, and can earn additional payments upon the achievement of certain development and commercial milestones.

“Ensemble is thrilled to support Alexion’s cutting edge scientific and clinical programs with our ever increasing capability for macrocycle-based drug discovery,” said Dr. Michael D. Taylor, CEO of Ensemble Therapeutics. “This new collaboration with a leading biopharmaceutical innovator focused on rare diseases speaks to the breadth of utility of Ensemble’s discovery platforms to address clinically important yet challenging drug targets,” Dr. Taylor added.

“Alexion looks forward to a productive collaboration with Ensemble as we seek to broaden the number of pathways toward developing potentially transformative first-in-class drug candidates for patients with selected severe and life-threatening ultra-rare disorders,” said Martin Mackay, PhD, Executive Vice President, Head of Global R&D at Alexion. “This is a promising addition to our development initiatives as we seek to further expand our product portfolio.”

About Ensemblins

Ensemblins™ are a new class of synthetic macrocycles developed by Ensemble using its proprietary chemistry platforms, including DNA-Programmed Chemistry. Macrocyclic rings are found in many natural product-based drugs and bestow favorable pharmaceutical properties and powerful protein surface binding properties upon such drugs. Thus, macrocycles are uniquely suited to address many protein targets that cannot be modulated effectively by traditional small molecule pharmaceutical compounds. Macrocycles have been challenging to synthesize in large numbers and this has constrained their wider use in the industry. By extending beyond the limits of traditional small molecule drug discovery, Ensemble’s platform provides unmatched capabilities to successfully and reliably generate millions of macrocyclic Ensemblins as drug candidates, larger than any collection previously synthesized in the pharmaceutical industry.

About Ensemble Therapeutics

Based in Cambridge, MA, Ensemble Therapeutics is deploying its proprietary chemistry platforms to develop a novel class of therapeutics known as “Ensemblins”. Ensemble is leveraging its macrocycle drug discovery expertise to fuel its proprietary drug candidate pipeline while also pursuing collaborations with pharmaceutical partners. Prior to this agreement, Ensemble entered high-value partnerships including alliances with Boehringer Ingelheim, Genentech, Bristol-Myers Squibb and Pfizer to access Ensemble’s macrocycle libraries for purposes of affinity screening drug discovery against difficult-to-address targets. Ensemble’s internal discovery and development efforts are focused on the key therapeutic areas of oncology and immuno-inflammatory diseases, with its lead program, a small molecule antagonist of Interleukin-17, a cytokine implicated in multiple inflammatory and autoimmune diseases, poised to enter development with an orally active candidate by the end of 2013. For more information, visit: www.ensembletx.com.