About us

Toronto-based Encycle Therapeutics is built on a novel synthetic platform invented by Professor Andrei Yudin and colleagues, which enables the generation of enhanced peptide macrocycles, or nacellins. Nacellins approximate the dimensions of beta turns extremely well and, although reminiscent of conventional cyclic peptides, exhibit substantially improved passive membrane permeability, stability in the gut and inside cells, and solubility. The synthetic method is low-cost, high-yield and can cyclize small peptides that normally are not amenable to constraint.

Research Collaborations and
Independent Product Development

Encycle’s technology has been thoroughly explored and validated through collaborations with several entities, including AstraZeneca, GlaxoSmithKline, Merck and Pfizer, along with the Universities of Toronto and Sherbrooke. These collaborations have resulted in a large amount of empirical data, which have been exploited to elucidate quantitative relationships between nacellin structure, membrane permeability and oral bioavailability. Moreover, Encycle has created a library of >4,000 discrete nacellins, which has been screened by our scientists and by a variety of third parties.

We welcome additional opportunities to screen our library against targets of interest, particularly those intractable to small molecules.

Encycle is currently advancing two independent drug discovery and development programs. Our lead program is focused on the IND-enabling development of an orally bioavailable clinical candidate (ET3764), which inhibits integrin alpha-4-beta-7 as a means to treat of inflammatory bowel disease and other inflammatory disorders, whereas the secondary program involves the discovery of inhibitors of selected peptidyl-prolyl isomerases.

Non-biologic modulators of integrin alpha-4-beta-7 have been pursued for years, however low molecular weight entities that are both absorbed from the gut following oral administration and demonstrate appropriate selectivity for the protein have been elusive. Encycle’s ET3764 “threads this needle” and exhibit outstanding results in several in vivo efficacy and pharmacodynamics models.

Please click here to contact us for more information on our internal activities and opportunities for collaboration.




President and CEO


Andrei Yudin, PhD

Scientific Founder, SAB

Scientific Advisory Board


Vice President, Discovery and Operations, Encycle Therapeutics




Professor, Department of Chemistry, University of Toronto



Chief Executive Officer, Structural Genomics Consortium




Board Of Directors


President and CEO, MaRS Innovation



President and CEO, Encycle Therapeutics



Chairman of the Board and CEO, Stereotaxis



Professor, Department of Chemistry, University of Toronto



Senior Director, Investments, Accel-Rx Health Sciences Accelerator



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101 College Street, Suite 314, Toronto, ON, M5G 1L7


© Copyright 2016. Encycle Therapeutics, Inc. All rights reserved.


President and CEO

Dr. Jeffrey Coull has served as Encycle’s President and CEO since 2013. He is also an Adjunct Professor at the University of Toronto. Prior to joining Encycle, Jeff co-founded Chlorion Pharma, a venture-backed drug discovery company focused on neuropathic pain and epilepsy, and KineRx Neurosciences, a specialty pharmaceutical company that acquired the rights to a marketed movement disorder therapeutic. He holds a PhD in pharmacology from McGill University, and, upon convocation, received a Doctoral Prize from the Natural Sciences and Engineering Research Council of Canada, the countries highest distinction for doctoral research.

Andrei Yudin, PhD

President and CEO

Dr. Andrei Yudin founded Encycle in 2012 to apply and commercialize the proprietary synthetic methods he and his colleagues invented. He is a Professor in the Department of Chemistry at the University of Toronto, a Fellow of the Royal Society of Canada, and currently serves as Chair of the Board for Organic and Biomolecular Chemistry. Andrei has also received several major awards, including the 2010 Rutherford Medal and the 2015 Bernard Belleau Award in Medicinal Chemistry. He holds a PhD in chemistry from the University of Southern California, where he worked under the direction of Nobel Laureate Professor George A. Olah, and served as a postdoctoral fellow in the laboratory of Nobel Laureate Professor K. Barry Sharpless at the Scripps Research Institute.

Raphael Hofstein, PhD

President and CEO

Dr. Raphael Hofstein is Chairman of the Board at Encycle and serves as President and CEO at MaRS Innovation, which, along with Professor Yudin, was instrumental in the formation and seeding of Encycle Therapeutics in 2012. Rafi also serves on several other boards, including TriPhase Accelerator Corporation, Life Sciences Ontario and Quebec Consortium for Drug Discovery. Prior to taking the helm at MaRS Innovation, he held various senior roles at Ecogen in Langhorne, PA and in Israel, and was President and CEO of Hadasit, the commercialization company of Hadassah, the largest teaching hospital in Israel, among other positions in the life sciences. Rafi received his PhD in Life Sciences and Chemistry from the Weizmann Institute of Science.

Andrew Roughton, PhD

Vice President, Discovery and Operations, Encycle Therapeutics

Dr. Andrew Roughton is Encycle’s Vice President of Discovery and Operations and was the company’s first full-time employee. Before joining Encycle, he was a Senior Medicinal Chemist at Dalton Medicinal Chemistry, and previously, spent nearly 15 years as a Senior Principal Scientist at Pharmacopeia in Princeton, NJ. During this time Andrew was also a founding member and secretary of the NJ Biotechnology Chemistry Consortium. He completed his PhD in organic chemistry at the Max-Planck-Institut (Mūlheim a.d. Ruhr / Universität Essen) under Professors Martin Demuth and Kurt Schaffner, and a post-doctoral fellowship at Eidgenössische Technische Hochschule Zurich (ETH), where he focused on bioorganic chemistry under the guidance of Professor Steven Benner.