AILERON Therapeutics Appoints Tomi K. Sawyer as Chief Scientific Officer.

Expands Scientific Advisory Board to Include Two Distinguished Cancer Researchers:

David G. Nathan and Michael B. Kastan

CAMBRIDGE, Mass. -- AILERON Therapeutics, a biopharmaceutical company applying its proprietary Stapled Peptide technology to the development of breakthrough biologics for the treatment of cancer and other diseases, today announced that Tomi K. Sawyer, Ph.D., has joined the company as Chief Scientific Officer. Dr. Sawyer was most recently the Head of Chemistry for the Pfizer Research Technology Center in Cambridge, Mass. He will lead AILERON's internal and external drug discovery programs and will oversee the immediate expansion of its R&D capabilities.

"Tomi is an important addition to AILERON who will accelerate our efforts to bring our lead programs to the clinic. As one of the foremost experts in the field of peptide and peptidomimetic drug discovery, Tomi's decision to join AILERON as CSO is a testament to our recent scientific successes and the unique opportunity presented by the Stapled Peptide platform," said Joseph A. Yanchik III, CEO of AILERON.

"I'm very excited to join AILERON and lead the growth of its scientific organization as we build an innovative biotechnology company to create a novel class of breakthrough medicines," said Tomi K. Sawyer. "I have been very impressed by the unique pharmacological properties of stapled peptides, and the results to date suggest that AILERON's proprietary technology will have broad applicability to a large number of therapeutic targets for multiple diseases. We are bringing together a very talented team of scientists to leverage this extraordinary drug discovery opportunity, and I look forward to guiding AILERON's research and development efforts at this pivotal point in the company's history."

Dr. Sawyer was previously Senior Director, Pfizer Research Technology Center (Cambridge, Mass.) and concurrently served on Pfizer's Global Chemistry Leadership Team. In this capacity, he was responsible for drug discovery at the Cambridge facility, as well as global chemistry initiatives such as kinase-targeted innovative technologies. Prior to Pfizer, Dr. Sawyer held several leadership positions in drug discovery at ARIAD Pharmaceuticals including Senior Vice-President, Drug Discovery, where he led chemistry campaigns which successfully advanced the mTOR inhibitor AP23573 (recently partnered with Merck) and the second-generation Src/Abl kinase inhibitor AP24534 (a clinical candidate). He began his career at The Upjohn Company as a peptide chemistry and drug design scientist before moving on to a position at Parke-Davis/Warner-Lambert Company where he last served as Head, Structure-Based Design Chemistry. Dr. Sawyer is the recipient of ten international academic and corporate awards for outstanding drug discovery and innovative technologies. He is an inventor of more than 60 issued or filed scientific patents and is an author of more than 200 scientific publications including books, reviews, commentaries and research articles. Dr. Sawyer currently holds academic and research advisory appointments at the University of Massachusetts Medical School, Worcester and the University of Massachusetts, Amherst. He is the Founding Editor-in-Chief of Chemical Biology & Drug Design. Dr. Sawyer received a B.S. with Honors in chemistry from Moorhead State University and a Ph.D. with Distinction in organic chemistry from the University of Arizona.

In addition, AILERON announced two notable additions to its Scientific Advisory Board -- David G. Nathan, M.D. and Michael B. Kastan, M.D., Ph.D.

Dr. Nathan is President Emeritus, Dana-Farber Cancer Institute and the Robert A. Stranahan Distinguished Professor of Pediatrics and Professor of Medicine, Harvard Medical School. Dr. Nathan received his MD from Harvard Medical School in 1955, and was senior resident in medicine at Peter Bent Brigham Hospital and clinical associate at the National Cancer Institute. Between 1967 and 1984, he was chief of hematology at Children's Hospital Boston (CHB), and then chief of hematology and oncology at CHB and DFCI. He chaired the Department of Pediatrics from 1985 to 1995, and served as president of DFCI until 2000. Recent awards include the Howland Medal of the American Pediatric Society in 2003, the American Philosophical Society in 1999, the Annual Award for Excellence in Clinical Research (NIH) in 1996, the Henry Stratton Medal (American Society of Hematology) in 1995, and the National Medal of Science in 1990.

"We are very fortunate to be adding Dr. Nathan's deep experience in clinical oncology to AILERON's scientific advisory board as we build on discoveries initially made at the Dana-Farber Cancer Institute and Harvard University," said Yanchik. "Dr. Nathan's commitment to translating basic science from bench to bedside is well-known and highly regarded. His insights will be invaluable as we develop our own novel cancer therapeutics."

Dr. Kastan is a member of the St. Jude Children's Research Hospital faculty, Director of the Cancer Center, Director of the Molecular Therapeutics Division, and Co-Director of the Molecular Oncology Program. He is a recipient of the G.H.A. Clowes Memorial Award (American Association for Cancer Research, 2007), a member of the Johns Hopkins Society of Scholars, and is a Stohlman Scholar (Medical and Scientific Committee of the Leukemia Society of America). Dr. Kastan's research interests include the study of radiation biology, DNA damage and repair, tumor suppressor genes, and the determinants of chemosensitivity and radiosensitivity.

"Dr. Kastan is a world-class investigator of the molecular mechanisms of cancer development and treatment. As a member of AILERON's SAB, he will provide critical insight to our scientists as we advance our existing oncology programs and select new targets for discovery," said Yanchik. "Dr. Kastan shares our excitement at the prospect of developing a new class of targeted therapeutics for cancer and other diseases."

About AILERON Therapeutics, Inc.

AILERON Therapeutics is developing the first generation of peptide therapeutics directed at intra-cellular protein-protein interaction targets that are not addressable by current drug modalities. AILERON's proprietary cell penetrating "Stapled Peptide" technology is being applied to generate breakthrough therapeutics for the treatment of cancer and other diseases. AILERON believes that "Stapled Peptides" have the potential to become a major new class of drugs for intracellular and extracellular targets across therapeutic areas. AILERON Therapeutics is an emerging biopharmaceutical company based in Cambridge, Mass. For more information please visit www.aileronrx.com.