Aileron Therapeutics Successfully Completes First-Ever Stapled Peptide Clinical Trial

Safety and Pharmacokinetics of ALRN-5281, a Long-Acting Growth-Hormone-Releasing-Hormone Agonist, Established in Single-Ascending Dose Study

Aileron Therapeutics Successfully Completes First-Ever Stapled Peptide Clinical Trial

<0> Pure Communications, Inc.Dan Budwick, 973-271-6085 </0>

today announced the completion of the first-in-human study of its lead Stapled Peptide drug, ALRN-5281, a proprietary, long-acting growth-hormone-releasing hormone (GHRH) agonist for treating orphan endocrine disorders, including adult growth hormone (GH) deficiency and human immunodeficiency virus (HIV) lipodystrophy, as well as broader patient populations involving a wide variety of metabolic/endocrine diseases.

“The successful translation of a Stapled Peptide drug into human subjects has long been our goal. It is an important milestone for Aileron, as well as for the rapidly emerging Stapled Peptide field as a whole,” said Joseph A. Yanchik, III, president, chief executive officer and co-founder of Aileron. “We are proud to pioneer the first clinical trial of Stapled Peptides, and we look forward to continuing our leadership in the development and eventual commercialization of this promising therapeutic class.”

The initial Phase 1 trial evaluated the safety and tolerability of single ascending doses of ALRN-5281 administered by subcutaneous injection in healthy adult subjects. Additional study objectives included the evaluation of pharmacokinetics (PK) and exploratory pharmacodynamic (PD) biomarkers of ALRN-5281. Thirty-two subjects completed the study. There were no serious adverse events, dose-limiting safety findings, or tolerability issues leading to withdrawal during the study.

“We now have clinical data showing that Aileron’s Stapled Peptides are capable of delivering a drug product profile previously believed to be out of reach with traditional peptide-based therapeutics, in particular PK attributes that support once-weekly dosing,” said Hubert C. Chen, M.D., vice president of clinical development at Aileron. “We are encouraged by the prospects of ALRN-5281 to demonstrate improved safety, efficacy, and convenience over currently available GH and GHRH injections. The results of this initial trial will guide us in optimizing dose selection and frequency for ALRN-5281 as a potential best-in-class therapy.”

Stapled Peptides are a new class of drugs with a unique set of properties that fully capitalize on 25 years of genetic research to attack drivers of complex diseases, including cancer, endocrine/metabolic disorders and inflammation. The Stapled Peptide platform locks peptides into their biologically active shape and imparts pharmaceutical stability within the body. Stapled Peptide drugs, such as ALRN-5281, are derived from natural peptides and are designed to remain in a safe and effective therapeutic range longer than traditional peptide hormones. This new class of drugs represents a fundamental scientific breakthrough as they offer the most advanced way to replicate normal human physiology to treat human disease.

ALRN-5281 is a proprietary, long-acting GHRH agonist for treating orphan endocrine disorders, including adult GH deficiency and HIV lipodystrophy, as well as broader patient populations involving a wide variety of metabolic/endocrine diseases. Relative to GH injections, GHRH therapy produces a more physiological response, thereby minimizing safety and tolerability issues associated with chronic, excess GH replacement.

Aileron Therapeutics is creating one of the first new classes of drugs in 20 years. Our proprietary Stapled Peptide drugs uniquely capitalize on 25 years of genetic research to attack the key drivers of complex diseases such as cancer, metabolic and endocrine conditions and inflammation. By harnessing one of the most common, but elusive, structures in nature - the alpha helical peptide - we believe that we can dramatically improve the treatment of these diseases and positively impact the lives of millions of patients. For more information, please visit .