aTyr Pharma Completes Enrollment for Phase 1 Rare Disease Program

First Administration to Human Subjects of a New Protein Class, Physiocrines

SAN DIEGO – February 24, 2014 – aTyr Pharma, a rare disease therapeutics enterprise, announced today the first administration of Resokine IV to healthy human volunteers. The study is being conducted in healthy male and female volunteers in the European Union. aTyr plans to develop Resokine IV as a potential therapeutic for rare disorders where a patient’s immune system is imbalanced. Resokine belongs to a new class of proteins called Physiocrines, which were discovered by aTyr scientists. This study represents the first administration to humans of Physiocrines.

“The progression of Resokine IV into Phase 1 development reflects a significant step forward by our team to realize our mission: to treat patients with grave, rare diseases having no real treatment options with meaningful medicines that we discover, develop and commercialize,” said John Mendlein, Ph.D., CEO and executive chairman of aTyr Pharma.  “This is the first Physiocrine ever administered to humans – a huge milestone for this emerging field.”

Resokine is a member of the Physiocrine family, a newly discovered class of proteins, and we believe it possesses therapeutically relevant immuno-homeostasis properties. aTyr’s clinical study is primarily focused on safety and tolerability profile of this new human protein. The healthy volunteer study was designed to test a range of doses of intravenous administered Resokine IV.

“Our rare disease team created a preclinical and protein production foundation that will help establish our new therapeutic paradigm of immuno-homeostasis in rare disorders prudently, quickly and effectively,” continued Dr. Mendlein. “Our healthy volunteer study will pave the way for our patient trials in multiple, well-defined rare disease populations to occur later in 2014.  As our first protein selected for clinical development from our pipeline, we believe the Resokine pathway is a key player in immuno-homeostasis in a variety of rare disease states.”

About Physiocrines

Among their various homeostatic functions, some Physiocrines act as extracellular signaling molecules to orchestrate immuno-homeostasis in response to stress and other physiological changes. Physiocrines comprise naturally occurring proteins derived from tRNA synthetases that play fundamental roles in the function of human physiology and restoring pathophysiological states to a healthier state. aTyr is currently focused on Physiocrines that act as endogenous modulators of our immune system. Physiocrines offer the opportunity for modulating biological pathways through newly discovered naturally occurring mechanisms, many of which may provide multiple therapeutic advantages, including improved efficacy and reduced side effect profiles compared to many existing therapeutics.

About aTyr Pharma

aTyr Pharma is developing  a pipeline of therapeutic products based on Physiocrine biology. To protect these products aTyr built a dominant intellectual property estate comprising over 200 patent applications and patents. aTyr’s key programs are currently focused on rare disorders where the immune system is imbalanced. These diseases are serious potentially life threatening autoimmune conditions, for which there are currently no effective, safe, long term treatments. The privately held biotech was founded by The Scripps Research Institute Professor Paul Schimmel, a leading aminoacyl tRNA synthetase scientist, and is backed by top life sciences investors Alta Partners, Cardinal Partners, Domain Associates and Polaris Partners.