aTyr Pharma is a public biotherapeutics company (NASDAQ: LIFE) that researches and develops Physiocrine-based therapeutics for treatment of rare diseases with an immune component. aTyr's key programs are currently focused on severe, rare diseases characterized by immune imbalance for which there are currently limited or no treatment options.

The company’s leading drug candidate, Resolaris is being evaluated in clinical trials for treatment of adult patients with facioscapulohumeral muscular dystrophy (FSHD), limb-girdle muscular dystrophy 2B (LGMD2B), and early onset FSHD. Resolaris is thought to halt muscle deterioration by modulating the immune system and promoting tissue homeostasis.

The company was founded in 2005 and is headquartered in San Diego, CA, and led by CEO John Mendlein, Ph.D., J.D.

In 2005, aTyr was founded by Paul Schimmel, Ph.D., and Xiang-Lei Yang, Ph.D., two aminoacyl tRNA synthetase scientists at The Scripps Research Institute. In 2009, Bruce Beutler, M.D., recipient of the 2011 Nobel Prize in Physiology or Medicine, joined aTyr as a member of the scientific advisory board.

In April 2007, Polaris Partners and Alta Partners co-led a $10.5 million Series B financing. In October 2010, Series C financing totaled $23 million and was led by Domain Associates. This round was followed by a $49 million Series D in August 2013.

aTyr was a winner of the 2011 Red Herring 100 North America Award for discovering and developing innovative medicines based on Physiocrine biology.

In January 2015, aTyr announced its first FSHD patient enrolled in a Phase 1b/2 clinical trial of Resolaris. In February and April of that same year, Resolaris received EMA Orphan Drug Designation and U.S. FDA Orphan Designation for treatment of FSHD.<ref>the pharma letter: EMA Orphan Drug status for aTyr’s Resolaris in FSHD (Feb. 18, 2015)</ref>

In April 2015, aTyr raised $76 million in a Series E, led by Sofinnova Ventures, and filed for an IPO. The company began trading as LIFE on the Nasdaq stock exchange.

In October 2015, aTyr initiated a Phase 1b/2 clinical trial on Resolaris for patients with LGMD2B and the following month initiated a Phase 1b/2 clinical trial in patients with early onset FSHD. aTyr’s second IND candidate, ATYR 1923 (iMod.Fc), was selected in November 2015. ATYR 1923 is an engineered fusion protein. ATYR 1923 was developed for the potential treatment of severe pulmonary diseases with an immune and fibrotic component, including interstitial lung disease.

Throughout 2016 and into the first half of 2017 aTyr released data on three Phase 1b/2 trials for Resolaris in adults with FSHD or LGMD2B, and early onset FSHD patients (ages 16–20). Data from these trials showed encouraging results for safety, tolerability, immunogenicity and pharmacokinetic profile, and signals of clinical activity in regards to muscle strength (Manual Muscle Testing) and disease burden (Individualized Neuromuscular Quality of Life score – INQoL).

Homeostasis, or the coordinated regulation of tissues within the body, is fundamental to the maintenance of the overall health of an organism. Lack of homeostasis can lead to disease and death. The process of homeostasis was first described in 1865 by the French physiologist Claude Bernard and Walter Cannon later coined the term. In the 150 years since this discovery, many proteins associated with homeostatic pathways have been discovered, ranging from insulin to erythropoietin.

aTyr was founded after Dr. Schimmel discovered several nontranslational functions of aminoacyl tRNA synthetases, which are primarily responsible for the production of a vital component of protein synthesis, aminoacyl-tRNAs. [23] These nontranslational functions have since been shown to play an important role in maintaining homeostasis. [23] One of these nontranslational functions is modulation and regulation of the immune response. [23] This modulatory activity is a result of Physiocrines, a novel class of proteins that are present as biologically active signaling regions of the tRNA synthetases. aTyr’s research is based on the premise that Physiocrines are involved in orchestrating homeostatic activities to help the body restore diseased or damaged tissue to a healthier state.

By researching and understanding the role of Physiocrines in immune modulation, aTyr has developed two IND candidates.