aTyr Pharma
aTyr Pharma is a clinical-stage biotherapeutics company developing protein therapeutics derived from tRNA synthetase biology for fibrosis and inflammation, with lead candidate efzofitimod in development for interstitial lung diseases including pulmonary sarcoidosis and SSc-ILD.
- Company typePublic
- Founded2005
- HeadquartersSan Diego, United States
- Headcount51–100
- GTM typeB2B
- OfferingHardware or Manufacturing
What aTyr Pharma does
aTyr Pharma is a clinical-stage biotherapeutics company founded in 2005 and headquartered in San Diego, California, that translates tRNA synthetase biology into novel protein therapeutics for fibrosis and inflammation. Its proprietary platform comprises a library of 300+ protein compositions derived from all 20 human cytosolic tRNA synthetases, protected by 220+ issued or allowed patents across 21 patent families. The company's lead candidate, efzofitimod (ATYR1923), is a first-in-class immunomodulator derived from a splice variant of histidyl-tRNA synthetase that selectively modulates activated myeloid cells through neuropilin-2 (NRP2) to resolve inflammation without immune suppression.
In September 2025, the global Phase 3 EFZO-FIT study of efzofitimod in 268 pulmonary sarcoidosis patients failed to meet its primary endpoint, triggering an 83% stock decline and multiple securities class action lawsuits. The company has requested an FDA Type C meeting for mid-April 2026 to determine the regulatory path forward, and continues to run the Phase 2 EFZO-CONNECT study in systemic sclerosis-related ILD. Earlier-stage assets include ATYR0101 (DARS-derived, LTBP1-binding) and ATYR0750 (AARS-derived, FGFR4 ligand) for fibrosis indications, and the Pangu BioPharma subsidiary in Hong Kong is developing bispecific antibodies targeting NRP2 for cancer in collaboration with HKUST.
The business model is that of a pre-revenue clinical-stage biotech: aTyr funds development through equity raises (most recently ~$30.7M via Jefferies in August 2025 and a $50M public offering in February 2023) and intends to generate revenue through commercialization of efzofitimod following regulatory approval, with Kyorin Pharmaceutical holding Japan rights. The company has not established product pricing. Future commercial GTM relies on specialty pharmacy distribution and physician outreach for interstitial lung disease, with orphan-designated indications in pulmonary sarcoidosis and SSc-ILD representing the addressable patient base of over 500,000 in the US and over 3 million globally.
aTyr Pharma firmographics
Firmographics- Name
- aTyr Pharma
- Legal name
- aTyr Pharma Inc.
- Website
- https://atyrpharma.com
- Company type
- Public
- Founded year
- 2005
- Operating status
- Operating
- Headcount range
- 51–100 employees
- Short description
- aTyr Pharma is a clinical-stage biotherapeutics company developing protein therapeutics derived from tRNA synthetase biology for fibrosis and inflammation, with lead candidate efzofitimod in development for interstitial lung diseases including pulmonary sarcoidosis and SSc-ILD.
- Ownership category
- akta.pro rank
aTyr Pharma industry classification
Industry- Product category
- Biopharmaceutical Therapeutics
- NAICS
- Biological Product (except Diagnostic) Manufacturing (325414), Pharmaceutical Preparation Manufacturing (325412)
- SIC
- Biological Products, (No Disgnostic Substances) (2836), Pharmaceutical Preparations (2834)
- akta.pro primary industry
- Recombinant Protein Therapeutics (enzymes, hormones, growth factors) (HLAAAAAB)
- akta.pro secondary industries
- Therapeutic Peptides & Protein/Peptide Biologics (HLAAAAAH), Engineered Protein Therapeutics (de novo/AI-designed proteins, novel scaffolds) (HLAAAAAJ), Immunology & Autoimmune Specialty Pharmaceuticals (HLAIACAB)
Keywords
Where aTyr Pharma is headquartered
LocationHeadquarters
- HQ city
- San Diego
- HQ country
- United States
- HQ region
- North America
Offices2 records
Markets served
aTyr Pharma business model
Business model- GTM type
- B2B
- Offering type
- Hardware or Manufacturing
- Cost components
- Technology or R&D, Personnel, Operations, Marketing or Sales, Infrastructure
Revenue model
- Pharmaceutical Development and Commercialization: As a clinical-stage biotechnology company, aTyr Pharma is pre-revenue and focused on developing therapeutic candidates through clinical trials. The company expects to generate revenue through eventual commercialization of efzofitimod and other pipeline candidates upon regulatory approval.
Go-to-market motion1 record
Distribution channels1 record
Marketing channels4 records
aTyr Pharma product offering
Product offeringCore offering
aTyr Pharma is a clinical-stage biotherapeutics company developing tRNA synthetase-derived protein biologics for fibrosis and inflammation. Its lead candidate, efzofitimod (ATYR1923), is an immunomodulator in Phase 3 development for pulmonary sarcoidosis and Phase 2 for systemic sclerosis-related ILD (EFZO-CONNECT). The pipeline additionally includes ATYR0101 and ATYR0750, fusion proteins targeting fibrosis and FGFR4-mediated pathways respectively.
Product overview
aTyr Pharma is a clinical-stage biotechnology company leveraging evolutionary intelligence to translate tRNA synthetase biology into new therapies for fibrosis and inflammation. The company's product portfolio centers on efzofitimod (ATYR1923), a novel biologic immunomodulator derived from histidyl-tRNA synthetase that selectively modulates myeloid cells through neuropilin-2. Efzofitimod is the lead candidate in Phase 3 development for pulmonary sarcoidosis and Phase 2 for systemic sclerosis-related ILD. The broader pipeline includes ATYR0101 (a DARS-derived LTBP1 modulator for fibrosis) and ATYR0750 (an AARS-derived FGFR4 modulator for liver disorders), both in preclinical stages. The company operates through its Pangu BioPharma subsidiary in Hong Kong for antibody discovery and maintains an extensive intellectual property portfolio covering over 300 protein compositions derived from all 20 tRNA synthetases.
Differentiator
Problem solved
Functional benefit
Brands
- EFZO-FIT: Phase 3 clinical trial name for efzofitimod in pulmonary sarcoidosis
- EFZO-CONNECT
Products and services
- Efzofitimod (ATYR1923) A novel biologic immunomodulator and lead therapeutic candidate derived from a naturally occurring splice variant of histidyl-tRNA synthetase (HARS) that selectively modulates activated myeloid cells through neuropilin-2 (NRP2) to resolve inflammation without immune suppression and potentially prevent fibrosis progression. In clinical development for pulmonary sarcoidosis (Phase 3 EFZO-FIT) and systemic sclerosis-related ILD (Phase 2 EFZO-CONNECT).
- ATYR0101 A fusion protein derived from a domain of aspartyl-tRNA synthetase (DARS) that binds to latent-transforming growth factor beta-binding protein 1 (LTBP1), which regulates TGF-beta. Early data suggest ATYR0101 exerts antifibrotic effects by inducing apoptosis of myofibroblasts. Being developed for multiple fibrotic diseases including pulmonary fibrosis, systemic sclerosis, and liver and kidney fibrosis.
- ATYR0750 A fusion protein derived from a domain of alanyl-tRNA synthetase (AARS) that acts as a novel ligand to fibroblast growth factor receptor 4 (FGFR4). FGFR4 is involved in cellular processes including cell proliferation, differentiation and tissue repair, with a role in inflammation and fibrosis particularly in liver diseases.
Quantifiable outcome
- Phase 3 EFZO-FIT study enrolled 268 patients with symptomatic pulmonary sarcoidosis across US, Europe, Japan and Brazil
- +2 more outcomes
Companies that use aTyr Pharma
Customer profileSegments2 records
Ideal customer profiles3 records
aTyr Pharma technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature4 records
aTyr Pharma partnerships and signals
Strategic signalPartnerships
Three partnerships are on record, tiered core and minor.
- Kyorin Pharmaceutical Co., Ltd.coreKyorin Pharmaceutical holds partnership rights for the development and commercialization of efzofitimod for interstitial lung disease (ILD) in Japan. This regional partnership provides local regulatory and commercial expertise for the Japanese market.
- Hong Kong University of Science and Technology (HKUST)coreResearch collaboration with HKUST for basic and translational research in tRNA synthetase biology. The collaboration, supported by Hong Kong government's Innovation and Technology Commission through a two-year grant, focuses on developing a high-throughput platform for bispecific antibody development targeting Neuropilin-2 (NRP2) for cancer applications. Milestones achieved include establishing an innovative antibody discovery platform and developing a novel single-cell antibody discovery approach.
- Dualsystems Biotech AGminorCollaboration for translating the tRNA synthetase platform into new drug candidates for fibrosis and inflammation.
Scale indicators7 records
Recent moves5 records
Expansion highlights6 records
aTyr Pharma competitors and assessment
Company assessmentDirect peers
- FibroGen: Clinical-stage biopharmaceutical company developing therapeutics for fibrosis and inflammation. Comparable in therapeutic focus area, clinical-stage profile, and small-cap public status to aTyr.
- Pliant Therapeutics: Clinical-stage biotech developing integrin-based therapeutics for idiopathic pulmonary fibrosis and other fibrotic diseases. Direct competitor in ILD/fibrosis with similar clinical-stage risk profile.
- Galapagos NV: European biotech with a significant IPF and ILD franchise (historical JAK/tyk2 programs). Comparable as a fibrosis-focused clinical-stage player with similar late-stage trial exposure.
Broad incumbents
- United Therapeutics: Established pulmonary and ILD-focused biopharma commercializing products in PAH and pulmonary fibrosis. Comparable as ILD therapeutic developer with broader portfolio and commercial reach.
- Boehringer Ingelheim: Large pharma with nintedanib (OFEV) approved for IPF, SSc-ILD, and progressive fibrosing ILD. Represents the incumbent therapeutic standard against which efzofitimod must compete in ILD.
- Roche / Genentech: Major biopharma with pirfenidone (Esbriet) approved for IPF and active immunology pipeline. Incumbent ILD therapeutic competitor with broad development resources.
- Horizon Therapeutics: Specialty biopharma focused on rare and autoimmune diseases (acquired by Amgen). Comparable as a rare-disease immunology commercial-stage player that represents the type of strategic acquirer relevant to aTyr.
Emerging players
- Prometheus Biosciences: Clinical-stage immunology biotech (acquired by Merck in 2023) developing precision therapeutics for immune-mediated diseases. Comparable in immunology mechanism focus and clinical-stage biotech profile.
- Kiniksa Pharmaceuticals: Clinical-stage biotech developing immunology therapeutics for rare and autoimmune diseases. Comparable as small-cap immunology biotech with similar clinical execution requirements.
- ChemoCentryx: Late-stage rare immunology biotech (acquired by Amgen for $3.7B in 2022) that developed TAVNEOS. The Head of Commercial at aTyr previously led TAVNEOS commercial strategy here — directly comparable small-cap rare-disease immunology developer.
Market position
Strengths4 records
Weaknesses5 records
Competitive moat4 records
Key risks6 records
Key highlights7 records
Customer concentration
aTyr Pharma social profiles
Digital presenceaTyr Pharma compliance and trust
Trust signalCompliance1 record
aTyr Pharma financial estimates
Financial estimateRevenue estimate
Valuation estimate
aTyr Pharma leadership team
Management profileNumber of profiles
Profiles12 records
aTyr Pharma subsidiaries and ownership
Company hierarchySubsidiaries1 record
aTyr Pharma funding detail
Funding detailFunding overview
Funding rounds12 records
Investors19 records
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
aTyr Pharma M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about aTyr Pharma
What does aTyr Pharma do?
aTyr Pharma is a clinical-stage biotherapeutics company developing tRNA synthetase-derived protein biologics for fibrosis and inflammation. Its lead candidate, efzofitimod (ATYR1923), is an immunomodulator in Phase 3 development for pulmonary sarcoidosis and Phase 2 for systemic sclerosis-related ILD (EFZO-CONNECT). The pipeline additionally includes ATYR0101 and ATYR0750, fusion proteins targeting fibrosis and FGFR4-mediated pathways respectively.
Is aTyr Pharma a public or private company?
aTyr Pharma is a public company. It is classified as public and is currently operating.
When was aTyr Pharma founded?
aTyr Pharma was founded in 2005. It employs 51 to 100 people.
Where is aTyr Pharma based?
aTyr Pharma is headquartered in San Diego, United States, in the North America region.
How does aTyr Pharma make money?
One revenue line is on record: pharmaceutical Development and Commercialization.
Who are aTyr Pharma's main competitors?
Direct peers on record are FibroGen, Pliant Therapeutics and Galapagos NV. Broad incumbents are United Therapeutics, Boehringer Ingelheim, Roche / Genentech and Horizon Therapeutics. Emerging players are Prometheus Biosciences, Kiniksa Pharmaceuticals and ChemoCentryx.
Does aTyr Pharma have an API?
No public API is recorded for aTyr Pharma.
What industry is aTyr Pharma in?
aTyr Pharma's product category is Biopharmaceutical Therapeutics. Its primary akta.pro industry code is HLAAAAAB, Recombinant Protein Therapeutics (enzymes, hormones, growth factors), with a secondary code of HLAAAAAH, Therapeutic Peptides & Protein/Peptide Biologics. Its NAICS code is 325414 and its SIC code is 2836.