What Ajax Therapeutics does

Ajax Therapeutics was a clinical-stage biopharmaceutical company founded in 2019 and headquartered in New York City (with a Cambridge, MA listed address in some records) that developed first-in-class Type II JAK2 inhibitors for the treatment of myeloproliferative neoplasms (MPNs), including myelofibrosis, polycythemia vera, and essential thrombocythemia. The company's lead asset AJ1-11095 is the first JAK2 inhibitor to enter clinical trials that binds the Type II conformation of the JAK2 kinase, a mechanistically distinct approach from all approved Type I JAK2 inhibitors (e.g., ruxolitinib) that addresses a significant unmet need in patients who have failed or become resistant to Type I therapy. A second preclinical candidate, AJ1-10502, demonstrated enhanced selectivity and reductions in mutant cell fraction in bone marrow and spleen not observed with ruxolitinib. The company applied state-of-the-art computational chemistry and structural biology via a founding partnership with Schr\u00f6dinger, Inc. (which held approximately 6% equity) and licensed intellectual property from Memorial Sloan Kettering Cancer Center.

The business model was asset-development-led rather than commercial: Ajax operated with 1\u201310 employees and raised approximately $143 million in equity across seed, Series A (2021), and Series C (2024) rounds to advance drug candidates through clinical development and pursue strategic exit. The company generated no commercial product revenue and instead monetized its pipeline through licensing, strategic partnerships, or acquisition. Distribution was entirely indirect, relying on scientific conference presentations (ASH, EHA), FDA regulatory milestones (Orphan Drug Designation, December 2025), and press releases to communicate clinical progress to potential partners and acquirers. In April 2026, Eli Lilly acquired Ajax for up to $2.3 billion in cash (upfront plus milestone payments), with Lilly having previously participated as a founding strategic investor in the 2024 Series C. The Phase 1 trial of AJ1-11095 (NCT06343805) reported 70% of evaluable patients achieving at least 35% spleen volume reduction and 70% achieving 50% or greater symptom improvement at week 12, with reductions in driver mutation variant allele frequency observed in 21 of 23 patients and no dose-limiting toxicities. Post-acquisition, Ajax operates as a wholly owned subsidiary of Eli Lilly with its pipeline integrated into Lilly's hematology portfolio.

Name

Ajax Therapeutics

Legal name

Ajax Therapeutics, Inc.

Website

https://ajaxtherapeutics.com

Company type

Private

Founded year

2019

Operating status

Acquired

Headcount range

1–10 employees

Short description

Ajax Therapeutics was a clinical-stage biopharmaceutical company developing first-in-class Type II JAK2 inhibitors for myeloproliferative neoplasms, with lead asset AJ1-11095 in Phase 1 trials for myelofibrosis. The company was acquired by Eli Lilly in April 2026 for up to $2.3 billion.

Ownership category

akta.pro rank

Headquarters

HQ city

Cambridge

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Marketing or Sales

Revenue model

1. Acquisition/Strategic Sale: Ajax Therapeutics' primary revenue model involved developing novel drug candidates through clinical stages and seeking acquisition or strategic partnership with larger pharmaceutical companies. The company was acquired by Eli Lilly in April 2026 for up to $2.3 billion, representing the primary exit and revenue realization for investors and stakeholders.
2. FDA Orphan Drug Designation: The company pursued regulatory exclusivity through FDA Orphan Drug Designation for AJ1-11095 for the treatment of myelofibrosis, which provides market exclusivity benefits and regulatory advantages for rare disease therapeutics.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels4 records

Core offering

Ajax Therapeutics develops next-generation Type II JAK2 small-molecule inhibitors for the treatment of myeloproliferative neoplasms (MPNs), with lead candidate AJ1-11095 in Phase 1 clinical trials for myelofibrosis. The company applies computational chemistry and structural biology, through its founding partnership with Schrödinger, Inc., to design selective JAK2 inhibitors that bind the Type II conformation and reduce mutant JAK2 allele burden, addressing resistance to approved Type I JAK2 inhibitors such as ruxolitinib.

Product overview

Ajax Therapeutics is a biopharmaceutical company developing a pipeline of next-generation Type II JAK2 inhibitors for myeloproliferative neoplasms (MPNs). The company's lead product is AJ1-11095, a first-in-class Type II JAK2 inhibitor currently in Phase 1 clinical trials for myelofibrosis. The company also has a preclinical candidate, AJ1-10502. The products leverage computational chemistry and structure-based drug design in partnership with Schrödinger, Inc. to develop more selective and potent JAK2 inhibitors that can reduce mutant JAK2 allele burden and potentially modify disease progression, addressing limitations of currently approved Type I JAK2 inhibitors.

Differentiator

Problem solved

Functional benefit

Products and services

• AJ1-11095 AJ1-11095 is a first-in-class Type II JAK2 inhibitor in Phase 1 clinical development for myelofibrosis. It is the first JAK2 inhibitor to enter the clinic that binds the Type II conformation of the JAK2 kinase, offering a differentiated mechanism from all currently approved Type I JAK2 inhibitors such as ruxolitinib. The drug targets patients with primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis who have failed prior Type I JAK2 inhibitor therapy, and aims to reduce mutant JAK2 allele burden for disease-modifying therapy.
• AJ1-10502 AJ1-10502 is a next-generation, second-generation Type II JAK2 inhibitor with enhanced selectivity and improved efficacy versus Type I JAK2 inhibitors such as ruxolitinib. Preclinical data demonstrated significant reductions in mutant cell fraction within bone marrow and spleen not observed with Type I JAK2 inhibitors, supporting its potential as a disease-modifying therapy for myeloproliferative neoplasms.

Quantifiable outcome

• 70% of patients achieved at least 35% spleen volume reduction (SVR35) at week 12 in Phase 1 trial
• +5 more outcomes

Segments1 record

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Four partnerships are on record, tiered flagship, core and minor.

• Eli Lilly and CompanyflagshipStrategic or Co-development Partner · 27 April 2026Eli Lilly acquired Ajax Therapeutics in April 2026 for up to $2.3 billion to expand its oncology pipeline focused on myeloproliferative neoplasms. The acquisition centers on Ajax's lead candidate AJ1-11095, a first-in-class Type II JAK2 inhibitor currently in Phase 1 clinical development for myelofibrosis and polycythemia vera.
• Schrödinger, Inc.coreTechnology or Integration · 1 January 2024Schrödinger, Inc. is the founding partner of Ajax Therapeutics, providing industry-leading computational drug discovery and protein structure platforms. Schrödinger holds approximately 6% equity in Ajax. The partnership enables Ajax to apply state-of-the-art computational chemistry and structural biology throughout the drug discovery process.
• Memorial Sloan Kettering Cancer Center (MSK)coreStrategic or Co-development Partner · 3 June 2021Memorial Sloan Kettering Cancer Center (MSK) participated as a research institution in the $40 million financing round. Dr. Ross Levine from MSK serves on Ajax's Scientific Advisory Board and board of directors. MSK has intellectual property rights licensed to Ajax.
• NYU Langone HealthminorStrategic or Co-development Partner · 3 June 2021NYU Langone Health participated as a research institution in the $40 million financing round for Ajax Therapeutics in June 2021.

Scale indicators5 records

Recent moves6 records

Expansion highlights5 records

Others

• Schrödinger, Inc. Schrödinger was Ajax's founding computational drug-discovery partner (~6% equity) and provider of structure-based design platforms. It is an enabling/ecosystem participant rather than a competitor, but deeply comparable as a discovery platform model.

Direct peers

• Incyte Corporation: Incyte markets ruxolitinib (Jakafi), the leading approved Type I JAK1/2 inhibitor and standard of care in myelofibrosis — directly competing with Ajax's Type II JAK2 inhibitor AJ1-11095 in the same MPN indication.
• GSK (Sierra Oncology acquisition): GSK acquired Sierra Oncology and markets momelotinib (Omjjara), a JAK1/2 and ACVR1 inhibitor approved for myelofibrosis — directly competing with AJ1-11095 in the second-line MPN setting.
• Swedish Orphan Biovitrum (Sobi): Sobi acquired CTI BioPharma and markets pacritinib (Vonjo), a JAK2/IRAK1 inhibitor approved for myelofibrosis — a direct competitor to AJ1-11095 in the ruxolitinib-failure and cytopenic MF settings.
• Bristol-Myers Squibb: BMS (via the Celgene acquisition) markets fedratinib (Inrebic), an approved JAK2 inhibitor for myelofibrosis. BMS is a direct competitor in the Type II JAK2 / MPN space.

Broad incumbents

• Pfizer: Pfizer markets the JAK inhibitor Xeljanz (tofacitinib) and has broader hematology/oncology franchises, making it a broad incumbent with overlapping JAK-family and hematology capabilities relevant to MPN drug development.
• Novartis: Novartis is Lilly's predecessor in Ajax's CMO background and commercializes Jakavi (ruxolitinib) ex-US. As a global oncology/hematology incumbent, Novartis represents a broader peer with overlapping MPN commercial interests.

Emerging players

• Disc Medicine: Disc Medicine is developing bitopertin (a glycine transport inhibitor) for erythropoietic protoporphyria and exploring MPN applications — an emerging hematology-focused biotech with overlapping rare hematology expertise.
• Kartos Therapeutics: Kartos is developing navitoclax (BCL-2/BCL-xL inhibitor) in combination with ruxolitinib for myelofibrosis — a focused emerging competitor pursuing disease-modifying claims in the same MPN space.
• Geron Corporation: Geron markets imetelstat (Rytelo), a first-in-class telomerase inhibitor approved in lower-risk MDS and in development for myelofibrosis — an emerging competitor with a different mechanism but overlapping MPN patient population.

Market position

Strengths4 records

Weaknesses5 records

Competitive moat4 records

Key risks7 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/ajax-therapeutics

Revenue estimate

Valuation estimate

Number of profiles

Profiles8 records

Funding overview

Funding rounds3 records

Investors11 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Ajax Therapeutics