Greywolf Therapeutics doses first participants with axSpA in novel ERAP1 inhibitor trial

• Single ascending dose (SAD) portion completed in healthy volunteers, with dose-proportional pharmacokinetics (PK), clear evidence of ERAP1 target engagement, and no safety or tolerability concerns observed
• GRWD0715 dosed in first participants with axial spondyloarthritis (axSpA) in the multiple ascending dose (MAD) portion of the Phase 1/2 EAST-1 study (NCT07047703)
• US composition-of-matter patent granted for GRWD0715
• Discovery partnership with Genomics continues to inform planned expansion into a broad range of autoimmune disease by identifying ERAP-associated indications, including IBD and psoriatic arthritis
  
  

OXFORD, United Kingdom, Sept. 08, 2026 (GLOBE NEWSWIRE) -- Greywolf Therapeutics, the clinical-stage biotech company advancing novel antigen modulation treatments for cancer and autoimmune diseases, today reports significant progress in their Phase 1/2 study in axial spondyloarthritis (axSpA) and broader autoimmunity strategy.

GRWD0715, a first-in-class oral ERAP1 inhibitor to treat CD8⁺ T cell-mediated autoimmunity, has now been dosed in participants with axSpA after the completion of the SAD portion of its Phase 1/2 study (EAST-1) in healthy volunteers, demonstrating dose-proportional PK, clear evidence of ERAP1 target engagement, with no safety or tolerability concerns observed.

ERAP1 carries one of the strongest genetic associations with axSpA after HLA-B27, and the genetic interplay between these two critical components of the antigen presentation machinery firmly highlight the target’s potential to address the source of autoimmune disease pathology.

The ongoing MAD portion in participants with axSpA is expected to generate PK/PD, translational biomarker and preliminary clinical endpoint data to inform dose selection for the placebo-controlled Phase 2a proof-of-concept portion of the study, planned to start in H2 2027.

ERAP1 and ERAP2 are among the most consistently observed genetic associations across autoimmunity. Greywolf’s strategic partnership with Genomics continues to strengthen their autoimmunity pipeline, combining large-scale genetic data with clinical and translational insights. Genomics is analyzing variants in ERAP1 and ERAP2 — genes originally associated with autoimmune disease risk through genome-wide association work led by Genomics’ CEO Professor Sir Peter Donnelly — across conditions including inflammatory bowel disease and psoriatic arthritis.

These insights are directly informing how Greywolf prioritizes indications beyond axSpA, their first target indication for GRWD0715, and help to validate the broader opportunity for ERAP inhibition as the company accelerates their autoimmunity expansion.

Peter Joyce, CEO & Co-founder, Greywolf Therapeutics, said:

"We continue to make remarkable progress in autoimmunity. Dosing our first participants with axSpA after promising healthy volunteer data, securing US patent protection for GRWD0715, and fueling our indication expansion through our partnership with Genomics are significant achievements.

"These milestones reinforce our conviction that ERAP inhibition can fundamentally change how we treat axSpA and broader autoimmune conditions, opening a novel route towards a potential functional cure by targeting the source of autoimmunity: the presentation of autoantigens."

About Greywolf Therapeutics

‍Greywolf Therapeutics is a clinical-stage biotech company advancing novel antigen modulation treatments for cancer and autoimmune diseases.

The company’s first-in-class small molecules are developed to control T cell activation by modulating antigen presentation, altering how cells appear to the immune system so it can recognize and target them correctly.

Greywolf’s oncology treatment (GRWD5769) is delivering promising Phase 1/2 data in patients with solid tumors, demonstrating a good safety and tolerability profile, as well as generating durable clinical responses across multiple tumor types. The company’s autoimmunity treatment (GRWD0715) is progressing in a Phase 1/2 trial to treat the source of axial spondyloarthritis ahead of a planned expansion into other autoimmune indications.

Greywolf is headquartered in Oxford, UK.

More information: Website | LinkedIn

About axSpA

Axial spondyloarthritis (axSpA) is a chronic immune-mediated inflammatory disease affecting mainly the spine and sacroiliac joints, causing persistent back pain and stiffness, and presenting generally before the age of 40. It affects ~0.5–1.4% of the population, with over 80% of cases in HLA-B27–positive individuals. Men and women are affected roughly equally, though forms of axSpA that cause changes in X-rays of the SI joints (radiographic axSpA) are more common in men. Symptoms may also involve hips, peripheral joints such as knees, wrists, shoulders and others, as well as extra-musculoskeletal manifestations such as eyes (uveitis), skin (psoriasis), or the gut (inflammatory bowel diseases). There’s no cure, but NSAIDs, DMARDs (biologic and synthetic) and non-pharmacological therapy help reduce pain, control inflammation, and maintain mobility to prevent long-term spinal damage.

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