Artax Presents Phase 2a Results of AX-158 for Plaque Psoriasis

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At the Society for Investigative Dermatology 2025 Annual Meeting in San Diego, California, Artax Biopharma shared Phase 2a late-breaking trial results (NCT05725057) of AX-158, a first-in-class oral Nck modulator for patients with mild to moderate plaque psoriasis.¹

“We’re highly encouraged by the safety profile observed in our Phase 2a study and the notable impact of our oral Nck modulator AX-158 on key disease biomarkers and clinical severity scores,” Rob Armstrong, PhD, Chief Executive Officer of Artax, said in a statement. “These results further support the potential of AX-158 to offer a truly novel mechanism to modulate TCR signaling rather than inhibit it, and we’re committed to continuing to advance this promising candidate to meet the unmet needs of patients with T cell-mediated autoimmune diseases.”¹

The investigational oral, small molecule immunomodulator, which acts as a T cell receptor, was tested among 31 participants between the ages of 18 and 60 at multiple centers in the UK. In the prospective, randomized, double-blind, placebo-controlled study, participants were randomized 2:1 to receive a single daily dose of 10mg AX-158 (n = 21) or placebo (n = 10) for 28 days. A 30-day safety period was also initiated at the conclusion of the trial. The first patient was dosed in February 2024.²

“From my blinded analysis of the patient samples in this phase 2a study, it is clear that AX-158 shows a clear impact on T cells and related biomarkers in this patient population,” James Krueger, MD, PhD, Head of Laboratory for Investigative Dermatology at the Rockefeller University and member of the Scientific Advisory Board at Artax, said.¹

AX-158 10 mg was found to be safe and well-tolerated with no Grade ≥ 3 treatment-related adverse effects and no serious or opportunistic infections. There was a single incidence of Grade 2 neutropenia in the arm (4.8%). None of the participants discontinued the therapy due to adverse events.

Patients with moderate disease, a Psoriasis Area and Severity Index (PASI) of >6, showed a positive response trend (34.6%). At the conclusion of the trial, only the patients who received AX-158 reached PASI50 or greater. These safety and efficacy findingscorrespond with what was observed in previous phase 1 study.

According to longitudinal skin biopsies, the number of CD8+ T cells was reduced significantly in patients treated with AX-158. In extended RNAseq analysis, the responder group showed 52% improvement in pathologic IL-17A levels. More specifically, 281 psoriasis-related gene sets were significantly downregulated (p < 0.05). The biomarker analyses also showed statistically significant impacts on the IL-17 and IL-12 signaling pathways, validating Nck immunomodulation for psoriasis and potentially other autoimmune diseases.

Unlike traditional autoimmune therapies that broadly shut down immune responses, Nck modulators increase T cell tolerance to self-antigens while simultaneously preserving their normal immune function against foreign pathogens. According to the abstract, AX-158 may help prevent self-reactive T cell responses that drive autoimmune pathobiology. It has the capability to be used as monotherapy or in combination with another therapy.

Scott Batty, MD, Chief Medical Officer of Artax, concluded, “We are deeply grateful to the investigators, their teams, and all the participants who made this progress possible. AX-158 has a unique mechanism of action that modulates TCR signaling to restore tolerance to self while maintaining response against pathogens. We are excited to continue advancing AX-158 and exploring its broad potential across T cell-driven autoimmune diseases, including atopic dermatitis and rheumatoid arthritis.”¹

References

1. Artax Biopharma presents Phase 2a results for oral Nck modulator AX-158 in late-breaking session at the Society for Investigative Dermatology 2025 Annual Meeting. Globe Newswire. May 9, 2025. Accessed May 9, 2025. https://www.globenewswire.com/news-release/2025/05/09/3078045/0/en/Artax-Biopharma-presents-Phase-2a-results-for-oral-Nck-modulator-AX-158-in-late-breaking-session-at-the-Society-for-Investigative-Dermatology-2025-Annual-Meeting.html

2. Artax announces first patient dosed in phase 2a psoriasis trial evaluating AX-158. News release. PR Newswire. February 13, 2024. Accessed May 9, 2025. https://www.prnewswire.com/news-releases/artax-announces-first-patient-dosed-in-phase-2a-psoriasis-trial-evaluating-ax-158-302060157.html