XBiotech (XBIT) Receives FDA Clearance for Phase 2 Trial of Vilamakitug in Axial Spondyloarthritis

XBiotech Inc. (NASDAQ: XBIT) received FDA clearance to advance vilamakitug into Phase 2 clinical trials for axial spondyloarthritis, the company announced June 16, 2026. The authorization permits the biotechnology firm to test the experimental antibody therapy in patients with the chronic inflammatory spinal disease. Axial spondyloarthritis affects approximately 1.4 million Americans, causing pain and stiffness in the spine and sacroiliac joints. Vilamakitug targets interleukin-1 alpha, a pro-inflammatory cytokine implicated in the condition's progression. The Phase 2 study will evaluate efficacy and safety parameters in a larger patient cohort following earlier-stage assessments. The Austin-based company's announcement represents a regulatory milestone, clearing the path for mid-stage development. Current treatment options for axial spondyloarthritis include TNF inhibitors and IL-17 blockers, suggesting a competitive landscape for novel therapies. XBiotech has not disclosed the trial's enrollment target or expected completion timeline.