XBiotech Inc. (NASDAQ: XBIT) announced its Investigational New Drug application for a Phase II clinical trial evaluating vilamakitug in patients with active axial spondyloarthritis has completed the FDA's 30-day review period without clinical hold. The company can now proceed with patient enrollment in the United States.

The V-SPINE study will evaluate 400 mg of vilamakitug administered as 16 weekly subcutaneous injections versus placebo in 150 adult participants with active axial spondyloarthritis. The primary endpoint measures the proportion of participants achieving an ASAS40 response at Week 16. The study includes a 12-week open-label extension where all participants receive vilamakitug.

Marina Magrey, M.D., serves as Study Chair. Magrey is Division Chief of Rheumatology at University Hospitals Cleveland Medical Center and Professor of Medicine at Case Western Reserve University School of Medicine. The clinical protocol was developed with guidance from a panel of rheumatology experts.

Vilamakitug is an IgG4 monoclonal antibody that neutralizes interleukin-1α, a pro-inflammatory cytokine. The company states the antibody targets inflammation that contributes to synovial and entheseal inflammation, bone resorption, cartilage degradation, and joint pain in spondyloarthritis.

"FDA clearance of the PT064 protocol is a significant step forward for our vilamakitug program and for patients living with axial spondyloarthritis," said Sushma Shivaswamy, Ph.D., Interim Chief Executive Officer and Chief Scientific Officer at XBiotech.

XBiotech previously developed bermekimab, another anti-IL-1α antibody, which was sold in December 2019 in a transaction valued at up to $1.35 billion. The company retained rights to develop anti-IL-1α antibodies in areas outside dermatology.