XBiotech Begins Phase II Trial of Vilamakitug for Active Axial Spondyloarthritis
Tuesday, June 16, 2026
XBiotech has announced that the U.S. Food and Drug Administration (FDA) has completed its 30-day review of the Investigational New Drug (IND) application for the V-SPINE (PT064) Phase II clinical trial without placing the study on clinical hold. The approval allows the company to begin patient enrolment in the United States and restart its rheumatology development programme.
The Phase II study will assess the safety and effectiveness of vilamakitug in adults with active axial spondyloarthritis (axSpA). The clinical protocol was developed under the leadership of Dr Marina Magrey, Chief of Rheumatology at University Hospitals Cleveland Medical Center, with support from a scientific advisory board comprising leading rheumatology specialists from several academic and research institutions.
The V-SPINE trial is a randomised, double-blind, placebo-controlled study involving 150 adult patients. Participants will receive either 400 mg of vilamakitug through weekly subcutaneous injections for 16 weeks or a placebo. The main objective is to measure the proportion of patients achieving an ASAS40 response at Week 16. Following this period, all participants will be eligible to receive vilamakitug during a 12-week open-label extension.
The company stated that many patients with axial spondyloarthritis continue to experience inadequate disease control despite the availability of approved biologic treatments, highlighting the need for additional therapeutic options.
Vilamakitug, also known as XB2001 and Natrunix, is an IgG4 monoclonal antibody designed to neutralise interleukin-1 alpha (IL-1α), an inflammatory cytokine linked to joint inflammation, bone loss, cartilage damage and chronic pain in spondyloarthritis. By targeting this early inflammatory pathway, the treatment is being investigated for its potential to reduce disease activity and limit structural damage, including in patients who have not responded adequately to existing biologic therapies.
Source: globenewswire.com
