A Phase 2 interventional study of vilamakitug and placebo in Axial Spondyloarthritis, Ankylosing Spondylitis and r-axSpA, sponsored by XBiotech, Inc.. Not yet recruiting. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-05-14.
Sponsored by XBiotech, Inc. · Phase 2, Interventional, and Treatment
The goal of this clinical trial is to find out if the study drug will work as a new therapy for axSpA patients. This study is placebo-controlled, and evaluates if study drug can treat symptoms of axSpA, including global disease activity, pain, function and inflammation.
Researchers will compare vilamakitug to a placebo (no active drug) to see if the study drug works in axSpA patients to treat symptoms. Participants will take the assigned study treatment for 16 weeks for double blind period and potentially 12 weeks for open label extension.
186 studies on the registry are indexed under Axial Spondyloarthritis; 57 are open to participants now.
This study's planned enrollment of 150 is above the median of 108 across 122 interventional studies indexed under Axial Spondyloarthritis.
Browse Axial Spondyloarthritis studies →XBiotech, Inc. is the lead sponsor of 8 studies on the registry; 2 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 3 (60%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
weekly dose of vilamakitug
Drug: vilamakitug
placebo
Drug: placebo
Vilamakitug is a monoclonal antibody preparation, indistinguishable from a natural antibody isolated from a healthy human.
Also known as: XB2001, Natrunix
placebo
Percentage of participants achieving ASAS40.
ASAS40 response is defined at least a 40% improvement in at least three of the four main ASAS domains, with no worsening in the remaining domain: Patient Global Assessment of Disease Activity (Q3 of ASDAS-CRP), Pain Assessment (BASDAI Q2), physical function (Bath Ankylosing Spondylitis Functional Index \[BASFI\]), and Inflammation (represented by the mean of the two morning stiffness BASDAI questions Q5 and Q6).
Time frame: Baseline to week 16
Patient Global Assessment of Disease Activity (PGADA) using Q3 of ASDAS-CRP
Time frame: Baseline to week 16
Spinal pain [Numeric Rating Scale (NRS) using Question 2 of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)]
Time frame: Baseline to week 16
Physical function using Bath Ankylosing Spondylitis Functional Index (BASFI)
Time frame: Baseline to week 16
Inflammation, defined as the mean of Questions 5 and 6 of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)
Time frame: Baseline to week 16
No study locations are listed for this record.
Start is estimated for Sep 2026; primary completion for Sep 2028, 24 months later.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in May 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Vilamakitug
XBiotech, Inc.