Natrunix in HLA-B27 Positive Subjects With Axial Spondyloarthritis

NCT06526377 | Not Yet Recruiting Phase 2 FDA Drug

• 1 other identifier: PT064
• Study Type: interventional
• Target: 60
• Locations: 0 countries
• Sites: N/A

Brief Summary

Double-blind, placebo-controlled, randomized trial of Natrunix in combination with Standard of Care in patients with Axial Spondyloarthritis

Conditions

Axial Spondyloarthritis

Outcome Measures

Primary Outcomes (1)

• Assessment of Spondyloarthritis International Society (ASAS) criteria will be used to determine proportion of subjects achieving 40% Improvement (ASAS40 response)

  In this study, sponsor will assess the safety and effectiveness of Natrunix (human antibody preparation) in combination with Standard of Care to determine the ASAS40 response rate. ASAS response is the measure of improvement in percentage of Axial Spondyloarthritis (AxSpA) disease. Patients who achieved at least 40% improvement on Assessment of Spondyloarthritis International Society (ASAS40) at week 12 will be considered as an ASAS40 responder for the primary analysis.

  At 12 weeks from Baseline

Secondary Outcomes (4)

• Improvement/Deterioration in Patient's Global Assessment of Disease (PGA) Activity (using Numerical Rating Scale (NRS))

  At 12 weeks from Baseline

• Pain assessment (using Numerical Rating Scale (NRS))

  At 12 weeks from Baseline

• Improvement/Deterioration in Function (Bath Ankylosing Spondylitis Functional Index (BASFI))

  At 12 weeks from Baseline

• Improvement/Deterioration in inflammation (mean of questions 5 and 6 on the Bath Ankylosing Spondylitis Disease Activity Index [BASDAI])

  At 12 weeks

Other Outcomes (42)

• ASAS40 response

  At Weeks 1, 3, 5, 8 and 10 from Baseline

• ASAS20 response

  At Weeks 1, 3, 5, 8, 10, and 12 from Baseline

• ASAS50 response

  At Weeks 1, 3, 5, 8, 10, and 12 from Baseline

Study Arms (2)

Natrunix 400 mg Natrunix in Combination with Standard of Care

EXPERIMENTAL

This arm will have 40 subjects receiving Natrunix in Combination with Standard of Care in HLA-B27 Positive Patients with Axial Spondyloarthritis

Drug: Natrunix

Placebo in combination with Standard of Care

EXPERIMENTAL

This arm will have 20 subjects receiving Placebo in Combination with Standard of Care in HLA-B27 Positive Patients with Axial Spondyloarthritis

Drug: Placebo

Interventions

Natrunix DRUG

Natrunix is a monoclonal antibody preparation. Natrunix antibody is indistinguishable from a natural antibody isolated from a healthy human. Natrunix is expected to be the safest, most effective therapy for alleviating inflammatory pain and mitigating damage, mainly in the spine and sacroiliac joints, in AxSpA patients.

Also known as: Vilamakitug

Natrunix 400 mg Natrunix in Combination with Standard of Care

Placebo DRUG

Placebo

Placebo in combination with Standard of Care

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Positive for HLA-B27 and have at least 2 additional SpA features OR Positive for HLA-B27 and has radiological evidence of sacroiliitis from either X-ray or MRI from patient's medical records.
• Must have active disease at screening, according to either Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), with disease severity of ≥ 4 or ASDAS-CRP (Ankylosing Spondylitis Disease Activity Score - C Reactive Protein) ≥ 2.1
• Subject must be DMARD naive, including those who previously declined DMARD treatment options, OR previously discontinued DMARD treatment after initial trial of no more than 12 total weeks

You may not qualify if:

• History of treatment with Natrunix
• Have received any prior, or are currently receiving, treatment with opiates, csDMARDS, biologic DMARDs, JAK inhibitors, or other immunomodulatory agents for more than 12 weeks at any point prior to enrollment OR within 12 weeks prior to enrollment
• Treatment with more than one csDMARD (such as methotrexate and sulfasalazine etc.) , biologic DMARD (such as Etanercept and Infliximab etc.), JAK inhibitor (such as Tofacitinib and Upadacitinib etc.), or any combination thereof prior to enrollment Currently requiring regular dosing regimen corticosteroids (excluding PRN dosing) Treatment with biologics that target CD20 (Rituximab or any other anti-CD20 antibody) prior to enrollment
• Clinically significant laboratory abnormalities per PI's discretion
• Positive for active HIV, hepatitis B or C

Sponsors & Collaborators

• XBiotech, Inc.: lead

MeSH Terms

Conditions

Axial Spondyloarthritis

Condition Hierarchy (Ancestors)

Spondylarthropathies; Spondylarthritis; Spondylitis; Spinal Diseases; Bone Diseases; Musculoskeletal Diseases; Ankylosis; Joint Diseases; Arthritis

Central Study Contacts

Haritha Pallapotu

CONTACT

(512) 386-2992; hpallapotu@xbiotech.com

Norma Gonzalez

CONTACT

512.386.2903; ngonzalez@xbiotech.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 15, 2024
• First Posted: July 29, 2024
• Study Start (Estimated): August 15, 2026
• Primary Completion (Estimated): February 28, 2027
• Study Completion (Estimated): April 30, 2027
• Last Updated: December 15, 2025

Record last verified: 2025-12