Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Recruiting

A Study of Tulisokibart for Adults with Radiographic Axial Spondyloarthritis (Ankylosing Spondylitis)

Verified siteInvestigational
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

This study is looking at a condition called radiographic axial spondyloarthritis, which is also known as ankylosing spondylitis. This is a type of arthritis that mainly affects the spine and can cause long-term pain and stiffness in the back. The inflammation can eventually lead to some of the small bones in the spine growing together. The study will test a medication called tulisokibart, which is also referred to by its code name MK-7240. This medication is given as an injection under the skin using a pre-filled device. Some people in the study will receive tulisokibart while others will receive a placebo.

The purpose of this study is to find out how well tulisokibart works compared to placebo in people with radiographic axial spondyloarthritis and to check how safe it is. The study will measure whether the medication helps reduce disease activity and improve symptoms. The main focus will be on checking how many people show significant improvement in their condition after 16 weeks of treatment.

During the study, participants will receive either tulisokibart or placebo through injections under the skin. The study team will regularly check how participants are doing by looking at various aspects of their condition, including back pain levels, how well they can perform daily activities, stiffness, fatigue, and overall quality of life. Some participants will also have imaging tests such as magnetic resonance imaging to see if there are changes in inflammation in the spine and joints. The study will also track any side effects or health problems that occur during the treatment period.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Treatment Assignment

    Upon joining the study, you will be randomly assigned to one of two treatment groups. This process is called randomization and ensures fairness in the study.

    One group will receive tulisokibart, the medication being tested. The other group will receive a placebo, which looks identical but contains no active medication.

    Neither you nor your doctor will know which treatment you are receiving. This is called a double-blind study and helps ensure accurate results.

  2. Step 2

    Receiving Study Medication

    You will receive injections of either tulisokibart or placebo under your skin. This type of injection is called subcutaneous.

    The medication comes in a pre-filled injector, which is a ready-to-use device containing the solution for injection.

    The frequency and duration of injections will be determined by the study schedule provided to you by the study staff.

  3. Step 3

    Study Visits and Assessments Through Week 16

    You will attend regular study visits where various assessments will be performed to monitor your condition and safety.

    At Week 16, several important evaluations will be conducted to measure how well the treatment is working.

    During these visits, you will be asked questions about your back pain, including pain during the day and at night.

    Your ability to perform daily activities and your overall function will be assessed using standardized questionnaires.

    If you have enthesitis, which is inflammation where tendons or ligaments attach to bone, this will be evaluated at your visits.

    Your spine and joint flexibility will be measured through physical examinations.

  4. Step 4

    Imaging Studies

    You will undergo magnetic resonance imaging (MRI) scans of your spine and sacroiliac joints (the joints at the base of your spine connecting to your pelvis).

    These scans will be performed at baseline before treatment starts and again at Week 16.

    The MRI scans help doctors see inflammation in your spine and joints that cannot be detected through physical examination alone.

  5. Step 5

    Health and Quality of Life Assessments

    You will complete several questionnaires throughout the study to assess how your condition affects your daily life.

    These questionnaires evaluate your disease activity, physical function, fatigue levels, and overall health status.

    The assessments help measure whether the treatment improves your quality of life and ability to perform everyday tasks.

  6. Step 6

    Safety Monitoring

    Throughout the study, you will be monitored for any adverse events, which are any unwanted or unexpected medical occurrences.

    You should report any new symptoms, health changes, or concerns to the study staff at each visit.

    Safety assessments will continue throughout your participation in the study.

  7. Step 7

    Continuation Beyond Week 16

    The study continues beyond Week 16, with ongoing treatment and monitoring.

    You will continue to attend regular study visits for assessments and to receive study medication.

    The total duration of your participation will be determined by the study protocol and explained to you by the study staff.

Who can join the trial?

6 criteria

  • You must have a confirmed diagnosis of axial spondyloarthritis, which is a type of inflammatory arthritis that mainly affects the spine and the joints where the spine connects to the pelvis
  • You must meet the ASAS classification criteria, which is a set of specific medical standards used by doctors to confirm this condition
  • You must have experienced back pain for at least 3 months or longer
  • Your back pain symptoms must have started before you turned 45 years old
  • You can be male or female to participate in this study
  • You must be an adult to take part in this trial

Who cannot join the trial?

3 criteria

  • The source data does not provide specific exclusion criteria (reasons why you cannot participate) for this clinical trial
  • To find out which conditions or situations would prevent you from joining this study, you would need to obtain the complete trial information from the research team
  • Exclusion criteria are specific medical conditions, medications, or other factors that make it unsafe or inappropriate for someone to participate in a research study
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

  • Tulisokibart

    is an investigational medication being tested in this study for the treatment of a type of inflammatory arthritis that affects the spine. This medication is designed to help reduce inflammation and improve symptoms in people with this condition. In this trial, tulisokibart is being compared to a placebo to see how well it works and how safe it is.

  • Placebo

    is an inactive substance that looks like the real medication but contains no active treatment. It is used in this study to compare against tulisokibart to help researchers understand whether the actual medication is effective.

What is already known about the treatment

Tulisokibart – Tulisokibart is an investigational medication currently being studied in clinical trials for the treatment of radiographic axial spondyloarthritis, also known as ankylosing spondylitis, which is a chronic inflammatory condition affecting the spine and joints. This drug is a biologic therapy that works at the molecular level by targeting specific proteins involved in the inflammatory process that causes pain, stiffness, and potential fusion of the spinal bones. The medication is being tested in a Phase 2b study to determine its effectiveness and safety, with researchers measuring how well it reduces disease symptoms compared to placebo treatment. The form of administration has not been specified in the available trial information, but biologic medications like this are typically given by injection under the skin or through an intravenous infusion.

Investigated diseases

Radiographic Axial Spondyloarthritis – Radiographic axial spondyloarthritis, also known as ankylosing spondylitis, is a chronic inflammatory disease that primarily affects the spine and the sacroiliac joints where the spine connects to the pelvis. The condition causes inflammation in these areas, leading to pain and stiffness in the back and hips. Over time, the ongoing inflammation can cause the vertebrae in the spine to fuse together, reducing flexibility and mobility. This fusion process happens gradually as new bone forms in response to the persistent inflammation. The disease typically begins in early adulthood and progresses slowly over many years. As the condition advances, it can cause the spine to become rigid and less able to bend or move normally.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2025-521059-21-00Protocol codeMK-7240-013Estimated enrolment323 patientsSponsorMerck Sharp & Dohme LLC

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.