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Orelabrutinib in Patients with Primary Progressive Multiple Sclerosis

Fast replyInvestigationalNo placebo
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What is this trial about?

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

This clinical trial is studying Primary Progressive Multiple Sclerosis (PPMS), a form of multiple sclerosis that slowly gets worse over time. The treatment being tested is orelabrutinib, an oral tablet taken by mouth, and it is being compared with placebo tablets that look the same. The purpose of the study is to see whether orelabrutinib can help delay disability getting worse in people with PPMS.

People in the study are assigned by chance to receive either orelabrutinib or placebo. The study is set up so that neither the participants nor the study doctors know which treatment is being given during the trial. Treatment is taken over time, and the study follows participants to see how their condition changes during the study period.

PPMS can affect walking, balance, hand use, and other body functions. Disability progression means a gradual increase in these problems. The study is designed to compare how often this worsening happens in the two groups.

The research process

The trial runs in 3 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Study treatment begins

    After joining the study, you are assigned to receive either orelabrutinib or a placebo. A placebo is a tablet that looks the same as the study medicine but does not contain the active drug.

    The study is randomized, which means the treatment assignment is decided by chance. It is also double-blind, which means neither you nor the study team knows which tablet you are receiving during the study.

    Orelabrutinib is taken by mouth as a tablet at a dose of 80 mg. The placebo is taken in the same way and is made to match the orelabrutinib tablet in appearance, shape, size, and weight.

    The study treatment continues during the study period until the trial ends, unless the study plan says otherwise.

  2. Step 2

    Monitoring for disability progression

    During the trial, your condition is followed to see whether disability gets worse over time.

    The main outcome is the time until a confirmed disability progression event occurs. Confirmed means that the change is still present for at least 12 weeks.

    Disability progression is measured in one of three ways: an increase in the expanded disability status scale (EDSS), a slower timed 25-foot walk test (T25FWT), or a worse result on the 9-hole peg test (9HPT).

    For the EDSS, disability progression means a score increase of at least 1.0 point if the starting score is 5.0 or lower, or at least 0.5 points if the starting score is higher than 5.0.

    For the T25FWT, disability progression means at least a 20% increase in the time needed to walk 25 feet.

    For the 9HPT, disability progression means at least a 20% increase in the time needed to complete the test.

  3. Step 3

    Study completion

    The trial continues until the study period ends.

    The estimated study period runs from 2026-05-29 to 2030-07-02.

Who can join the trial?

4 criteria

  • Be 18 to 60 years old when signing the informed consent form, which is the document that explains the study and shows that the person agrees to join.
  • Have a diagnosis of Primary Progressive Multiple Sclerosis (PPMS) based on the McDonald criteria, which are medical rules doctors use to confirm multiple sclerosis.
  • Have documented evidence that disability has gotten worse over the 24 months before screening, and this worsening must be independent of clinical relapse, meaning it happened without a sudden attack or flare-up of symptoms.
  • Have an EDSS score between 3.0 and 6.5 at screening. The EDSS, or Expanded Disability Status Scale, is a score doctors use to measure how much multiple sclerosis affects movement and daily activities.

Who cannot join the trial?

5 criteria

  • Having relapsing-remitting multiple sclerosis (RRMS), which means MS with attacks or flare-ups followed by periods of recovery.
  • Having secondary progressive multiple sclerosis (SPMS), which means MS that started with relapses and later became steadily worse.
  • Having an immune system disorder other than MS, or having any condition that needs treatment with corticosteroids by mouth, by vein (intravenous), by muscle injection (intramuscular), or by injection into a joint (intra-articular).
  • Having another neurological disorder in the past or now that could look like MS. A neurological disorder is a disease of the brain, spinal cord, or nerves.
  • Having any other serious active medical condition, meaning a significant health problem that is currently present and may affect study participation.
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Investigated drugs

Orelabrutinib is an oral tablet taken by mouth in this study. It is the main study medicine being tested to see whether it can slow down disability getting worse in people with primary progressive multiple sclerosis. The trial is looking at how well it works and how safe it is compared with placebo.

What is already known about the treatment

Orelabrutinib - Orelabrutinib is an oral tablet taken by mouth, usually once daily, and it is being studied in clinical trials for its use in people with certain immune-related diseases. It is a Bruton’s tyrosine kinase inhibitor, which means it blocks a protein that helps immune cells send signals and become active; by reducing these signals, it may help lower harmful inflammation. In medicine and the medical literature, it is still considered an investigational drug in many countries, but it has been studied most often for blood cancers and is now being explored for nervous system diseases such as primary progressive multiple sclerosis. Its main proposed use is to slow disease worsening by calming overactive immune activity that may damage the nervous system.

Investigated diseases

Primary progressive multiple sclerosis - A form of multiple sclerosis in which symptoms steadily worsen from the start rather than appearing in repeated attacks. It mainly affects movement, balance, strength, and coordination, and the changes usually build up gradually over time. Walking may become slower and more difficult, and hand use may also become less precise.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2025-524316-11-00Protocol codeZB020-03-001Estimated enrolment705 patientsSponsorZenas Biopharma (USA) LLC

sourced from the EU Clinical Trials Register and site verification

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

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