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Study on the Effects of Fipaxalparant in Patients with Diffuse Cutaneous Systemic Sclerosis

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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 focused on studying a condition known as Diffuse Cutaneous Systemic Sclerosis, a rare disease that causes the skin and other organs to become thick and hard. The trial will use a medication called Fipaxalparant, also known by its code name HZN-825. This medication is taken in the form of a tablet and works as a selective antagonist of a receptor called LPAR1, which is involved in the disease process.

The purpose of the study is to evaluate how effective, safe, and tolerable HZN-825 is for patients with Diffuse Cutaneous Systemic Sclerosis. Participants in this study will take the medication twice a day for a period of 52 weeks. This study is an extension of a previous trial, meaning it continues the research from an earlier phase to gather more information about the medication's effects over a longer period.

Throughout the study, participants will be monitored to see how their condition changes, particularly looking at lung function and physical abilities. The study aims to provide valuable insights into the potential benefits and any side effects of using HZN-825 for treating Diffuse Cutaneous Systemic Sclerosis.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the trial

    Participation begins after completing a previous trial phase. Eligibility requires completion of the double-blind treatment period in Trial HZNP-HZN-825-301.

    Written informed consent is necessary to proceed.

  2. Step 2

    Treatment administration

    The medication used in this trial is Fipaxalparant, administered in tablet form.

    The dosage is taken orally twice a day (BID) for a duration of 52 weeks.

  3. Step 3

    Monitoring and evaluation

    Regular evaluations are conducted to assess the efficacy, safety, and tolerability of the treatment.

    Primary evaluation includes changes in lung function, specifically the forced vital capacity (FVC) percentage predicted at Week 52.

  4. Step 4

    Secondary assessments

    Additional assessments include changes in health assessment questionnaire-disability index (HAQ-DI), medical doctor global assessment (MDGA), patient global assessment (PTGA), and physical effects subscale of the SSPRO-18 at Week 52.

  5. Step 5

    Completion of the trial

    The trial concludes after 52 weeks of treatment and evaluation.

    The estimated end date for the trial is July 31, 2026.

Who can join the trial?

6 criteria

  • You must provide written informed consent, which means you agree to participate in the study after being fully informed about it.
  • You must have completed the previous part of the study, called the double-blind Treatment Period, which lasted 52 weeks. If you stopped the study early for reasons other than safety or side effects, you might still be able to join if the study doctor agrees.
  • You need to be willing and able to follow the treatment plan and attend all required check-ups and evaluations for the entire duration of the study.
  • Both men and women can participate in the study.
  • The study includes people from a range of age groups, including adults and older adults.
  • The study may include people who are considered part of a vulnerable population, which means they might need extra protection or care.

Who cannot join the trial?

8 criteria

  • Patients who have not completed the initial 52-week clinical trial (HZNP-HZN-825-301) cannot participate.
  • Patients with any other serious health conditions that might interfere with the study cannot participate.
  • Patients who are pregnant or breastfeeding cannot participate.
  • Patients who are currently using other medications that might interfere with the study drug cannot participate.
  • Patients with a history of allergic reactions to similar medications cannot participate.
  • Patients who have participated in another clinical trial within the last 30 days cannot participate.
  • Patients with a history of drug or alcohol abuse within the past year cannot participate.
  • Patients who are unable to comply with the study requirements cannot participate.
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Investigated drugs

HZN-825 is a medication being studied for its effectiveness, safety, and how well patients can tolerate it. It is used in patients with diffuse cutaneous systemic sclerosis, a condition that affects the skin and other organs. HZN-825 works by blocking a specific receptor in the body, known as LPAR1, which may help reduce symptoms of the disease. This trial is an extension of a previous study, allowing researchers to gather more information over a longer period.

What is already known about the treatment

HZN-825 – This medication is administered orally, typically taken twice a day. It is currently being studied in clinical trials for its effectiveness, safety, and tolerability in treating diffuse cutaneous systemic sclerosis, a rare autoimmune disease. HZN-825 works by selectively blocking the LPAR1 receptor, which is believed to play a role in the disease's progression. It is classified as a selective antagonist, targeting specific pathways involved in the condition.

Investigated diseases

Diffuse Cutaneous Systemic Sclerosis – This is a rare autoimmune disease characterized by the hardening and tightening of the skin and connective tissues. It primarily affects the skin but can also involve internal organs such as the lungs, heart, and kidneys. The disease progresses with the overproduction of collagen, leading to thickened skin and sometimes causing joint pain and stiffness. As it advances, it may result in reduced mobility and function of affected areas. The condition can vary greatly in severity and progression among individuals. It is part of a group of diseases known as scleroderma.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-509783-23-00Protocol codeHZNP-HZN-825-302Estimated enrolment248 patientsSponsorHorizon Therapeutics Ireland Designated Activity Company

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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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