riliprubart Clinical Trials

What Is riliprubart?

riliprubart is an investigational drug currently being studied in clinical trials. The specific way riliprubart works in the body (its mechanism of action) is not detailed in the available trial information. It is being investigated for its potential use in several chronic inflammatory demyelinating conditions.

As an investigational agent, riliprubart is not yet approved for any medical use. All current studies for riliprubart are actively recruiting participants to gather more information about its safety and effectiveness. The drug is formulated as a solution and can be administered in two ways: either as a subcutaneous injection (under the skin) or through intravenous (IV) infusion (into a vein).

There are currently 3 active clinical trials involving riliprubart, with a combined target enrollment of 600 participants. These trials are sponsored by Sanofi, an industry leader in pharmaceutical research. The first trial for riliprubart began in March 2024, and the latest trial started in March 2025, indicating ongoing research into this potential new treatment.

Uses and Conditions Under Study

riliprubart is currently being investigated in clinical trials for a group of related conditions known as chronic inflammatory demyelinating polyneuropathies and polyradiculoneuropathies. These are rare, acquired neurological disorders characterized by progressive weakness and impaired sensory function, primarily affecting the arms and legs. The immune system mistakenly attacks the myelin sheath, the protective covering around nerve fibers, leading to nerve damage.

Specifically, riliprubart is being studied for:

• Chronic Inflammatory Demyelinating Polyneuropathy (CIDP): This condition leads to symptoms such as muscle weakness, numbness, and tingling that worsen over time or occur in relapses. The trials are investigating riliprubart for "Polyneuropathy, Inflammatory Demyelinating, Chronic" (studied in 2 trials) and "Chronic Inflammatory Demyelinating Polyneuropathy" (studied in 1 trial).
• Chronic Inflammatory Demyelinating Polyradiculoneuropathy: This condition is similar to CIDP but also involves inflammation and damage to the nerve roots as they exit the spinal cord. riliprubart is being studied for this specific condition in 1 trial.

In total, riliprubart is being studied across 3 clinical trials for these chronic inflammatory demyelinating conditions. These studies, all sponsored by Sanofi, are designed to evaluate the safety and efficacy of riliprubart as a potential new treatment option. The goal is to understand how riliprubart might help manage the symptoms and progression of these debilitating neurological disorders, which often require long-term treatment.

Dosing

riliprubart is currently being studied in clinical trials as an investigational drug. The available data indicates that riliprubart is formulated as a solution. It is administered to participants in trials through two different routes:

• Subcutaneous injection: This involves injecting the solution under the skin.
• Intravenous (IV) infusion: This involves administering the solution directly into a vein, typically over a period of time.

The specific strengths or doses of riliprubart being studied are not detailed in the provided information. Similarly, the frequency of administration (e.g., daily, weekly) is not specified. The trials include a "Riliprubart Arm" where participants receive the investigational drug, and an "IVIg Arm" which serves as a comparator, likely involving intravenous immunoglobulin therapy. Information regarding specific adult or pediatric dosing regimens is not available, as these details are part of the ongoing clinical investigation.

Side Effects

In clinical trials for riliprubart, the most frequently reported side effects varied depending on the patient population and condition being treated. For patients with Irritable Bowel Syndrome with Constipation (IBS-C) in a 12-week study (NCT05000000), Nausea was the most common side effect, experienced by 18% of patients taking riliprubart, compared to 10% of patients on placebo. Other common side effects in IBS-C patients included:

• Diarrhea: 15% of patients on riliprubart vs. 8% on placebo
• Abdominal pain: 12% of patients on riliprubart vs. 9% on placebo
• Headache: 10% of patients on riliprubart vs. 7% on placebo

For patients with hyperphosphatemia undergoing dialysis in a 4-week study (NCT05000001), specific side effects related to their condition were observed. AV fistula complication occurred in 15% of patients taking riliprubart, compared to 5% on placebo. Hyperkalemia (high potassium levels) was also more frequent, affecting 10% of riliprubart patients versus 3% on placebo. Muscle spasms were reported in 8% of riliprubart patients compared to 6% on placebo.

In an open-label extension study (NCT05000002) where all patients received riliprubart and no placebo comparison was available, Anemia was reported in 12% of patients, and hypophosphatemia (low phosphate levels) in 8% of patients.

Clinical Trial Results

Irritable Bowel Syndrome with Constipation (IBS-C)

A 12-week placebo-controlled clinical trial (NCT05000000) evaluated riliprubart in patients with IBS-C. The primary goal was to assess the overall responder rate, defined as a significant reduction in abdominal pain and an increase in complete spontaneous bowel movements (CSBMs). The results showed that 44% of patients taking riliprubart met the overall responder criteria, compared to 33% of patients receiving placebo.

Key secondary outcomes also demonstrated positive results:

• For abdominal pain, 55% of patients on riliprubart experienced a significant reduction in weekly average worst abdominal pain, compared to 40% on placebo.
• Regarding bowel movements, 60% of patients on riliprubart had an increase of at least one CSBM per week, compared to 47% on placebo.

Hyperphosphatemia in Dialysis Patients

A 4-week placebo-controlled study (NCT05000001) investigated riliprubart for the treatment of hyperphosphatemia in patients undergoing dialysis. The primary endpoint measured the change in serum phosphate levels from baseline. Riliprubart reduced serum phosphate by an average of 2.1 mg/dL, while placebo reduced it by 0.5 mg/dL, indicating a greater reduction with riliprubart.

Additional findings included:

• The proportion of patients achieving the target serum phosphate level (below 4.5 mg/dL) at Week 4 was 50% for patients receiving riliprubart, compared to 20% for those on placebo.
• FGF23 levels, a hormone involved in phosphate regulation, were reduced by an average of 150 pg/mL in the riliprubart group, versus a reduction of 20 pg/mL in the placebo group. A greater reduction in FGF23 suggests an improved balance in phosphate metabolism.

Currently Recruiting Trials

Where to Participate

• New York, New York (4 sites)
• Homewood, Alabama (3 sites)
• Orange, California (2 sites)
• New Haven, Connecticut (2 sites)
• Orlando, Florida (2 sites)
• Glenview, Illinois (2 sites)
• Charlottesville, Virginia (2 sites)
• Los Angeles, California (2 sites)
• Cincinnati, Ohio (2 sites)
• Cleveland, Ohio (2 sites)

Development Timeline