Long-term Evaluation of Riliprubart (SAR445088) Safety and Efficacy in Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) Patients

The primary objective of this study is to determine the long-term **safety** and tolerability of riliprubart in participants with chronic inflammatory demyelinating polyneuropathy (CIDP). This is clinically relevant as CIDP is a progressive immune-mediated neuropathy that can lead to significant disability, and understanding the safety profile of riliprubart is crucial for its potential therapeutic use.

Secondary objectives include:

• Evaluating the long-term efficacy of riliprubart using the Inflammatory Neuropathy Cause and Treatment (INCAT) disability scale, which is important for assessing the impact of the treatment on functional disability associated with CIDP.
• Assessing the long-term efficacy of riliprubart with additional measures of functional disability and strength, providing a comprehensive evaluation of its therapeutic benefits in managing CIDP symptoms.

The clinical trial involves a total of **204 participants** diagnosed with **chronic inflammatory demyelinating polyneuropathy (CIDP)**, a condition categorized under immune system diseases. The study population includes both male and female subjects, with an age range spanning from 18 to 65 years. Participants were selected based on their prior involvement in specific studies (PDY16744, EFC17236, or EFC18156) and their current treatment with riliprubart. The trial includes a vulnerable population, indicating that special considerations are in place to ensure their safety and well-being. Participants are required to adhere to contraception guidelines throughout the study, aligning with local regulations. The selection process ensures that all participants are capable of providing informed consent, demonstrating their understanding and compliance with the study's requirements.

The clinical trial is designed to evaluate the long-term safety and efficacy of **riliprubart** in participants with chronic inflammatory demyelinating polyneuropathy (CIDP). This study is a Phase 5, randomized, double-blind, controlled trial. The trial is expected to commence on April 1, 2025, and conclude by July 31, 2029, with an estimated duration of 36 months for each participant. The trial will involve multiple study visits, beginning with an inclusion (screening) visit to assess eligibility based on specific criteria, including prior completion of treatment in related studies and agreement to use contraception during the study period.

Participants will undergo regular follow-up visits to monitor safety and efficacy outcomes, including the occurrence of adverse events, serious adverse events, and any clinically significant abnormalities in laboratory tests, electrocardiograms, and vital signs. Secondary endpoints will assess the percentage of participants who remain relapse-free, experience improvement from baseline, and changes in disability scores, grip strength, and muscle strength over time. The end-of-study visit will conclude the participant's involvement, ensuring all data is collected and any necessary follow-up care is arranged.

Participant involvement is expected to last up to 36 months, with conditions for early termination including the occurrence of adverse events leading to treatment discontinuation or non-compliance with study protocols. The trial will utilize a solution for injection in a pre-filled pen, administered via subcutaneous injection, with a maximum daily dose of 300 mg. The study aims to provide comprehensive data on the long-term use of riliprubart in managing CIDP, contributing valuable insights into its safety and therapeutic potential.

The clinical trial involves the administration of **riliprubart**, an experimental medication designed to evaluate its long-term safety and efficacy in participants with chronic inflammatory demyelinating polyneuropathy (CIDP). Riliprubart is formulated as a **solution for injection in a pre-filled pen**. The active substance, riliprubart, is a protein of other origin, developed by Sanofi Aventis Recherche et Développement (SAR). The medication is administered via **subcutaneous injection**. The maximum daily dose is 300 mg, with a total maximum dose of 300 mg over the treatment period. The treatment duration is set for a maximum of 36 months.

In this study, riliprubart is the primary investigational product, and no additional non-experimental treatments, such as standard-of-care therapy, placebo, or comparator treatments, are specified. The trial does not include a pediatric formulation, and riliprubart has been designated as an orphan drug, indicating its use for a rare condition. Participant compliance with the dosing schedule will be monitored throughout the study to ensure adherence to the prescribed regimen.

The efficacy of riliprubart in the clinical trial for participants with **chronic inflammatory demyelinating polyneuropathy (CIDP)** will be assessed using several secondary endpoints. These include the percentage of participants who remain relapse-free since the first dose of riliprubart in the parent studies (PDY16744, EFC17236, or EFC18156), and the percentage of participants experiencing improvement from baseline. Additionally, changes from baseline will be measured in the Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, the Inflammatory Rasch-built Overall Disability Scale (I-RODS), grip strength (measured in kilopascals for the dominant hand), and the Medical Research Council-Sum Score (MRC-SS) for muscle strength over time.

The collection and analysis of these efficacy parameters will be conducted at specified timepoints throughout the study. The use of validated scales such as the INCAT and I-RODS will ensure the reliability of the assessments. These measures will provide comprehensive data on the functional and symptomatic improvements in participants, contributing to the overall evaluation of riliprubart's efficacy in managing CIDP.