A randomized, double-blind, placebo-controlled, parallel-group study to assess the efficacy, safety, and tolerability of SAR444336 in participants with microscopic colitis in clinical remission with budesonide.

The primary objective is to evaluate the efficacy of SAR444336 as steroid-free therapy in participants with microscopic colitis as compared to placebo. This objective addresses the clinical need for alternative maintenance therapies that can sustain clinical remission without continued corticosteroid exposure, thereby potentially reducing steroid-related adverse effects in this patient population.

The secondary objectives include:

• Evaluate the safety and tolerability of SAR444336

• Evaluate the pharmacokinetics of SAR444336

• Evaluate immunogenicity in participants treated with SAR444336

This clinical trial enrolled a total of **5 participants** diagnosed with **microscopic colitis**, including all histological subtypes. The study population comprised both **male and female** adults and elderly individuals. Participants were required to have a histologically confirmed diagnosis of microscopic colitis and to be currently receiving **budesonide therapy** with documented clinical remission from at least 2 weeks before screening. Eligible participants had experienced at least one microscopic colitis relapse in the 8 months prior to screening that required treatment with budesonide. The trial included individuals with a **body mass index** ranging from 18 to 35 kg/m² at the screening visit. The selection process ensured that participants met specific diagnostic and treatment history requirements, and all contraceptive methods used were consistent with local regulations. No vulnerable populations were included in this trial.

This is a randomized, double-blind, placebo-controlled, parallel-group phase 2 clinical trial designed to assess the efficacy, safety, and tolerability of **SAR444336** in participants with **microscopic colitis** who are in clinical remission while receiving **budesonide** therapy. The primary objective is to evaluate the efficacy of SAR444336 as a steroid-free maintenance therapy compared to placebo in maintaining clinical remission in this patient population. The investigational medicinal product SAR444336 is a **solution for injection** administered via **subcutaneous use**, with a maximum treatment period of 20 weeks. The control group receives a matched placebo for the test product. The trial is categorized as a phase 2 study investigating **digestive system diseases**, specifically targeting colitis microscopic as confirmed by **MedDRA** classification.

Eligible participants must have a histologically confirmed diagnosis of microscopic colitis, including all histological subtypes, and must be currently receiving budesonide therapy with documented clinical remission from at least 2 weeks before screening. Additionally, participants must have experienced at least one microscopic colitis relapse in the 8 months prior to screening that required treatment with budesonide. Inclusion criteria also specify that participants must have a **body mass index** within the range of 18 to 35 kg/m² (inclusive) at the screening visit, and all contraceptive methods used must be consistent with local regulations. The trial excludes certain participants based on criteria that are defined in the protocol but not detailed in the available information.

The primary endpoint of the study is the proportion of participants achieving sustained steroid-free clinical remission. Secondary endpoints include the incidence of **treatment-emergent adverse events** (TEAEs), **serious adverse events** (SAEs), and **adverse events of special interest** (AESIs). Additional secondary endpoints assess the incidence of permanent discontinuation of the study investigational medicinal product and study withdrawals due to treatment-emergent adverse events. The trial also evaluates plasma concentrations of SAR444336 and the incidence of treatment-emergent **anti-drug antibody** (ADA) against SAR444336 to assess immunogenicity and pharmacokinetic profiles.

The estimated recruitment start date for this trial is October 15, 2025, with an estimated study completion date of May 6, 2027. Participant involvement is expected to extend through the treatment period and subsequent follow-up visits as defined in the study protocol. The study design includes a screening visit for eligibility assessment, treatment visits during the active intervention phase, follow-up visits to monitor safety and efficacy parameters, and an end-of-study visit to complete final assessments. Conditions that may lead to early termination from the study include the occurrence of treatment-emergent adverse events necessitating discontinuation, withdrawal of consent by the participant, protocol violations, or other safety concerns as determined by the investigator or sponsor.

The experimental treatment under investigation is **SAR444336**, a solution for injection containing the active substance SAR444336, which is classified as a protein of other origin. The investigational medicinal product is manufactured by Sanofi Aventis Recherche et Developpement (SAR). SAR444336 is administered via the **subcutaneous route**. The maximum treatment period for this investigational product is 20 weeks. The study is designed to evaluate the efficacy of SAR444336 as a steroid-free therapy in participants with **microscopic colitis** in clinical remission following budesonide treatment.

The control treatment consists of a matched **placebo** for the test product. The placebo is designed to match the experimental treatment to maintain blinding throughout the study. The placebo is administered according to the same schedule and route as the active investigational product to ensure comparability between treatment groups in this randomized, double-blind, placebo-controlled, parallel-group study.

Efficacy will be assessed through the evaluation of the proportion of participants with sustained steroid-free clinical remission, which serves as the primary endpoint. This parameter will measure the ability of SAR444336 to maintain clinical remission in participants with microscopic colitis without the need for continued steroid therapy, as compared to placebo. The treatment period is planned for 20 weeks during which efficacy outcomes will be evaluated.

Secondary endpoints will include safety and tolerability parameters such as the incidence of treatment-emergent adverse events, serious adverse events, and adverse events of special interest. Additionally, the incidence of study investigational medicinal product permanent discontinuations and study withdrawals due to treatment-emergent adverse events will be monitored. Pharmacokinetic assessments will involve the measurement of plasma concentrations of SAR444336, and immunogenicity will be evaluated through the incidence of treatment-emergent anti-drug antibody against SAR444336.