Upon joining the study, the participant will be randomly assigned to receive either the study medication, rosnilimab, or a placebo. This process is double-blind, meaning neither the participant nor the study team will know which treatment is being administered.

The study medication, rosnilimab, is administered as a solution for injection. It is given subcutaneously, which means it is injected under the skin.

The dosage and frequency of administration will be determined by the study protocol and communicated to the participant at the start of the trial.

Throughout the study, participants will undergo regular monitoring and assessments to evaluate the effectiveness and safety of the treatment.

These assessments will include measuring changes in disease activity using the DAS28-CRP score, which is a measure of rheumatoid arthritis activity based on joint counts and blood tests.

The primary evaluation will occur at Week 12, where the main focus will be on the mean change from baseline in the DAS28-CRP score.

This evaluation will help determine the primary efficacy of the treatment.

Secondary evaluations will also take place at Week 12, assessing various response rates such as ACR20, ACR50, and ACR70, which indicate different levels of improvement in rheumatoid arthritis symptoms.

Additional assessments will include the proportion of participants achieving low disease activity or remission based on DAS28-CRP and CDAI scores.

The study is expected to conclude by March 2026. Participants will be informed of the study’s outcomes and any relevant findings related to their health and treatment.