Comprehensive Report on the Investigational Agent GS-0151

I. Executive Summary

GS-0151 is an investigational therapeutic antibody currently in Phase I clinical development for the treatment of Rheumatoid Arthritis (RA). Developed by Gilead Sciences following its acquisition of MiroBio, where the compound was known as MB-151, GS-0151 functions as an agonist of the Programmed Cell Death Protein 1 (PD-1) receptor.[1] This mechanism represents a novel immunomodulatory approach for autoimmune diseases, aiming to restore immune homeostasis by enhancing inhibitory signaling in hyperactive immune cells. The ongoing Phase Ib clinical trial (NCT06902519 / GS-US-667-6882) is designed to evaluate the safety, tolerability, and pharmacokinetics of GS-0151 in adult participants with RA. The acquisition of MiroBio and the subsequent advancement of GS-0151 into clinical trials, with an anticipated start in March 2025 and a primary completion date in December 2026 [2], underscore Gilead Sciences' strategic commitment to expanding its inflammation pipeline with innovative therapeutic modalities.[4] The development of GS-0151 is a tangible manifestation of this strategy, leveraging external innovation to address unmet needs in complex autoimmune conditions.

II. Introduction to GS-0151

A. Overview and Therapeutic Rationale