Yarrow Biosciences

Yarrow Bioscience is a clinical-stage biotechnology company dedicated to developing transformative therapies for autoimmune thyroid diseases. The company's lead program, YB-101 (also known as GS-098), is a potentially first-in-class humanized monoclonal antibody that targets the thyroid-stimulating hormone receptor (TSHR). YB-101 is designed to block the pathogenic autoantibodies that drive Graves' disease and thyroid eye disease. Founded by RTW Investments, Yarrow is currently advancing YB-101 toward a Phase 1b/2b clinical trial in the United States. In December 2025, the company announced a reverse merger with VYNE Therapeutics to transition into a publicly traded entity on the Nasdaq.