U.S.-based Yarrow Bioscience is branching out, picking an autoimmune thyroid disease drug from China as its lead candidate.
Through a potential $1.37 billion deal, New York-headquartered Yarrow gains ex-China rights to a potential first-in-class antibody targeting the thyroid-stimulating hormone receptor (TSHR) for the treatment of Graves’ disease and thyroid eye disease.
The candidate, coded GS-098, was developed by Shanghai Scizeng Medical Technology, a subsidiary of Changchun GeneScience (GenSci) Pharmaceutical.
Yarrow, financially backed by its founder RTW Investments, will pay GenSci's Scizeng $70 million upfront and $50 million in near-term development milestone payments. The deal could eventually be worth up to $1.365 billion, with Scizeng entitled to tiered double-digit royalties on the drug’s future ex-China sales.
“This collaboration represents a tremendous opportunity for Yarrow and GenSci to advance GS-098 (YB-101) toward meaningful clinical milestones in both Graves’ disease and thyroid eye disease,” Rebecca Frey, Yarrow CEO and RTW venture partner, said in a Dec. 15 release, adding that the drug’s mechanism of action “has the potential to transform the treatment landscape.”
The molecule was designed to bind to TSHR and thereby block its autoantibody-induced activation. It inhibits the synthesis and release of thyroid hormones, suppresses the proliferation of thyroid cells and prevents the release of inflammatory factors that contribute to hyperthyroidism and related eye conditions, GenSci’s parent company, Changchun High-Tech, explained in a securities filing (Chinese) to the Shenzhen Stock Exchange.
In August 2024, GenSci obtained clearance from U.S. and Chinese authorities to begin clinical trials of GS-098 for thyroid-associated eye disease, and then a green light to test the medicine in China for Graves’ disease this October.
TSHR is an emerging target in autoimmune thyroid disease. Ollin Biosciences launched in September with $100 million and Jason Ehrlich, M.D., developer of Roche’s blockbuster eye disease med Vabysmo, at the helm. One of the biotech’s named assets is a preclinical TSHF/IGF-1R bispecific antibody that the firm plans to develop in thyroid eye disease and Graves’ disease.
Other companies working on TSHR include Crinetics Pharmaceuticals, Merida Therapeutics and Septerna, which are all still in preclinical stage.
GenSci and its parent, Changchun High-Tech, represent the recent trend in which established pharmaceutical companies in China are beefing up their capabilities and ambitions in innovative drugs. Other large Chinese pharma companies, such as Fosun Pharma, Hengrui Pharma and Sino Biopharma, have all made major business development deals this year.