Sanofi Ventures and Janus Henderson co-led a $125m Series B round in Diagonal Therapeutics.

Sanofi Ventures, a corporate venture capital arm of Sanofi, and Janus Henderson, an investment management company, co-led a $125m Series B round in Diagonal Therapeutics, a biotechnology company developing disease-modifying clustering antibodies, with a participation from Deep Track Capital, EcoR1 Capital, Logos Capital, Balyasny Asset Management, Woodline Partners, Atlas Venture, BVF Partners, Lightspeed Venture Partners, RA Capital Management, Frazier Life Sciences, Viking Global Investors, RV Invest, Velosity Capital, Biovision Ventures and Checkpoint Capital. Proceeds will support advancement of DIAG723, a first-in-class, disease-modifying clustering antibody designed to correct the underlying cause of hereditary hemorrhagic telangiectasia (HHT) and pulmonary arterial hypertension (PAH), conditions that collectively impact hundreds of thousands of people around the world. Diagonal expects to initiate its first-in-human trial for DIAG723 in HHT patients during the first half of 2026.