Oversubscribed Series A financing led by M Ventures, Hadean, Sofinnova and 4BIO will support clinical development of Actithera’s fibroblast activation protein (FAP) candidate and expand its proprietary radioligand platform

Actithera, a biotech pioneering next-generation radioligand therapies (RLTs), has closed a $75.5 million Series A round to accelerate clinical development of its lead fibroblast activation protein (FAP) targeting candidate and broaden its innovative radiopharmaceutical pipeline.

Co-led by founding investor M Ventures alongside Hadean Ventures, Sofinnova Partners, and 4BIO Capital, the round also saw participation from Bioqube Ventures, Innovestor’s Life Science Fund, Investinor, Surveyor Capital (a Citadel company), and Arkin Bio Ventures II.

Actithera’s proprietary platform combines medicinal chemistry with radiochemistry to develop small molecule radioligands designed for prolonged tumor retention and rapid systemic clearance — addressing limitations seen in current RLTs. This three-pillar approach includes novel covalent targeting strategies optimized for tumor residence time, enhancing precision, safety, and efficacy.

Founder and CEO Dr Andreas Goutopoulos, has more than 25 years in pharma drug discovery. He said:
“We set out to apply structure-based and kinetics-driven drug design principles to radiopharmaceuticals. This oversubscribed financing validates our approach to engineer radioconjugates that stay longer in tumors, enabling more effective and convenient treatments for patients.”

Karl Naegler, partner at Sofinnova Partners, added: “Actithera represents a meaningful shift in oncology with radioligand therapies that could redefine therapeutic indices. We’re excited to support this next-generation platform.”

The new funds will enable Actithera to advance its lead FAP-targeting candidate into clinical trials across multiple indications, while expanding its discovery platform and preclinical pipeline. The Series A also brings several new investors onto Actithera’s Board, broadening the company’s leadership team as it scales.

Roger Franklin, partner at Hadean Ventures, added: “Their platform aligns pharmacokinetics with therapeutic effect in a way that could transform patient outcomes in radioligand therapy.”