Ratio Therapeutics has raised $70m in a Series C financing to advance its targeted radiotherapeutics pipeline and expand manufacturing infrastructure for radiopharmaceutical development.
The Boston-based clinical-stage pharmaceutical company said the round brings total capital raised to more than $240m, with participation from existing investors Duquesne Family Office and Bristol Myers Squibb, alongside new investors including Catalio Capital Management, Eli Lilly and Wasatch Group.
Ratio plans to use the funding to progress its lead candidate, [Ac-225]RTX-2358, through the Phase I/II ATLAS study in patients with relapsed or refractory soft tissue sarcoma, while advancing a next-generation radioligand therapy (RLT) candidate towards the clinic.
The company added that it also intends to expand its discovery pipeline and scale its radiopharma manufacturing capabilities to support future clinical and commercial demand.
"This financing reflects the confidence our investors and strategic partners have in the progress we have made to date and the opportunities that lie ahead," said Dr Jack Hoppin, CEO of Ratio Therapeutics.
"Ratio is a leader in radiopharmaceutical innovation and it has backed up science with execution — hitting clinical milestones, deepening strategic partnerships and building the manufacturing infrastructure this modality demands," added Sue Meng, Managing Director of Duquesne Family Office.
Our investment reflects our strong conviction in Ratio's platform and its potential to change outcomes for patients.
Building manufacturing capacity
The investment follows several recent steps to strengthen Ratio’s manufacturing and supply chain infrastructure.
In May of this year, the company expanded its collaboration with the CDMO PharmaLogic to increase clinical manufacturing capacity for [Ac-225]RTX-2358 at its Idaho Falls facility and support larger multi-dose batches.
Ratio is also developing a planned 65,000-square-foot radiopharma research and manufacturing facility in Salt Lake City, Utah, which is expected to become operational in the second half of 2027.
The site is intended to provide vertically integrated manufacturing capacity for Ratio’s pipeline.
Securing isotope supply
Supply security is another consideration for Ac-225-based therapies.
Ratio entered a strategic agreement with PanTera in June to strengthen its long-term supply of the alpha-emitting isotope, as the radiopharma sector prepares for growing demand.
The need for scalable infrastructure is becoming increasingly important as targeted alpha therapies move towards later-stage development.
A 2026 EMA report identified radionuclide supply shortages, particularly for alpha-emitting radionuclides, as a key vulnerability for radiopharma manufacturing.
In the ATLAS study, [Ac-225]RTX-2358 is being evaluated as a FAP-targeted alpha-particle therapy.
The trial uses a dose-escalation design and is intended to establish a recommended dose for subsequent Phase II expansion.
Ratio said the new funding will also support its preparations for its fifth IND filing.
