Radiopharmaceutical developer Ratio Therapeutics has raised $70 million in Series C funding to advance a class of cancer drugs that deliver radiation directly to tumors.
The round, announced August 3, 2026, drew new investors Catalio Capital Management, Eli Lilly and Wasatch Group, alongside existing backers the Duquesne Family Office and Bristol Myers Squibb — a notable show of big-pharma interest in targeted radiotherapy.
What Ratio is building
The company develops radioligand therapies: molecules that seek out markers on cancer cells and carry a radioactive payload to destroy them while sparing healthy tissue. Its lead candidate, [Ac-225]RTX-2358, targets fibroblast activation protein (FAP) and is being tested in advanced sarcomas in the Phase 1/2 ATLAS trial. The pipeline is built on two in-house platforms — the Trillium pharmacokinetic-tuning technology and the Macropa chelator system — and extends to targets including GRPR and, through a Novartis partnership, SSTR2.
Where the money goes
Ratio said the proceeds will fund the ATLAS trial, move a next-generation radioligand candidate into the clinic, broaden discovery to new cancer targets, and scale up manufacturing — a persistent bottleneck in a field that depends on short-lived radioactive isotopes. “This financing reflects investor confidence in progress made and opportunities ahead,” chief executive Jack Hoppin said, calling the proceeds “instrumental across development and supply of targeted radiopharmaceuticals.”