Ratio Therapeutics announces first patient dosed in FAP-targeted radiopharmaceutical study

The trial is being conducted in collaboration with Lantheus, a company developing diagnostics, radiotherapeutics and artificial intelligence solutions, and PharmaLogic, a contract development and manufacturing organization (CDMO) specializing in radiopharmaceuticals.

Ratio’s clinical candidate, RTX-1363S, is a highly selective, high affinity FAP inhibitor that will be radiolabeled with copper-64 (Cu-64), a positron-emitting radionuclide with a half-life of 12.7 hr.

In the first study, biodistribution and pharmacokinetics will be evaluated following a single injection of RTX-1363S in a small subset of patients.

Study subjects will be screened within 28 days of administration and up to 6 eligible subjects will be enrolled, including 3 female and 3 male subjects. Results from the study will inform further development of RTX-1363S as a FAP-targeted tumor imaging agent.

FAP is a membrane-bound dipeptidyl peptidase that is specifically expressed in activated fibroblasts. The ubiquitous expression of FAP in cancer-associated fibroblasts across nearly all epithelial-derived cancers paired with the low abundance in normal tissues, makes it a unique target to exploit for tumor imaging for a wide variety of cancers such as breast, pancreatic, lung and stomach cancer.

Dr. John Babich, president and chief scientific officer at Ratio, said: “Today marks a major milestone for Ratio as we take a crucial step forward in the development of our FAP-targeted imaging agent. Cancer-associated fibroblasts selectively expressing FAP comprise up to 90% of the tumor mass in highly desmoplastic cancers, including pancreatic, breast, and colorectal. RTX-1363S has the potential to transform the way we detect and monitor various epithelial-derived cancers.”

Etienne Montagut, chief business officer at Lantheus, commented: “We are delighted by our collaboration with Ratio Therapeutics in advancing the clinical development of RTX-1363S as a FAP-targeted diagnostic to the clinic. By leveraging our expertise in radiopharmaceuticals, we aim to contribute to the early detection and accurate monitoring of epithelial-derived cancers. This partnership exemplifies our commitment to Find, Fight and Follow disease by delivering innovative solutions to improve cancer care, ultimately leading to better patient outcomes.”

Scott Holbrook, chief strategy officer and general manager at Pharmalogic, added that the company is ‘honored’ to contribute its manufacturing expertise in radiopharmaceuticals to this clinical trial, advancing diagnostics for epithelial-derived cancers.

“This further strengthens our commitment to production and development of novel radiopharmaceuticals to advance cancer treatments and quality of life for cancer patients,” he said.