March 29, 2023 — Ratio Therapeutics Inc., a pharmaceutical company that employs a suite of innovative technologies to develop best-in-class radiopharmaceuticals for the monitoring and treatment of cancers, today announced the licensing of a Granzyme B-targeted agent for PET imaging applications from Merck, known as MSD outside the United States and Canada.
Under the terms of the agreement, Merck will provide Ratio with several candidates and supporting preclinical and CMC data of its Granzyme B-targeted agent for PET imaging applications. Ratio will also be responsible for clinical development and will build a GMP production network for the PET imaging agent across North America, Western Europe, Japan, Australia, and beyond.
“We are thrilled to contribute our knowledge in nuclear medicine to advance the development of a novel imaging diagnostic in immunology and work alongside Merck, a global biopharmaceutical leader that has demonstrated a strong commitment to innovation and excellence for more than a century,” said Dr. Jack Hoppin, Ratio’s Chairman and Chief Executive Officer. “The development of a Granzyme B-targeted agent for PET imaging has the potential to monitor responses to therapeutic interventions in clinical research.”
Granzyme B is an enzyme released by activated immune cells, such as natural killer and cytotoxic T cells, with the primary function of killing tumor cells and normal cells infected with viruses. As such, Granzyme B holds potential to serve as a PET imaging biomarker to monitor immune cell activation in a variety of inflammatory diseases, autoimmune diseases, cancer and infection. The ability to visualize and quantify localized immune response empowers physicians to measure the early efficacy of therapies and modify treatment accordingly.
For more information: www.ratiotx.com
March 30, 2026 
