
SRI’s FOX Three peptide platform to deliver precision radionuclide therapy targeted at hard-to-treat tumors.
SRI formed a strategic partnership with Kalekona Radiotheranostics, a biotech startup focused on breakthrough radiopharmaceuticals, to accelerate peptide receptor radionuclide therapy (PRRT) for pancreatic ductal adenocarcinoma and glioblastoma.
“Our FOX Three platform enables rapid, tumor-specific delivery of radionuclides,” said David Parekh, CEO of SRI. “SRI’s multidisciplinary biotech expertise and innovative delivery technology, along with our collaboration with Kalekona, brings new therapeutic approaches to patients with serious cancers faster than ever.”
Radiotheranostics merges nuclear imaging and radionuclide therapy to diagnose and treat cancer in a single, highly targeted workflow. PRRT works like a guided missile to reach its target: a diagnostic version carries a PET-detectable isotope that highlights tumors, while a therapeutic version swaps in a radioisotope that destroys cancer cells.
“SRI’s decades of experience and proven FOX Three platform give us the confidence that we’ll be able to move fast on this important work.” — Ronald H.W. Lorijn
SRI’s FOX Three Molecular Guidance System (MGS) creates peptide carriers that can be interchanged between two isotopes, providing a seamless transition from detection to treatment.
“MGS peptides locate tumors within minutes, remain bound long enough to provide high-resolution images or deliver the therapeutic payload, and do not harm the surrounding healthy tissue,” said Kathlynn Brown, President of SRI’s Biosciences Division and Chief Science Officer of Kalekona. “This type of delivery will enhance diagnostic precision and targeted treatment while minimizing collateral radiation exposure.”
Historically, PRRT has been limited to neuroendocrine tumors because suitable targeting peptides were scarce. The FOX Three platform generates custom peptides for any cancer type, opening PRRT to pancreatic and brain tumors that lack effective radiotherapies.
“Kalekona’s mission is to translate breakthrough radiopharmaceuticals into real-world therapies,” said Ronald H.W. Lorijn, CEO of Kalekona. “SRI’s decades of experience and proven FOX Three platform give us the confidence that we’ll be able to move fast on this important work.”



