NETRF-funded Research Sets the Stage for Study Exploring Use of Terbium-161 in NETs

A new clinical trial being conducted at a single center in Switzerland aims to explore a therapy using a novel somatostatin receptor subtype 2 antagonist labelled with Terbium-161 (161Tb-DOTA-LM3). The study is sponsored by University Hospital, Basel, in collaboration with the Swiss National Science Foundation and the Paul Sherrer Institute and builds upon research funded by NETRF.

The goal of the proof-of-concept study is to measure the therapeutic index of 161Tb-DOTA-LM3 in comparison to the current standard treatment with 177Lu-DOTATOC in gastroenteropancreatic neuroendocrine tumors (GEP-NET). 

In 2018, Roger Schibli, PhD, of the Paul Scherrer Institute in Switzerland, received a two-year Petersen Investigator award to explore the safety of the 161Tb-DOTA-LM3 radionuclide as a more effective peptide receptor radionuclide therapy, or PRRT. Dr. Schibli and his colleagues developed a new therapy based on terbium radionuclides, which have distinct radioactive properties compared to Lu 177. They evaluated the improved ability of 161Tb-DOTATOC to kill neuroendocrine tumor cells in a pre-clinical setting before proceeding with the first-in-human study. Due to its different radiation-emitting properties, Dr. Schibli and his colleagues found that 161Tb-labeled molecules are more effective in killing cancer cells and that killing single cancer cells could represent a paradigm shift in the treatment of neuroendocrine cancer. 

Study Design

Damian Wild, MD, PhD, leads the current proof-of-concept trial at University Hospital, Basel. The study, which is expected to begin in December 2022, will enroll up to 16 patients who have metastasized and non-secreting GEP-NETs (grade 1 and 2). 

Patients will be randomized into two treatment groups. In the first phase of the study, one test injection with 161Tb-DOTA-LM3 and 177Lu-DOTATOC will be administered in both randomized groups in a different order, followed by approximately 3 cycles of PRRT in both groups. In the second phase, two test injections with 161Tb-DOTA-LM3 with different peptide amounts will be administered in both treatment groups in a different order, followed by approximately two cycles of PRRT with 161Tb-DOTA-LM3.

Next Steps

Additional information on the study can be found at Interested participants should talk to their treatment team about eligibility and determine if the study is aligned with their treatment goals.