What is Lutetium-177 OPS-201?
This is a ‘next generation’ Peptide receptor radionuclide therapy (PRRT) or more specifically the radiopharmaceutical that binds to both activated and unactivated somatostatin receptors which are upregulated on these tumours. There is far higher binding via this mechanism than standard octreotate. The technical name of the radiopharmaceutical is Satoreotide tetraxetan lutetium-177 (author’s note, I’m guessing but it could be a variant of Lanreotide). It was once named JR11.
What’s the difference to the current approved therapy?
Conventional PRRT (e.g. Lutathera, Lu177 Dotatate) is based on a somatostatin receptor ‘agonist’ approach, whereas 177Lu Ops 201 Satoreotide is a receptor ‘Antagonist’. The differences are quite technical but in the most layman terms , the antagonist has the capability of attaching (binding) to more receptors, including those in a ‘resting’ or ‘inactive’ state, spends more time on the tumor than agonist based therapies. The result is a higher number of receptor binding sites and greater tumor uptake. In addition it is said to show an improved tumor-to-kidney dose ratio compared to 177Lu-DOTA-TATE.
This would also be reflected in the theranostic use of the drug in Ga68 imaging (i.e. Ga68 Satoreotide).
This presentation from Theranostics Australia
The Clinical Trial
The clinical trial is named “Study to Evaluate the Safety and Preliminary Efficacy of 177Lu-OPSC001 in NETs”. The protocol involves 3 cycles 8 weeks apart of intravenous Lu-177 OPS-201. All patients will have baseline Ga-68 octreotate imaging performed.
The treatment is available for all NET patients with a histologically confirmed diagnosis of:
- unresectable GEP NET (Grade I and Grade II according to WHO classification (2010, Annex 01), functioning and non-functioning).
- unresectable “typical lung NET” or “atypical lung NET” are acceptable (with the exception of Large Cell Bronchial Neuroendocrine Neoplasms and Small Cell Lung Cancers).
- malignant, unresectable pheochromocytoma or paraganglioma
Patients who have previously had Lu-177 octreotate (e.g. Lutathera) are not eligible. Patients may have had any other treatment including chemotherapy, radiotherapy or Somatostatin Analogues (e.g. octreotide, landreotide).
There are other inclusion and exclusion criteria to be found within the clinical trial document. The trial is due to compete in May 2022.
Where is the Trial based?
At the time of writing and according to the Clinical Trial document, Australia (Melbourne and Perth), Austria (Vienna), Denmark (Aarhus), Switzerland (Basel), UK (Royal Free London). Two sites are also listed in France (Nantes and Toulouse) but trial document currently marked as not yet recruiting.
What about USA?
I also found an additional trial based in Memorial Sloan Kettering New York designed to take a theranostic approach by using Satoreotide (JR11) for the pre-treatment imaging, e.g. Ga68 satoreotide (JR11) and the 177Lu version for treatment. The clinical trial document indicates this trial is active but NOT RECRUITING and is entitled “Theranostics of Radiolabeled Somatostatin Antagonists 68Ga-DOTA-JR11 and 177Lu-DOTA-JR11 in Patients With Neuroendocrine Tumors”
Thanks for reading
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