What is Lutetium-177 OPS-201? (note: any new trials may be given a new name)

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 between the currently 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).

Useful reading:

This presentation from Theranostics Australia

The Clinical Trial (NCT02592702) – now terminated

The clinical trial was named “Study to Evaluate the Safety and Preliminary Efficacy of 177Lu-OPSC001 in NETs”.  The protocol involved 3 cycles 8 weeks apart of intravenous Lu-177 OPS-201. All patients had baseline Ga-68 octreotate imaging performed.

The therapy was 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 had previous Lu-177 octreotate (e.g. Lutathera) were not eligible. Patients may have had any other treatment including chemotherapy, radiotherapy or Somatostatin Analogues (e.g. octreotide, landreotide).

There were other inclusion and exclusion criteria to be found within the clinical trial document.  

Where was the Trial based?  

At the time of writing and according to the Clinical Trial document, Australia (Melbourne and Perth), Austria (Vienna), Canada (CHU de Quebec), Denmark (Aarhus), Switzerland (Basel), UK (Royal Free London).  Two sites were also listed in France (Nantes and Toulouse).  Two sites in USA (City of Hope California and MD Anderson Texas).  Another site in USA carried out a similar trial at MSK New York where the sponsors reported “In this trial of heavily treated NETs, preliminary data are promising for the use of ¹⁷⁷Lu-satoreotide tetraxetan. Additional studies are ongoing to determine optimal therapeutic dose/schedule” – results posted here.

You may also find these PRRT related articles useful:

PRRT Overview plus locations 

Trial of Targeted Alpha-emitter Therapy (TAT) – 212 Pb-AR-RMX

COMPETE trial 177Lu Edotreotide-Solucin