64Cu-DOTATATE – a potential expansion of the Somatostatin Receptor PET Imaging for Neuroendocrine Cancer?


Edit 10 Jan 2019: RadioMedix and Curium Announce FDA Fast Track Designation For 64Cu-Dotatate.  Read more by clicking here.

Curium and RadioMedix Inc. announce an exclusive agreement to develop and commercialize 64Cu-Dotatate, an investigational positron emission tomography (PET) diagnostic agent for patients with Neuroendocrine Tumors (NETs). RadioMedix is currently engaged in Phase III clinical trials of the agent and expects to file a New Drug Application with the Food and Drug Administration in 2019. This partnership builds on the initial development work conducted by RadioMedix and will benefit from Curium’s regulatory, manufacturing, distribution, and commercial expertise. The radionuclide is not new, it’s been in use for some time, mainly in Denmark.

64Cu is a PET isotope that can be produced at a central location in quantities to meet the commercial needs of hospitals and imaging centers without the supply limitations of nuclear generator-based PET isotopes,” said Ebrahim Delpassand, MD, CEO of RadioMedix. “Once approved, 64Cu-Dotatate will be available to patients in medical centers with PET capability across the country. This will address the shortage or lack of availability of somatostatin analogue PET agents that we are currently experiencing in many parts of the U.S.”

Ga68 PET Shortages explained

This statement is in relation to the current shortage of Ga68 PET radionuclide. For those not aware, the Society of Nuclear Medicine and Molecular Imaging (SNMMI) has written a letter to the FDA about ongoing shortages of generators that produce gallium-68 (Ga-68), a radioisotope used regularly in medical imaging. The letter—available here.

The letter explains that Ga-68 is currently used to produce NETSPOT from Advanced Accelerator Applications (a Novartis company), which was approved in June 2016 to help treat neuroendocrine tumors (NETs) in adult and pediatric patients using PET. NETSPOT, however, is only approved using specific generators. And those generators are only approved for either 400 uses or one year, whichever comes first. This has led to shortages throughout the United States.

SNMMI notes some possible remedies for this shortage. For instance, “a temporary exemption to the 400-elution limit would have a major impact on NETSPOT capacity for patients,” according to the letter. In addition, using a wider variety of generators to produce NETSPOT or using cyclotron-produced gallium chloride are two other methods that could improve production in a relatively short amount of time. “Further discussion with the manufacturers is necessary,” the authors added.

Read more about Ga68 PET and its use in Neuroendocrine Cancer – click here. Worth also noting that RadioMedix is also involved in a number of NET related initiatives including:

1. Trials for a new type of PRRT called ‘Targeted Alpha-emitter Therapy (TAT) – I’ve written about this previously. Read my article here.
2. An exclusive distributor for the TM Isotopen Technologien München AG (ITM) PRRT product currently in trial. I wrote about this here.

How does 64Cu-Dotatate compare with Ga68 PET and Octreotide Scans?

To learn more about previous studies on 64Cu-Dotatate, here’s 2 articles published in the Journal of Nuclear Medicine which are a head to head comparison of 64Cu-Dotatate with Ga68 Dotatoc and with 111 Indium Octreotide (Octreoscan).

Head-to-Head Comparison of 64Cu-DOTATATE and 68Ga-DOTATOC PET/CT: A Prospective Study of 59 Patients with Neuroendocrine Tumors – http://jnm.snmjournals.org/content/58/3/451.full

PET/CT (left) and PET (right) scans of patient with intestinal NET and multiple metastases. More lesions are seen in intestinal region with 64Cu-DOTATATE than with 68Ga-DOTATOC.

Conclusion: 64Cu-DOTATATE has advantages over 68Ga-DOTATOC in the detection of lesions in NET patients. Although patient-based sensitivity was the same for 64Cu-DOTATATE and 68Ga-DOTATOC in this cohort, significantly more lesions were detected by 64Cu-DOTATATE. Furthermore, the shelf life of more than 24 h and the scanning window of at least 3 h make 64Cu-DOTATATE favorable and easy to use in the clinical setting.

64Cu-DOTATATE PET for Neuroendocrine Tumors: A Prospective Head-to-Head Comparison with 111In-DTPA-Octreotide in 112 Patients –http://jnm.snmjournals.org/content/56/6/847.full

Multiple small liver metastases (>10), peritoneal solitary tumor mass, and 3 lymph node metastases shown on 64Cu-DOTATATE PET/CT in patient with pancreatic NET. No foci were detected by 111In-DTPA-OC SPECT (Precedence scanner). All findings on PET were confirmed to be true-positive. (A) 111In-DTPA-OC planar images. (B) 64Cu-DOTATATE maximum-intensity-projection image with arrows pointing at liver and lymph node metastases. Insert is fused PET/CT of peritoneal solitary tumor mass. (C) Axial CT and SPECT of liver. (D) Axial CT and PET of liver revealing several small liver metastases.

Conclusion: With these results, we demonstrate that 64Cu-DOTATATE is far superior to 111In-DTPA-OC in diagnostic performance in NET patients. Therefore, we do not hesitate to recommend implementation of 64Cu-DOTATATE as a replacement for 111In-DTPA-OC.

Summary

The shortage of Ga68 PET radionuclide caused by limitations of the generators in use is unfortunate. Reading the SNMMI letter, I think progress can be made downstream. However, the introduction of a new scanning agent could be useful as long as the trials prove its safety and efficiently and is comparable to current tools. There is no news of any plans to extend this potential new radionuclide outside the US but I suspect that would change following an FDA approval.

If you can see it, you can detect it!

Thanks for reading

Ronny

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Remember ….. in the war on Neuroendocrine Cancer, let’s not forget to win the battle for better quality of life!

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Theranostics for Neuroendocrine Cancer – A Find and Destroy Mission

 

theranostics
Courtesy of Pashtoon Kasi MD on Twitter https://twitter.com/pashtoonkasi/status/1078675398601396224

 

Theranostics is a joining of the words therapeutics and diagnostics. You may also see it conveyed as ‘Theragnostics’ and these terms are interchangeable.  The basic aim of theranotistics is to find and then destroy the ‘bad guys‘.  With Neuroendocrine Cancer, finding the tumours (the bad guys) can often be a challenge – they can be small and/or difficult to find – they are sometimes expert at camouflage.  Moreover, once found, they can then be difficult to treat (destroy), as they can often prove resistant to conventional cancer drugs and many are inoperable due to sheer quantity, spread and positioning.  When they are found and identified, it’s also really helpful to know from the intelligence gathered, how successful the destroy (therapeutic) part of the mission might be.

The nuclear scan uses the same nuclear material as the therapy, therefore if you cancer lights up on the nuclear scan, then the therapy will find its way to the cancer and hopefully work well. That is the beauty of theranostic pairing, i.e. the use of the same agent in the diagnostics – the ability to find, estimate likely success criteria and then hopefully destroy – or at least reduce the capability of the tumours and extend life.

A great example of an approved Theranostic Pair in Neuroendocrine Cancer, is the combination of the Somatostatin Receptor based Ga68  PET scan using NETSPOT or SomaKit TOC™ (US/Europe respectively) and Peptide Receptor Radiotherapy (PRRT) using Lutathera which both target NETs expressing the same somatostatin receptor, with PRRT intended to kill tumor cells by emitting a different kind of low-energy, short-range radiation than that of the diagnostic version. As mentioned above, the Ga68 PET scan can give a reasonably indication of therapeutic success using PRRT based on measurements taken during the scan (too complex for this article).

Theranostics – a step towards personalised medicine – graphic courtesy of Advanced Accelerator Applications.

THERANOSTICS – FIND

Octreoscan vs Ga68 PET

Ga68 PET 

Newer imaging agents targeting somatostatin receptors (SSTR) labelled with 68 Ga have been developed, namely, DOTATATE, DOTATOC and DOTANOC. They are collectively referred to as SSTR PET.

The full titles of the 3 types are:

68Ga-DOTA-Phe1-Tyr3-Octreotide (TOC),
68Ga-DOTA-NaI3-Octreotide (NOC),
68Ga-DOTA-Tyr3-Octreotate (TATE).

The main difference among these three tracers (DOTA-TOC, DOTA-NOC, and DOTA-TATE) is their variable affinity to SSTR subtypes. All of them can bind to SSTR2 and SSTR5, while only DOTA-NOC shows good affinity for SSTR3.

These agents have several benefits over In111-pentetreotide (Octreotide scan), including improved detection sensitivity, improved patient convenience due to the 2 hour length of the study (compared to 2 or 3 days with Octreoscan), decreased radiation dose, decreased biliary excretion due to earlier imaging after radiotracer administration, and the ability to quantify uptake. The quantification of the uptake can help decide whether a patient is suitable for PRRT. Eventually, all Octreotide scans should be replaced with SSTR PET.  To confirm the advantages of SSTR PET over Octreotide scans, a study comprising 1,561 patients reported a change in tumour management occurred in over a third of patients after SSTR PET/CT even when performed after an Octreotide scan. Worth pointing out that SSTR PET is replacing the ageing Octreotide scan and not conventional imaging (CI).  You can see the recommended scenarios for use of SSTR PET in this article published by the Journal of Nuclear Medicine

Ga68 PET scans have been in many locations for some time. Current excitement is focused on USA locations with Ga68 PET (NETSPOT) only recently approved (DOTATATE). Other countries/scan centres may use one of the other types of imaging agent.

Read much more about this scan in my detailed article on Ga68 PET here.

So SSTR PETs above have the ability to find and estimate likely success criteria for therapy.  We are now in a position to move on to ‘THERApy’ – e.g.  Peptide Receptor Radiotherapy or PRRT.

THERANOSTICS – DESTROY

click on picture to watch video

Lutathera® (note the ‘THERA’ which makes up the brand name)

Definitions:

Europe Approval: LUTATHERA®(lutetium (177Lu) Oxodotreotide) is indicated for the treatment of unresectable or metastatic, progressive, well differentiated (G1 and G2), somatostatin receptor positive gastroenteropancreatic neuroendocrine tumours (GEPNETs) in adults.

USA Approval: LUTATHERA® (lutetium Lu 177 dotatate) is indicated for the treatment of somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs), including foregut, midgut and hindgut neuroendocrine tumors in adults.

For commercial purposes, the drug may be slightly different on a regional basis. For all intents and purposes it does the same job.

As an example of how the drug is administered, please watch this short video from the European site:

Video courtesy of Advanced Accelerator Applications

Please see the following post for a summary of PRRT activity worldwide.  Please note this linked article is not designed to contain a list of every single location or country available – please bear that in mind when you read it – CLICK HERE

I’m very grateful to the team at Advanced Accelerator Applications (a Novartis Company) for allowing me to use their site for graphics and videos.

In another ‘theranostic’ development, check out my article on the Satoreotide trial (Ops 201/202) from Ipsen (of Lanreotide fame) – click here to read – the trial is recruiting.

Thanks for reading

Ronny

I’m also active on Facebook. Like my page for even more news. I’m also building up this site here: Ronny Allan

Disclaimer

My Diagnosis and Treatment History

Most Popular Posts

Sign up for my twitter newsletter

Read my Cure Magazine contributions

Remember ….. in the war on Neuroendocrine Cancer, let’s not forget to win the battle for better quality of life!

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