Researchers are testing the drug Sapanisertib to see if it can halt the progression of pancreatic NETs (pNETs) which cannot be surgically removed, have not responded to other treatment, and have spread to other parts of the body.
What is Sapanisertib?
Sapanisertib is one of a group of targeted therapy drugs that interferes with tumor progression by inhibiting an enzyme known as mTOR which a tumor cell needs for growth. In fact this is the same technique used in Afinitor (Everolimus), already approved for NETs.
It is also being tested in a number of different advanced cancers, including bladder, kidney, breast, liver, and certain types of lung cancers, among others.
The Clinical Trial
The primary goal of the phase II study is to evaluate how well pNET tumors respond to Sapanisertib. To qualify for this trial patients must have advanced pNET that cannot be surgically removed, and which have not responded to previous treatment with similar drugs. All participants will receive Sapanisertib, and will be checked periodically to see if their tumors are responding to the drug.
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided at this link which provides more details about the Sapanisertib pNET trial – click here and check the inclusion and exclusion criteria; and other data. There are 354 study locations across the USA.
I’ve posted extensively about this subject on Facebook early last year, focused on the ongoing Neuroendocrine Cancer trial in Uppsala Sweden. I wanted to incorporate this information into a single article ready for future news, whilst at the same time updating you on further developments in the field of Oncolytic Viruses for Neuroendocrine Cancer.
What exactly are Oncolytic Viruses?
Oncolytic Viruses infects and breaks down cancer cells but not normal cells. Oncolytic viruses can occur naturally or can be made in the laboratory by changing other viruses. Certain oncolytic viruses are being studied in the treatment of cancer. Some scientists say they are another type of immunotherapy whilst others say it’s too early to classify as such. The good news is that Neuroendocrine Cancer seems to figure in this work with two of these viruses apparently working on mice to date. Listed below are two active projects involving NETs, one directly and one indirectly.
The Uppsala Trial – AdVince
There has been no real update on what is happening since I posted last year. Hopefully, positive thinking indicates no news is good news. If anyone has anything more than what I’ve written or linked to in this article, please let me know. I’ll briefly described what’s happening and then you can link to my Facebook article if you need more background.
The trial is called AdVince after Vince Hamilton who funded it. Unfortunately he died before he saw any output but his forward thinking and benevolence lives on and might hopefully help NET patients in the longer term. It’s quite a small trial and is being conducted in Uppsala University Sweden, a famous European NET Centre of Excellence and where many people from across the world attend to take advantage of PRRT availability and experience and is home to famous NET specialist Kjell Öberg, MD, PhD, a professor of endocrine oncology.
A Swedish man (Jan-Erik Jannsson) was the first to get the virus to their cancer (NETs) using a genetically modified virus.
Unfortunately, I was given the news from a source close to the trial that Jan died last year of pneumonia. I have no evidence to suggest his death is in anyway connected to the trial but I’m told he was an ill man prior to the trial commencing. I have therefore dedicated this post to him. RIP Jan.
The initial data presented by the trial indicated that AdVince can be safely evaluated in a phase I/IIa clinical trial for patients with liver-dominant NET. The last I heard from the trial is that they are trying to recruit a further 12 patients to Phase IIa (the trial document allows for up to 36).
Read more background on my Facebook post here: Click here
The trial document on Clinical Trials Website: Click here
This is an oncolytic viral therapy currently in phase III and phase Ib/II clinical trials for use against primary liver (Hepatocellular Carcinoma) and Colorectal cancers, respectively. Pexa-Vec is a weakened (or attenuated) virus that is based on a vaccine used in the eradication of smallpox. The modified virus is injected directly into the cancer tumour, to grow inside these rapidly growing cancer cells and hopefully kill them.
According to the Colorectal Clinical Trial, the aim of the study is to evaluate whether the anti-tumor immunity induced by Pexa-Vec oncolytic viral therapy can be enhanced by immune checkpoint inhibition i.e. they are testing it in conjunction with Immunotherapy drugs (Durvalumab, and a combination of Durvalumab and Tremelimumab).
The Hepatocellular Carcinoma trial (Phocus) is at Phase III where the sponsors are evaluating Pexa-Vec to determine if it can slow the progression of advanced liver cancer and improve quality of life.
The work is a collaboration forged between University of California San Francisco (UCSF) vascular researcher Donald McDonald, MD, PhD, and researchers at San Francisco-based biotech SillaJen Biotherapeutics Inc. (formerly Jennerex Biotherapeutics, Inc.), a subsidiary of SillaJen, Inc., headquartered in Korea.
So what’s the Neuroendocrine Connection with Pexa-Vec?
As part of the research, McDonald’s lab injected it intravenously into mice genetically modified to develop pancreatic neuroendocrine cancer. They found that the virus failed to infect healthy organs or make the animals ill, but succeeded in infecting blood vessels within tumors. These initial infections caused the vessels to leak and expose the tumor cells to the virus. In these experiments, the virus managed to infect and destroy only a small proportion of tumor cells directly, the researchers found, but within five days of the initial infection, the rest of the tumor began to be killed by a powerful immune reaction.
“At first small spots of the tumor were infected, but then most of the tumor started to die,” McDonald said. “We were able to show that while only about five percent of cells were infected by the virus, the number of cells that were killed was more than ten times higher. As far as I know, no one has ever done this kind of analysis.”
McDonald’s team wondered whether they could improve the efficacy of the virus by adding in a second drug called Sutent (sunitinib) that blocks blood vessel growth and alters immune function. The combination worked, with significantly greater tumor killing than with the virus alone. When the researchers examined the tumors, they discovered that the second drug acted by making the immune system hyper-alert to tumor proteins released by the viral infection, rather than through effects on tumor blood vessels.
Clearly it’s still early days in the Oncolytic Virus field with minimum breakthrough in terms of success on humans. In terms of the Neuroendocrine connection, it is exciting that two programmes are showing results (albeit in mice). We wait to hear from Uppsala on how the human test of AdVince is coming along. My agents are scanning the internet every day looking for any comment. If you want to learn more about Oncolytic Viruses in general – there’s a great summary here.
Cabozantinib is an oral drug which works by blocking the growth of new blood vessels that feed a tumour. In addition to blocking the formation of new blood cells in tumours, Cabozantinib also blocks pathways that may be responsible for allowing cancers cells to become resistant to other “anti-angiogenic” drugs. It is a type of drug called a growth blocker. Cabozantinib has been studied or is already in research studies as a possible treatment for various types of cancer, including prostate cancer, ovarian cancer, brain cancer, thyroid cancer, lung cancer, and kidney cancer. During my research, I found that it has a connection to Medullary Thyroid Cancer (MTC) which is a type of Neuroendocrine Cancer, frequently associated with Multiple Endocrine Neoplasia (MEN). Cabozantinib, under the brand name of ‘Cometriq’ was approved by the FDA in 2012 for use in MTC. Read more about Cometriq here. It’s also been approved by the FDA for advanced renal cell carcinoma (RCC) (branded as Cabometyx). I also discovered that there is an exclusive licensing Agreement with the manufacturers (Elelixis) and Ipsen (of Lanreotide fame) to commercialize and develop Cabozantinib in regions outside the United States, Canada and Japan
Growth blockers are a type of biological therapy and include tyrosine kinase inhibitors, proteasome inhibitors, mTOR inhibitors, PI3K inhibitors, histone deacetylase inhibitors and hedgehog pathway blockers. Cabozantinib is a tyrosine kinase inhibitor (TKI). They block chemical messengers (enzymes) called tyrosine kinases. Tyrosine kinases help to send growth signals in cells so blocking them stop the cell growing and dividing. Some TKIs can block more than one tyrosine kinase and these are known as multi-TKIs.
So Capozantinib is a tyrosine kinase inhibitor and is therefore a biological therapy and growth blocker just like Everolimus (Afinitor) and Sunitinib (Sutent). Very technical process but in the simplest of terms, Cabozantinib is designed to disrupt the actions of VEGF (a growth factor) and MET (a growth factor receptor) which promote spread of cancerous cells through the growth of new blood vessels. Whilst we are on this subject, please note Everolimus (Afinitor) is an mTOR inhibitor and Sunitinib (Sutent) is a tyrosine kinase inhibitor. Many people think these drugs are a type of chemo – that is incorrect, these are targeted biological therapies. See more on this by clicking here.
What is the current trial status of Capozantinib?
It’s currently in an ‘Open-Label’ ongoing Phase II Study but is not currently recruiting participants. According to the documentation below, a Phase III trial is in development. The results of the Phase II trial have been presented to both European and US conferences, including NANETS 2017. The trial is currently confined to Massachusetts in the US in two Boston hospitals (Massachusetts General and Dana-Farber). Dr Jennifer Chan is involved with some input from Dr Matthew Kulke – both known NET specialists. The primary study (final data) is scheduled for Oct 2018 with a projected study end date of Apr 2022.
According to the trial documentation and informed comment on the trial data to date, the drug targets both Pancreatic Neuroendocrine Tumours (pNETs) and mainstream GI types (e.g. small intestine, appendix, lung, rectum and others). However, these tumours are described as “locally unresectable or metastatic, histologically-confirmed, carcinoid (sic) or pancreatic neuroendocrine tumor. Tumors must be considered well- or moderately differentiated (see article). Patients with poorly differentiated neuroendocrine carcinoma or cell carcinoma are excluded from the study”.
(Author’s note – this is an old trial document and the term “moderately differentiated has been phased out since publication).
You can read the trial documentation by clicking here. The drug also has a temporary short name of XL184.
A funded piece of research by the NET Research Foundation – check it out here – looks like they are trying to figure out what patients might benefit from Cabozantinib using biomarker data to predict response.
UPDATED 2018 – There’s also another trial focussed on unresectable metastatic Pheochromocytomas and Paragangliomas
A Phase 2 Study to Evaluate the Effects of Cabozantinib in Patients with Unresectable Metastatic Pheochromocytomas and Paragangliomas
BOSTON — Cabozantinib (Cabometyx) may benefit patients with malignant pheochromocytomas and paragangliomas, according to results of a phase II trial presented here.
Patients receiving cabozantinib (Cometriq) treatment experienced notable tumor shrinkage in the lymph nodes, liver, and lung metastases, according to Camilo Jimenez, MD, of the MD Anderson Cancer Center in Houston, and colleagues.
Additionally, progression-free survival significantly increased after treated to 12.1 months (range 0.9-28) compared with just 3.2 months prior to treatment, they reported at the American Association of Clinical Endocrinologists (AACE) annual meeting.
Cabozantinib treatment was also tied to an improvement in blood pressure and performance status, as well as remission of diabetes among these patients.
“Malignant pheochromocytomas and paragangliomas are frequently characterized by an excessive secretion of catecholamines. [Patients] have a large tumor burden and they have a decreased overall survival,” explained Jimenez. “Tumors are frequently very vascular and frequently associated with bone metastases. In fact, up to 20% of patients who have malignancy of pheochromocytomas and paragangliomas may have predominant bone metastases.”
He added that “an interesting aspect of this tumor is that C-MET receptor mutation have been found in occasional patients with malignant pheochromocytomas and paragangliomas.”
Cabozantinib is an anti-angiogenic tyrosine kinase inhibitor, which also targets RET, MET, and AXL. It is approved for metastatic medullary thyroid cancer, and was more recently approved for first-line treatment of advanced renal cell carcinoma.
“MET pathway is also involved in the development of bone metastases. In fact, cabozantinib is a very effective medications for patients who have bone metastases in the context of cancer of different origins,” Jimenez said.
In order to be eligible for the trial, patients with confirmed pheochromocytoma or paraganglioma had to be ineligible for curative surgery, have ≥3 months life expectancy, no risk for perforation or fistula, and adequate organ functioning. Prior to cabozantinib initiation, patients could not receive chemotherapy or biologic agents within 6 weeks, radiation within 4 weeks, or MIBG within 6 months.
Following histological confirmation of disease progression >1 year according to RECIST 1.1, the trial included 14 patients with measurable disease and eight patients with predominant/exclusive bone metastases. Fifteen patients subsequently enrolled into the trial, six of whom had germline mutations of the SDHB gene.
All participants were all started at an initial daily dose of 60 mg of cabozantinib, which was subsequently reduced down to between 40 to 20 mg due to toxicity in 13 patients based on tolerance.
The majority of these patients with measurable disease experienced some level of disease response. Six patients reported a partial response, defined as over a 30% reduction, while three patients achieved moderate response, marked by a 15%-30% reduction. Five of the patients with predominant bone metastases reported disease stabilization, according to results of an FDG-PET scan. One patient experienced disease progression while on treatment.
Overall, cabozantinib was generally well-tolerated without any grade 4 or 5 treatment-related adverse events reported. Some of the most common adverse events reported included grade mild dysgeusia, hand and foot syndrome, mucositis, fatigue, weight loss, and hypertension, according to the authors.
Primary Source – American Association of Clinical Endocrinologists meeting – AACE 2018; Abstract 142. attended my Medscape writers
I generated this blog article to add value rather than just post the outputs for your own perusal. I hope you find it useful.
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. 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 Pairin 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).
Nuclear medicine makes it possible by using the same molecular targeting compound to create diagnostic and therapeutic drugs, which work as theranostic pairings. Advanced Accelerator Applications’ theranostic platform is based on radiolabelling a single targeting molecule with either gallium Ga-68 for diagnostic use or lutetium Lu-177 for therapeutic use. AAA’s pipeline now includes several theranostic drug pairings for oncology indications including prostate and breast cancer; and gastrointestinal stromal tumors (GIST).
THERANOSTICS – FIND
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 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
Lutathera® (note the ‘THERA’ which makes up the brand name)
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.
PRRT with LUTATHERA®
LUTATHERA® solution for infusion is a ‘radiolabelled somatostatin analog (SSA)’ comprised of a radionuclide (Lutetium-177) and a peptide (differs between Europe and USA)
The relevant SSA binds with high affinity to the somatostatin receptors (SSTR) overexpressed in malignant neuroendocrine cells such as the ones found in GEP-NETs.
Lutetium-177 is a β particle emitting radionuclide, with a mean penetration range of 0.67 millimetres in tissue (maximum penetration range of 2.2 mm) which is sufficient to kill targeted tumour cells with a limited effect on neighbouring normal cells.
The affinity for SSTRs and the specificity of binding ensures a high level of specificity in the delivery of radiation to the tumour. Before starting treatment with LUTATHERA®, imaging must confirm the presence of these receptors in tumour tissues.
As an example of how the drug is administered, please watch this short video from the European site:
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
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