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.
On the heels of the approval of PRRT in USA and whilst we all wait on positive national announcements of PRRTapproval in UK and elsewhere, here’s news of a new PRRT compound undergoing a phase 3 clinical trial. Isotopen Technologien München AG (ITM), a specialized radiopharmaceutical company, today announced the enrolment of the first patient recruited in Europe for the COMPETE phase III clinical trial at theUniversity Hospital Marburg, Germany. The CEO of ITM said “This marks the starting point of COMPETE in Europe, whereby we expect a rapid increase in the number of recruits.” I actually met these guys at ENETS 2018 – sounds great.
What is the COMPETE trial?
COMPETE is led as an international pivotal multi-center phase III clinical trial evaluating the efficacy and safety of (no-carrier-added) n.c.a.177Lu-Edotreotide (Solucin®) and the trial is comparing it to Everolimus (Afinitor). The trial runs until Dec 2020. The enrolment requires patients with inoperable, progressive, somatostatin-receptor positive neuroendocrine tumors of gastroenteric or pancreatic origin (GEP-NET). The primary endpoint is progression-free survival (PFS). The study will be conducted predominantly in Europe, North America, South Africa and Australia (ITM is waiting on FDA clearance to include North American locations in the trial). The first patient to be enrolled and treated was in Australia. The clinical trial document (see references below) indicates its for non-functional GI tumours but for non-functional and functional pNETs. The list of locations can also be found in the clinical trial document. The usual inclusion/exclusion rules apply but the most notable would appear to be an exclusion for those with prior exposure to any PRRT or mTor inhibitor such as Everolimus (Afinitor).
What is 177Lu-Edotreotide (Solucin®) ?
The compound under investigation, Solucin®, is known as a Targeted Radionuclide Therapy (TRT) agent, which consists of the targeting molecule Edotreotide, an octreotide-derived somatostatin analogue and ITM´s EndolucinBeta® (no-carrier-added Lutetium-177). EndolucinBeta® is a synthetic, low-energy beta-emitting isotope of Lutetium, a recently EMA approved pharmaceutical precursor. The radiopharmaceutical Solucin® is administered as an intravenous infusion, specifically targeting and destroying the tumor cells with ionizing radiation. Solucin® received an Orphan Designation (EMA/OD/196/13) for the treatment of GEP-NET, based on early clinical experience, which has demonstrated a substantial clinical benefit with increased PFS and quality of life.
From ITM’s website … “Edotreotide contains DOTA which functions as a chelator for radioisotopes and TOC, a synthetic Somatostatin receptor ligand” (chelator and ligand are just fancy names for ‘bonding’ or ‘binding’). “The compound Edotreotide binds with high affinity Somatostatin receptors and retains both its receptor binding properties and its physiological function when labeled with 177Lu. Somatostatin receptors are predominantly overexpressed by neuroendocrine tumors. 177Lu-Edotreotide, upon binding to Somastotatin receptors in vivo is internalized and retained by tumor cells.”
“Compared to 90Y-Edotreotide, 177Lu-Edotreotide Targeted Radionuclide Therapy in NET was found to be less haematotoxic and associated with a longer median overall survival. That was highly significant for patients with low tumor uptake as well as for patients with extra hepatic and solitary metastases. In a retrospective Phase II trial 177Lu-Edotreotide showed a low uptake/dose delivered to normal organs and very high tumor-to-kidney ratio.”
Other Spin offs from ITM
Interestingly the company is also working on a ‘theranostic pair’ for imaging and treating bone metastases – see graphic below. It does not say whether this includes NET bone metastases but I don’t see why not given the connection with Solucin. However, please note this is some years away from fruition.
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) – some texts describe thelattero two as chemotherapy but this is just not accurate.
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?
A Phase III trial is now recruiting entitled “Cabozantinib S-malate in Treating Patients With Neuroendocrine Tumors Previously Treated With Everolimus That Are Locally Advanced, Metastatic, or Cannot Be Removed by Surgery”.
The trial has 172 locations across the US (see link below). The primary study (final data) is scheduled Jan 1st 2021.
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.
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.
Please note that taking part in a clinical trial is a big decision and must be considered carefully in conjunction with your specialists if necessary. This article is not suggesting this trial is right for you. Please check the inclusion and exclusion criteria in the trials document carefully. (Pheo/Para patients see other clinical trial link above)
I’m continually seeing certain drugs for treatment of Neuroendocrine Tumours (NETs) described as chemotherapy. I think there must be some confusion with more modern drugs which are more targeted and work in a different way to Chemotherapy.
I researched several sites and they all tend to provide a summary of chemotherapy which is worded like this: Chemotherapy means:
a treatment of cancer by using anti-cancer medicines called cytotoxic drugs. Cytotoxic medicines are poisonous (toxic) to cancer cells. They kill cancer cells or stop them from multiplying. Different cytotoxic medicines do this in different ways. However, they all tend to work by interfering with some aspect of how the cells divide and multiply. Two or more cytotoxic medicines are often used in a course of chemotherapy, each with a different way of working. This may give a better chance of success than using only one. There are many different cytotoxic medicines used in the treatment of cancer. In each case the one (or ones) chosen will depend on the type and stage of your cancer. Interestingly, there are several statements along the lines of ‘Cytotoxic medicines work best in cancers where the cancer cells are rapidly dividing and multiplying’, a key issue with lower grade NETs.
Well known chemotherapy treatments for NETs include (but are not limited to): Capecitabine (Xeloda), Temozolomide (Temodal), Fluorouracil (5-FU), Oxaliplatin (Eloxatin) Cisplatin, Etoposide (Etopophos, Vepesid), Carboplatin, Streptozotocin (Zanosar). Some of these may be given as a combination treatment, e.g. CAPecitabine and TEMozolomide (CAPTEM).
In the past, any medication used to treat cancer was regarded as chemotherapy. However, over the last 20 years, new types of medication that work in a different way to chemotherapy have been introduced. Many of these new types of medication are known as targeted therapies. This is because they’re designed to target and disrupt one or more of the biological processes that cancerous cells use to grow and reproduce. They are classed as biological therapy. In contrast, chemotherapy medications are mostly systemic in nature and designed to have a poisonous effect on cancerous cells, thus the term ‘cytotoxic’.
The following well known NETs treatment are not really chemotherapy and describing them in this way is not only misleading but may actually cause alarm to other patients. Furthermore, if you check any authoritative NET Cancer specialist or advocate organisation; any general and authoritative cancer site or the manufacturer’s websites; you will not see the drugs below listed within the term chemotherapy.
Somatostatin Analogues e.g. Sandostatin (Octreotide), Somatuline (Lanreotide). Although these drugs have an anti-cancer effect for some, they are in fact hormone inhibitors and are therefore a hormone therapy.
Everolimus (Afinitor). This is a targeted biological therapy or more accurate a mammalian target of rapamycin (mTOR) inhibitor. It is a type of treatment called a signal transduction inhibitor. Signal transduction inhibitors stop some of the signals within cells that make them grow and divide. Everolimus stops a particular protein called mTOR from working properly. mTOR controls other proteins that trigger cancer cells to grow. So everolimus helps to stop the cancer growing or may slow it down.
Sunitinib (Sutent). This is a targeted biological therapy or more accurate a protein (or tyrosine) kinase inhibitor. Protein kinase is a type of chemical messenger (an enzyme) that plays a part in the growth of cancer cells. Sunitinib blocks the protein kinase to stop the cancer growing. It can stop the growth of a tumour or shrink it down.
I can only speculate why some of the confusion exists but I do have some personal experience I can quote too. Firstly I believe it could be easier for some people to describe the new agents as ‘chemotherapy’ rather than explain things such as somatostatin analogues, ‘mammalian target of rapamycin (mTOR) inhibitors’, protein kinase inhibitor or angiogenesis inhibitors. Another reason could be that health insurance companies do not have the correct database structures in place on their IT systems and therefore need to ‘pigeon hole’ drugs into the closest category they can see. Often this is chemotherapy and this only adds to the confusion. In the days when I had health insurance, my Lanreotide injections were coded as chemotherapy on all my bills. I challenged it and this is how they explained the issue.
In the last 12-24 months, there seems to have been announcement after announcement of new and/or upgraded/enhanced diagnostics and treatment types for Neuroendocrine Cancer. Scans, radionuclide therapies, combination therapies, somatostatin analogues, biological therapies, etc. Some of the announcements are just expansions of existing therapies having been approved in new (but significant) regions. Compared to some other cancers, even those which hit the headlines often, we appear to be doing not too badly. However, the pressure needs to stay on, all patients need access to the best diagnostics and treatments for them; and at the requisite time.There’s even more in the pipeline and I’m hoping to continue to bring you news of new stuff as I have been doing for the last year.
Some of these new diagnostics and treatments will benefit eligible patients who are in diagnosis/newly diagnosed and also those living with the disease. As we’re now in our awareness month, let’s recap:
Many NET Patients will undergo a nuclear scan to confirm CT results and/or to detect further neuroendocrine activity. Basically, a nuclear substance is mixed with a somatostatin analogue, injected into the patient who is then scanned using a 360-degree gamma camera. As gamma cameras are designed to show up radioactive activity; and as Neuroendocrine Tumour cells will bind to the somatostatin analogue, it follows that the pictures provided will show where Neuroendocrine tumours are located. Many people will have had an ‘Octreotide’ Scan (or more formally – Somatostatin Receptor Scintigraphy) which is still the gold standard in many areas. The latest generation of nuclear scans is based on the platform of the Gallium (Ga) 68 PET Scan. The principles of how the scan works is essentially as described above except that the more efficient radioactive/peptide mix and better scan definition, means a much better picture providing more detail (see example below). It’s important to note that positive somatostatin receptors are necessary for both scans to be effective. Europe and a few other areas have been using the Ga-68 PET scans for some time (although they are still limited in availability by sparse deployment). The latest excitement surrounding this new scan is because they are currently being rolled out in USA. Read about the US FDA approval here. You may hear this scan being labelled as ‘NETSPOT’ in USA but this is technically the name for the preparation radiopharmaceutical kit for the scan which includes a single-dose injection of the organic peptide and the radionuclide material. Take a look at a comparison of both scans here:
This slide from a recent NET Research Foundation conference confirms the power of more detailed scanning.
Peptide Receptor Radionuclide Therapy (PRRT)
Similar to above, this treatment has been in use in Europe and other places for some time but is also to be formally deployed in USA if, as is expected, the US FDA approval is positive at the end of this year (Read here). In the most basic terms, this is a treatment whereby a peptide is mixed with a radionuclide and is drip fed over a number of treatments (normally up to 4 spaced out over a year). The concept of delivery of the ‘payload’ to the tumours is actually very similar to the preparation for a radionuclide scan as described above, the key difference is the dosage and length of exposure whilst the tumours are attacked. Once again, receptors are important. The NETTER series of trials showed good results and this is an excellent addition to the portfolio for those patients who are eligible for this treatment. Fingers crossed for the US FDA announcement due by the end of this year. Also fingers crossed that PRRT returns to the NHS England & Wales portfolio of available treatments next year. The Carcinoid Cancer Foundation has an excellent summary of PRRT here.
PRRT and Chemo Combo
Whilst on this subject, I also want to highlight the innovative use of combo therapies in Australia where they are combining PRRT and Chemo (PRCRT). I blogged about this here:
Somatostatin Analogues and their Delivery Systems
Somatostatin analogues are a mainstay treatment for many NET Patients. These drugs target NET cell receptors which has the effect of inhibiting release of certain hormones which are responsible for some of the ‘syndromic’ effects of the disease. Again, receptors are important for the efficacy of this treatment. You can read the ‘geeky’ stuff on how they work here. These drugs mainly comprise Octreotide (provided by Novartis) and Lanreotide (provided by Ipsen). The latter has been around in Europe for 10 years and was introduced to North America earlier this year. Octreotide has been around for much longer, almost 17 years. When you consider these peptides have also been used to support nuclear scans that can detect the presence of tumours; and that studies have shown they also have an anti-tumour effect, they really are an important treatment for many NET Patients. I’ve blogged about new somatostatin analogues in the pipeline and you can read this here. This blog also contains information about new delivery systems including the use of oral capsules and nasal sprays (…….. very early days though).
Treatment for Carcinoid Syndrome
For maintenance and quality of life, the release of a Telotristat Ethyl for Carcinoid Syndrome is an exciting development as is the first new treatment for Carcinoid Syndrome in 17 years. This is a drug which is taken orally and inhibits the secretion of serotonin which causes some of the symptoms of the syndrome including diarrhea. It must be emphasised it’s only for treating diarrhea caused by syndrome and might not be effective for diarrhea caused by other factors including surgery. Read about how it works and its target patient group in my blog here.
The announcement of a clinical trial for the Oncolytic Virus (an Immunotherapy treatment)specifically for Neuroendocrine Tumours is also very exciting and offers a lot of hope. Click the photo for the last progress update.
Earlier this year, AFINITOR became the first treatment approved for progressive, non-functional NETs of lung origin, and one of very few options available for progressive, non-functional GI NET, representing a shift in the treatment paradigm for these cancers. It’s been around for some time in trials (the RADIANT series) and is also used to treat breast and kidney cancer. It’s manufactured by Novartis (of Octreotide fame). It has some varying side effects but these appear to be tolerable for most and as with any cancer drug, they need to weighed against the benefits they bring.
In technical terms, AFINITOR is a type of drug known as an ‘mTOR’ inhibitor (it’s not a chemo as frequently stated on NET patient forums). Taken in tablet form, it works by blocking the mTOR protein. In doing so, AFINITOR helps to slow blood vessels from feeding oxygen and nutrients to the tumour.
Check out Novartis Afinitor website for more detailed information. There’s an excellent update about AFINITOR rom NET expert Dr James Yao here. The US FDA approval can be found here.
………. and relax! Wow, I’ve surprised myself by collating and revising the last 12-24 months. Dr James Yao also agrees – check out his upbeat message in the attached2 page summary. You may also like another upbeat message from Dr Jonathan Strosberg by clicking here.
Neuroendocrine Cancer – who’d have thought it? ….. a bit of a dark horse.
Thanks for reading
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