
Small tumours – big impact
In oncology, a “small” tumour generally refers to a mass that is 2cm or less in diameter. Tumours under 1 cm are often described as
Von Hippel-Lindau disease (VHL) is an autosomal dominant disease that can predispose individuals to multiple neoplasms. Germline pathogenic variants in the VHL gene predispose individuals to specific types of benign tumors, malignant tumors, and cysts in many organ systems. These include central nervous system hemangioblastomas; retinal hemangioblastomas; clear cell renal cell carcinomas and renal cysts; pheochromocytomas, cysts, cystadenomas, and neuroendocrine tumors of the pancreas; endolymphatic sac tumors; and cystadenomas of the epididymis.
It is an oral hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor. As an inhibitor of HIF-2α, belzutifan reduces transcription and expression of HIF-2α target genes associated with cellular proliferation, angiogenesis and tumor growth.
On August 13 2021, FDA approved belzutifan (Welireg) to treat adults who have several tumors associated with VHL. Specifically, the drug is approved to treat VHL-associated renal cell carcinoma (a type of kidney cancer), central nervous system hemangioblastomas (a type of noncancerous tumor that forms in the brain or spinal cord), and pancreatic neuroendocrine tumors that don’t require immediate surgery.
This is the first US FDA approved treatment for VHL
Those who know the linkages between pheo/para and VHL will have spotted that was missed from the FDA approval wording. I have no idea at this time but will continue researching to see why the drug was not suitable/approved for this associated tumour group. According to the US NIH, approximately 10% to 20% of people with VHL will develop pheochromocytoma.
(But see related clinical trial information below).
This question actually came up in my private patient group. It’s a great question.
(But see related clinical trial information below).
Given the VHL linkages above to both of these groups of NETs, clearly scientists are looking to see if this drug has any efficacy in sporadic versions.
Just as Belzutifan was about to be approved, a new clinical trial was scheduled under ClinicalTrials.gov Identifier: NCT04924075. The key difference is that this trial is to evaluate the efficacy and safety of Belzutifan monotherapy in participants with advanced pheo/para and pNET or von Hippel-Lindau (VHL) Disease-Associated Tumors in 3 different cohorts. The third cohort for VHL will also include VHL related pheo/para and pNET patients. The primary objective of the study is to evaluate the objective response rate (ORR) of belzutifan per RECIST 1.1) by blinded independent central review (BICR).
This is an international trial taking place in many European, North American and Asian countries.
It would provide another outlet for treatment of sporadic Pancreatic NET and Pheo/Para. But it would also add Pheo/Para to the VHL associated approvals list.
1. FDA Approval of Belzutifan – click here
2. ClinicalTrials.gov Identifier: Belzutifan/MK-6482 for the Treatment of Advanced Pheochromocytoma/Paraganglioma (PPGL), Pancreatic Neuroendocrine Tumor (pNET), or Von Hippel-Lindau (VHL) Disease-Associated Tumors (MK-6482-015) – Full Text View – ClinicalTrials.gov
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 in the clinical trials document. It’s very important to check the trial inclusion and exclusion criteria before making any contact. If you need questions, the articles here is very useful Questions to Ask About Clinical Trials | Cancer.Net
The inclusion of any trial within this blog should not be taken as a recommendation by Ronny Allan.
I am not a doctor or any form of medical professional, practitioner or counsellor. None of the information on my website, or linked to my website(s), or conveyed by me on any social media or presentation, should be interpreted as medical advice given or advised by me. Neither should any post or comment made by a follower or member of my private group be assumed to be medical advice, even if that person is a healthcare professional as they are not members of the private group or followers of my sites in any official capacity. Please also note that mention of a clinical service, trial/study or therapy does not constitute an endorsement of that service, trial/study or therapy by Ronny Allan, the information is provided for education and awareness purposes and/or related to Ronny Allan’s own patient experience. This element of the disclaimer includes any complementary medicine, non-prescription over the counter drugs and supplements such as vitamins and minerals.
Whenever I post about a trial or study, some people get excited without understanding that these new treatments and capabilities can very often take years to come to fruition and it’s also possible that clinical trials can be halted, or that national approval agencies will not approve the final product. Plus, not everyone will be eligible, so always check the exclusion and inclusion criteria in the relevant clinical trials document. Please bear that in mind when reading studies/clinical trials posted on RonnyAllan.NET
Thanks for reading.
I’m also active on Facebook. Like my page for even more news. Help me build up my new site here – click here and ‘Like’
Sign up for my newsletters – Click Here
My Diagnosis and Treatment History
Check out my online presentations
Check out my WEGO Health Awards
Like my new awareness page – click here or on the photo. (Like rather than follow please!)


In oncology, a “small” tumour generally refers to a mass that is 2cm or less in diameter. Tumours under 1 cm are often described as

“Invisible cancer” typically refers to malignancies that evade early detection or disguise themselves as other common, non-life-threatening ailments. This term is very frequently associated with

Disclaimer: The information in this Spotlight is provided for general information and education only. It is not intended to replace the advice of a

Just back from holiday thus why the late publication! Summary of May 2026 on RonnyAllan.NET I think the main story of May is similar to March and

This blog provides general educational information only. It does not offer medical advice, diagnosis, or treatment. Patients should always consult their clinical team for personalised

Before you read thisThis information is designed to help you understand how vitamins work in the body and how certain NET-related factors might affect them.

🟧A general‑population overview with NET‑specific considerations where relevant. Disclaimer: This Spotlight provides general educational information about Vitamin E. It is not a substitute for medical

Disclaimer: This Spotlight provides general educational information about Vitamin A. It is not a substitute for medical advice. Individual needs vary, particularly for those with

Disclaimer: Educational and advocacy content only. Not a substitute for medical advice. Two hundred injections. It’s a milestone that carries weight — not because of
Subscribe to get the latest posts sent to your email.
Subscribe now to keep reading and get access to the full archive.