NCI Support for Basic Science Paves Way for Kidney Cancer Drug Belzutifan
Posted on by Norman "Ned" Sharpless, M.D., National Cancer Institute
There’s exciting news for people with von Hippel-Lindau (VHL) disease, a rare genetic disorder that can lead to cancerous and non-cancerous tumors in multiple organs, including the brain, spinal cord, kidney, and pancreas. In August 2021, the U.S. Food and Drug Administration (FDA) approved belzutifan (Welireg), a new drug that has been shown in a clinical trial led by National Cancer Institute (NCI) researchers to shrink some tumors associated with VHL disease , which is caused by inherited mutations in the VHL tumor suppressor gene.
As exciting as this news is, relatively few people have this rare disease. The greater public health implication of this advancement is for people with sporadic, or non-inherited, clear cell kidney cancer, which is by far the most common subtype of kidney cancer, with more than 70,000 cases and about 14,000 deaths per year. Most cases of sporadic clear cell kidney cancer are caused by spontaneous mutations in the VHL gene.
This advancement is also a great story of how decades of support for basic science through NCI’s scientists in the NIH Intramural Research Program and its grantees through extramural research funding has led to direct patient benefit. And it’s a reminder that we never know where basic science discoveries might lead.
Belzutifan works by disrupting the process by which the loss of VHL in a tumor turns on a series of molecular processes. These processes involve the hypoxia-inducible factor (HIF) transcription factor and one of its subunits, HIF-2α, that lead to tumor formation.
The unraveling of the complex relationship among VHL, the HIF pathway, and cancer progression began in 1984, when Bert Zbar, Laboratory of Immunobiology, NCI-Frederick; and Marston Linehan, NCI’s Urologic Oncology Branch, set out to find the gene responsible for clear cell kidney cancer. At the time, there were no effective treatments for advanced kidney cancer, and 80 percent of patients died within two years.
Zbar and Linehan started by studying patients with sporadic clear cell kidney cancer, but then turned their focus to investigations of people affected with VHL disease, which predisposes a person to developing clear cell kidney cancer. By studying the patients and the genetic patterns of tumors collected from these patients, the researchers hypothesized that they could find genes responsible for kidney cancer.
Linehan established a clinical program at NIH to study and manage VHL patients, which facilitated the genetic studies. It took nearly a decade, but, in 1993, Linehan, Zbar, and Michael Lerman, NCI-Frederick, identified the VHL gene, which is mutated in people with VHL disease. They soon discovered that tumors from patients with sporadic clear cell kidney cancer also have mutations in this gene.
Subsequently, with NCI support, William G. Kaelin Jr., Dana-Farber Cancer Institute, Boston, discovered that VHL is a tumor suppressor gene that, when inactivated, leads to the accumulation of HIF.
Another NCI grantee, Gregg L. Semenza, Johns Hopkins School of Medicine, Baltimore, identified HIF as a transcription factor. And Peter Ratcliffe, University of Oxford, United Kingdom, discovered that HIF plays a role in blood vessel development and tumor growth.
Kaelin and Ratcliffe simultaneously showed that the VHL protein tags a subunit of HIF for destruction when oxygen levels are high. These results collectively answered a very old question in cell biology: How do cells sense the intracellular level of oxygen?
Subsequent studies by Kaelin, with NCI’s Richard Klausner and Linehan, revealed the critical role of HIF in promoting the growth of clear cell kidney cancer. This work ultimately focused on one member of the HIF family, the HIF-2α subunit, as the key mediator of clear cell kidney cancer growth.
The fundamental work of Kaelin, Semenza, and Ratcliffe earned them the 2019 Nobel Prize in Physiology or Medicine. It also paved the way for drug discovery efforts that target numerous points in the pathway leading to clear cell kidney cancer, including directly targeting the transcriptional activity of HIF-2α with belzutifan.
Clinical trials of belzutifan, including several supported by NCI, demonstrated potent anti-cancer activity in VHL-associated kidney cancer, as well as other VHL-associated tumors, leading to the aforementioned recent FDA approval. This is an important development for patients with VHL disease, providing a first-in-class therapy that is effective and well-tolerated.
We believe this is only the beginning for belzutifan’s use in patients with cancer. A number of trials are now studying the effectiveness of belzutifan for sporadic clear cell kidney cancer. A phase 3 trial is ongoing, for example, to look at the effectiveness of belzutifan in treating people with advanced kidney cancer. And promising results from a phase 2 study show that belzutifan, in combination with cabozantinib, a widely used agent to treat kidney cancer, shrinks tumors in patients previously treated for metastatic clear cell kidney cancer .
This is a great scientific story. It shows how studies of familial cancer and basic cell biology lead to effective new therapies that can directly benefit patients. I’m proud that NCI’s support for basic science, both intramurally and extramurally, is making possible many of the discoveries leading to more effective treatments for people with cancer.
 Belzutifan for Renal Cell Carcinoma in von Hippel-Lindau Disease. Jonasch E, Donskov F, Iliopoulos O, Rathmell WK, Narayan VK, Maughan BL, Oudard S, Else T, Maranchie JK, Welsh SJ, Thamake S, Park EK, Perini RF, Linehan WM, Srinivasan R; MK-6482-004 Investigators. N Engl J Med. 2021 Nov 25;385(22):2036-2046.
 Phase 2 study of the oral hypoxia-inducible factor 2α (HIF-2α) inhibitor MK-6482 in combination with cabozantinib in patients with advanced clear cell renal cell carcinoma (ccRCC). Choueiri TK et al. J Clin Oncol. 2021 Feb 20;39(6_suppl): 272-272.
Von Hippel-Lindau Disease (Genetic and Rare Diseases Information Center/National Center for Advancing Translational Sciences/NIH)
Clear Cell Renal Cell Carcinoma (National Cancer Institute/NIH)
Belzutifan Approved to Treat Tumors Linked to Inherited Disorder VHL, Cancer Currents Blog, National Cancer Institute, September 21, 2021.
The Long Road to Understanding Kidney Cancer (Intramural Research Program/NIH)
[Note: Acting NIH Director Lawrence Tabak has asked the heads of NIH’s institutes and centers to contribute occasional guest posts to the blog as a way to highlight some of the cool science that they support and conduct. This is the first in the series of NIH institute and center guest posts that will run until a new permanent NIH director is in place.]
Precision Oncology: Gene Changes Predict Immunotherapy Response
Posted on by Dr. Francis Collins
There’s been tremendous excitement in the cancer community recently about the life-saving potential of immunotherapy. In this treatment strategy, a patient’s own immune system is enlisted to control and, in some cases, even cure the cancer. But despite many dramatic stories of response, immunotherapy doesn’t work for everyone. A major challenge has been figuring out how to identify with greater precision which patients are most likely to benefit from this new approach, and how to use that information to develop strategies to expand immunotherapy’s potential.
A couple of years ago, I wrote about early progress on this front, highlighting a small study in which NIH-funded researchers were able to predict which people with colorectal and other types of cancer would benefit from an immunotherapy drug called pembrolizumab (Keytruda®). The key seemed to be that tumors with defects affecting the “mismatch repair” pathway were more likely to benefit. Mismatch repair is involved in fixing small glitches that occur when DNA is copied during cell division. If a tumor is deficient in mismatch repair, it contains many more DNA mutations than other tumors—and, as it turns out, immunotherapy appears to be most effective against tumors with many mutations.
Now, I’m pleased to report more promising news from that clinical trial of pembrolizumab, which was expanded to include 86 adults with 12 different types of mismatch repair-deficient cancers that had been previously treated with at least one type of standard therapy . After a year of biweekly infusions, more than half of the patients had their tumors shrink by at least 30 percent—and, even better, 18 had their tumors completely disappear!
A Surprising Match: Cancer Immunotherapy and Mismatch Repair
Posted on by Dr. Francis Collins
Mismatch repair genes have long been a source of fascination to basic biologists. Normally, these genes serve to fix the small glitches that occur when DNA is copied as cells divide. Most of the original work was done in bacteria, with no expectation of medical relevance. But, as often happens, basic science studies can provide a profoundly important foundation for advances in human health. The relevance of mismatch repair to cancer was dramatically revealed in 1993, when teams led by Bert Vogelstein of Johns Hopkins University School of Medicine, Baltimore, and Richard Kolodner, then of Harvard Medical School, Boston, discovered that mutations in human mismatch repair genes play a key role in the development of certain forms of colorectal cancer [1, 2].
That discovery has led to the ability to identify individuals who have inherited misspellings in these mismatch repair genes and are at high risk for colorectal cancer, providing an opportunity to personalize screening by starting colonoscopy at a very early age and, thereby, saving many lives. But now a new consequence of this work has appeared. Vogelstein and his colleagues report that mismatch repair research may help fight cancer in a way that few would have foreseen two decades ago: predicting which cancer patients are most likely to respond to a new class of immunotherapy drugs, called anti-programmed death 1 (PD-1) inhibitors.