FDA Approval Brings Hope for Patients With Rare Neuroendocrine Tumors
It’s a diagnosis few people expect, and even fewer may recognize: a neuroendocrine tumor.
This group of rare cancers can be slow-growing, hard to detect and even harder to treat once the cancer has spread. But thanks to a national clinical trial led in part by Moffitt Cancer Center, patients with neuroendocrine tumors have a powerful tool to fight back.
In March 2025, the Food and Drug Administration approved Cabometyx for adults and adolescents as young as 12 with previously treated advanced, hard-to-remove or metastatic neuroendocrine tumors.
Moffitt was the top-enrolling site in the phase 3 trial that helped secure the approval.
“This is a very rare cancer, so it takes a long time to accrue patients,” said Jonathan Strosberg, MD, leader of Moffitt’s Neuroendocrine Tumor Division and the Gastrointestinal Oncology Department Research Program. “But ultimately, over 300 patients were accrued across multiple institutions, and Moffitt played a big role.”
Understanding Neuroendocrine Tumors
Neuroendocrine tumors can form almost anywhere in the body but are most common in the pancreas, gastrointestinal tract or lungs. Some grow slowly and cause few symptoms, while others can be aggressive and difficult to control.
“The annual incidence of neuroendocrine tumors as a whole is probably about 6 per 100,000,” Strosberg said. “But when we talk about patients with metastatic disease — especially advanced, progressive disease — the numbers are smaller.”
For patients with metastatic neuroendocrine tumors, treatment options have been limited. That’s why the FDA approval of Cabometyx for this type of cancer is so important.
Strong Results
Cabometyx isn’t new to the world of cancer. It has been used to treat kidney, liver and thyroid cancers.
“Cabometyx, the brand name, or the generic name, cabozantinib, is an oral pill that works by blocking several key proteins that help tumors grow and spread,” Strosberg explained. “It targets the VEGF receptor, which promotes angiogenesis — tumoral blood vessel growth — and other receptors like MET and AXL, which are involved in cancer progression.”
The FDA approval is significant because it’s the first time an angiogenesis targeting drug has been approved for neuroendocrine tumors outside the pancreas.
“This is the first time we’ve had a drug like this approved for tumors that originate in the gastrointestinal tract or lungs,” Strosberg said. “It covers a broad range of neuroendocrine tumors, and the results were positive.”
The phase 3 trial, known as CABINET, showed that Cabometyx significantly delayed tumor growth.
For patients with pancreatic neuroendocrine tumors, the drug held off cancer progression for 14 months on average. For patients with tumors outside the pancreas, the drug added about four extra months before the cancer worsened.
“The drug substantially prolonged progression-free survival, which is important,” Strosberg said. “That’s usually the primary endpoint for neuroendocrine tumor trials.”
Researchers believe the drug likely helps patients live longer, but more research is needed.
“We think it probably improves overall survival duration, but we just don’t have sufficient numbers and statistical power to prove that,” Strosberg said.
A Convenient Option
Cabometyx is a daily pill, which can be more convenient than other treatments. But like many cancer therapies, it comes with side effects.
“Patients often experience tiredness. Sometimes they develop diarrhea or a painful rash on the hands and feet,” Strosberg said. “Many patients require dose reductions. That’s not unusual for this type of drug. So in many cases, we start at a lower than the FDA-approved dose.”
For patients at Moffitt and beyond, Cabometyx is now widely available. For Strosberg, the approval marks a significant milestone in his work with neuroendocrine tumors.
“We don’t have a lot of approved drugs for this disease,” he said. “There are only about four or five that have been FDA-approved based on good quality phase 3 trials. So, as someone who treats neuroendocrine tumors, this is a landmark event.”
