FDA oncology advisory committee to weigh Exelixis' Cabometyx in neuroendocrine tumors

Before Exelexis’ Cabometyx can pass muster with the FDA in its hopeful neuroendocrine tumors indication next April, it will have to first face the agency’s Oncologic Drugs Advisory Committee (ODAC) in March 2025.

An ODAC panel of external experts will go over the final results of Cabometyx’s phase 3 CABINET trial in previously treated advanced pancreatic neuroendocrine tumors (pNET) and advanced extra-pancreatic neuroendocrine tumors (epNET), which form the basis of Exelixis’ approval bid, the company disclosed in a release. Upon assigning the company a target decision date of April 3, 2025, the FDA also granted the med an orphan drug designation.

In a Tuesday note, analysts at William Blair pointed to the same process neuroendocrine tumor meds Novartis’ Afinitor and Pfizer’s Sutent went through before ultimately making it to market. With the “outsized benefit” Cabometyx offers in epNETs and pNETS, the analysts remain confident that the drug will fare the same. Citi analysts agree, citing the strength of Exelixis’ phase 3 CABINET trial, which was stopped early at an interim analysis last August due to significant progression-free survival improvements.

In the 290-patient study, Cabometyx helped those in the pNET cohort live longer without their disease getting worse for a median of 11.4 months compared with just three months on placebo. In the epNET group, the therapy nearly tripled placebo’s median of 3.2 months of progression-free survival with 8.3 months. 

With few treatment options and a low survival rate for the advanced tumors, an approval stands to benefit the 161,000 to 192,000 people living with advanced NET in the U.S., according to Exelixis.

Analysts at Leerink Partners suggested in a Wednesday note that the ODAC could be tied to the drug’s safety profile or its survival analysis in the CABINET study. The strong progression-free survival analysis “did not appear to translate to a definitive survival benefit,” the analysts pointed out. 

Still, the Leerink team noted that Afinitor had an unfavorable overall survival trend in its study but ended up winning approval, suggesting that the FDA “may be willing to approve a drug in this indication irrespective of overall survival trends.” In the CABINET trial, Cabometyx at least showed numerical improvements in overall survival across pNET and epNET groups, although the size of risk reduction was much smaller compared with its showing in progression-free survival.

Cabometyx first hit the U.S. market in 2016 as a monotherapy for patients with advanced kidney cancer and has since picked up approvals in previously treated liver cancer, thyroid cancer, and again in kidney cancer as a first-line combo treatment with Bristol Myers Squibb’s Opdivo. The drug brought in U.S. revenues of $475.7 million in the third quarter.

While Exelixis awaits its advisory committee meeting, partner Ipsen is waiting on a decision in Europe after submitting the CABINET results to the European Medicines Agency in September.

Meanwhile, the pair isn’t as in synch on regulatory plans for Cabometyx’s combination with Roche’s Tecentriq in metastatic castration-resistant prostate cancer (mCRPC) after it failed to show a statistically significant overall survival benefit in a phase 3 study. While Exelixis plans to pursue a U.S. nod in that indication, Ipsen opted not to chase a nod in its territories outside the U.S. and Japan, citing an “anticipated challenging regulatory environment.”