Exelixis Shows Cabometyx Extends Progression‑Free Survival Across Neuroendocrine Tumor Subtypes

Exelixis disclosed results from a prespecified subgroup analysis of its pivotal CABINET study, which evaluated cabozantinib (CABOMETYX) versus placebo in patients with previously treated advanced NET. The trial enrolled 298 participants with pancreatic or extra‑pancreatic NET and randomized them 2:1 to receive the drug at 60 mg daily. While the overall study already demonstrated a statistically significant improvement in progression‑free survival (PFS), the new data show that this benefit is consistent regardless of whether tumors are hormone‑producing (functional) or not.

In the non‑functional cohort, cabozantinib reduced the risk of disease progression by 74% (hazard ratio 0.26, p<0.001). Median PFS more than tripled to 9.4 months compared with just 3.1 months on placebo. For functional NET—tumors that secrete hormones and cause symptoms such as flushing or diarrhea—the hazard ratio was 0.40 (p=0.012), translating into a median PFS of 12.7 months versus 5.4 months for the control arm. These figures suggest cabozantinib can both slow tumor growth and potentially alleviate hormone‑related symptom burden, an important consideration for clinicians managing complex NET cases.

From an investor perspective, the data come at a pivotal moment. Cabozantinib received FDA and EU approvals last year for previously treated advanced NET, adding to its existing indications in renal cell carcinoma, hepatocellular carcinoma, thyroid cancer, and others. The drug now holds a unique position as the only oral therapy approved for both pancreatic and extra‑pancreatic NET after prior systemic treatment. With an estimated 161,000–192,000 U.S. patients living with unresectable or metastatic NET—a population that is expanding as incidence rises—the market opportunity is sizable. Analysts note that the drug’s price point and reimbursement profile are comparable to other oral tyrosine‑kinase inhibitors, which could support steady revenue growth.

The safety profile reported in the subgroup analysis aligns with what clinicians have observed across cabozantinib’s indications. Grade 3/4 hypertension occurred in roughly one‑fifth of patients in both functional and non‑functional groups, while fatigue and diarrhea were also common but manageable with dose adjustments. No new safety signals emerged, which should allay concerns about unexpected toxicities as the indication widens.

Exelixis also highlighted its pipeline, mentioning an upcoming phase 3 STELLAR‑311 trial of zanzalintinib, an investigational oral kinase inhibitor being evaluated against everolimus in earlier‑line NET therapy. Success there could further cement Exelixis’s foothold across the treatment continuum—from first‑line to later‑line settings—potentially creating cross‑selling opportunities and enhancing overall franchise value.

In the short term, the immediate impact on EXEL's stock may be muted; the share price currently trades near $50.48, slightly below its 52‑week high, with consensus analysts targeting around $47.33. However, the data bolster the company’s narrative of delivering meaningful clinical benefit in a niche but growing oncology segment. Investors should monitor upcoming ASCO presentations for any additional efficacy or overall survival signals, as well as payer response to expanded labeling. If cabozantinib can capture even a modest share of the NET market—estimated at several hundred million dollars annually—it would add a durable revenue stream that complements Exelixis’s existing oncology portfolio.

Overall, the CABINET subgroup results provide concrete evidence that cabozantinib is effective across the heterogeneous NET landscape. This strengthens Exelixis’s competitive positioning, supports its recent approvals, and lays groundwork for future pipeline expansion—all factors that could translate into incremental earnings growth over the next few years.