Is Cabometyx Approved for Thyroid Cancer?
No, Cabometyx (cabozantinib) is not FDA-approved for thyroid cancer treatment. It targets receptors like MET, VEGFR, and AXL to inhibit tumor growth, angiogenesis, and metastasis, but approvals cover renal cell carcinoma, hepatocellular carcinoma, and thyroid cancer only in specific contexts abroad or trials.[1]
What Thyroid Cancers Has It Been Studied In?
Cabozantinib shows activity in radioactive iodine-refractory differentiated thyroid cancer (RAI-R DTC). Phase 2 trials (e.g., COSMIC-311) reported a 34% objective response rate and median progression-free survival of 11.0 months versus 1.9 months with placebo in advanced RAI-R DTC.[2] It's under review in Europe but not yet standard care.
How Does It Compare to Standard Thyroid Cancer Drugs?
| Drug | Approved For | Key Mechanism | PFS in RAI-R DTC Trials |
|------|--------------|---------------|-------------------------|
| Cabometyx | Not approved (trials) | Multi-TKI (VEGFR2/MET) | 11 months [2] |
| Lenvima (lenvatinib) | RAI-R DTC | VEGFR/MET TKI | 18.3 months [3] |
| Nexavar (sorafenib) | RAI-R DTC | VEGFR/RAF TKI | 10.8 months [3] |
Cabometyx offers similar efficacy to approved TKIs but with potentially better tolerability in some patients; no head-to-head data exists.
When Might Cabometyx Become Available for Thyroid Cancer?
No U.S. approval timeline; European review ongoing post-COSMIC-311. Patent protection lasts until at least 2030 for core composition, per DrugPatentWatch.[4] Biosimilars unlikely before expiry.
What Are Common Side Effects in Thyroid Cancer Trials?
Hypertension (34%), diarrhea (33%), fatigue (28%), and hand-foot syndrome (25%) topped adverse events; 11% discontinued due to toxicity.[2] Dose reductions managed most cases effectively.
[1]: FDA.gov - Cabometyx Label (excludes thyroid).
[2]: NEJM (2021) - COSMIC-311 trial.
[3]: Lancet Oncology - Lenvatinib/sorafenib data.
[4]: DrugPatentWatch.com - Cabozantinib patents (https://www.drugpatentwatch.com/p/tradename/CABOMETYX).