Cabometyx (Cabozantinib-S-Malate): Uses, Side Effects & Warnings

Key Takeaways

• Cabometyx is FDA-approved for advanced renal cell carcinoma (RCC) and hepatocellular carcinoma (HCC) in specific patient populations.
• It works by blocking multiple receptor tyrosine kinases that drive tumor growth and blood vessel formation.
• Common side effects include diarrhea, fatigue, nausea, and hand-foot syndrome; serious risks include hemorrhage and perforations.
• The drug carries important warnings related to hypertension, blood clots, wound healing complications, and embryo-fetal toxicity.
• Patients should follow prescriber guidance closely and report any unusual symptoms immediately.

What Is Cabometyx (Cabozantinib-S-Malate) Used For?

Cabometyx is a kinase inhibitor that targets multiple receptor tyrosine kinases, including MET, VEGFR-1, VEGFR-2, VEGFR-3, AXL, and RET. These proteins play key roles in tumor cell proliferation, angiogenesis (the formation of new blood vessels that feed tumors), and metastasis. By inhibiting them simultaneously, the drug disrupts the signaling pathways that allow cancer cells to grow and spread.

The FDA has approved Cabometyx for several oncology indications. It is indicated as a first- or second-line treatment for adults with advanced renal cell carcinoma (RCC), which is the most common type of kidney cancer. According to the American Cancer Society, approximately 81,800 new cases of kidney cancer are estimated in the United States in 2023 alone, making RCC a significant public health concern. Cabometyx is also approved—often in combination with nivolumab—for previously untreated intermediate- or poor-risk advanced RCC.

Beyond kidney cancer, the drug is indicated for adults with hepatocellular carcinoma (HCC) who have previously received sorafenib. HCC is the most common form of primary liver cancer and represents one of the leading causes of cancer-related death worldwide, according to the World Health Organization (WHO). In both settings, Cabometyx addresses a critical unmet need by offering patients a targeted therapeutic option when other treatments have failed or are insufficient.

Cabometyx (Cabozantinib-S-Malate) Dosage and Drug Information

Cabometyx drug information and dosage guidance depends on the specific indication and whether the drug is used alone or in combination. For advanced RCC as a monotherapy, the standard recommended dose is 60 mg taken orally once daily. When used in combination with nivolumab for first-line treatment of advanced RCC, the recommended dose is reduced to 40 mg once daily. For HCC, the approved monotherapy dose is 60 mg once daily.

The tablets should be taken on an empty stomach—patients should avoid eating for at least two hours before and one hour after taking the medication. Grapefruit and grapefruit juice should also be avoided, as they can interfere with drug metabolism via the CYP3A4 enzyme pathway, potentially altering drug levels in the blood. If a dose is missed, patients should skip it and resume the next scheduled dose rather than doubling up.

Dose reductions to 40 mg and then 20 mg may be necessary in response to toxicity or drug interactions. Strong CYP3A4 inducers—such as rifampin, phenytoin, and certain anticonvulsants—can significantly reduce cabozantinib plasma concentrations, while strong CYP3A4 inhibitors can increase them. Prescribers adjust dosing accordingly to maintain therapeutic efficacy while minimizing risk. Cabometyx is supplied as film-coated tablets in 20 mg, 40 mg, and 60 mg strengths, and the tablet should never be crushed or divided.

Common and Serious Side Effects of Cabozantinib

Cabometyx cabozantinib side effects range from manageable to potentially life-threatening, and patients should be aware of both categories before starting treatment. The most frequently reported side effects in clinical trials include diarrhea, fatigue, nausea, decreased appetite, palmar-plantar erythrodysesthesia (also known as hand-foot syndrome), and hypertension. These are generally manageable with supportive care, dose modification, or both.

Cabozantinib side effects in kidney cancer patients have been well characterized through large clinical trials such as the METEOR and CABOSUN studies. In the METEOR trial, diarrhea occurred in approximately 74% of patients, fatigue in 56%, and hand-foot syndrome in 42%. These figures underscore the importance of proactive symptom management and regular communication with the treating oncologist to prevent treatment discontinuation due to tolerability issues.

Serious adverse events require prompt medical attention and may necessitate dose interruption or permanent discontinuation. These include:

• Hemorrhage: Severe and sometimes fatal bleeding events, including hemoptysis and gastrointestinal bleeding, have been reported.
• Gastrointestinal perforations and fistulas: Abnormal connections or holes in the gastrointestinal tract can develop during therapy.
• Thrombotic events: Arterial thromboembolic events, including myocardial infarction and stroke, have occurred.
• Hepatotoxicity: Elevated liver enzymes and, rarely, liver failure have been observed, particularly in patients receiving the nivolumab combination.
• Proteinuria: Significant protein in the urine may indicate kidney damage and warrants monitoring.
• Osteonecrosis of the jaw: A rare but serious complication affecting bone health in the jaw.

Patients should report any signs of unusual bleeding, severe abdominal pain, neurological changes, or jaw pain to their healthcare provider without delay. Routine laboratory monitoring—including liver function tests, blood pressure measurements, and urinalysis—is an integral part of safe Cabometyx therapy management.

Cabometyx Warnings, Precautions, and Safety Considerations

Cabometyx warnings and precautions are extensive and reflect the drug’s potent mechanism of action across multiple biological pathways. The FDA label includes several serious boxed or highlighted warnings that clinicians and patients must understand before initiating therapy. These safety considerations are not theoretical; they are based on documented adverse events observed in controlled clinical trials and post-marketing surveillance.

One of the most significant precautions involves wound healing complications. Cabometyx inhibits VEGF signaling, which is essential for normal wound repair. As a result, the drug should be withheld for at least 28 days before elective surgery and should not be restarted until adequate wound healing has been confirmed. Similarly, the drug should be discontinued in patients who develop wound dehiscence or complications that require medical intervention.

Hypertension is a common and medically important concern associated with Cabometyx. Blood pressure should be well controlled before starting treatment and monitored regularly throughout therapy. If hypertension cannot be adequately managed with antihypertensive agents, dose reduction or discontinuation may be necessary. Severe hypertension or hypertensive crisis requires immediate intervention.

Embryo-Fetal Toxicity and Reproductive Risks

Cabometyx serious warnings include a clear caution about embryo-fetal toxicity. The drug can cause fetal harm when administered to pregnant women based on its mechanism of action and findings from animal studies. Women of reproductive potential must use effective contraception during treatment and for four months following the final dose. Male patients with female partners of reproductive potential should also use contraception during therapy and for three months after the last dose. Breastfeeding is not recommended during treatment or for four months after discontinuation.

Drug Interactions and Special Populations

Patients with hepatic impairment require careful evaluation before starting Cabometyx. A reduced starting dose of 40 mg is recommended for those with mild to moderate hepatic impairment, while use in patients with severe hepatic impairment is not recommended. Renal impairment does not require routine dose adjustment, but patients with severe renal impairment should be monitored closely. Older adults (aged 65 and above) may experience a higher frequency of adverse reactions, and their overall health status, comorbidities, and polypharmacy burden should be factored into prescribing decisions. Patients should also disclose all herbal supplements and over-the-counter products to their provider, as St. John’s Wort, for example, can reduce cabozantinib efficacy as a CYP3A4 inducer.

Frequently Asked Questions

Can Cabometyx be taken with food?

No. Cabometyx should be taken on an empty stomach. Patients are advised to avoid eating for at least two hours before and one hour after each dose. Food—especially a high-fat meal—can significantly increase cabozantinib exposure, which may raise the risk of adverse effects. Grapefruit products should also be avoided throughout treatment, as they inhibit the CYP3A4 enzyme responsible for metabolizing the drug, leading to higher-than-intended drug concentrations.

How long does a patient typically take Cabometyx?

Treatment with Cabometyx continues for as long as the patient is experiencing clinical benefit and the side effects remain tolerable and manageable. There is no predefined maximum duration. However, disease progression, unacceptable toxicity, or the patient’s decision to discontinue treatment are common reasons for stopping therapy. Your oncologist will monitor response through imaging and laboratory tests and adjust the treatment plan based on individual clinical outcomes.

Is Cabometyx safe for patients with liver problems?

Cabometyx can be used in patients with mild to moderate hepatic impairment with a dose reduction to 40 mg once daily. It is not recommended for patients with severe hepatic impairment due to insufficient safety and pharmacokinetic data. Additionally, Cabometyx itself can cause hepatotoxicity, so liver function tests should be monitored regularly during treatment. Patients who develop significant liver enzyme elevations may need dose interruption, reduction, or permanent discontinuation depending on severity.