Cabozantinib is a targeted therapy that blocks several proteins involved in tumour growth and blood vessel formation, including VEGFR2, MET, and AXL. In advanced non-small cell lung cancer (NSCLC), particularly in tumours with MET alterations, doctors may use it alone or combined with immunotherapy when earlier treatments stop working. Like most targeted agents, cabozantinib has predictable, drug-specific side effects. Two of the most common are hand-foot skin reaction (HFSR) and diarrhea. Both can affect quality of life and treatment adherence. Both respond well to early, consistent action.
Clinical trials have documented these reactions in detail. In the METEOR phase III trial, 74% of patients experienced diarrhea of any grade and 42% developed palmar-plantar erythrodysesthesia syndrome – the medical term for HFSR – at any grade. Both reactions are expected, not exceptional. Good caregiver support keeps reactions at Grade 1 or 2, so treatment can continue with supportive care. Catching Grade 3 severity early lets the cancer team step in.
| Axis | Hand-Foot Skin Reaction (HFSR) | Diarrhea |
|---|---|---|
| Any-grade incidence | 42% in the METEOR trial | 74% in the METEOR trial |
| Typical onset | Often within the first 2-4 weeks of treatment | Often within the first 4 weeks of treatment |
| Grade 3+ rate | Varies; blistering or ulceration signals the need for urgent care-team contact | 13% in the METEOR trial |
| First-line caregiver action | Apply urea 20% cream twice daily; use padded, well-fitting footwear | Loperamide 4 mg after first loose stool; increase clear fluid intake |
| Dose review threshold | Grade 3 or intolerable Grade 2 despite consistent skin care | Grade 3 lasting more than 3 days despite anti-diarrheal medication |
Incidence and grade data: Choueiri et al., METEOR trial (PMC5024539). Diarrhea dose-review threshold: Adverse-event management review for cabozantinib (PMC5905684).
Caregivers play a direct role in stopping these reactions from escalating. Having the right supplies at home before the first dose (thick emollient cream, loperamide, clear fluids, and well-padded footwear) means you’ll be ready when symptoms start. The sections below describe each reaction in detail and give you step-by-step guidance.
Hand-Foot Skin Reaction: What It Is and How It Progresses
HFSR with cabozantinib develops at pressure points first: the heel, the ball of the foot, and the fingertips. It forms because VEGFR inhibition disrupts the small blood vessels that supply the skin in those areas. Published reviews of cutaneous adverse effects from cabozantinib show symptoms range from mild hyperkeratosis and tingling to painful blisters and erosions in more severe cases. Meta-analysis shows HFSR in approximately 54% of patients receiving cabozantinib.
Oncologists grade HFSR using the NCI Common Terminology Criteria for Adverse Events (CTCAE):
- Grade 1: Mild tingling, numbness, or redness without significant pain. Skin may feel rough or thickened at pressure points. Daily activities are unaffected.
- Grade 2: Painful redness, swelling, or small blisters. Walking or gripping may be uncomfortable. Some daily activities are limited.
- Grade 3: Severe blistering, ulceration, or pain that prevents basic daily tasks. Treatment must be held and the care team contacted the same day.
A Daily Skin Care Routine for Caregivers
A 2024 review of skin toxicity management in cancer treatment, published in a NIH-indexed journal, recommends starting a moisturizing routine before the first dose, not after symptoms appear. Preventive steps include applying alcohol-free emollient creams, avoiding hot water on the hands and feet, wearing thick cotton socks and padded insoles, and avoiding tight footwear. Sunscreen with SPF 30 or higher on exposed skin is also advised. These steps require no prescription and can start on day one of treatment.
For Grade 1 HFSR, urea 20% cream applied twice daily is a first-line option. Clobetasol 0.05% cream once daily may be added and requires a prescription. For Grade 2, use a high-potency steroid cream alongside the urea cream, and a short course of an analgesic such as an NSAID may help with discomfort. Guidance on managing cabozantinib adverse events recommends early dermatology referral rather than waiting for symptoms to worsen – a referral at Grade 1 is better than one at Grade 3.
A practical daily checklist for caregivers:
- Inspect the soles of both feet and the palms each morning for new redness, skin thickening, or blisters.
- Apply urea cream to hands and feet after washing – pat skin dry gently, do not rub.
- Confirm footwear is well-fitted with extra cushioning at the heel and ball of foot.
- Keep wash water lukewarm and provide rubber gloves for dishwashing or cleaning tasks.
- Photograph any new skin changes with a phone and date each photo. The care team will want to see how symptoms progress between appointments.
Diarrhea on Cabozantinib: How Common and How Serious
Diarrhea is the most frequent side effect of cabozantinib. In the METEOR trial, 74% of patients experienced diarrhea of any grade and 13% had grade 3 or worse. At a starting dose of 60 mg once daily, diarrhea was severe enough to require a dose reduction in 16% of patients. Symptoms often begin within the first four weeks, making the initial month the most important time to have a management plan in place and supplies on hand.
Grading follows the same NCI CTCAE framework:
- Grade 1: Up to three extra loose stools per day above the person’s usual baseline. Manageable with diet changes and increased fluids.
- Grade 2: Four to six extra stools per day. Limits some daily activities. Loperamide and dietary adjustments are both used.
- Grade 3: Seven or more extra stools per day, incontinence, or the need for intravenous fluids. Requires same-day contact with the cancer team – do not wait for the next scheduled visit.
Managing Diarrhea: A Step-by-Step Approach
A 2025 review of gastrointestinal toxicities from targeted cancer therapies recommends starting loperamide at the first loose stool. The standard starting dose is 4 mg after the first unformed bowel movement, followed by 2 mg every two hours – or 4 mg every four hours overnight – up to a maximum of 16 mg per day. Loperamide is available without a prescription. Even so, tell the cancer team when it is being used regularly, because frequent or severe diarrhea can signal a need for dose adjustment or further evaluation.
Dietary changes that may reduce stool frequency during a diarrhea flare:
- Offer smaller, more frequent meals rather than three large ones.
- Provide low-fibre, easily digestible foods: plain rice, bananas, boiled chicken, toast, and boiled potatoes.
- Avoid raw vegetables, high-fat foods, caffeine, alcohol, and dairy until stools return to normal.
- Prioritise hydration: water, oral rehydration solutions, clear broth, and electrolyte drinks. Dehydration is the main risk when diarrhea continues for more than a day.
- Keep a daily log of stool frequency, consistency, and any blood or unusual colour. This record is essential at every clinic visit and for any telephone triage call.
Appetite loss often accompanies diarrhea in people on targeted therapy. For guidance on food strategies when appetite is already reduced, the article on managing appetite loss in advanced lung cancer covers practical approaches that can run alongside the bowel-management steps above.
Dose Modifications: What the Oncology Team May Do
Cabozantinib uses a structured dose step-down when a Grade 3 or intolerable Grade 2 toxicity does not resolve with supportive care. The standard starting dose is 60 mg once daily. If a toxicity requires action, the drug is held until the adverse event returns to Grade 1 or the person’s baseline, then restarted at the next lower level – typically 40 mg daily. A further reduction moves to 20 mg daily. Doses reduced for toxicity are not re-escalated later, even if the lower dose is well tolerated. This step-down approach is used in cabozantinib trial protocols that studied it in combination with nivolumab in recurrent Stage IV NSCLC.
Consistent caregiver management of Grade 1 and 2 reactions directly supports this strategy. Catching and treating a skin reaction or diarrhea episode before it reaches Grade 3 reduces the chance of a dose hold that interrupts treatment momentum. Your log of symptoms and photos provides the care team with the information they need to make the right call at the right time.
Patients can ask their care team about Cabotres 60 (Cabozantinib 60 mg), the standard starting-dose formulation. The dose prescribed and any reductions remain the sole decision of the treating oncologist.
When to Contact the Oncology Team Immediately
Contact your cancer team the same day if any of these occur:
- Open blisters, sores, or ulcers on the hands or feet
- Fever of 38 degrees Celsius (100.4 degrees Fahrenheit) or higher alongside diarrhea
- Seven or more loose stools per day, or any blood or black colour in the stool
- Signs of dehydration: dizziness, no urination for eight or more hours, confusion, or rapid heartbeat
- Skin changes spreading beyond the hands and feet
- Any Grade 2 or worse symptom that has not improved after 48 hours of consistent home management
Building a Home Supply Toolkit Before Treatment Starts
Having supplies ready before the first dose reduces stress when symptoms arrive. A practical caregiver toolkit for cabozantinib treatment includes: urea 20% cream (prescription), clobetasol 0.05% cream (prescription, for Grade 2 skin reactions), thick plain-cotton gloves and socks, padded insoles, alcohol-free daily hand and foot cream, loperamide 2 mg capsules, oral rehydration sachets, a digital thermometer, and a notebook or phone app to log symptoms and stool counts each day.
For background on the biomarker testing that guides whether cabozantinib is the right choice for a specific lung tumour, the article Lung Cancer Biomarkers: What Every New Patient Should Know explains how MET, RET, and VEGFR testing fits into the diagnostic workup.
Caregivers and patients planning their supply chain can see what is available in the targeted therapy category to understand what formulations are available and discuss sourcing options with their care team before treatment begins.
If the person you care for is taking other prescription medications, is pregnant, or is breastfeeding, speak with a clinician before adding any new over-the-counter product to the routine. This article is for general information and is not a substitute for medical advice. Always consult your oncologist or care team about your specific situation.
