Dabrafenib (Tafinlar; Finlee dispersible tablets)

Dabrafenib at a glance

Dabrafenib blocks an altered growth-control protein called BRAF. Treatment requires an appropriate BRAF tumour-test result and specialist assessment. Tafinlar is the verified brand for capsules; US Tafinlar also includes tablets for oral suspension. Finlee is a European dabrafenib dispersible-tablet product with its own paediatric prescription. These formulations must not be exchanged without a new dosing plan.

A usual adult capsule dose is 150 mg twice daily, approximately 12 hours apart, on an empty stomach. Children's doses and suspension doses depend on body weight. Your prescribed dose may be lower because of side effects.

Important issues include fever, skin changes, new skin cancers, eye inflammation and medicine interactions. Trametinib adds precautions involving the heart, lungs, bleeding and clots. Tests and prompt symptom reporting remain important even though treatment is taken at home.

How dabrafenib works

BRAF helps transmit signals telling cells when to grow. Certain BRAF changes can leave this signal switched on. Dabrafenib inhibits the altered protein and can reduce the growth signal. It is a kinase inhibitor, a type of targeted therapy, rather than conventional chemotherapy or checkpoint immunotherapy.

Trametinib blocks MEK, another part of the same signalling pathway. Blocking two points can be useful in the right clinical situation, but the combination has additional side effects. Do not take one medicine as a substitute for the other or change either dose independently.

A suitable mutation does not guarantee benefit. The cancer's wider biology, previous treatment and your health also matter. Likewise, the presence or absence of side effects cannot tell you whether the treatment is working. Your follow-up assessments answer that question.

How the team decides whether it is suitable

The team reviews the diagnosis, the precise BRAF result, previous treatment and applicable prescribing information. BRAF V600 changes, including V600E and sometimes V600K depending on the clinical setting, are relevant. A report saying only “BRAF mutation” may need clarification. Dabrafenib is not suitable for every BRAF alteration. In tumours without an appropriate BRAF change, BRAF inhibitors can paradoxically stimulate growth signals.

Tell the clinician about heart or lung disease, high blood pressure, diabetes, liver or kidney problems, eye disease, bleeding, blood clots and previous cancers. Report any previous severe allergy to the medicine or its ingredients. Significant liver or kidney impairment needs individual assessment because dosing evidence is limited. Also mention glucose-6-phosphate dehydrogenase deficiency, usually shortened to G6PD deficiency: this inherited enzyme problem can increase the risk of red blood cells breaking down.

Discuss previous and planned radiotherapy. Dabrafenib can increase reactions in irradiated tissues, including when the two treatments are given at different times. The oncology and radiotherapy teams need to coordinate the plan.

Before treatment starts

Blood tests assess blood counts, liver and kidney function, blood salts and glucose as appropriate. Pregnancy testing is needed if pregnancy is possible. Skin examination establishes a baseline for detecting new lesions. The team may also examine the mouth, neck and other areas and review scans for additional cancers, following the product guidance and your clinical situation.

When trametinib is included, a heart scan checks pumping function before treatment. Blood pressure and any existing breathing or visual problems are reviewed. Report recent diarrhoea, poor fluid intake or an infection; these can make early treatment harder to manage.

Ask for a written fever plan before the first dose. It should identify when to withhold treatment, who will assess you, which fever medicines are suitable and who authorises restarting. Keep a thermometer available and save your hospital's urgent advice number. A caregiver should also understand the plan if they help with medicines.

How to take dabrafenib

Capsules, meals and the daily routine

A usual adult starting prescription is two 75 mg capsules twice daily. Take doses about 12 hours apart, at consistent times, at least one hour before or two hours after food. Swallow capsules whole with water; do not open, crush or break them. Food can change absorption, so avoid varying between fed and fasted dosing.

If trametinib is prescribed, it is usually taken once daily with either the morning or evening dabrafenib dose. Its own formulation instructions still apply. Your pharmacist can help build a practical meal-and-medicine timetable. Treatment generally continues daily; planned interruptions must be agreed with the team.

Missed doses, vomiting and accidental extra doses

Take a forgotten dabrafenib dose only if there are more than six hours before the next scheduled dose. Otherwise skip it. Never double a dose. If you vomit after taking it, do not replace the dose; take the next one at its usual time. Contact the team if vomiting continues or you cannot keep fluids down.

Trametinib has a different missed-dose rule, based on 12 hours before the next dose. Do not apply dabrafenib's six-hour rule to both medicines. If you take too much of either drug, contact your treating service immediately and take the packaging with you if assessment is needed.

Suspension and dispersible tablets

US Tafinlar 10 mg tablets for oral suspension and European Finlee 10 mg dispersible tablets require preparation in water. They are not tablets to swallow whole, chew or crush. A clinician must prescribe the correct formulation and dose; paediatric capsule and suspension schedules are not identical at every weight.

The pharmacist should demonstrate the supplied dosing cup, prescribed water volume, mixing, rinsing and administration. Give the suspension promptly after preparation and discard it if not used within 30 minutes. Supported oral-syringe and feeding-tube methods exist, but tube size and flushing instructions must be checked against the product. Do not put opened capsules into a feeding tube.

Suspension is also normally taken on an empty stomach. The labels allow on-demand breast milk or formula for a young child unable to tolerate fasting; this is a feeding exception for the child receiving treatment, not permission for a mother taking dabrafenib to breastfeed. Discuss the child's feeding plan with the specialist team. Finlee contains benzyl alcohol; its leaflet calls for monitoring breathing symptoms in children under three and particular caution with liver or kidney impairment.

Keeping and handling the medicine

Keep medicine in its original container, tightly closed and protected from moisture, with the drying canister left inside. Never swallow the canister. US Tafinlar storage is 20–25°C (68–77°F), with permitted brief excursions to 15–30°C (59–86°F); European products have their own storage wording. Follow your pack, particularly in hot weather. Keep out of children's reach and return unwanted medicine to the pharmacy. Trametinib storage may be different: check both packs.

Monitoring and checking whether treatment is working

Appointments review symptoms, doses and missed doses, with blood tests according to your treatment plan. Kidney function is monitored during treatment and deserves particular attention during severe fever or dehydration. Glucose monitoring is important if you already have diabetes or high glucose. European combination guidance recommends liver tests every four weeks for the first six months, then as clinically needed.

Heart scans with trametinib are performed before treatment, about one month after starting and then approximately every two to three months. Blood pressure is checked during treatment. New breathlessness, swelling or palpitations should be reported between appointments.

Skin checks continue during treatment and afterwards. US guidance specifies examination every two months during treatment; European guidance recommends monthly checks. Both include monitoring for up to six months after stopping, with the European plan allowing adjustment when another cancer treatment starts. Report a new or changing lesion promptly instead of waiting for the next examination.

Scans and clinical assessments help the team judge benefit. A temporary pause or dose reduction may allow side effects to settle without abandoning treatment. Different complications require different decisions about the two medicines; restarting is a clinical decision, not something to infer from feeling better.

Common side effects and practical management

Fever and chills: a specific action plan

Dabrafenib can cause fever, and fever is more frequent with trametinib. It can recur and may cause dehydration, low blood pressure or kidney injury. Infection can produce the same symptoms, so never assume it is simply a drug effect.

Contact your hospital urgently at its stated temperature threshold. UK patient guidance uses 37.5°C (99.5°F) or above, or below 36°C (96.8°F) with possible infection; serious illness can also occur without fever. At 38°C (100.4°F) or above, withhold dabrafenib and trametinib if used together, and seek immediate advice. For recurrent episodes, your written plan may instruct you to hold both at the first fever symptoms.

Do not use fever tablets to conceal symptoms and continue dosing. The team may check for infection and kidney problems, give fluids or prescribe fever treatment. Steroids are sometimes used for recurrent or complicated episodes after assessment. Under US guidance, restart may be considered only after recovery for at least 24 hours; the clinician decides the dose and timing.

Skin, hands, feet and hair

Dryness, rash, itching, thickened patches and wart-like growths can occur. Palms and soles may become sore. Use gentle skin care, moisturiser and comfortable footwear, and report painful areas before walking becomes difficult. Protect skin from strong sunlight with clothing and sunscreen. Hair may thin or change texture; complete hair loss is not inevitable. A new growth needs examination even if it looks harmless.

Skin reactions localised in tattoos have been reported with dabrafenib and trametinib. Tell the team about new inflammation or other changes within a tattoo. How often these reactions occur is not known.

Digestion, appetite and energy

Nausea, vomiting or bowel changes can interfere with meals and dosing. Use the prescribed anti-sickness treatment. Report continuing diarrhoea, vomiting, reduced urine or difficulty drinking promptly; a medicine pause or fluid replacement may be needed. Severe abdominal pain is not something to manage as ordinary indigestion.

Small meals between fasting windows may be easier when appetite is low. Ask for dietetic support if weight is falling. Fatigue, headaches and muscle or joint aches can occur. Gentle activity and rest may help, but sudden weakness, severe headache or muscle pain with dark urine needs assessment. Check painkillers with the team first.

Important side effects requiring assessment

New cancers and serious skin reactions

New skin cancers, including squamous cell carcinoma and new melanoma, can develop. New cancers outside the skin have also been reported. Report a changing mole, new lump, non-healing sore or unusual bleeding. Many skin lesions can be removed without ending treatment, but only examination can determine what they are.

A spreading painful rash, blisters, peeling skin, mouth sores or rash with fever and facial swelling may indicate a severe skin reaction, including Stevens–Johnson syndrome or drug reaction with eosinophilia and systemic symptoms (DRESS), which can affect internal organs. Withhold dabrafenib and trametinib if used together and seek urgent medical assessment; extensive blistering or severe illness warrants emergency care. Confirmed severe cutaneous adverse reactions require permanent discontinuation under specialist care.

Eyes, heart and lungs

Dabrafenib can cause uveitis, inflammation inside the eye. Pain, redness, light sensitivity or blurred vision needs urgent assessment. Both eyes can be affected. Trametinib can cause additional retinal problems, including blocked retinal veins or fluid beneath the retina. Sudden loss of vision is an emergency.

With trametinib, weakened heart pumping or lung inflammation can develop. Report a new cough, breathlessness, swelling, rapid weight gain or palpitations immediately. Severe breathing difficulty, chest pain or collapse needs emergency care. The team may withhold one or both drugs while investigating.

Bleeding, clots and abdominal complications

Combination treatment can cause serious bleeding or blood clots. Vomiting blood, black stools, coughing blood or a sudden severe headache requires urgent assessment. Heavy bleeding, stroke-like symptoms or chest pain with sudden breathlessness requires emergency care. One swollen painful leg or arm also needs immediate advice.

Severe persistent abdominal pain, particularly with vomiting, fever or a swollen abdomen, can signal pancreatitis, bowel inflammation or a hole in the bowel. Seek urgent assessment rather than taking extra painkillers and waiting.

Blood, glucose, kidneys and inflammation

Blood counts can fall, increasing infection, anaemia or bleeding risk. G6PD deficiency can increase susceptibility to red-cell breakdown: report unusual pallor, dark urine, yellow eyes or breathlessness. Increased thirst and frequent urination can indicate high glucose. Yellow skin or eyes, reduced urine and persistent vomiting also need prompt investigation.

Tumour lysis syndrome means that rapid tumour-cell breakdown disrupts blood chemistry and can harm the kidneys or heart. Higher-risk patients need closer tests and a hydration plan. Markedly reduced urine, severe weakness, muscle cramps, confusion or palpitations requires immediate assessment.

Haemophagocytic lymphohistiocytosis, or HLH, is a serious excessive inflammatory response reported with the combination. Persistent fever with swollen glands, unusual bruising or pronounced illness needs urgent assessment. Treatment is interrupted if suspected and stopped if confirmed. Sarcoidosis, a different inflammatory condition, can also occur with the combination and sometimes resemble cancer changes on scans.

Reactions involving radiotherapy

Dabrafenib can worsen radiation injury or trigger inflammation in a previously irradiated area. Most reported reactions involve skin, but internal tissues can be affected. Tell both teams about treatment timing and promptly report new pain, swelling, skin inflammation or neurological symptoms after radiotherapy. Do not choose your own treatment-break interval.

Other medicines, supplements and vaccinations

Dabrafenib is affected by enzymes that process medicines and can also speed up the removal of other drugs. Important examples include certain antibiotics, antifungals, HIV medicines, seizure medicines, warfarin, digoxin, steroid medicines and hormonal contraception. Strong inhibitors of CYP3A4 or CYP2C8 should be avoided; potent enzyme-inducing medicines also need an alternative where possible. The pharmacist must check the complete list when treatment starts, changes or stops. Warfarin may need extra INR blood tests; digoxin may need additional monitoring.

Avoid St John's wort. Check herbal, Ayurvedic and nutritional products before using them. Avoid grapefruit and Seville oranges, including juices or supplements containing them. Acid-reducing medicines are not expected to meaningfully reduce dabrafenib absorption in current European guidance, but still include them in the interaction check.

Discuss vaccinations with the oncology team, including travel vaccines. Whether a vaccine is suitable depends on whether it is live, your blood counts, accompanying treatment and timing. Do not assume a universal post-treatment waiting period or stop cancer treatment to receive a vaccine.

Everyday life during treatment

Keep a brief record of doses, fever episodes and symptoms. This helps distinguish a repeated pattern from a new problem. Arrange meals around fasting windows and drink regularly unless you have a prescribed fluid restriction. Large amounts of fluid are not automatically safe if heart or kidney function is impaired.

Work, school and physical activity can be adapted to energy levels. Avoid driving or machinery when dizzy, fatigued or affected by visual symptoms. Before travel, plan medicine storage, meal times, dose timing and access to urgent care. Keep medicines in their original labelled packaging.

Tell dentists and other clinicians about both cancer medicines before procedures or new prescriptions. Ask the team about sexual comfort, infection precautions and contraception. Emotional strain is also a treatment issue: support from the nursing team, counselling or a patient group can help you manage uncertainty without carrying it alone.

Fertility, contraception, pregnancy and breastfeeding

Dabrafenib may harm an unborn baby. Discuss pregnancy plans before starting and contact the team immediately if pregnancy occurs or is suspected. Fertility may be affected in women and men; reduced sperm production may be irreversible. Ask about preservation options before treatment if future children matter to you.

For patients who can become pregnant, dabrafenib alone requires effective contraception during treatment and for two weeks afterwards. Hormonal contraception may become less reliable, so arrange an effective non-hormonal alternative with the team. With trametinib, the longer interval applies: US guidance specifies four months after its last dose; European guidance specifies 16 weeks. Obtain your actual end date.

US guidance also advises condoms for men, including those who have had a vasectomy, to protect pregnant partners or partners who can become pregnant during treatment and for two weeks after dabrafenib alone; trametinib extends this to four months after its last dose. European labels do not give the same male post-treatment interval, so retain the personalised advice for your products.

Do not breastfeed while taking treatment. US dabrafenib guidance continues this restriction for two weeks after the last dose; US trametinib guidance extends it to four months. European information advises against breastfeeding during treatment without specifying the same fixed post-treatment interval. Ask when breastfeeding may safely resume and do not use the shorter dabrafenib interval for combination treatment.

After treatment finishes

Continue scheduled scans, blood tests and skin surveillance. Skin and other new-cancer monitoring may continue for up to six months, and new symptoms should still be reported. Follow the longer contraception and breastfeeding plan when trametinib was included.

The effects on other medicines do not disappear immediately. For example, warfarin or digoxin monitoring may need adjustment after dabrafenib stops. Tell every prescriber the stop date. Return unused supplies and obtain clear instructions if treatment has been paused rather than permanently stopped.

Frequently asked questions