If you are diagnosed with advanced melanoma, your treatment can increasingly be selected according to the genetic changes found within your tumour. One of the most important is a BRAF V600 mutation, which can make your melanoma suitable for medicines designed to block specific cancer-growth signals.
The COLUMBUS trial studied encorafenib and binimetinib in people with unresectable or metastatic BRAF V600-mutant melanoma. Its results help you understand how this targeted combination works, what benefits were demonstrated and where it fits alongside other modern melanoma treatments.
What Was the COLUMBUS Trial?
COLUMBUS was an international, randomised, open-label Phase III trial involving people with unresectable locally advanced or metastatic melanoma containing a BRAF V600 mutation. If your melanoma carries this mutation, the study is relevant because it investigated treatments specifically designed to target the abnormal signalling driving your cancer.
Part 1 randomised 577 participants to encorafenib plus binimetinib, encorafenib alone or vemurafenib alone. The primary comparison assessed progression-free survival with the combination against vemurafenib, while researchers also examined overall survival, tumour response and safety.
Why Was the COLUMBUS Study Needed?
BRAF-targeted treatment had already changed melanoma care before COLUMBUS, but treatment resistance remained an important limitation. If your melanoma initially responds to a BRAF inhibitor, abnormal signalling can eventually reactivate and allow your cancer to progress.
Researchers therefore wanted to determine whether a newer BRAF inhibitor combined with a MEK inhibitor could provide stronger and more sustained disease control. COLUMBUS helped establish whether encorafenib plus binimetinib could offer you another evidence-based targeted treatment option.
What Is a BRAF V600 Mutation?
BRAF is a gene involved in the MAPK signalling pathway, which helps regulate how your cells grow and divide. When your melanoma contains a BRAF V600 mutation, abnormal signalling can keep this pathway switched on and encourage uncontrolled cancer-cell growth.
Approximately half of cutaneous melanomas have a BRAF mutation, with V600 changes among the most clinically important. Testing your tumour helps your healthcare team establish whether treatment targeting BRAF and MEK could be appropriate for you.
Why Does Molecular Testing Matter to You?
Targeted therapy only works when the molecular target it is designed to block is present. Your specialist therefore needs confirmation of an appropriate BRAF mutation before considering encorafenib and binimetinib for your melanoma.
Molecular testing prevents you from receiving a targeted medicine that is unlikely to benefit you. It also gives your specialist important information for comparing targeted treatment with immunotherapy and other treatment strategies.
How Does Encorafenib Work?
Encorafenib is a BRAF inhibitor. If your melanoma carries an appropriate BRAF V600 mutation, the medicine blocks abnormal BRAF activity and interferes with signals encouraging your melanoma cells to grow and divide.
Blocking BRAF can slow tumour growth, but melanoma cells can sometimes restore activity elsewhere within the pathway. This is one reason your specialist generally uses encorafenib together with a MEK inhibitor rather than relying on BRAF inhibition alone.
How Does Binimetinib Work?
Binimetinib is a MEK inhibitor that acts further along the same MAPK signalling pathway. By blocking MEK, it can reduce another important signal your melanoma cells use for continued growth.
When you receive binimetinib with encorafenib, two parts of the pathway are targeted simultaneously. This dual approach can improve disease control compared with BRAF inhibition alone, although it does not guarantee that your melanoma will never become resistant.
Why Are BRAF and MEK Inhibitors Combined?
Blocking BRAF alone can initially control BRAF-mutant melanoma, but your cancer may eventually reactivate signalling through the MAPK pathway. Adding a MEK inhibitor provides a second point of suppression and can make your treatment more effective.
For you, the practical aim is better tumour control and a longer period before your melanoma progresses. Combination therapy can also alter the pattern of treatment-related side effects compared with BRAF-inhibitor monotherapy.
How Was the COLUMBUS Trial Designed?
Part 1 included 577 participants with unresectable locally advanced or metastatic BRAF V600E- or V600K-mutant melanoma. Participants had not previously received a BRAF or MEK inhibitor, although previous immunotherapy was permitted in specified circumstances.
The table below shows the main treatment groups and clinically important outcomes that can help you interpret the COLUMBUS findings.
| Trial Feature | Encorafenib + Binimetinib | Encorafenib Alone | Vemurafenib Alone |
| Part 1 participants | 192 | 194 | 191 |
| Treatment | Encorafenib 450 mg once daily + binimetinib 45 mg twice daily | Encorafenib 300 mg once daily | Vemurafenib 960 mg twice daily |
| Median progression-free survival | 14.9 months | 9.6 months in updated analysis | 7.3 months |
| Median overall survival | 33.6 months | 23.5 months | 16.9 months |
| Objective response | About 63% in the original analysis | About 51% | About 40% |
| Main primary comparison | Combination versus vemurafenib | Not the primary comparison | Comparator for the primary endpoint |
| What this means for you | Strong disease-control evidence for the combination | Demonstrates activity of encorafenib | Provides the main monotherapy comparator |
What Did Progression-Free Survival Show?
Progression-free survival describes how long participants remained alive without their melanoma worsening. Median progression-free survival was 14.9 months with encorafenib plus binimetinib compared with 7.3 months with vemurafenib.
These figures are population averages rather than a prediction of your personal outcome. Your melanoma may respond for a shorter or longer period depending on your disease biology, disease burden, previous treatment and other clinical factors.
What Did Overall Survival Show?
Longer follow-up showed a median overall survival of 33.6 months with encorafenib plus binimetinib compared with 16.9 months with vemurafenib. This strengthened the evidence that the combination could provide meaningful benefit for appropriately selected people with advanced BRAF-mutant melanoma.
You should not interpret median survival as a deadline or an estimate of exactly how long you will live. Some people benefit for considerably longer, while others may have melanoma that progresses earlier despite treatment.
Research Insight
Seven-year follow-up provides useful information about people who experience particularly durable benefit. The seven-year overall-survival rate was reported as 27.4% with encorafenib plus binimetinib, while the seven-year progression-free-survival rate was 21.2%.
For you, these long-term results show that a proportion of patients can experience prolonged benefit, but they do not mean targeted therapy cures every advanced melanoma. Researchers identified long-term responders, while many other participants experienced disease progression during follow-up.
Did the Combination Shrink Melanoma Tumours?
The original COLUMBUS analysis reported an objective response in approximately 63% of participants receiving encorafenib plus binimetinib. This means many participants experienced measurable tumour shrinkage, but a substantial proportion did not meet the formal response criteria.
If your melanoma is causing symptoms because of its size or location, a relatively rapid response can sometimes be clinically useful. Your specialist will use scans and your symptoms to assess whether your particular melanoma is responding.
Does Combination Therapy Prevent Treatment Resistance?
No targeted treatment can guarantee that resistance will never develop. Although combined BRAF and MEK inhibition suppresses the MAPK pathway at two points, your melanoma cells may eventually develop alternative ways of sustaining their growth.
COLUMBUS demonstrated that progression occurred later on average with encorafenib plus binimetinib than with vemurafenib. For you, it is therefore more accurate to describe the combination as delaying progression rather than permanently preventing treatment resistance.
What Side Effects Should You Know About?
Encorafenib and binimetinib can cause side effects even though they are targeted medicines. You may experience problems such as tiredness, nausea, diarrhoea, vomiting, abdominal discomfort, muscle pain or joint pain, although your individual experience can differ.
Some less common complications can be more serious and require monitoring or prompt assessment. You should know which symptoms to report rather than assuming that every new problem is simply an expected part of treatment.
Why Are Skin Checks Still Important?
BRAF inhibitors can be associated with new skin lesions, including cutaneous squamous cell carcinoma and new primary melanoma. You should therefore continue checking your skin even though your medicine is being used to treat melanoma.
Your clinical team may arrange regular dermatological examinations during treatment and for a period after it ends. If you notice a new or changing lesion, you should report it rather than assuming that it is harmless.
How Is Encorafenib Plus Binimetinib Used in the UK?
NICE recommends encorafenib plus binimetinib as an option for adults with unresectable or metastatic BRAF V600 mutation-positive melanoma. However, having a BRAF mutation does not automatically mean targeted therapy will be your first systemic treatment.
For untreated stage IV or unresectable stage III melanoma, NICE generally recommends immunotherapy when it is suitable. Targeted BRAF–MEK treatment may be offered when immunotherapy is contraindicated or when rapid disease progression means there may not be enough time for an adequate immune response.
UK Guidance Note
Your treatment choice should take account of more than your BRAF result. NICE advises considering your performance status, other medical conditions, risk and tolerability of treatment toxicity, symptomatic brain metastases, disease burden, speed of progression and other aspects of tumour biology.
This means you and your oncologist need to consider the whole clinical picture before choosing between immunotherapy and targeted treatment. Your BRAF status gives you an additional treatment option; it does not determine the decision on its own.
What If Your Melanoma Is Progressing Quickly?
Targeted BRAF–MEK therapy can sometimes produce responses relatively quickly, which may matter if your melanoma has a high disease burden or is progressing rapidly. In these situations, your specialist may decide that waiting for an immune response is less appropriate.
Your treatment still needs individual assessment because rapid disease control is only one consideration. Your general health, melanoma distribution, symptoms, brain involvement and treatment risks can all affect the final recommendation.
What About Melanoma That Has Spread to the Brain?
Brain metastases can significantly influence your treatment plan. Your specialist will consider whether your brain metastases are causing symptoms, whether you require corticosteroids and whether local treatments such as surgery or radiotherapy are relevant.
You should not assume that the original COLUMBUS trial provides complete evidence for every person with melanoma brain metastases. Your treatment may need to draw on evidence from other studies and discussion within a specialist melanoma multidisciplinary team.
Clinical Tip
If your melanoma has a BRAF V600 mutation, ask your specialist why targeted therapy or immunotherapy is being recommended first in your particular situation. Understanding whether the decision is influenced by rapid progression, symptoms, disease burden, brain metastases or other factors can make your treatment plan easier to understand.
You should also ask which symptoms need urgent reporting once treatment begins. Knowing your personalised monitoring plan can help you recognise important complications early without becoming concerned about every minor symptom.
Is Encorafenib Plus Binimetinib Better Than Every Other BRAF–MEK Combination?
COLUMBUS did not directly compare encorafenib plus binimetinib with every other BRAF–MEK inhibitor combination. You therefore cannot use the trial to conclude that this combination is universally superior to alternatives such as dabrafenib plus trametinib.
NICE considers both encorafenib plus binimetinib and dabrafenib plus trametinib targeted options in relevant clinical circumstances. Your specialist can consider differences in safety, previous treatment, your medical history and other practical factors when discussing the most appropriate option for you.
Why Should Your Treatment Be Individualised?
Two people can have BRAF V600-mutant melanoma and still need different treatment strategies. Your melanoma burden, symptoms, previous therapy, other illnesses, brain involvement and overall fitness can all influence which option gives you the most appropriate balance of benefit and risk.
Your preferences are also important. You should understand how your treatment is taken, what monitoring it requires, which side effects may occur and what alternatives are available before making a shared treatment decision.
What Could Future Melanoma Research Mean for You?
Melanoma research continues to investigate treatment sequencing, resistance mechanisms and new ways of combining targeted therapy with other treatments. These studies may eventually help your specialist predict more accurately which treatment is likely to work best for you.
Research is also exploring why some people remain long-term responders while others develop resistance relatively quickly. A better understanding of these differences could make your future melanoma treatment increasingly personalised.
Evidence Note
COLUMBUS provides strong randomised Phase III evidence that encorafenib plus binimetinib improves progression-free survival compared with vemurafenib in the trial population. Updated analyses also demonstrated longer overall survival and durable benefit in a proportion of participants.
You should nevertheless recognise the limits of the evidence. COLUMBUS did not establish that this combination is superior to every other BRAF–MEK combination, does not guarantee long-term response for you and should not replace an individual treatment discussion with your specialist.
Myth vs Fact
| Myth | Fact |
| COLUMBUS tested only two treatment groups | Part 1 included encorafenib plus binimetinib, encorafenib alone and vemurafenib alone |
| Every comparison was a primary endpoint | The primary endpoint compared progression-free survival for the combination with vemurafenib |
| Combination treatment prevents resistance | It delayed progression, but resistance can still develop |
| Everyone experienced tumour shrinkage | The original response rate was approximately 63% with the combination |
| Longer survival means advanced melanoma is cured | Durable responses occur, but cure cannot be guaranteed |
| Every BRAF mutation makes you eligible | An appropriate BRAF V600 mutation must be confirmed |
| A BRAF mutation automatically means targeted therapy comes first | UK treatment selection also considers immunotherapy and your clinical circumstances |
| Targeted treatment only causes mild side effects | Serious cardiac, ocular, muscular, bleeding and other complications can occur |
| COLUMBUS proved this combination is better than every BRAF–MEK treatment | Different BRAF–MEK combinations were not directly compared |
| You no longer need skin monitoring while receiving melanoma treatment | BRAF inhibitors can be associated with new skin malignancies |
Key Takeaways
- COLUMBUS showed that encorafenib plus binimetinib improved disease control compared with vemurafenib in advanced BRAF V600-mutant melanoma.
- You should know that long-term benefit is possible, but targeted therapy does not guarantee permanent control or prevent resistance.
- Your BRAF result is important, but your specialist also considers disease speed, symptoms, general health and suitability for immunotherapy.
- You need specialist monitoring during treatment because cardiac, eye, muscle, liver, skin and other complications can occur.
Frequently Asked Questions
1. What was the COLUMBUS trial?
COLUMBUS was a randomised Phase III trial involving people with unresectable or metastatic BRAF V600-mutant melanoma. If your tumour has this mutation, the study provides important evidence about treatment with encorafenib plus binimetinib.
2. What does a BRAF V600 mutation mean for you?
A BRAF V600 mutation causes abnormal signalling that encourages your melanoma cells to grow. If testing confirms an appropriate mutation, your specialist may consider BRAF- and MEK-targeted treatment among your available options.
3. How do encorafenib and binimetinib work?
Encorafenib blocks abnormal BRAF signalling while binimetinib blocks MEK further along the same pathway. Using both medicines can suppress the growth signals affecting your melanoma more effectively than BRAF inhibition alone.
4. Did the combination improve progression-free survival?
Yes. Median progression-free survival was 14.9 months with encorafenib plus binimetinib compared with 7.3 months with vemurafenib. You should view these figures as trial averages rather than a prediction of your personal treatment duration.
5. Can this treatment cure your advanced melanoma?
You may experience a long-lasting response, but targeted therapy cannot guarantee that your advanced melanoma will be permanently cured. Your disease can eventually become resistant, which is why continued monitoring remains important.
6. Will targeted treatment always be chosen before immunotherapy?
No. If you have untreated stage IV or unresectable stage III melanoma, current UK guidance generally prioritises immunotherapy when it is suitable. Your specialist may consider targeted therapy when immunotherapy is unsuitable or rapid disease control is particularly important.
7. What side effects should you report?
You should report significant new symptoms such as visual changes, unusual breathlessness, muscle weakness, dark urine, unexplained bleeding, severe rash or new skin lesions. Your oncology team will explain which symptoms require urgent assessment during your treatment.
8. Why do you need BRAF testing?
BRAF testing tells your healthcare team whether the molecular target for these medicines is present in your melanoma. Without an appropriate mutation, encorafenib plus binimetinib is unlikely to provide the intended targeted benefit.
9. Is encorafenib plus binimetinib the best targeted combination for everyone?
No. COLUMBUS did not directly establish superiority over every other BRAF–MEK combination. Your specialist should choose your treatment according to your melanoma characteristics, previous treatment, side-effect risks and personal circumstances.
10. Why do you still need follow-up during treatment?
Your healthcare team needs to assess whether your melanoma remains controlled and whether treatment is causing important side effects. Regular follow-up also gives you an opportunity to report new symptoms and discuss whether your treatment remains appropriate.
Final Thoughts: What Does the COLUMBUS Trial Mean for You?
The COLUMBUS trial established encorafenib plus binimetinib as an important targeted option for advanced BRAF V600-mutant melanoma, with improved progression-free and overall survival compared with vemurafenib in the study population. Your treatment decision should still reflect your individual melanoma, current UK treatment guidance and the balance between expected benefit and potential toxicity.
If you’d like to book a consultation with a dermatologist in London, you can contact us at the London Dermatology Centre.
References:
- Dummer, R., Ascierto, P.A., Gogas, H.J. et al. (2018) ‘Encorafenib plus binimetinib versus vemurafenib or encorafenib in patients with BRAF-mutant melanoma: a multicentre, open-label, randomised phase 3 trial’, The Lancet Oncology, 19(5), pp. 603–615. Available at: https://pubmed.ncbi.nlm.nih.gov/29573941/
- Dummer, R., Flaherty, K.T., Robert, C. et al. (2022) ‘COLUMBUS 5-year update: a randomised, open-label, phase III trial of encorafenib plus binimetinib versus vemurafenib or encorafenib in patients with BRAF V600-mutant melanoma’, Journal of Clinical Oncology. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC9916040/
- Schadendorf, D., Dummer, R., Flaherty, K.T. et al. (2024) ‘COLUMBUS 7-year update: A randomized, open-label, phase III trial of encorafenib plus binimetinib versus vemurafenib or encorafenib in patients with BRAF V600E/K-mutant melanoma’, European Journal of Cancer, 204, 114073. Available at: https://pubmed.ncbi.nlm.nih.gov/38723373/
- NICE (2022) ‘Melanoma: assessment and management (NG14)’. Available at: https://www.nice.org.uk/guidance/ng14/chapter/recommendations
- NICE (2019) ‘Encorafenib with binimetinib for unresectable or metastatic BRAF V600 mutation-positive melanoma (TA562)’. Available at: https://www.nice.org.uk/guidance/TA562
- Electronic Medicines Compendium (2026) ‘Braftovi 75 mg hard capsules – Summary of Product Characteristics’. Available at: https://www.medicines.org.uk/emc/product/9500/smpc
- Electronic Medicines Compendium (2026) ‘Mektovi 15 mg film-coated tablets – Summary of Product Characteristics’. Available at: https://www.medicines.org.uk/emc/product/9501/smpc