Immunotherapy for Melanoma — Why This Cancer Responds More Often

Most people diagnosed with melanoma are not candidates. A melanoma found early is removed by surgery, and nothing is given afterwards. Immunotherapy has a defined role in two situations: melanoma that has spread and cannot be removed by surgery, and melanoma that has been fully removed but carries a high risk of returning.

Stage decides which of those conversations you are having. Melanoma that is thin and confined to the skin is handled by surgery and follow-up. Melanoma that has reached lymph nodes, or spread further, is where systemic treatment enters the discussion at all.

Your medical history matters next. Active autoimmune disease, an organ transplant, or ongoing high-dose steroids can make immunotherapy unsuitable or higher-risk. Checkpoint inhibitor treatment works by loosening restraints on the immune system rather than by attacking the tumour directly, so an immune system that is already over-active is a genuine problem, not a technicality.

Then there is the subtype, and this is where Indian patients are often misled by what they read. Most published melanoma data comes from sun-exposure-driven melanoma on skin that gets a lot of sunlight. In India, melanoma much more often starts on the sole of the foot, on the palm, under a nail, or on an internal lining such as the mouth, nose or gut. Those are different diseases under one name, and they respond less well.

Finally, one thing patients expect to find here and do not. In several cancers a biomarker score is the gatekeeper for immunotherapy — in head and neck cancer, for example, a CPS score decides who is offered it, as CPS Score in Head and Neck Cancer: What It Decides sets out. Melanoma is not run that way. Eligibility here rests on stage, subtype and fitness, not on a single score.

Nothing on this page decides eligibility. That rests on the biopsy report, the stage, previous treatment and overall fitness, read together by a medical oncologist.

Because melanoma carries an unusually high number of genetic mutations. Each mutation can produce an abnormal protein that immune cells recognise as foreign. That makes melanoma more visible to the immune system than almost any other cancer. It is why checkpoint inhibitor immunotherapy was tested and approved in melanoma before any other disease.

The mutations come mostly from ultraviolet light. Sunlight damages the DNA of pigment-producing skin cells over many years, and a melanoma that develops from that damage arrives already carrying thousands of small genetic errors. Cancers that develop without that kind of sustained external damage tend to look far more like normal tissue to the immune system, and are correspondingly harder for it to act against.

Melanoma was also the disease that proved the principle. Before checkpoint inhibitors existed, advanced melanoma was one of only two cancers routinely treated with immune-based therapy at all, because doctors had recorded melanomas occasionally shrinking without any treatment. That observation is much of why melanoma was the first place the modern class was tried, and why every later approval in other cancers was built on what was learned here.

The honest half of this page starts here. The advantage described above belongs to sun-driven melanoma. Acral melanoma, on the sole, the palm or under a nail, and mucosal melanoma, on internal linings, are not caused by ultraviolet damage. They carry far fewer mutations, and guideline bodies report lower response rates for them. Those two subtypes make up a much larger share of melanoma in India than they do in the populations most trials recruited from.

That does not make immunotherapy irrelevant for Indian patients. It makes the first question a different one. Before any published figure means anything to you, you need to know which melanoma you have.

Guidance from bodies such as NCCN and ESMO, as of August 2026, reports measurable tumour shrinkage in around half of patients with advanced sun-driven melanoma treated with two immunotherapy drugs together, and in roughly four in ten treated with a single checkpoint inhibitor. Those are objective response figures, not survival figures, and they describe trial populations, not individuals.

Read the table below with the right-hand column, not just the middle one. What a published response rate does not tell you is usually more decision-relevant than the number itself.

This page will not attach a percentage to an individual case, and you should be wary of any page that does. Ask your oncologist what the published figures are for your subtype and stage, and ask what they are drawn from.

In a proportion of patients, yes. Melanoma has the longest published follow-up of any cancer treated with checkpoint inhibitors, because it was treated first. Some patients who responded have remained free of active disease for years after finishing treatment. Oncologists call this a durable response, and they use that careful phrase deliberately rather than any stronger word.

This is the part of melanoma treatment that genuinely is encouraging, and it does not need overselling. With most cancer drugs, benefit continues only while the drug is being given. Immunotherapy is different in principle: the drug does not act on the tumour, it acts on immune cells, and an immune response that has been established can carry on after the drug stops. That is why treatment in melanoma is often planned to run for a defined period rather than indefinitely.

Three honest limits sit alongside that. First, the durable group is a minority of everyone treated, not the majority. Second, late relapses are documented in the same long follow-up that shows the durable responses, so a long remission is not certainty. Third, nobody can identify in advance who will fall into that group — there is no test, at present, that predicts it.

Follow-up therefore continues after treatment ends. Scans at set intervals, skin examination, and checks on the lymph node areas carry on for years. At CION, immunotherapy itself is given as day care at our centres, while assessment and follow-up CT and PET-CT imaging is coordinated at partner imaging centres.

One more thing worth knowing before your first assessment scan. A melanoma deposit can look slightly larger early on because immune cells have flooded into it, not because the cancer has grown. Oncologists call this pseudoprogression. It is uncommon, but it is real, which is why one early scan rarely ends treatment on its own and a confirmation scan is usually done first.

• Which subtype does the biopsy report say? Sun-driven cutaneous melanoma, acral melanoma on the sole, palm or nail bed, or mucosal melanoma on an internal lining. This single line changes which published evidence applies to your case, and it changes it a lot.
• Is this treatment aimed at shrinking something, or at preventing a return? Advanced disease and post-surgery adjuvant treatment are completely different goals. Only the first has a response rate at all.
• Does the report mention a BRAF mutation? If it does, a second class of treatment applies as well, and the order in which the two are used is a real decision your oncologist should explain rather than assume.
• Is the figure I was quoted a response rate or a survival figure? They are not the same thing, they are often mixed up online, and only one of them describes what a scan will show after a few cycles.
• What happens if it does not work? Ask this at the start, not later. Knowing there is a defined next step, and what it is, makes the first decision easier to take rather than harder.

• In head and neck cancer a single biomarker score is the gatekeeper melanoma does not have — CPS Score in Head and Neck Cancer: What It Decides explains how one number opens or closes the door there.
• Food-pipe cancer shows the opposite pattern to melanoma, with immunotherapy used alongside other treatment rather than as the lead option — see Immunotherapy for Oesophageal Cancer.
• Stomach and gastro-oesophageal cancer is another place where eligibility turns on test results rather than on the cancer type alone — Immunotherapy for Stomach and Gastro-Oesophageal Cancer sets out which ones.
• For how immunotherapy is delivered, monitored and paid for across our centres, see Immunotherapy at CION Cancer Clinics.

Still unsure how any of this applies to a specific melanoma diagnosis? Book a free consultation and a medical oncologist will go through the reports with you.