Does immunotherapy actually work — honest response rates, by cancer type

Across all cancers combined, published trials generally report objective response rates for checkpoint inhibitor immunotherapy ranging from roughly 15% to 60%, depending heavily on the specific cancer type, biomarker status, and whether it is used alone or in combination with another checkpoint inhibitor or chemotherapy. There is no single "immunotherapy response rate" that applies to everyone.

Most patients who ask about immunotherapy are not eligible for it. It is approved for specific cancers, often only at certain stages, and frequently requires a positive biomarker result — such as PD-L1 expression above a set threshold, or MSI-High/dMMR status — before it is used at all. If you haven't had biomarker testing yet, that test result, not this page, is where the real answer to "will it work for me" starts.

The rest of this page sets out sourced response-rate ranges by cancer type, what "response" actually means on a scan, and what genuinely decides your own chances — without implying that immunotherapy works the same way for everyone who asks about it.

These ranges are indicative and drawn from published trial data, not a CION-specific outcome guarantee. Your oncologist will give you a figure specific to your cancer, stage, and biomarker results.

A response is a defined, measured shrinkage of visible tumour on a CT or PET-CT scan, assessed against a standardised system (commonly RECIST) — not a feeling, a symptom improvement, or a doctor's general impression. Every response rate quoted anywhere on this page is a scan-based measurement.

• Complete response — all visible disease has disappeared on scans.
• Partial response — a significant, defined reduction in tumour size.
• Stable disease — the tumour neither shrinks nor grows meaningfully; not counted in the "response rate", but not the same as the treatment failing.
• Progressive disease — the tumour grows beyond a defined threshold, or new disease appears.

"Overall response rate" is simply complete responses plus partial responses, added together, out of everyone treated in a study. It intentionally does not include stable disease, which is a separate, still meaningful outcome — see the FAQ below on scans that don't show a response.

A scan that doesn't show shrinkage is not automatically a dead end. Immunotherapy can produce stable disease — the cancer neither shrinking nor growing — which is not classified as a "response" but can still mean it is being controlled, sometimes for a long time. Occasionally a scan appears worse shortly after starting treatment before later scans improve (pseudoprogression), which is why an apparent worsening is usually confirmed with a follow-up scan rather than acted on immediately.

If repeat scans confirm the cancer is genuinely progressing, the realistic paths your oncology team will discuss with you honestly include switching to a different treatment approach, joining a clinical trial where eligible, or choosing best supportive care focused on comfort and quality of life. Not continuing treatment is a real, respected option in this conversation, not a failure — the right choice depends entirely on your own priorities, fitness, and what the cancer is doing.

• Who Is Eligible for Immunotherapy — and Who Is Not — the biomarker and cancer-type criteria behind the response-rate ranges on this page.
• Is Immunotherapy Only for Stage 4 Cancer? — why stage alone doesn't decide eligibility or response.
• How Long Does Immunotherapy Take to Work? — what to expect on the calendar, once treatment starts.
• Immunotherapy at CION Cancer Clinics — the full picture of how CION supports patients through this decision.

This page is for general information and does not replace a consultation. Response-rate ranges are approximate, drawn from published clinical trial data, and describe groups of patients — they are not a prediction of what will happen for any individual patient.

Thousands have asked this exact question before starting

Wanting real numbers instead of reassurance is not pessimism — it's how informed patients make this decision. Our team walks through your specific case, honestly.