Bold opening: Immunotherapy isn’t a miracle cure, but it has dramatically reshaped how we treat head and neck cancers—and that shift matters for patients and families alike. And this is the part most people miss: a meaningful number of patients do achieve durable, long-lasting benefits, even if the initial tumor shrinkage isn’t dramatic. Below is a clear, beginner-friendly overview of how immunotherapy works in head and neck cancer, who tends to benefit most, what clinical trials show about effectiveness and survival, and what real-world experiences look like for those with advanced disease.
What counts as immunotherapy in head and neck cancer
Immunotherapy for head and neck cancers most often involves PD-1 inhibitors, notably pembrolizumab and nivolumab. These drugs interrupt a checkpoint that cancer cells use to hide from the immune system. By blocking PD-1, they empower T-cells to recognize and attack tumor cells more effectively. Importantly, immunotherapy helps the immune system do its job rather than directly killing cancer cells itself.
Why responses vary between patients
Responses aren’t uniform. Some people see rapid, substantial tumor shrinkage; others experience stable disease or minimal change. Researchers now know that tumor characteristics—such as PD-L1 expression, HPV status, and the surrounding immune environment—play a significant role in determining who benefits most.
What high-quality evidence shows about effectiveness
Clinical trials provide the most reliable data on immunotherapy’s performance in this setting. Two pivotal studies are KEYNOTE-048 (pembrolizumab as a first-line option) and CheckMate 141 (nivolumab for recurrent or metastatic disease after chemotherapy).
In KEYNOTE-048, pembrolizumab alone produced an overall response rate around 17%, with noticeably higher responses (up to 23%) in tumors with high PD-L1 expression (CPS ≥20). When pembrolizumab was combined with chemotherapy, the response rate rose to 36%, making this combination particularly appealing for patients needing faster tumor control. Survival benefits were clear, especially for those with high PD-L1 expression, and several responses persisted for years in some patients.
CheckMate 141 studied nivolumab in patients whose cancer had returned or progressed after chemotherapy. The overall response rate was about 13%, which might look modest, but durability mattered most: many responses lasted well over a year, and overall survival improved versus standard chemotherapy. This durability—responses that endure beyond the initial treatment period—is a hallmark of immunotherapy.
Overall, across major studies, immunotherapy’s success rate—defined by meaningful, lasting tumor shrinkage—generally falls in the 15–36% range. The exact figure depends on tumor biology, prior treatments, and PD-L1 status. While not as high as some other cancers, the quality and longevity of responses can have a substantial impact on life quality and survival.
Subgroups with higher likelihood of benefiting
- HPV-positive (p16-positive) oropharyngeal cancers: These tumors often respond better to immunotherapy, with improvements in overall survival observed in trials.
- High PD-L1 expression: Tumors with elevated PD-L1 levels (especially CPS ≥20) show the strongest responses and survival advantages with pembrolizumab, alone or with chemotherapy.
- Recurrent or metastatic disease: For cancers that have returned or spread, immunotherapy offers a meaningful chance for long-term disease control, even if initial response rates are modest.
- Patients previously treated with chemotherapy: Immunotherapy can still provide survival benefits after prior chemotherapy, as shown in CheckMate 141.
Why success isn’t solely about tumor shrinkage
Immunotherapy often yields slower, steadier gains compared with chemotherapy. Some patients experience what’s called pseudoprogression—tumors appearing larger early on due to immune cell infiltration before shrinking. As a result, clinicians emphasize endpoints beyond shrinkage, such as overall survival, duration of response, and quality of life.
How long immunotherapy can control cancer after a response
For those who respond, benefits can last for many months or even years. In KEYNOTE-048, about 60% of responders remained in response two years after starting treatment. In CheckMate 141, some nivolumab responders continued to benefit beyond three years of follow-up.
Possible side effects to be aware of
Immunotherapy is generally better tolerated than chemotherapy, but it can still cause side effects. Most are mild—fatigue, rash, diarrhea, or low-grade inflammation. Because these drugs boost the immune system, they can occasionally trigger immune-related side effects affecting the thyroid, colon, liver, or lungs. Early detection and close monitoring help keep these effects manageable.
Questions to discuss with your oncologist
- How does my PD-L1 (CPS) status influence my chances of a benefit?
- What is my HPV status, and how does that affect treatment options?
- Has my cancer recurred after prior therapy, and would immunotherapy be used alone or with chemotherapy?
- Do we need rapid tumor shrinkage, or is durable disease control acceptable?
- What are my overall health considerations and potential side effects?
Key takeaway
Immunotherapy isn’t a universal cure for head and neck cancer, but it has fundamentally changed the expected course for many patients. For eligible individuals, it can offer meaningful survival benefits and an improved quality of life, even if only a subset experiences dramatic tumor shrinkage. If you or a loved one is navigating this disease, discuss with your oncology team how immunotherapy might fit into the treatment plan, including potential combinations and the likelihood of benefit based on your tumor biology.
Further resources
Read more about head and neck cancers and relevant trials on OncoDaily, including updates from ESMO 2025 and related trial summaries.
Written by Armen Gevorgyan, MD
