How effective Is Keytruda for metastatic melanoma?
Keytruda (pembrolizumab) is an immunotherapy known as a PD-1 inhibitor, approved by the FDA for the treatment of unresectable or metastatic melanoma. This therapy has transformed the outlook for many patients with advanced melanoma, offering the potential for extended survival and durable responses in some cases. In this article, we will review how Keytruda works to treat metastatic melanoma and its effectiveness.
Clinical Effectiveness
Keytruda’s effectiveness has been demonstrated in several large clinical trials, most notably the KEYNOTE-006 study. Here are the key findings:
- Survival Outcomes: At 10 years, 34% of patients treated with Keytruda were still alive, compared to 23.6% for those treated with ipilimumab, another immunotherapy. The median overall survival (OS) for Keytruda was 32.7 months, more than double that of ipilimumab (15.9 months).
- Progression-Free Survival (PFS): Median PFS was 9.4 months for Keytruda versus 3.8 months for ipilimumab.
- Response Rates: In clinical trials, 27% of patients experienced partial tumor shrinkage, and 6% had complete disappearance of tumors with Keytruda. In contrast, only 10% and 1% of patients achieved these responses with ipilimumab, respectively.
- Long-Term Benefit: Approximately one in three patients treated with Keytruda for metastatic melanoma are alive at 10 years, underscoring the potential for long-lasting benefit in responders.
It’s important to note that while Keytruda can offer significant benefits, not all patients respond to treatment. However, those who do respond often experience prolonged disease control and improved quality of life.
Mechanism of Action: How Does Keytruda Work for Melanoma?
Keytruda works by targeting the PD-1 pathway, a mechanism that some cancer cells use to hide from the immune system. By blocking PD-1, Keytruda helps reactivate T cells, enabling the immune system to recognize and attack melanoma cells throughout the body. Unlike chemotherapy, which kills cancer cells directly, Keytruda empowers the immune system to do the work, potentially leading to more durable responses.
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Treatment Duration and Administration
Keytruda is given as an intravenous (IV) infusion, typically every 3 or 6 weeks, depending on the dosing schedule. Each dose is given over approximately 30 minutes. Treatment continues until the cancer progresses or the patient experiences unacceptable side effects, often for up to two years. Some patients may stop earlier if they achieve a complete response or cannot tolerate the therapy.
Eligibility for Metastatic Melanoma Treatment
Keytruda is suitable for patients with unresectable or metastatic melanoma, regardless of whether their tumors carry a BRAF mutation. It is often used as a first-line treatment and can be considered for patients who have not previously received immunotherapy, as well as those who have progressed after other treatments.
Key Takeaways
Keytruda offers the possibility of significantly-improved survival for a subset of patients with advanced melanoma. While not everyone responds, those who do may experience durable, life-extending benefits. As always, treatment decisions should be personalized, considering individual health factors and discussed with an oncology team.
This is not all the information you need to know about Keytruda (pembrolizumab) for safe and effective use and does not take the place of your doctor’s directions. Review the full patient medication guide and discuss this information and any questions you have with your doctor or other health care provider.
References
- Keytruda. How Keytruda Works. Accessed on June 24, 2025 at https://www.keytruda.com/how-does-keytruda-work/
- Keytruda [package insert]. Updated June 2025. Merck Sharp & Dohme LLC. Accessed on June 24, 2025 at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=9333c79b-d487-4538-a9f0-71b91a02b287
- Long, G. V., et. al. 2024. Pembrolizumab versus ipilimumab for advanced melanoma: 10-year follow-up of the phase III KEYNOTE-006 study. In: Annals of Oncology. DOI: https://doi.org/10.1016/j.annonc.2024.08.2330
- National Comprehensive Cancer Network. 2025. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®): Melanoma: Cutaneous. Accessed on June 24, 2025 at https://www.nccn.org/professionals/physician_gls/pdf/cutaneous_melanoma.pdf
- Robert, C., Schachter, J., Long, G. V., Arance, A., Grob, J. J., Mortier, L., Daud, A., Carlino, M. S., McNeil, C., Lotem, M., Larkin, J., Lorigan, P., Neyns, B., Blank, C. U., Hamid, O., Mateus, C., Shapira-Frommer, R., Kosh, M., Zhou, H., Ibrahim, N., … KEYNOTE-006 investigators (2015). Pembrolizumab versus Ipilimumab in Advanced Melanoma. The New England journal of medicine, 372(26), 2521–2532. https://doi.org/10.1056/NEJMoa1503093
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- Keytruda Information for Consumers
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