- Keytruda is an immunotherapy drug approved for multiple cancer types since 2014
- It activates the immune system by blocking PD-1 to help T-cells attack cancer cells
- The drug is prescribed based on biomarkers like PD-L1, MSI-H, and tumour mutational burden
Keytruda is an immunotherapy drug that is prescribed to cancer patients and is used to treat different types of cancer. It was first approved by the FDA in 2014 for the treatment of advanced or unresectable melanoma (a form of skin cancer). Following its success in treating melanoma, it was then approved for treating several forms of cancer. In India, Keytruda is approved by the Drug Controller General of India (DCGI) for multiple cancer types. As of recent approvals, it covers 14 indications across eight tumour types. This drug was developed by Merck & Co. and currently, it is the only one to manufacture this drug.
NDTV spoke to oncologists who explained why they prescribe Keytruda to cancer, when the drug is prescribed and how the drug works. Dr. Pooja Babbar, Consultant and Unit Head, Medical Oncology, Fortis Hospital Manesar, said, "With more than 15 years of expertise in medical oncology, I have witnessed a major change in the way we treat cancer, especially since the introduction of immunotherapy, such as Keytruda."
What Is Keytruda?
Keytruda (pembrolizumab) is a breakthrough immunotherapy widely used in modern cancer care. It is prescribed across cancers such as lung, melanoma, head and neck, gastric, and triple-negative breast cancer. Dr. Hemanth Parigala, Consultant - Surgical Oncologist, Gleneagles AWARE Hospital, LB Nagar, Hyderabad, said, "Clinically, it is given as first-line treatment in patients whose tumours show high PD-L1 expression, as well as in adjuvant or neoadjuvant settings to reduce recurrence risk or shrink tumours before surgery. It is also used in advanced or metastatic disease, especially when cancer progresses after standard chemotherapy."
How Does Keytruda Work?
Dr. Abhinav Narwariya, Consultant & Unit Head - Medical Oncology at Max Hospital, Shalimar Bagh says that Keytruda is an immunotherapy drug, which is also known as an immune checkpoint inhibitor. Explaining the functioning of the drug, Dr. Narwariya said that our body has a system to control our own immune system. If this doesn't work, it will lead to autoimmune disease. So, there are brakes applied on our immune system, which prevent such diseases. This immunotherapy drug or immune checkpoint inhibitors release those brakes, which causes our own immune system to become activated so much that it recognises the cancer cells and kills them. "This is how immunotherapy works. Immunotherapy doesn't cause side effects like classical chemotherapy because it only kills the cancer cells and not the normal cells," adds Dr. Narwariya.
What makes Keytruda unique is its mechanism. Dr. Babbar said, "Rather than directly attacking cancer cells, it empowers the patient's immune system to identify and destroy them more effectively. This has led to better survival rates and improved quality of life for many patients."
In simple terms, Keytruda works by targeting the PD-1 immune checkpoint receptor on T-cells. Cancer cells often evade immune detection by activating this pathway, effectively switching off the body's immune response. By blocking PD-1, Keytruda reactivates T-cells, enabling them to recognise and attack cancer cells. "This immune-based approach can produce sustained and durable responses, marking a shift from conventional chemotherapy to precision immuno-oncology, though careful monitoring is required for immune-related side effects," added Dr. Parigala.
When Do Oncologists Prescribe Keytruda?
Keytruda has biomarker-based approvals, including for tumours with high microsatellite instability (MSI-H), mismatch repair deficiency (dMMR), or high tumour mutational burden, making it applicable across tumour types.
Dr. Babbar shared, "We usually prescribe Keytruda when certain biomarkers, such as PD-L1, MMR and TMB are present or mostly in stage IV cancer either alone or in combination with chemotherapy or in second or third line when the disease does not respond well to conventional treatments with improved and durable long term outcomes in terms of responses, progression free duration and survival in cancer like lung, melanoma, renal cell carcinoma, cervix cancer and many more cancer. The treatment has been extended to earlier stages of breast cancer specifically in triple negative breast cancer, which shows promising results for better long-term outcomes and lower chances of cancer recurrence."
"Immunotherapy has done wonders, especially Keytruda. It is a very safe drug, which doesn't cause many side effects, and it is approved in lung cancer, head and neck cancer, colon cancer, stomach cancer, and kidney cancer, among others," said Dr. Narwariya. He further cautions that the drug is made by only one company in the world, so it should be brought by that company specific vendor and should be taken only under the guidance of a qualified oncologist.
Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.
