Which Cancers Does Keytruda Work On? Apollo Oncologists Explain Effectiveness

Keytruda is an immunotherapy drug that is used to treat different types of cancers. The drug helps the body's own immune system to fight the cancer cells. Developed and sold by Merck & Co., the drug was first approved by the FDA in 2014 for the the treatment of advanced or unresectable melanoma (a form of skin cancer). The Drug Controller General of India (DCGI) has approved Keytruda for multiple cancer types. As of recent approvals, it covers 14 indications across eight tumour types. Scientifically known as pembrolizumab, this drug has transformed cancer treatment for many patients worldwide.

Oncologists spoke to NDTV wherein they explained the working of the drug and which cancer Keytruda works on. Dr. Shefali Sardana, Lead consultant, Medical Oncology (Gastrointestinal, Hepatobiliary and Gynae Oncology) at Indraprastha Apollo Hospital, said, "Immune checkpoint inhibitors such as Pembrolizumab (Keytruda), Nivolumab, and Durvalumab etc have significantly reshaped the treatment landscape across multiple cancers, including lung, melanoma, gastrointestinal, head and neck, and genitourinary malignancies. Their approval across diverse tumour types reflects a shift from organ-based therapy to biology-driven treatment, where the immune system becomes the central therapeutic tool."

Which Cancer Does Keytruda Work On?

Dr. Nikhil Suresh Ghadyalpatil, Director of Medical Oncology, Apollo Hospitals, Jubilee Hills, Hyderabad shared the list of approved indications in India.

• Non-Small Cell Lung Cancer & Small Cell Lung Cancer
• Advanced or Metastatic Melanoma
• Head and Neck Squamous Cell Carcinoma
• Triple-Negative Breast Cancer
• Renal Cell Carcinoma (Kidney Cancer)
• Classical Hodgkin Lymphoma
• Urothelial Carcinoma (Bladder & Urinary Tract)
• Cervical & uterine Cancer
• Stomach cancer

Also read: What Is Keytruda And Why Is Everyone Talking About It In India's Cancer Fight?

Working Of Keytruda

Cancer cells are clever. They wear a 'disguise', a protein called PD-L1 that binds to immune cells and tricks the body into ignoring the tumour. Keytruda blocks this interaction, removing the disguise. Once unmasked, your own immune system recognises the cancer and attacks it. "In essence, Keytruda doesn't fight cancer for you, it helps you fight your own cancer," adds Dr. Ghadyalpatil.

How Is Keytruda Different From Chemotherapy?

Dr. Sardana explains that the most compelling advantage of immunotherapy is the durability of response. Unlike chemotherapy, which often provides temporary disease control, immunotherapy can lead to sustained remission in a subset of patients, even after stopping treatment. This 'long tail' benefit has been particularly evident in melanoma and non-small cell lung cancer, offering the possibility of long-term survival in advanced disease.

Another important clinical advantage is activity in traditionally difficult-to-treat sites such as the brain. Select patients with limited brain metastases have shown meaningful intracranial responses, especially when treated early and with good performance status. However, these benefits are not universal and depend on tumour biology and host immune factors.

Dr. Ghadyalpatil explains that unlike chemotherapy, which attacks all rapidly dividing cells, Keytruda is highly targeted. Most patients:

• Keep their hair
• Continue working and daily routines
• Experience far less nausea, weakness, and infection risk

What sets Keytruda apart is its durable response. Many patients remain in remission for years after treatment ends, an outcome rarely seen with traditional chemotherapy. For some, it's not just life-extending; it's life-restoring.

Limitations Of Keytruda

While Keytruda has changed the way several forms of cancers are treated, it too has its limitations. Drugs like these introduce a distinct spectrum of immune-related adverse events. These may involve the skin, thyroid, lungs, liver, and gastrointestinal tract. Dr. Sardana said, "While most are manageable with prompt recognition and corticosteroid therapy, severe toxicities can occasionally be life-threatening, underscoring the need for vigilance and patient education."

Dr. Ghadyalpatil further explains that since the drug activates the immune system, it can occasionally cause immune-related side effects of mild inflammation of the skin, thyroid, lungs or gut. "Though uncommon, any organ can be affected. The good news: when caught early, these are very manageable, often with a short course of steroids. Keytruda also has very few interactions with other medicines, a significant advantage for patients on multiple drugs," he adds.

Also read: Oncologists Explain Why They Prescribe Keytruda To Cancer Patients, When And How It Works

Choosing The Right Patient

Not every patient needs Keytruda, and not every cancer responds equally. Your oncologist uses biomarker tests to match the right patient with the right drug. Biomarkers such as PD-L1 expression, MSI-H/dMMR status, and tumour mutational burden help guide selection. This is the essence of modern oncology tailoring treatment to your tumour's biology, not a one-size-fits-all approach.

In conclusion, immunotherapy represents a major advance, but its success lies in appropriate case selection, rational use, and careful toxicity management to maximize benefit for the right patient. With immunotherapy, we are no longer just treating cancer. We are teaching the body to heal itself.

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.