Keytruda, known scientifically as pembrolizumab, is a leading immunotherapy drug developed by Merck & Co, designed to treat multiple types of cancer by utilizing the body's immune system. Approved by the U.S. FDA in 2014, it has become the best-selling drug globally, generating $29.5 billion in revenue in 2024. In India, the drug is priced at approximately ₹3 lakh ($3,600 USD) per month, making it a significant financial burden for many patients. However, the Patient Access Programme from Merck offers a way for patients to receive the drug at a reduced cost. The Indian government has also removed customs duties on Keytruda to enhance accessibility amid rising cancer rates, which are projected to increase from 14.13 lakh cases in 2022 to 24.56 lakh by 2045. Despite the high costs, the potential introduction of generic versions after Keytruda's patent expiration in 2028 could reduce prices by up to 70%. An investigation by The Indian Express revealed a troubling counterfeit market for Keytruda, highlighting systemic issues in drug access and hospital oversight, emphasizing the need for patients to ensure they are receiving genuine products.