Keytruda: An Overview

Keytruda is the brand name for pembrolizumab, an immunotherapy drug by Merck & Co (MSD), used in treating various cancers. It falls under the category of "checkpoint inhibitors," which help the body's immune system recognize and attack cancer cells.

Mechanism of Action

• Keytruda blocks the PD-1 receptors on T cells, preventing them from binding with PD-L1 receptors on cancer cells, allowing T cells to identify and attack cancerous cells.

Global and Financial Impact

• First approved in 2014 by the US FDA for advanced skin cancer.
• Used globally for lung, cervical, renal cell, and aggressive breast cancers, among others.
• Generated $29.5 billion in sales in 2024, nearly half of Merck & Co's revenue.

Comparison with Other Cancer Treatments

Immunotherapy, such as Keytruda, utilizes the immune system to target cancer cells, unlike chemotherapy and radiotherapy, which directly kill cancer cells but can also harm healthy cells.

Keytruda's Role in Immunotherapies

• Part of monoclonal antibodies category, designed to bind with specific targets in the immune system.
• Other treatments include CAR-T cell therapy and mRNA vaccines for cancer.

Availability and Costs in India

• Available in tertiary care hospitals, with generic versions existing for some monoclonal antibodies.
• Standard dosage: 200 mg every three weeks; costs over Rs 3 lakh monthly without insurance.
• Patient Access Programme offers 30 free vials on purchasing five, under certain income conditions.

Healthcare Coverage

• Third-party health insurance can cover initial doses; specialised cancer care policies may cover the drug fully.
• Government health schemes like CGHS also provide access.

Challenges and Future Prospects

Cost and Patent Issues

• High costs due to complex manufacturing and patent rights; patent set to expire in 2028.
• Generic versions could reduce costs by up to 70%.

Market Importance

• India's cancer incidence is rising, highlighting the need for affordable treatments.
• Government initiatives have waived customs duty on Keytruda to reduce costs.

Concerns: Counterfeit Market

• Investigation by The Indian Express and ICIJ uncovered counterfeit Keytruda market fueled by high costs and lack of access.
• Counterfeits are often in genuine packaging, making detection difficult.

Ensuring Genuine Purchase

• Buy through hospital pharmacies or patient access programs to ensure authenticity.