Cancer treatment has changed dramatically in the last decade. Earlier, most patients were treated with surgery, chemotherapy, or radiation. While these treatments are still important, a newer approach called immunotherapy has brought fresh hope.
One of the most well-known immunotherapy drugs today is Keytruda.
What is Keytruda?
Keytruda is the brand name of pembrolizumab, a medicine used to treat several types of cancer. It is manufactured by Merck & Co..
It is currently used in cancers such as:
Lung cancer
Melanoma (skin cancer)
Head and neck cancers
Kidney cancer
Bladder cancer
Certain types of colorectal cancer
Many other advanced or metastatic cancers
Over the years, its approved indications have expanded significantly.
How Does Keytruda Work?
Our immune system is designed to detect and destroy abnormal cells, including cancer cells.
However, cancer is clever.
Cancer cells use a “shield” mechanism to hide from the immune system. One of these mechanisms involves a protein called PD-1 (Programmed Death-1), which acts like a brake on immune cells.
Keytruda works by:
Blocking the PD-1 pathway Removing the “brake” on immune cells Allowing T-cells to recognize and attack cancer cells
In simple words:
Keytruda helps the body’s own immune system fight cancer more effectively.
Unlike chemotherapy, which directly kills rapidly dividing cells, Keytruda activates the immune response. That is why it is called immunotherapy.
Why Is Keytruda So Important?
It has improved survival in many advanced cancers. In some patients, it provides long-lasting responses. It can be used alone or in combination with chemotherapy. In certain cancers, it has replaced chemotherapy as first-line treatment.
For some patients with advanced disease, it has transformed cancer from a rapidly fatal illness into a more controllable condition.
The Major Concern: Cost
One of the biggest limitations of Keytruda is its cost.
It is an expensive biologic drug. Treatment often requires multiple cycles over months. Total cost can run into several lakhs per cycle in India, and even higher globally.
Because of this, many patients cannot afford it without insurance coverage or government support.
Cost remains a major barrier in developing countries.
What Happens When the Patent Ends?
Keytruda is currently under patent protection. However, patents do not last forever.
Once the patent expires:
Other pharmaceutical companies can manufacture biosimilars (similar versions). Competition usually reduces prices. Access becomes easier.
This has already happened with many cancer drugs in the past. When generics enter the market, affordability improves significantly.
If biosimilar pembrolizumab becomes widely available at lower cost, it could dramatically change cancer care accessibility in countries like India.
A Ray of Hope for Society
Cancer cases are increasing worldwide. At the same time, medical science is advancing rapidly.
Drugs like Keytruda represent a shift in thinking:
Instead of attacking cancer directly, we empower the immune system.
When the cost barrier reduces in the coming years, immunotherapy may become more accessible to middle-class and lower-income patients. That could mean:
Better survival rates Improved quality of life More personalized cancer treatment Greater hope for families facing cancer
Final Thoughts
Keytruda is not a miracle cure. It does not work for every patient. It can also have side effects due to immune overactivation.
However, it represents one of the most important breakthroughs in modern oncology.
As patents expire and biosimilars enter the market, this powerful therapy may become affordable to many more patients.
And that is where the real transformation may begin — not just in hospitals, but in society as a whole.
Cancer treatment is evolving. Immunotherapy is leading the way.