FDA Approves A Revolutionary Cancer Drug
Cancer-a disease where abnormal cells multiply by escaping the vigilance of the immune system-is one of the most widespread diseases of our time. Blamed for an annual mortality rate of 7.6 million by the American Institute for Cancer Research, this is a disease that has warranted attention from pharmaceutical companies who are engaging in a research race to find a possible cure for it. In this ongoing research race, a group of scientists took a new approach to shrink or eliminate tumors. They decided that immunotherapy is the correct path to to take in order to synthesize a new type of cancer drug which can potentially change the course of cancer research.
As scientists raced to find a more effective treatment for cancer, a group of scientists from the Dana-Farber Cancer Institute published a research study in 2001 which indicated how cancer cells were able to escape from the scrutinizing screening practices of the immune system. The study indicated that cancer cells that escaped the cautious eye of the immune system did so by having a cell surface protein called PD-L1. This cell surface protein was able to trick T cells- a type of immune system cell- into classifying the cancerous cell as non-threatening or non-cancerous. This breakthrough brought attention to a potentially new and effective way to treat cancer that pharmaceutical companies and scientists paid no heed to. The research study developed this idea that if a PD-L1 blocker drug could be made, the immune system would be able to recognize these cancerous cells and shrink the size of the tumor or eliminate it.
Following this train of thought, multiple clinical trials were conducted since 2001. Just recently, a drug called Pembrolizumab (trade named as Keytruda) was incorporated in a scientific study of 66 cancer patients whose tumors either disappeared completely or decreased in size substantially after the drug was injected into the their bodies. In fact, the study indicates 18 of the subjects' tumors had completely disappeared. By looking at this impressive track record, the FDA recently approved this drug for use which is something to celebrate. However, it is currently available only to patients suffering from advanced lung, melanoma and bladder cancers. Moreover, this form of treatment costs a hefty 156,000 dollars a year which certainly is a let down considering the true potential this drug has in saving lives.
The drug works by blocking the PD-L1 cell surface protein which makes T immune cells recognize the cancerous cell as safe. T-Cells usually function by binding to an MHC cell surface protein which showcases the antigen that is causing trouble. However, if the T-cell binds to a PD-L1 cell surface protein by linking its PD-1 receptor as shown on the left part of the figure below, it will avoid initiating the process to initiate the death of the cancerous cell leading to a malignant tumor. In order to stop this, Keytruda blocks the PD-L1 and PD-1 receptor proteins by providing an antibody which attaches to the respective cell surface proteins as shown on the right side of the figure below. This helps the T-cell recognize the the cancer cell is cancerous instead of wrongly classifying as non-cancerous. This correct classification triggers a cascade of biochemical reactions that lead to the death of the cancerous cell. This explanation helps account for the reduction in tumor size which has been indicated by the 66 subject clinical trial that used this drug.
We are on the verge of seeing a revolution in cancer cure. However, certain factors such as high treatment costs can prevent us from witnessing it as soon as possible. Moreover, it lowers the actual potential that this drug has by reducing the number of people who can afford it. So for now, we can be confident that this is a step taken in the right direction and hope that this drug becomes available to the masses soon.
If you would like to donate money to cancer research you can donate to the Dana-Farber Cancer Insitute by clicking the link below.
https://www.kintera.org/site/c.8eIIJWPvG7IQF/b.9127925/k.8B74/Make_a_Gift/apps/ka/sd/donorcustom.asp
Citations
