Introduction:
The United States’ Food and Drug
Administration (FDA) has approved a first-of-its-kind drug that uses a
modified version of the herpes virus to infiltrate and reduce the size
of cancer tumors. (The HSV or Herpes Simplex Virus produces cold sores with individuals infected with HSV-1 and genital herpes with those that have the HSV-2 infection.These viruses are not only contagious but incurable.) (B) Amgen Incorporations have produced a drug called 'Imlygic' (that is injectable) which will be used on cancerous tumors. Malignant melanoma (aka: skin cancer tumors) that cannot be surgically removed as well as those who suffer from metastatic malignant melanomas (cancer has started to spread to other parts of the body or metastasizing) are to be injected with Imlygic. (B)
Research:
New medicines known in the medical or research field as immuno-therapies or immune-oncology have the ability to use the immune system of the human body to aid in attacking cancer cells. Approved by the FDA, these drugs have brought one of the very first significant advances in patient survival for specific cancer types such as lung cancer and melanoma. (A) Injected directly into tumor tissues, the herpes virus slips through and kills cancer cells.Once inside, the HSV-1 uses its own receptors to target and bind to the surface of the host cell membrane. Next, an 'entry pore' is developed where the virus can now inject its genetic material into the cell filtrating to the cell's nucleus. Subsequently, the host cell is now -hijacked by the virus- being forced to replicate its genetic viral code, host cell then bursts (now destroyed) and the new viral particles are released. This is the process that will be used to destroy cancerous tumor cells with a modified version of HSV-1. Presence of HSV-1 will trigger the immune system which will also end up aiding in the attack of the tumor. (B)
So how does this process affect melanoma cells specifically? Well, what the drug T-VEC (aka: talimogene laherparepvec) does is that is divides repeatedly into copies until the cancer cell membranes burst. As this is happening, the gene snippet produces a protein that stimulates the immune system to respond and ultimately kill melanoma cells of tumors.(A)
Results:
Although, this drug with the modified HSV-1 (the virus which causes cold sores) have shown groundbreaking results, the FDA stresses that it does not extend life. Results of the study showed that 16% that were injected with the drug did not show a dramatic increase in life expectancy. The effect only lasted 6 months. These patients' tumors shrunk compared to the 2% of patients who took more conventional cancer drugs. Regulators stressed that Imlygic had no effect on melanoma that had spread to the brain, lungs or other internal organs.(A)Trading one disease for another- Is it really worth it?
Links:(A) http://www.theguardian.com/science/2015/oct/28/us-approval-for-drug-that-turns-herpes-virus-against-cancer
(B)http://www.iflscience.com/health-and-medicine/herpes-virus-recruited-fight-against-skin-cancer
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