Using a Virus to Treat Cancer

Doctors estimate that in 2011, 1.6 million Americans were diagnosed with cancer, with around 600,000 who died [1]. Needless to say, any new cancer treatment will save millions of lives. The persistent endeavor to cure the world’s seventh most common cause of death [2] has led to many novel breakthroughs and revolutionary innovations.  While chemotherapy and radiation have conventionally been used for treating cancer, today’s emerging front-runner in the race to cure cancer is, in fact, a virus. This novel treatment identifies the specific traits of cancer cells and destroys the cancer cells without harming the benign cells [3]. Though in the past, this treatment has been regarded as ineffective, recent scientific progress has reincarnated the oncolytic virus to defeat cancer.

History

In the 1800s, scientists first noticed that the introduction of a virus could diminish a tumor. Recognizing this startling connection, scientists began researching the phenomenon in the early 20th century [4]. Research stalled, however, when scientists realized that oncolytic viruses were slow to attack tumors and more importantly, had to be injected at the site of the tumor in order to be effective. But despite the setbacks, research in oncolytic viruses has recently spiked, focusing on using a “friendlier” virus to fight cancer [4,5,6].

The Future

Currently, there are three such drugs that have the most potential to treat cancer effectively, Onyx 15, OncoVex, and JX-594. Onyx-015, developed by Onyx Therapeutics is currently undergoing testing to treat cancer and could finally defeat the dreaded disease. It detects the absence of p53, a specific protein that all cancer cells lack, thereby ignoring normal cells. The drug currently targets and destroys half of all major cancer types [7]. However, the drug is ineffective alone and needs to be coupled with chemotherapy for optimal use [8].

Another, possibly more effective, drug currently being developed is OncoVex, developed by BioVex, which was bought by biotechnology giant Amgen for $1 billion [9,10]. Clinically, OncoVex can function by itself [11,12] and does not need to be coupled with other treatments. Additionally, side effects are limited to flu-like symptoms and occasional inflammation [12]. However, the drug is administered through an intra-tumoral injection, so the drug must be injected into the tumor, preventing the drug from successfully treating metastatic tumors that have spread throughout the body [11]. In the meantime, Amgen expects Phase 3 trial results soon, and the Food and Drug Administration will then consider the drug for approval [10].

While Amgen attempts to develop an FDA-approved oncolytic virus, the Ottawa Hospital Research Institute’s Dr. John Bell is working on an oncolytic virus as well [13,14]. Bell’s drug, JX-594, appears to be unique because it takes the best traits of both Onyx-015 and OncoVex. Like Onyx-015, JX-594 seeks out and destroys cancer cells without harming normal cells, so it does not need targeted treatment. Additionally, like the OncoVex, it can function effectively without supplemental chemotherapy [10,15]. The positives of JX-594 include the minimal side effects and excellent efficiency [10,15,16]. Most importantly, this drug requires only a single injection that then fights all of the cancer [10,15]. Bell expects to administer Phase 2 testing specifically directed at liver and colon cancers in around 140 patients across the world [13].

Ethics and Controversy

While the oncolytic virus seems to have a promising future over traditional cancer treatments, there is still a certain amount of danger involved with introducing viruses to the human body. This threat can be especially risky with cancers that suppress the immune system. A study completed by the William Harvey Research Institute shows that the use of un-tested, replicating viruses could jeopardize the human body [17]. Since creating the oncolytic virus requires altering the genes of the virus, it could potentially mutate and introduce a new strain of disease.

Additionally, based on earlier research, oncolytic viruses are known to attack tumors slowly. This was one of the major reasons that research and potential usage of oncolytic viruses stalled in the 20th century. Considering oncolytic viruses’ slow effect, it would be possible for the cancer cells to evolve and adapt around the viruses, like cases where bacteria have become resistant to antibiotics due to widespread use of antibiotics. This would not only render the treatment useless, but also create a new invincible cancer. Understanding this possibility is important going into clinical testing for most drugs.

In studying oncolytic viruses as a widespread treatment for cancer, it is important to prevent the possibility of a threatening mutation of both the virus and the tumor.

Society and Law

Cancer has a massive impact on society. It affects not only patients but also loved ones. Because cancer is so prevalent, any treatment would have far-reaching effects on society. With conventional treatments, side effects are devastating, ranging from physical sicknesses to psychological impacts even more excruciating than the cancer itself. With an oncolytic virus, patients could avoid suffering the painful and sometimes embarrassing side effects that they encounter today. Patients can avoid unnecessary surgeries that come with their own challenges, including risk of infection, adverse allergic reactions, and rehabilitation. Finally, families won’t have to see their loved ones suffer from the terrible side effects of cancer treatment.

The success of oncolytic viruses depends not only on their clinical backing, but also on the policies and laws that facilitate their continued research. Most of the research in this field has been conducted outside of America (in nations like Canada, China, Korea, and Sweden) [13]. American policy and laws limit the amount of research and testing scientists can do, especially with a drug that is controversial. American malpractice laws easily allow patients to file lawsuits against doctors, making doctors and researchers extremely cautious and conservative in using novel, innovative drugs to treat patients. Other nations around the world foster research by removing restrictive laws that limit a scientist’s research possibilities [18][19]. To promote research and use of oncolytic viruses, American policies must adapt to allow greater opportunities for researchers without compromising patient safety.

Conclusion

In his story on the possibility of using oncolytic viruses as a cancer treatment, Ira Flatow, the host of National Public Radio’s “Science Friday,” queried, ““We know viruses can cause disease, but can they also help cure it?” [17] As we can see through the medical breakthroughs created by this compelling research, there is clearly a very bright future ahead for oncology, and more specifically, the oncolytic virus. With more research and testing, the oncolytic virus has the chance to revolutionize medicine by not only being the most effective treatment of cancer, but also the most improbable treatment. The goal of science is to unravel the mysteries of the universe, and at times, scientists have to expand their horizons and find answers in the most unlikely places. Considering the pace at which this research has been progressing, viruses may indeed have the potential to be beneficial; we simply need to stay aware of the implications.

Ayush Midha is a student at The Harker School in California, a part of The Triple Helix High School chapter program. Follow The Triple Helix Online @tthepub and join us on Facebook.

References

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21. Image from http://www.aps.anl.gov/Science/Highlights/Content/APS_SCIENCE_20081021.php