In 2021, estimated number of new cases of cancer in United States will reach 1,898,1601 from which 608,5702 are believed to be fatal. Despite the fact that there are eight different cancer treatments that have been developed over the years, none of them guarantee that the cancer will be cured permanently and irreversibly. It should be noted that using animals in clinical trials to develop cure for incurable diseases have failed to translate to humans, leaving patients with insufficient treatment or without treatment at all (Archibald, K., 2018). However, using humans for clinical trials is an unpopular alternative to achieve maximum results in cancer research, and while to many it seems inconceivable that humans could be used for clinical trials instead of animals, such way of testing could have an immense impact in developing most eligible treatment for cancer.

No one can deny that clinical trials are an inevitable necessity to detect, prevent, or treat certain diseases. New medicines require testing because researchers must measure both the beneficial and the harmful effects of a compound on a whole organism (Animal Research, 2014). However, despite the possibility of voluntary participation in clinical trials, to date, animals are the main source for testing new drugs. In 2015, 820,8123 animals of different species were held captive in laboratories and used in clinical trials in United States. Meanwhile, in the same year, a relatively small number of 11,0604 United States citizens participated in clinical research, out of which only 588 people volunteered for oncology studies. But why is this a problem?

The answer is quite simple. Every cell in the body of every living organism contains deoxyribonucleic acid, or DNA. Comparing animal and human genetic data, scientists have found that mice and humans share about 85 percent of their DNA, which is one of the reasons why mice are commonly used in medical research (Deziel, C., 2018). However, the similarity of genes between humans and animals does not eliminate the fact that the DNA is not identical, but when it comes to the human genetic code, the situation is somewhat different.

Human body is built out of 3 billion5 genetic building blocks, from which only tiny amount is unique. Riccardo Sabatini, in his TED speech in 2016, demonstrated a visual perception of what is the code of life and how human genetics would look if it were written on a piece of paper. In his example, human DNA consisted of 262,000 pages of information, out of which just about 500 was unique. The main idea of such example was to indicate the fact, that humans are 99.9 percent genetically similar to each other. The remaining 0.1 percent simply describes different aspects such as eye, hair, skin color or whether he/she is predisposed to certain diseases (Ramsey, L., & Lee, S., 2018).

Based on such data, I believe it is also worth mentioning that newly discovered medicine, which has shown its suitability in the animal organism during clinical trials, may not always be suitable for treating human beings. An unsuitable medication may not only fail to perform its functions to suppress the disease, but could also severely damage the human body. A dramatic illustration of such damage was TGN1412 (Theralizumab), which almost killed six clinical trial volunteers in 2006 (Archibald, K., 2018).

Theralizumab, which was intended to treat B cell chronic lymphocytic leukemia and rheumatoid arthritis, has shown stunningly positive results in clinical trials, even with high doses of medication. In the course of medical research TGN1412 was tested in the animal’s body and was expected to be able to cure blood cancer or rheumatoid arthritis, or at least severely alleviate the pain of patients (Coghlan, A., 2006). Because of such positive results in clinical trials, Theralizumab was decided to be tested on six male volunteers.

Sadly, an injected antibody caused the opposite reaction in the human body. Around 60 to 90 minutes after the men received their injections, their bodies were flooded by a surge of inflammatory chemicals called cytokines, which combat severe infections like those seen in patients with blood poisoning (Coghlan, A., 2006). Within 48 hours, patients have experienced many excruciating and unpleasant symptoms, such as headaches, shivering, back pain, gut pain, diarrhea, swelling, nausea and lung pain. Their blood pressure dropped to a dangerously low level, lymphocytes and monocytes started fast vanishing and it became hard to breath (Coghlan, A., 2006). Although after 48 hours, men gradually regained strength and started to recover, all six began to suffer multi-organ failure, and had to be attached to kidney machines. In my opinion this event is a good indication that medicine suitability between animals and humans differ, therefore if new medication helps to fight a certain disease in the animal’s body, it does not mean that the human body will react in the same way.

Newer drugs are constantly being developed and tested in laboratories on various species of animals. It is understandable that many people, on the basis of human rights and ethics, would disagree with the idea that using humans in clinical trials instead of animals is an appropriate alternative to developing cure for cancer. However, even considering the indisputable genetic similarity between humans and animals, it should be kept in mind that DNA is not identical. Drugs continue to be tested in animal organisms, which may result in the test data being far out of touch with reality, and the newly discovered medicine may not properly perform its functions in the human body, as happened with Theralizumab. Therefore, we should strongly think about how actually important it is for us to overcome incurable diseases and finally take more serious actions in order to develop cure for cancer.


  1. Archibald, K. (2018). Animal Research Is an Ethical Issue for Humans as Well as for Animals. Journal of Animal Ethics, 8 (1), 1-11. Retrieved from:

  2. Animal Research (2014). Why Animals are Used. Retrieved from:

  3. Coghlan, A. (2006). Mystery over drug trial debacle deepens. Retrieved from:

  4. Deziel, C. (2018). Animals That Share Human DNA Sequences. Retrieved from:

  5. Ramsey, L., & Lee, S. (2018). Humans share almost all of our DNA with cats, cattle and mice. Retrieved from:

  6. Sabatini, R. (2016). How to read the genome and build a human being. Retrieved from: