Dr. Steven Durovic initially developed Krebiozen in Argentina after he noticed the spontaneous shrinkage or disappearance of some tumors in horses and cattle. Durovic inoculated horses with the bacterium which causes "lumpy jaw" and distilled a powder from their serum. He brought this to the United States where he introduced it to Dr. Andrew Conway Ivy who began study the compound, giving it to 22 cancer patients. According to Ivy 20 of these patients improved. The dosage for Krebiozen was on the order of 10-100 micrograms per week. At a 1951 press conference in Chicago Ivy presented his findings. Ivy is reported to have indicated only biological activity of Krebiozen, without hailing it as a cancer cure; other sources claim he announced finding a cancer cure.
Multiple third party organizations investigated Krebiozen. The American Medical Association (AMA) reported a review of 100 cases, stating that in 98 Krebiozen was ineffective. The National Cancer Institute reviewed over 500 cases coming to similar conclusions. In 1963 the Food and Drug Administration (FDA) obtained a sample, and had identified it as creatine, an amino acid derivative, readily available in a normal diet containing meat. Some samples were found to contain only mineral oil, and others only minute amounts of creatine. The FDA banned interstate shipment of Krebiozen.
Patients, however, reported feeling better and living well beyond their doctors' predictions. This was the source of the controversy: official organizations and doctors claimed Krebiozen was ineffective while other doctors claimed profound healing effects. Books on the subject from both sides arose and people began claiming conspiracy against Krebiozen.
Many stood against Krebiozen's claim, but few were as outspoken as George Stoddard, then the president of the University of Illinois. In a book titled "Krebiozen": the great cancer mystery, Stoddard attempts to "sort out the facts" around Krebiozen and condemns the practices surrounding its origins. Stoddard was forced to resign due in part to banning university facilities from being used on the drug, thought to violate rights to academic freedom. Association with the drug damaged Stoddard's reputation and he had to defend himself in a court battle against Ivy lasting eleven years. Stoddard held his stance against Krebiozen despite the severe repercussions it had on his career because he believed the damages the drug could have on the public were more important than protecting himself.
Many people went along with Krebiozen on blind trust of Doctor Ivy's reputation. Although many doctors and scientists did not personally believe in the drug, their actions can be summed up in a quote by Illinois senator Stephan Douglas: "as long as I am not responsible for the ethical values involved, I shall not interfere in any way." Although George Stoddard considered Ivy "a man of character and high professional standards" he refused to accept any claims about Krebiozen without facts to back it. His reliance on facts alone in spite of the opinion of authority figures is the quintessence of a professional skeptic.
As a result of the Kefauver Harris Amendment following the Thalidomide epidemic, drug manufacturers were now responsible for proving efficacy of their drugs for approval. Alma Hayden, one of the first African American scientists at the FDA, was assigned to identify Krebiozen's contents. With spectrophotometry her team identified the core ingredient as creatine, a substance attained through a regular diet. This discovery gave concrete evidence that Krebiozen has no real medicinal value, something only theorized by scientists before. Despite this, Senator Stephan Douglas held that the FDA test was "not competent" and required further testing. 
Ivy and Durovic were finally indicted with 49 charges including counts of fraud, submitting false information to the government, and many violations of the Food, Drug, and Cosmetic Act.  The heated trial included many citizens protesting and sharing their stories of how Krebiozen has helped in their lives. As a result of so many conflicting stories the verdict ended in a hung jury. According to Foreman Adolph J. Beranek: "We were convinced that it had some merit, and we were not in a position to kill it without a fair trial."
A Krebiozen test on patients would be immoral. For any physician to participate in such a test would be unethical to say the least. The Senate Resolution demands that we carry out a test which I consider almost a criminal act.
— Dr. Endicott of the NCI
A full efficacy study had not been performed on Krebiozen due to its questionable effectiveness from the very beginning. Such a study would require many cancer patients to receive Krebiozen exclusively for treatment and keep them from using standard treatment methods, which had demonstrable curative abilities. To run such a test on a drug that had already been shown worthless was deemed irresponsible and unethical. However, by not performing an official study, Ivy and Durovic were able to evade consequences in the trial and continue selling their drug for years following, possibly impacting many more lives.
Many American citizens were outraged at the dismissal of Krebiozen. Several cancer patients declared that Krebiozen had made them feel better. Some stated that they had been told they only had a few months to live, but, after taking Krebiozen, they had survived for years. Krebiozen supporters founded the Cancer Survivors of Krebiozen group. One of Krebiozen's most dedicated supporters, Laine Friedman, was the chairman of this group. Mrs. Friedman's husband, George Friedman, had developed cancer in 1961.  Mrs Friedman, having heard that Krebiozen was a possible cancer cure, used it to treat George. Even though her husband eventually died from his cancer, Mrs. Friedman was convinced that Krebiozen had benefited him, stating, "Krebiozen kept him alive and made his death a peaceful one. There is no doubt of that in my mind."  In 1963, she led a white house march in support of Krebiozen. 
One explanation for Krebiozen's perceived benefits is the placebo effect. Placebo means "I shall please" in Latin and typically refers to a treatment with no medicinal value.  When successful medical treatments were limited, doctors gave sugar pills to many patients, hoping that the placebo effect would make patients feel better. Often, the belief that a medicine will heal brings about actual changes in the body. Dr. Anne Harrington stated that placebos are "lies that heal".  Multiple studies have been performed to analyze the placebo effect. A Texas study assigned patients suffering from knee pain to one of three groups. Two of the groups received different types of knee surgery, but the other group received a 'fake' surgery. The patients in the 'fake' surgery group were anesthetized and were given small cuts on their knees to imitate the marks made by surgery. This fake surgery group, two years later, reported the same pain relief as the surgery groups.  Although researchers are not sure what causes the placebo effect, one theory is placebos lower a patient's stress, increasing the body's ability to heal. 
Unfalsifiability occurs when no observation can contradict the statement. No one, for example, can contradict a cancer patient's claims to feeling better after a drug administration. Along this vein, no one can say the drug did not cause the improvement. Such a conclusion can be shown to be unlikely, but not incorrect.
Lessons in professionalism and ethics
The Krebiozen scandal is both an example of confirmation bias and unfalsifiability. Cancer is an emotional subject, but it is the duty of professionals to look past the emotions for the facts. No fault can be found in a longing for a cancer cure; fault is found when that longing clouds judgement in drug development and other professional capacities. It is possible that much of the controversy could have been avoided had a double-blind study of Krebiozen been performed early on. Instead Dr. Ivy administered the drug and determined the results. Similarly, while the drug was shown to be a common compound, it is impossible to say it wasn't helping some patients.
In light of this: It is the duty of the professional to seek objectivity in their decision making. This manifests itself in two way: the professional must evaluate information received from authoritative sources, and the professional, as an authoritative source, must evaluate information they are going to disseminate. The professional must be aware of their own biases and those of others; evaluation of information with these biases in mind can allow for more objective decision making. In the Krebiozen case this would have meant more experimentation for confidence in efficacy of the drug before releasing it to the public, including a double blind study to reduce bias, and determination of the chemical makeup to reduce unfalsifiability.
"Without Ivy, there would have been no Krebiozen ... After all, Doctor Ivy was no cancer quack.
— Dr. George Wakerlin, director of the American Heart Association
The epidemic and damages resulting from Krebiozen could easily be considered the result of Dr. Durovic. He brought the substance to the U.S. and introduced its "amazing abilities." However, these claims may have been quickly passed off as quackery if not for Dr. Ivy's support. Using his influential credibility as a professional to extol Krebiozen, he was able to bring an unproven miracle cure into widespread use. Although Ivy did not create the drug itself he bears the brunt of responsibility for failure to do what is right for the public as a man of professional standing.
- [Goldman R. THE FANTASTIC KREBIOZEN STORY. Saturday Evening Post [serial online]. January 4, 1964;237(1):15-19. Available from: Academic Search Complete, Ipswich, MA. ], "The Fantastic Krebiozen Story"
- , "Cancer: The Krebiozen Verdict"
- Stoddard, G. D. 1897-1981. (1955). "Krebiozen": the great cancer mystery. Boston: Beacon Press.
- BLAKESLEE, S. (1998). Placebos Prove So Powerful Even Experts Are Surprised: New Studies Explore the Brain’s Triumph Over Reality. New York Times, p. F1.