Our health has improved significantly due to advancements in medicine. We now live longer, better lives than we ever did before; however, most of these improvements took advantage of the sick and desperate.
Whenever a new drug, therapy, or treatment is developed, it must go through several phases of testing to ensure that it is effective, safe, and we understand its side effects. To achieve the most accurate results possible, we perform double blind testing. This form of testing involves at least two drugs, the new drug being tested and either the drug that is currently used to treat the disease or a placebo. Multiple drugs are required to provide a comparison to judge the new drugs efficacy.
Double blind testing avoids biased result because neither the patient nor the physician know which drug the patient is taking.
Thus, once a patient decides to participate in a clinical drug trial, there is approximately a 50% chance that the patient will be given either a placebo or an old drug that is known to be ineffective. With more pathogenic illnesses this can severely reduce a patients quality of life or even result in their death.
Normally the results of these studies are closely watched and if the investigators notice that one treatment method is significantly better than another they often switch all patients to the superior treatment. However, the patients on the inferior treatment will have already suffered significantly.
This means that many advancements in medicine required taking advantage of the desperation of very ill patients. If these patients were not desperate enough to go through clinical trials (wherein they may have been given a placebo), then the treatments would never have been tested and thus never approved for general use. Unfortunately, this is still the best method of treatment approval available to us today. Hopefully one day we will be able to perform robust drug testing without requiring patients to suffer phase 3 clinical trials...but that doesn't seem possible in the near future.