In deciding whether or not to approve a new drug, The U.S. Food and Drug Administration (FDA) is primarily concerned with the safety and efficacy. The agency performs a risk-benefit analysis and a successful drug will benefit patients without causing disproportionate harm. When determining drug safety, the FDA considers several factors, including the frequency and severity of adverse drug effects, the drug’s potential to cause long-term harm, and its overall safety profile in comparison to existing therapies.

In order to be considered effective by the FDA and physicians, a new drug must demonstrate the ability to improve at least one of the following: the way a patient feels, functions, or survives. In oncology, the goal of cancer drugs is often to improve survival. If a new drug can demonstrate that it produces at least one of these three outcomes, it can be said to provide clinical benefit. FDA reviewers weigh a drug’s clinical benefits against its  risks, including the toxicity, that influence the safety and tolerability of a drug in order to determine whether or not it should be approved. The type of clinical benefit that drug developers expect an experimental drug to provide plays a major role in guiding clinical trial design and the selection of endpoints. An endpoint measures clinical benefit.