In clinical trials, a washout period describes the length of time that someone enrolled in a trial must not receive any treatment before receiving the trial’s experimental treatment. A washout may be required before joining a trial or before changing treatments within a trial. In MBC trials, the washout period is often two to six weeks.
There are two main reasons researchers require a washout period: to study the effects of only the treatment being studied and to ensure participant safety by removing the possibility of drugs interacting with each other in unexpected ways. However, trials with longer washout periods can be challenging for people with fast-growing tumors or tumors that are causing symptoms and affecting quality of life.
Because of patient and advocate concerns about the washout period, clinical trial regulators are working with researchers and patients to determine more appropriate guidelines for washout periods. In April 2024, the Food and Drug Administration (FDA) issued new guidelines about washout periods.
Read the following articles to learn about why washout periods are required, concerns around requiring people to stop treatment, potential solutions to prespecified washout periods, and the FDA’s new guidance.
What is the Washout Period and Why is it Needed?
- Celerion: The washout period is the time before beginning a trial when you cannot receive any treatment or before you can change drugs while on a trial
- Lilly: The washout period is needed to ensure that the effects of treatment are due to the experimental drug and not a previous medication
Experts Comment on the New Guidelines From the FDA About Washout Periods
- Targeted Oncology: The FDA recommends that washout periods be based on what happens to the drug and to the person taking the drug (scroll to “Washout Periods and Concomitant Medications”)
Last Modified on July 1, 2024