The U.S. Food and Drug Administration (FDA) has introduced a new plan to help speed up the development of custom-made treatments for rare diseases. These treatments are designed specifically for individual patients or very small groups of people. The new plan, called the “plausible mechanism” pathway, was announced by FDA Commissioner Dr. Martin Makary and his top deputy, Dr. Vinay Prasad, in an article published in the New England Journal of Medicine. They explained that current rules can be too strict and slow down the development of these important treatments. The FDA plans to issue new guidelines to help companies and researchers bring these treatments to patients more quickly. There are over 7,000 rare diseases, many of which are so uncommon that companies may not find it profitable to develop treatments for them. However, new technologies like CRISPR gene editing offer hope for these patients. In recent years, there have been examples of researchers creating custom treatments for specific individuals. For example, in 2018, a girl with Batten disease received a custom treatment using RNA technology. More recently, researchers at the Children’s Hospital of Philadelphia developed a CRISPR-based treatment for a critically ill baby named KJ Muldoon within seven months. The FDA’s new plan aims to make it easier to develop and approve these types of treatments. To qualify, treatments must target the known cause of a disease, and developers must show that the treatment works and improves outcomes. The FDA will prioritize rare diseases, especially those that are deadly or cause serious disabilities in children. However, the new plan could also apply to common conditions where new treatments are urgently needed. The FDA believes that bespoke therapies are becoming more of a reality and this new plan will help bring them to patients who need them.