By: Janet Woodcock, M.D.
FDA helps bring precision medicine – in the form of targeted therapies — to people living with diseases that have specific genetic features.
Two recent FDA drug approvals point to an encouraging future for “precision medicine” — an approach for disease treatment that tailors medical therapies, including medications, to the needs of individual patients. These approvals involve diseases resulting from particular genetic characteristics identified by laboratory testing.
- In mid-May, FDA announced that we expanded the approval of Kalydeco (ivacaftor), enabling a larger number of patients with cystic fibrosis (CF) to benefit from the drug. The expanded approval includes CF patients with one of 23 additional rare mutations. Kalydeco is now indicated for 33 CF mutations, up from 10 previously.
- Also in May, we announced expanded approval for Keytruda (pembrolizumab) to treat patients whose cancers have a specific genetic feature. This is the first time FDA has approved a cancer treatment based on a genetic feature, rather than the location in the body where the cancer originated.
FDA has approved many more advances in precision medicines, also called “targeted therapies.” In the past 3 years alone, our Center for Drug Evaluation and Research has approved more than 25 new drugs that benefit patients with specific genetic characteristics. And we have approved many more new uses — also based on specific genetic characteristics — for drugs already on the market. Some of these drug approvals are for patients with rare genetic disorders. Others are new targeted therapies to treat cancer, hepatitis C, or HIV. Medication dosing for specific diseases may also be tailored to the individual.
Precision medicine holds great promise, but to continue developing targeted therapies, we will need scientific advances in the use and development of “biomarkers.” Biomarkers are indicators in the body that can be measured—like blood pressure, blood sugar, and tumor size. Tests to identify genetic variants are another form of biomarker. Biomarkers can enable health care professionals and researchers to identify patients at risk of disease, determine the stage of a disease, and predict the likelihood that a patient will benefit from a drug. They also play a role in drug development. A particular biomarker, for example, can be used to identify appropriate candidates for a clinical trial, such as those patients likely to respond to treatment. This can make it easier and faster to recruit patients and may result in a shorter time for drug approval. In a similar way, biomarkers can sometimes identify positive treatment effects before traditional clinical endpoints would. For instance, biomarkers might show a tumor shrinking before improvement in a patient’s condition is detected. So, using biomarkers in clinical trials can speed up the time it takes for an investigative drug to reach a patient.
The ability to identify useful biomarkers depends on how well scientists understand the disease they are seeking to treat. In some areas, such as cancer and infectious diseases, we have made real progress in understanding how these diseases develop and how to treat them with drug therapy. FDA continues to encourage drug developers to use strategies based on biomarkers. One way we do that is by ensuring that a given biomarker is really able to single out those patients who are likely to respond to a specific drug. Another way is using biomarkers to identify people whose disease is progressing rapidly. Beyond working on biomarkers for individual products, FDA also works with stakeholders and scientific consortia in qualifying biomarkers that can be used in the development of many drugs. Once qualified, these biomarkers may be used in the specified manner by any drug sponsor.
New provisions under the recently passed 21st Century Cures Act provide direction and opportunity for FDA to strengthen the science of biomarkers and to advance precision medicine. We believe it is important to make drugs such as Kalydeco and Keytruda available to as many patients as can benefit from them. FDA is actively pursuing more advances in targeted therapies.
Janet Woodcock, M.D., is the Director of FDA’s Center for Drug Evaluation and Research