Cystic fibrosis is a common genetic disease, relatively speaking. About one in 25 to 30 Caucasians are carriers of a cystic fibrosis mutation. But there are more than 1,700 mutations of the cystic fibrosis gene that can result in different disease symptoms.
Researchers and companies working on cystic fibrosis treatments are increasingly paying attention to which mutations a patient carries, and tailoring drugs to certain mutations.
Just recently, the FDA expanded its approval for one cystic fibrosis drug called Kalydeco. It had been approved for use in the case of ten of the mutations. Now it’s approved for 33.
They did it without a full clinical trial. The reason: each mutation is so rare, there just aren’t the hundreds of people a lab needs to do a clinical drug trial.
“You just can’t do it,” said Art Caplan, Professor of Bioethics at New York University's Langone Medical Center.
“Some of the things we usually see, like a randomized trial with hundreds or thousands of subjects, are not going to work because of the ability to pick out genetic differences among subjects, making it harder to do the big studies,” he said.
Another fundamental shift in this area of medicine has to do with how drugs are used. Labs are now investigating how a the same drug might treat a wide range of maladies.
“Some diseases that we don’t even think of as related -- let’s say, ALS, muscular dystrophy, and severe depression – they may turn out to have the same chemical pathway that you can block with a drug,” Caplan said.
“It is huge and it is the future.”