In a blinded clinical trial, neither the patient nor the clinician should know who is receiving placebo and who the active drug. But during a trial of Kalydeco (ivacaftor), a cystic-fibrosis treatment approved by the US Food and Drug Administration on 31 January, Drucy Borowitz says it was sometimes easy to tell the difference. “We had two brothers in the trial,” says Borowitz, a paediatric pulmonologist at the State University of New York in Buffalo. After two weeks, she says, the pair stepped out of the lift together and it was clear who was taking the drug. “The younger brother looked sturdier,” she says. “It reminded me of the change in appearance that we see in patients with cystic fibrosis after they have lung transplants.”
Kalydeco, made by Vertex Pharmaceuticals of Cambridge, Massachusetts, is the first drug to target a cause of cystic fibrosis rather than the condition’s symptoms. In doing so, it fulfils a promise made more than 20 years ago when a mutated gene, called cystic fibrosis transmembrane conductance regulator (CFTR), was first discovered and researchers spoke optimistically about developing drugs to correct it.