New cystic fibrosis drug approved by Health Canada

Health Canada has approved a new drug for treating some cystic fibrosis patients that was tested by researchers at the University of Toronto and St. Michael’s Hospital.

“For people with cystic fibrosis with a specific mutation — about three per cent of Canadians with cystic fibrosis — this drug will treat the basic CF defect in all cells in their body,” said Elizabeth Tullis, Professor of Medicine at U of T and Director of St. Michael’s Adult Cystic Fibrosis Clinic, the largest in North America. “This is a game-changing drug.”

The drug, Kalydeco, also known by its generic name ivacaftor, is manufactured by Vertex Pharmaceuticals.

Cystic fibrosis is an inherited chronic disease that affects the lungs and digestive system. A defective gene and its protein product cause the body to produce unusually thick, sticky mucus that clogs the lungs and leads to life-threatening lung infections. It also obstructs the pancreas and stops natural enzymes from helping the body break down and absorb food. The condition is the most common fatal genetic disease affecting Canadian children and young adults.

Tullis noted that researchers led by Professor Lap-Chee Tsui at U of T and The Hospital for Sick Children discovered the cystic fibrosis gene in 1989.

“Health Canada’s decision takes us full circle. Twenty-three years later we now have a therapy based on that discovery. It is an excellent example of personalized medicine.”

Toronto was the only site outside of the United States involved in the Phase 2 clinical trial for the drug and had the largest number of patients enrolled in the Phase 3 trial, results of which the New England Journal of Medicine published in 2011.

Tullis said people involved in the Phase 3 clinical trial had improved lung function, fewer chest infections and gained weight. “It worked in multiple organs in the body, and especially in the lungs, which is important as lung disease is the main cause of death in people with cystic fibrosis,” she said.

Tullis said the drug was approved for the three per cent of cystic fibrosis patients with the G551D genetic mutation, which means about 110-120 Canadians a year would benefit from it.

Kalydeco has already been approved by the Food and Drug Administration for use in the United States and by European regulators. The drug must now be reviewed by the Canadian Agency for Drugs and Technologies in Health, which will recommend whether provinces should add it to the list of drugs covered by publicly funded insurance programs.