At the end of 48 weeks, people treated with ivacaftor had on average an absolute increase in FEV1 of 10.4%, vs. a decline of 0.2% in the placebo group. Pulmonary exacerbations were reduced by about half in the ivacaftor group relative to the placebo group.In a second trial conducted in children age six to 11, the average improvement in FEV1 was an absolute increase of 12.5% in the ivacaftor group at 48 weeks, compared to a very slight decline in the placebo group. Other mutations
A third clinical trial examined the efficacy of ivacaftor in people with cystic fibrosis due to G1244E, G1349D, G178R, G551S, S1251N, S1255P, S549N, or S549R mutations. This trial, which included 39 people of age greater than six years, used a crossover design. The people in the trial had FEV1 averaging 78% of normal at baseline. The people in the trial were randomized to receive either ivacaftor or placebo for eight weeks. This was followed by a four to eight week washout period, then each group received the opposite treatment from what it received in the first part of the trial. At week 8, the people on treatment with ivacaftor experienced an average absolute improvement in FEV1 of 13.8%, but there was a strong dependence of the efficacy on the exact mutation that a patient had. The detailed data for different mutation types is shown in the U.S package insert. References
External links
"Ivacaftor". Drug Information Portal. U.S. National Library of Medicine. "Ivacaftor mixture with lumacaftor". Drug Information Portal. U.S. National Library of Medicine.
UK agencies estimated the cost per quality adjusted life year (QALY) at between £335,000 and £1,274,000 —well above the National Institute for Health and Care Excellence thresholds.The medication was not covered under the Ontario Drug Benefit plan until June 2014, when the Government of Ontario and the manufacturer negotiated for what "Ontario Health Minister Deb Matthews had called a "fair price" for taxpayers". The negotiations took 16 months and it was estimated that around 20 Ontarians required the medication at the time.The province of Alberta began covering the medication in July 2014, and in September the province of Saskatchewan became the third province to include it in its provincial medication plan.Delay in agreement on a price for Vertex to charge national health plans led to patient group protests in Wales, England, and Australia.As of March 2016, the combination medication cost $259,000 a year in the United States. Research
The clinical trials used in the regulatory approval of ivacaftor are described here. G551D mutation
Of the approximately 70,000 cases of cystic fibrosis worldwide, 4% (~3,000) are due to a mutation called G551D. The safety and efficacy of ivacaftor for the treatment of cystic fibrosis in patients with this mutation was examined in two clinical trials.The first trial was performed in adults having baseline respiratory function (FEV1) between 32% and 98% of normal for persons of similar age, height, and weight. The baseline average was 64%. Improvement in FEV1 was rapid and sustained.