This follows Health Canada‘s approval of Symdeko to treat people who have two copies of the F508del mutation in the CFTR gene (a copy inherited from each parent), or who have one copy of F508del mutation in the CFTR gene and at least one other variant in the gene that is responsive to the treatment.
Defects in the CFTR gene are the underlying cause of cystic fibrosis.
Some of treatment-responsive mutations are P67L, D110H, R117C, L206W, R352Q, A455E, D579G, S945L, S977F, R1070W, and D1152H. CF patients who don’t know their gene mutation may want to talk to their healthcare provider to learn if they have a Symdeko-sensitive mutation.
“This approval is an important milestone in our journey to enhance and expand treatment options for people living with CF,” Reshma Kewalramani, MD, executive vice president and chief medical officer at Vertex, said in a press release. “We have made rapid progress in developing multiple new medicines over the last year, and will continue to relentlessly invest in our science to treat the underlying cause of CF.”
Symdeko is a combination of tezacaftor (VX-661) and ivacaftor (sold under the brand name Kalydeco). This combination therapy was designed to resolve the impaired activity of CFTR protein caused by several genetic mutations linked to cystic fibrosis.
In February 2018 the U.S. Food and Drug Administration approved Symdeko for use in patients ages 12 and older who have two copies of the F508del mutation, or who have at least one mutation in the CF gene that is responsive to the treatment.
Currently, the European Medicines Agency (EMA) is evaluating Vertex’s Marketing Authorization Application for Symdeko, which is expected to be approved in the second half of 2018.
The most recent positive decision of Health Canada was supported by clinical data from the EVOLVE (NCT02347657) and EXPAND (NCT02392234) Phase 3 trials. The studies enrolled a total of 744 people with CF ages 12 and older who had two copies of the F508del mutation, or who had one F508del mutation and a second mutation predicted to be responsive to the combo therapy.
Data from both Phase 3 studies demonstrated that patients who were treated with Symdeko experienced clinically meaningful improvements in lung function compared to Kalydeco alone, evaluated by absolute change from baseline in percent predicted forced expiratory volume in one second (ppFEV1).
Also, patients in the EVOLVE trial treated with the combo therapy had a 35 percent reduction in the annualized rate of pulmonary exacerbations compared to those in the placebo group.
The participants who completed any of the pivotal Phase 3 studies had the opportunity to continue treatment with Symdeko in the 96-week open-label EXTEND Phase 3 (NCT02565914) rollover study.
Interim analyses of the of EXTEND trial were presented during the 41st European Cystic Fibrosis Society (ECFS) Conference held in June in Belgrade, Serbia.
The safety profile was consistent with that observed in the EVOLVE and EXPAND studies, and effectiveness measured as improvements in lung function were also maintained up to 48 weeks.
The data was presented in an oral presentation titled “A phase 3, open-label study of tezacaftor/ivacaftor (TEZ/IVA) therapy: interim analysis of pooled safety, and efficacy in patients heterozygous for F508del-CFTR and a residual function mutation,” and in a poster titled “A phase 3, open-label study of tezacaftor/ivacaftor (TEZ/IVA) therapy: interim analysis of pooled safety, and efficacy in patients homozygous for F508del-CFTR.”
“Ever since the discovery of the CF gene in Canada, the CF community has been hoping for a therapy that targets the root of the disease,” said Elizabeth Tullis, MD, Fellow of the Royal College of Physicians of Canada and director of the Toronto Adult Cystic Fibrosis Clinic at St. Michael’s Hospital.
“The approval of Symdeko brings great hope to people with CF and their families, and provides a new therapy for almost 50 percent of Canadians living with CF,” she added.