Results from a Phase 3 trial demonstrate that Symkevi (tezacaftor and ivacaftor combo), known as Symdeko in the U.S., is safe and can effectively improve lung clearance in children, from 6 to 11 years old, with cystic fibrosis (CF).
With these results, Vertex Pharmaceuticals — the company responsible for Symdeko/Symkevi development and marketing — is planning to submit a request to the European Medicines Agency in the second half of 2019 to expand Symkevi’s label to include this patient population — children who have CF due to two copies of the F508del mutation in the CFTR gene, or one copy of the F508del plus one residual function mutation.
This follows a previous supplementary new drug application that Vertex submitted in late 2018 with the U.S. Food and Drug Administration seeking the extended approval of Symdeko for the same indication.
“These data mark an important milestone in our efforts to expand treatment options for patients living with CF,” Reshma Kewalramani, MD, executive vice president and chief medical officer at Vertex, said in a press release.
Extension of Symkevi’s indication will bring “us a step closer to potentially providing more children with a treatment option that addresses the underlying cause of the disease,” Kewalramani added.
The Phase 3 clinical study (NCT03559062) enrolled 67 CF children, from 6 to 11 years old, across 23 sites in Europe and four in Australia. All participants had CF caused by either two copies of the F508del mutation — the most common genetic mutation in the CFTR gene known to cause the disease — or one copy of the F508del mutation and one residual function mutation.
The main goal of the study was to assess changes in lung clearance index (LCI) during the treatment period, which is a measure of lung ventilation capacity. LCI is considered a more sensitive measure to detect early lung disease than forced expiratory volume in one second (FEV1). Higher LCI scores indicate poorer lung function.
Upon completion of the treatment period, children treated with Symkevi showed a mean difference in LCI of -0.51 points, compared with the other groups, which indicates a significant improvement in lung clearance.
In general, the treatment was well-tolerated, as described in previous clinical studies and with no additional safety issues identified. The most common side effects reported in patients treated with Symkevi were cough, headache, and productive cough.
No serious adverse events or side effects leading to treatment discontinuation were observed.