Vertex hit by phase 3 cystic fibrosis failure

Vertex has suffered a setback after a new cystic fibrosis combination failed to show benefits in a sub-group of patients.

The company is to abandon its phase 3 study of VX-661 in combination with Kalydeco (ivacaftor) in people with one copy of the F508del mutation and one copy of a mutation that results in minimal CFTR protein function (F508del het/min).

Results from Part A of the trial failed to show any significant improvement in the patients’ lung function.

VX-661 is the company’s successor to lumacaftor, part of the Orkambi (lumacaftor + ivacaftor) combination.

“While we recognise that people with CF with minimal function mutations have a form of the disease that is particularly difficult to treat, we believed it was important to evaluate whether a dual combination of VX-661 and ivacaftor could provide some benefit to these patients given they do not today have a medicine to treat the cause of their disease,” said Vertex Chief Medical Officer Jeffrey Chodakewitz.

“These results suggest that a triple combination regimen may provide this group of people with CF the best chance at obtaining a meaningful benefit and we look forward to beginning the first study of a next-generation corrector together with VX-661 and ivacaftor in this group of patients later this year, pending data from our ongoing Phase 1 studies in healthy volunteers.”

Despite the setback, analysts say there is mileage in the combination of VX-661/Kalydeco thanks to other ongoing trials. The drug combination is being studied in three further phase 3 studies of distinct CF sub-groups who have at least one copy of the F508del mutation.

VX-661 could improve on Orkambi’s efficacy, and may also produce fewer drug-drug interactions and fewer tolerability and metabolic side-effects.

Two of these studies are expected to report in the first half of 2017, which could be a make-or-break period for the company.

Despite earning $426 million in revenues from Kalydeco and Orkambi in the second quarter, Vertex is still not making a profit. The company recorded a loss of $64.5 million for the period, down from $188.8 million in the same time last year.