Using a C-sweat test rather than using classic sweat tests or lung function measurements can more reliably assess the benefits of CFTR modulator therapies such as Kalydeco.

The team of researchers investigated the effects of Kalydeco on CFTR in healthy, non-CF individuals, using two complementary assays: sweat chloride levels (a standard for diagnosing CF), and CFTR-dependent sweat rate (C-sweat).

Results showed that Kalydeco significantly increased C-sweating, on average by 18%, confirming prior results that showed the therapy could increase CFTR opening even when the ion channel was working properly.