Nearly 90 percent of people with CF have at least one copy of the gene mutation which prevents the CF protein from forming the right shape. Corrector drugs help it form that right shape.

Correctors used in combination with potentiators work synergistically to lessen the symptoms of CF. In the newest modulator on the market, the correctors elexacaftor and tezacaftor are combined with potentiator ivacaftor to form Trikafta®, a triple combination used to treat people with CF who have a particular CF gene mutation.

Ivacaftor and lumacaftor, components of Orkambi®, are sometimes called “first-generation modulators” because they were the first modulators approved to treat people with CF. Tezacaftor, approved in February 2018 as part of Symdeko®, is also considered a first-generation modulator.

Elexacaftor is considered to be part of the “next-generation” modulators, which are potentially more effective than the first-generation modulators. Other next-generation therapies are in development. They also are likely to be part of a triple-combination therapy to provide more people with CF a variety of treatment options. It is important to have alternatives because individuals respond differently to these drugs. In addition, not everyone can safely take currently approved modulators as some experience side effects, have drug interactions, or have mutations that are not responsive.

Each of the three drugs in a triple-combination therapy addresses a different aspect of the defective CF protein at the same time. In combination, the results are often better than using one or two of the drugs alone.