Expanded PBS Listing for Trikafta®

The Pharmaceutical Benefits Scheme (PBS) listing for Trikafta^® (elexacaftor + tezacaftor + ivacaftor) has recently been expanded. Patients with cystic fibrosis are now eligible for subsidised therapy if they have at least one mutation in the CFTR (cystic fibrosis transmembrane conductance regulator) gene that is considered responsive to Trikafta^®. This update broadens access to this medication, including for patients with rarer mutations.

Trikafta^® is a CFTR modulator therapy with three active ingredients. Elexacaftor and tezacaftor are CFTR correctors and help stabilise defective CFTR protein. Ivacaftor is a CFTR potentiator that enhances the transport of sodium and chloride ions across cell membranes. Triple corrector–potentiator combinations, such as Trikafta^®, have demonstrated greater efficacy than dual combination therapies.

All three components are metabolised by CYP3A enzymes, therefore, there are several significant drug interactions. To be eligible for PBS subsidy, the patient must not be receiving a strong CYP3A inducer such as rifampicin, rifabutin, phenobarbital, carbamazepine, phenytoin, or St. John’s wort.

Trikafta^® is presented as tablets that should be swallowed whole or granules that may be mixed with soft food or liquid. Absorption is improved when doses are taken with a fat-containing meal or snack.