BACKGROUND/AIM:This investigator-initiated, open-labelled study describes safety and extrapulmonary outcomes of elexacaftor/tezacaftor/ivacaftor (ETI) treatment in people with cystic fibrosis after lung transplantation (pwCF + LTX), with particular focus on sino-nasal symptoms. ETI has not been systematically administered to people with cystic fibrosis after lunge transplantation (pwCF + LTX) due to lack of data from this subgroup and concerns about potential interactions with immunosuppressive therapy.
METHODS:All pwCF + LTX in Denmark were screened for eligibility and included participants were treated with ETI in standard dosages for 24 weeks, with examinations before and after ETI initiation. Eligibility criteria were at least one F508del mutation, estimated glomerular filtration rate (eGFR) above 30 ml/min/1,73m2, ≤Child-Pugh class B, did not already receive ETI, contraception usage for women, life expectancy exceeding study duration, and considered able to adhere to safety protocol. Safety was determined by calcineurin inhibitor (CNI) trough levels, biochemical markers of organ failure, adverse events, and hospital admissions. Examinations included blood samples (including trough levels of immunosuppressants), Sino-nasal Outcome Test 22 (SNOT-22), smell test, nasal endoscopy score and sinus CT scan, sweat test and spirometry.
RESULTS:Of the 36 pwCF + LTX screened, 24 were eligible and 17 accepted to participate. Five participants ended ETI treatment before study completion because of side effects, most commonly dizziness, flu-like symptoms, sleep problems, and gastrointestinal symptoms. The study showed striking effects on sino-nasal symptoms based on a significantly reduced sinonasal symptom score (SNOT-22) and CT scores; further, the ability to smell improved objectively and nasal endoscopy showed reductions in polyp size, edema and discharge. No effects were found on weight, HbA1C, and FEV1 % predicted. Most participants required reduction in CNI dose, but management of immunosuppression was uncomplicated.
CONCLUSION:ETI has a dramatic effect on sino-nasal symptoms and can safely be co-administered with CNI with careful monitoring of trough levels.