Drug-induced acne with elexacaftor/tezacaftor/ivacaftor in people with cystic fibrosis

Elexacaftor/tezacaftor/ivacaftor (ELX-TEZ-IVA) is a Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulator shown to improve lung function and reduce sweat chloride in people with Cystic Fibrosis (CF). The only commonly reported dermatologic adverse effect with CFTR modulators including ELX-TEZ-IVA is rash. In this case series, we describe 19 patients who reported new onset or worsening of acne after initiation of this drug to their CF pharmacist or another member of their CF care team. The mechanism and frequency of this adverse effect is unknown.     

Peripheral lung effect of elexacaftor/tezacaftor/ivacaftor in adult cystic fibrosis

Despite being an important patient group, adult cystic fibrosis patients with an FEV₁ below 40%predicted have been excluded from clinical trials with elexacaftor/tezacaftor/ivacaftor. We conducted a real-life 3 months follow-up study in 14 adult CF patients (median FEV₁ 34%predicted) demonstrating significant treatment effects in terms of FEV₁ (an increase of 12%predicted at 4 weeks, remaining stable thereafter). Corresponding decreases in lung clearance index LCI (by 31%predicted, down from baseline 247%predicted) and ventilation heterogeneity in the acinar compartment (Sacin) (by 411%predicted, down from baseline 798%predicted) suggest a distinct peripheral lung effect. One patient had intermittent treatment interruptions because of drug-induced liver injury. Our real-life data confirm that treatment with elexacaftor/tezacaftor/ivacaftor is effective in severely obstructive patients, and this is the first study to show time evolution of ventilation distribution improvement, pointing to the peripheral lung as the main site of treatment effect.     

Testicular pain following initiation of elexacaftor/tezacaftor/ivacaftor in males with cystic fibrosis

Elexacaftor/tezacaftor/ivacaftor (Trikafta) was approved by the Food and Drug Administration in October 2019 for treatment of cystic fibrosis (CF) in patients 12 years and older with at least one F508del mutation in the CFTR protein. There were no documented reports of testicular pain during clinical trials. In this case series, we discuss 7 males between 17 and 39 years of age who reported testicular pain or discomfort within the first two weeks of starting therapy. The precise mechanism of this side effect is unknown, but it may be related to restoration of CFTR function in the male reproductive tract. All patients experienced resolution of this side effect within a week after onset, regardless of the management, except for one. Further research is needed to determine short- and long-term impact of this drug on male fertility. Until more data is available, the authors recommend counseling patients on contraceptive options.     

Biliary disease and cholecystectomy after initiation of elexacaftor/ivacaftor/tezacaftor in adults with cystic fibrosis

Individuals with cystic fibrosis (CF) have an increased risk for gallbladder abnormalities and biliary tract disease, but the reported incidence of these manifestations of CF varies widely in the literature. With the approval of elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA), increasing numbers of CF patients have been initiated on highly effective cystic fibrosis transmembrane regulator (CFTR) modulator therapy. While elevations in hepatic panel are known potential side effects of CFTR modulators, there have been no published cases of biliary disease or acute cholecystitis attributed to these medications. In this case series, we describe seven patients at two adult CF centers with biliary colic shortly after initiation with ELX/TEZ/IVA, six of whom required cholecystectomy.     

The effect of elexacaftor/tezacaftor/ivacaftor (ETI) on glycemia in adults with cystic fibrosis

BackgroundCystic fibrosis related diabetes (CFRD) is associated with pulmonary decline and compromised nutritional status. Emerging data suggest that CFTR dysfunction may play a direct role in the pathogenesis of CFRD; however, studies investigating the effect of CFTR modulators on glycemic outcomes in patients with cystic fibrosis (CF) have shown mixed results. The impact of elexacaftor-tezacaftor-ivacaftor (ETI) on glycemic control is currently unknown. Our objective was to investigate the effect of ETI initiation on glycemia in adults with CF using continuous glucose monitoring (CGM).MethodsIn this prospective observational study, 34 adults with CF and at least one F508del CFTR mutation wore CGM sensors for 14 days prior to starting ETI and again 3-12 months after ETI initiation. Hypoglycemia symptoms were queried at each visit, and most recent anthropometric measures and spirometry data were obtained by chart review.ResultsTwenty-three participants completed the study. Compared to baseline, average glucose (AG), standard deviation (SD), % time >200 mg/dL, and peak sensor glucose decreased with ETI treatment, and % time in target range 70-180 mg/dL increased. Improvements in glycemic parameters were most notable in individuals with CFRD. There was no significant change in CGM-measured or self-reported hypoglycemia before and after ETI initiation.ConclusionInitiation of ETI in adults with CF was associated with improvement CGM-derived measures of hyperglycemia and glycemic variability with no effect on hypoglycemia. Further studies are needed to investigate underlying etiology of these changes and the long-term impact of ETI on glycemic control in patients with CF.     

Mental status changes during elexacaftor/tezacaftor / ivacaftor therapy

Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA, Trikafta) is the newest Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulator drug approved by the Food and Drug Administration. Post-marketing reports with earlier CFTR modulators suggest these medications can impact mood, and in clinical trials an adverse effect of headache was reported with all currently approved CFTR modulators. However, there are no other documented reports of mental status changes during clinical trials or in post-marketing reports with elexacaftor/tezacaftor/ivacaftor. In this case series, we describe 6 patients who reported “mental fogginess” or other mental status changes shortly after initiation of this drug. The mechanism of this patient-reported side effect is still unclear. All patients noticed a change within the first 3 months of therapy. The management differed in each case, with all four cystic fibrosis (CF) care teams utilizing a patient-centered decision-making approach to address this concern.     

Projecting the impact of delayed access to elexacaftor/tezacaftor/ivacaftor for people with Cystic Fibrosis

BackgroundTherapies that target the underlying defect in Cystic Fibrosis (CF) will likely impact the future characteristics of the CF population and healthcare utilization. The objectives of this study were to estimate the potential impact of elexacaftor/tezacaftor/ivacaftor on morbidity and mortality, and the impact of delayed access.MethodA microsimulation transition model was applied to Canadian CF Registry data to forecast lung disease severity, pulmonary exacerbations, deaths and transplants to 2030 under three scenarios: 1) no availability of elexacaftor/tezacaftor/ivacaftor, 2) availability in 2021 (‘early’) or 3) availability in 2025 (‘delayed’). Published Phase III data on treatment effects were used to estimate transition rates between disease severity states.ResultsUnder specific assumptions regarding disease state and treatment effect applied to the Canadian CF population it is projected that by 2030, early introduction of elexacaftor/tezacaftor/ivacaftor is expected to reduce the number of individuals with severe lung disease by 60% (95% CI 55.3; 63.9), increase the number of individuals with mild lung disease by 18% (95%CI 18.2; 19.0) and reduce the number of pulmonary exacerbations by 19% (95%CI 18.9; 19.5). Earlier introduction of elexacaftor/tezacaftor/ivacaftor could reduce deaths by 15% (95% 13.2; 18.4) and improve the median age of survival by 9.2 years (7.5; 10.8) over a 10-year period. The expected benefits of therapy are cumulative, therefore delayed access to elexacaftor/tezacaftor/ivacaftor will result in preventable health care utilization and deaths.ConclusionsDelayed access to elexacaftor/tezacaftor/ivacaftor will have a negative impact on lung health and survival in the CF population.     

Onset of systemic arterial hypertension after initiation of elexacaftor/tezacaftor/ivacaftor in adults with cystic fibrosis: A case series

Elexacaftor/tezacaftor/ivacaftor (ETI) is associated with major improvements in respiratory outcomes of individuals with cystic fibrosis (CF) and at least one Phe508del mutation. Although ETI was well tolerated in registration studies, the attention on adverse events not previously described is very high in the post-marketing phase. In this case series we report the onset of systemic arterial hypertension in 4 individuals with CF within the first weeks of starting therapy. All patients needed cardiac evaluation and started chronic anti-hypertensive therapy. Until more data is available, this report could foster the attention of CF physicians towards careful monitoring of cardiovascular parameters in patients starting ETI.     

Magnetic resonance imaging detects improvements of pulmonary and paranasal sinus abnormalities in response to elexacaftor/tezacaftor/ivacaftor therapy in adults with cystic fibrosis

BackgroundTherapy with Elexacaftor/Tezacaftor/Ivacaftor (ETI) was recently approved for adult cystic fibrosis (CF) patients with at least one F508del mutation. However, its effects on structural and functional lung abnormalities and chronic rhinosinusitis have not been studied by imaging.Methods19 adults with CF (mean age 31±9y, range 19–55y) underwent standardized chest magnetic resonance imaging (MRI), and nine also same-session sinonasal MRI, before (MRI1) and after (MRI2) at least one month (mean duration 5 ± 3mon) on ETI. 24 control CF patients (30±7y, range 20–44y) without ETI underwent longitudinal chest MRI, and eleven also sinonasal MRI, twice (mean interval 40±15mon). MRI was assessed using the validated chest MRI score and chronic rhinosinusitis (CRS)-MRI score. Forced expiratory volume in 1 s percent predicted (FEV1%) was measured in all patients.ResultsIn controls, the chest MRI global score and CRS-MRI sum score were stable from MRI1 to MRI2. In patients under ETI, the chest MRI global score improved (-11.4 ± 4.6, P<0.001), mainly due to reduction of bronchiectasis/wall thickening and mucus plugging subscores (-3.3 ± 2.2 and -5.2 ± 1.5, P<0.001, respectively). The improvement in chest MRI score correlated well with improved FEV1% (r=-0.703, P<0.001). The CRS-MRI sum score also improved in patients under ETI (-6.9 ± 3.0, P<0.001), mainly due to a reduction of mucopyoceles in the maxillary and ethmoid sinus (-50% and -39%, P<0.05, respectively).ConclusionsMRI detects improvements of chest MRI and CRS-MRI scores in adult CF patients who first received ETI, demonstrating reversibility of structural lung and paranasal sinus abnormalities in patients with established disease.     

Net benefit of ivacaftor during prolonged tezacaftor/elexacaftor exposure in vitro

BackgroundA decrease in the lumacaftor-mediated increase in F508del-CFTR function and expression upon prolonged exposure to ivacaftor (VX-770) has previously been described. However, the efficacy observed with ivacaftor-containing CFTR modulator therapies in vivo is in conflict with these reports. We hypothesized that a portion of the apparent decrease in CFTR function observed after prolonged ivacaftor exposure in vitro was due to an increase in constitutive CFTR-mediated ion transport.MethodsHuman nasal epithelial (HNE) cells were obtained by brushings from three CF individuals homozygous for the F508del CFTR mutation. Differentiated epithelia were pre-treated with prolonged (24 h) exposure to either lumacaftor (VX-809; 3 µM), tezacaftor (VX-661; 3 µM), elexacaftor (VX-445; 3 µM), and/or ivacaftor (0.1–6.4 µM) or DMSO (vehicle control), and CFTR function was assayed by Ussing chamber electrophysiology.ResultsIn cells treated with lumacaftor, constitutive CFTR activity was not increased at any concentration of co-treatment with ivacaftor. Constitutive CFTR activity was also unchanged in cells treated with the combination of tezacaftor and elexacaftor. An increase in constitutive CFTR activity above the DMSO controls was only observed in cells treated with the combination of tezacaftor and elexacaftor and co-treated with at least 0.1 µM ivacaftor.ConclusionsThese results demonstrate that ivacaftor is a critical component in the triple combination therapy along with tezacaftor and elexacaftor to increase constitutive CFTR function. This work further elucidates the mechanism of action of the effective triple combination therapeutic that is now the primary clinical tool in treating CF.     

Measuring the effect of elexacaftor/tezacaftor/ivacaftor combination therapy on the respiratory pump in people with CF using dynamic chest radiography

BackgroundThe CFTR modulator elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) leads to significant improvement in the symptoms and spirometry of people with cystic fibrosis (pwCF), but little evidence exists to understand its effect on respiratory pump function. Dynamic chest radiography (DCR) is a novel cineradiographic tool that identifies and tracks the chest wall and diaphragm throughout the breathing cycle, alongside fluoroscopic images of the chest of diagnostic quality.MethodsIn this observational work, we examined the spirometry and DCR of 24 pwCF before and after starting ELX/TEZ/IVA. DCR automatically tracked the hemidiaphragm midpoints and projected lung area (PLA) during tidal and deep breathing manoeuvres.ResultsppFEV₁ (61±18 to 73±22, P<0.001) and ppFVC (77±16 to 88±15, P<0.001) improved significantly. DCR demonstrated a significant increase in hemidiaphragm excursion on both the right (18±11 to 26±9 mm, P<0.001) and left (21±11 to 31±11 mm, P<0.001) sides, as well as maximum hemidiaphragm speed during inspiration (right 22±14 to 31±11 mm/s, P=0.03; left 28±11 to 37±16 mm/s, P=0.02). PLA at end-expiration was significantly reduced (334±71 to 290±72cm², P<0.001), with a significant increase in ΔPLA (83±40 to 117±36cm², P<0.001).ConclusionsDCR demonstrated significant improvements in hemidiaphragm excursion and ΔPLA in pwCF started on ELX/TEZ/IVA. These changes likely reflect a reduction in air trapping and improved elastic recoil of the chest, and are consistent with improvements seen in spirometry. The changes seen with DCR are physiologically plausible and correlate well with spirometry. DCR warrants further investigation as a tool for assessing the impact of CFTR-modulating therapies.     

Azithromycin and tezacaftor/ivacaftor is associated with first-degree heart block in an adult with cystic fibrosis

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene is expressed in the heart, but this is not known to cause myocardial dysfunction or abnormalities in the ECG in people with CF.CFTR modulators such as tezacaftor/ivacaftor improve lung function and overall health in people with CF. Minor adverse events have been reported in the early clinical trials, but no consistent changes in the ECGs have been reported.This case highlights an unusual side effect of first degree heart block that occurred after more than 8 months of azithromycin and tezacaftor/ivacaftor in combination. Drug withdrawal and reintroduction confirmed that neither drug alone, but only the combination, caused this change. As tezacaftor/ivacaftor is also present in elexacaftor/tezacaftor/ivacaftor, care may be needed to exclude this delayed interaction with azithromycin.     

Tezacaftor/ivacaftor in people with cystic fibrosis who stopped lumacaftor/ivacaftor due to respiratory adverse events

BackgroundIncreased rates of respiratory adverse events have been observed in people ≥12 years of age with cystic fibrosis homozygous for the Phe508del-CFTR mutation treated with lumacaftor/ivacaftor, particularly in those with percent predicted forced expiratory volume in 1 s (ppFEV₁) of <40%. We evaluated the safety, tolerability, and efficacy of tezacaftor/ivacaftor in people with cystic fibrosis homozygous for Phe508del-CFTR who discontinued lumacaftor/ivacaftor due to treatment-related respiratory signs or symptoms.MethodsParticipants ≥12 years of age with cystic fibrosis homozygous for Phe508del-CFTR with ppFEV₁ of ≥25% and ≤90% were randomized 1:1 and treated with tezacaftor/ivacaftor or placebo for 56 days.ResultsOf 97 participants, 94 (96.9%) completed the study. The primary endpoint was incidence of predefined respiratory adverse events of special interest (chest discomfort, dyspnea, respiration abnormal, asthma, bronchial hyperreactivity, bronchospasm, and wheezing): tezacaftor/ivacaftor, 14.0%; placebo, 21.3%. The adverse events were mild or moderate in severity. None were serious or led to treatment interruption or discontinuation. Overall, the discontinuation rate was similar between groups. The mean (SD) ppFEV₁ at baseline was 44.6% (16.1%) with tezacaftor/ivacaftor and 48.0% (18.1%) with placebo. The posterior mean difference in absolute change in ppFEV₁ from baseline to the average value of days 28 and 56 was 2.7 percentage points with tezacaftor/ivacaftor vs placebo.ConclusionsTezacaftor/ivacaftor was generally safe, well tolerated, and efficacious in people ≥12 years of age with cystic fibrosis homozygous for Phe508del-CFTR with ppFEV₁ of ≥25% and ≤90% who previously discontinued lumacaftor/ivacaftor due to treatment-related respiratory signs or symptoms.