CFTR modulators: transformative therapies for cystic fibrosis.

DISCLOSURES: No funding contributed to the writing of this commentary. Both authors are employed by the Cystic Fibrosis Foundation. The Cystic Fibrosis Foundation has entered into therapeutic development award agreements and licensing agreements to assist with the development of CFTR modulators that may result in intellectual property rights, royalties, and other forms of consideration provided to CFF. Some of these agreements are subject to confidentiality restrictions and, thus, CFF cannot comment on them.

The effectiveness and value of novel treatments for cystic fibrosis.

DISCLOSURES: Funding for this summary was contributed by Arnold Ventures, California Health Care Foundation, Harvard Pilgrim Health Care, and Kaiser Foundation Health Plan to the Institute for Clinical and Economic Review (ICER), an independent organization that evaluates the evidence on the value of health care interventions. ICER's annual policy summit is supported by dues from Aetna, America's Health Insurance Plans, Anthem, Allergan, Alnylam, AstraZeneca, Biogen, Blue Shield of CA, Boehringer-Ingelheim, Cambia Health Services, CVS, Editas, Express Scripts, Genentech/Roche, GlaxoSmithKline, Harvard Pilgrim, Health Care Service Corporation, HealthFirst, Health Partners, Johnson & Johnson (Janssen), Kaiser Permanente, LEO Pharma, Mallinckrodt, Merck, Novartis, National Pharmaceutical Council, Pfizer, Premera, Prime Therapeutics, Regeneron, Sanofi, Spark Therapeutics, and United Healthcare. Seidner, Rind, and Pearson are employed by ICER. Tice reports contracts to his institution, University of California, San Francisco, from ICER during the conduct of this study. Wherry has nothing to disclose.

Cost-Effectiveness of Ivacaftor Therapy for Treatment of Cystic Fibrosis Patients With the G551D Gating Mutation.

OBJECTIVES: Cystic fibrosis (CF) is a rare genetic disease with no cure. Until recently, treatment has targeted symptoms of the disease and not the disease-causing genetic defect. Ivacaftor is included in a new class of breakthrough drugs targeting the genetic defects of CF. We sought to estimate the long-term cost-effectiveness of ivacaftor from a US payer perspective. METHODS: We developed an individual-level microsimulation model that followed a cohort of heterogeneous US CF patients over a lifetime. The primary outcome of interest was quality-adjusted life years (QALYs). We also compared unadjusted life years, count of acute pulmonary exacerbations, and count of lung transplants over a lifetime between patients treated with ivacaftor plus best supportive care and patients treated with best supportive care alone. We conducted one-way and probabilistic sensitivity analyses to test the impact of various model inputs and uncertainties. RESULTS: We found a substantial increase in QALYs, life years, and treatment costs over a lifetime for patients treated with ivacaftor plus best supportive care versus best supportive care alone. Discounted results for ivacaftor were 22.92 QALYs and $8 797 840 in total lifetime costs compared to 16.12 QALYs and $2 336 366 lifetime costs for best supportive care alone. The incremental cost-effectiveness ratios (ICERs) were $950 217 per QALY. Results from the probabilistic sensitivity analysis indicated a 0% chance that ivacaftor was cost-effective at a willingness-to-pay (WTP) threshold of $500 000 per QALY. CONCLUSIONS: Treatment with ivacaftor plus best supportive care versus best supportive care alone is not cost-effective at or near commonly accepted WTP thresholds.

Health Care Cost in Patients With Schizophrenia Treated With Brexpiprazole Versus Other Oral Atypical Antipsychotic Therapy.

PURPOSE: Brexpiprazole is an oral atypical antipsychotic (OAA) for the treatment of schizophrenia (SCZ). This study compared all-cause and psychiatric inpatient hospitalization and medical costs in adult patients with SCZ newly treated with brexpiprazole versus other US Food and Drug Administration-approved OAAs in a real-world setting. METHODS: This retrospective cohort study analyzed data from: (1) the IBM MarketScan Commercial and Medicare Supplemental databases, and the MarketScan Multi-State Medicaid database; and (2) the de-identified Optum Clinformatics Datamart. Adult patients were identified if they had SCZ and initiated either brexpiprazole or another OAA during the study identification period (July 1, 2015, to September 30, 2016, for MarketScan Commercial and Medicare Supplemental and for Optum; July 1, 2015, to June 30, 2016, for MarketScan Multi-State Medicaid) and had ≥12 months of continuous enrollment before (baseline) and after (follow-up) the first treatment date. Linear regression analyses were performed to test associations between treatment groups (brexpiprazole vs another OAA) and costs (total and medical); negative binomial regression models were used to estimate number of hospitalizations per year, adjusting for baseline characteristics and medication adherence to index treatment during the 12-month follow-up. FINDINGS: The final study sample consisted of 6254 patients with SCZ: 176 initiated brexpiprazole; 391, ziprasidone; 453, paliperidone; 523, lurasidone; 786, aripiprazole; 1234, quetiapine; 1264, olanzapine; and 1427, risperidone. Controlling for baseline characteristics and medication adherence, the adjusted number of hospitalizations (both all-cause and psychiatric), all-cause total costs, and all-cause medical costs did not differ across groups. Brexpiprazole users had the lowest mean psychiatric costs among all OAA users ($12,013; 95% bootstrap CI, 7488-16,538). Compared with brexpiprazole users, paliperidone (incidence rate ratio [95% CI], 1.52 [1.05-2.19]; P = 0.027) and quetiapine (incidence rate ratio [95% CI], 1.47 [1.04-2.07]; P = 0.029) users had more psychiatric hospitalizations per year. Paliperidone had higher psychiatric costs than brexpiprazole (total, $32,066 [95% bootstrap CI, 28,779-35,353] vs $23,851 [18,907-28,795]; medical, $19,343 [16,294-22,392] vs $12,013 [7488-16,538]). Psychiatric medical costs were also $6744 higher in olanzapine users (95% bootstrap CI, 1694-11,795; P = 0.009) than in brexpiprazole users. IMPLICATIONS: Patients with SCZ treated with brexpiprazole had fewer psychiatric hospitalizations and lower psychiatric costs than those treated with paliperidone. Differences in the number of all-cause hospitalizations and medical costs among treatments were not statistically significant. Although treatment decisions are driven by a number of factors (eg, clinical circumstances and drug costs), choice of OAA may affect health care costs.

Adherence to lumacaftor-ivacaftor therapy in patients with cystic fibrosis in France.

BACKGROUND: Lumacaftor-ivacaftor combination is a promising treatment for cystic fibrosis (CF) patients homozygous for the F508del-CFTR mutation. Optimal adherence is essential to achieve full health outcomes benefits. METHODS: This retrospective study used pharmacy refills data to calculate proportion of days covered (PDC). Adherence was defined as a PDC ≥80%. A logistic regression analysis was conducted to examine factors associated with medication adherence. RESULTS: Ninety-six patients were included in the final cohort for analysis. The mean PDC was 96%  ± 14 at 6 months, and 91% ± 17 at 12 months. The proportion of adherent patients was 89% and 83% at 6 and 12 months respectively. Age and ppFEV1 were found to affect medication adherence. CONCLUSIONS: Considering the medico-economic impact of CFTR modulator therapy, high adherence rates to lumacaftor-ivacaftor found in this study are encouraging.

Orphan Drug Pricing and Costs: A Case Study of Kalydeco and Orkambi.

BACKGROUND: A common narrative is that high prices are necessary for "orphan drugs" because of the fewer patients. In the context of state health insurance systems, the high prices create significant challenges because of limited budgets. RESULTS: This study carefully examines both costs and revenues of two drugs for cystic fibrosis (ivacaftor and lumacaftor), showing that, for this important example, prices are not high because of fewer patients. The study then explores the justifications usually given for high orphan drug prices, including the need to support research and development for new drugs. Each of these standard justifications is shown to be inadequate; instead, it appears that the exercise of market power in the presence of insurance is the dominant driver of high prices. INTERPRETATION: Insurers need to re-examine how they address high-priced drugs.

Medication Adherence, Health Care Utilization, and Costs in Patients With Major Depressive Disorder Initiating Adjunctive Atypical Antipsychotic Treatment.

PURPOSE: The purpose of this study was to compare medication adherence, health care utilization, and cost among patients receiving adjunctive treatment for major depressive disorder (MDD) with brexpiprazole, quetiapine, or lurasidone. METHODS: Using Truven Health MarketScan® Commercial, Medicaid, and Medicare Supplemental Databases, we identified adults with MDD initiating adjunctive treatment with brexpiprazole, quetiapine, or lurasidone (index atypical antipsychotic [AAP]). We compared medication adherence and persistence measured by proportion of days covered (PDC) and treatment duration of index AAP, all-cause and psychiatric hospital care (hospitalization or emergency department visit), and medical costs during 6-month follow-up. Models performed included logistic regression for hospital care, linear regression for PDC and cost, and Cox proportional hazards regression for time to discontinuation, adjusting for demographic, clinical, and utilization differences during the 6 months before index AAP. FINDINGS: The total sample included 778 brexpiprazole, 626 lurasidone, and 3458 quetiapine therapy initiators. Adjusting for baseline differences, the risk of discontinuation of index AAP was statistically significantly higher for quetiapine than for brexpiprazole (hazard ratio [HR] = 1.13; 95% CI, 1.02-1.25; P = 0.023) and did not differ between lurasidone and brexipiprazole (HR = 1.14; 95% CI, 1.00-1.29; P = 0.054). The adjusted rate of all-cause hospitalization or emergency department visit in the postindex period was lowest for brexpiprazole at 27.4% (95% CI, 24.0%-31.0%), compared with 31.1% (95% CI, 27.3%-35.2%) for lurasidone and 35.3% (95% CI, 33.5%-37.1%) for quetiapine (P< 0.001 for all comparisons). Quetiapine users had increased all-cause costs compared with brexpiprazole users (estimate = $2309; 95% CI, $31-$4587; P = 0.047); all-cause medical costs did not differ between lurasidone and brexpiprazole (estimate = $913; 95% CI, $-2033 -$3859; P = 0.543). Adjusted psychiatric hospital care, psychiatric costs, and PDC did not differ significantly among the groups. IMPLICATIONS: In patients with MDD and a variety of insurance types, brexpiprazole use was associated with statistically significantly lower risks of discontinuation, risk of hospital care (hospitalization and ED visits), and all-cause medical costs compared with adjunctive quetiapine. Differences between brexpiprazole and lurasidone were not statistically significant. These findings suggest that drug choice is associated with subsequent health care utilization and costs.

Cost-effectiveness of twice-daily indacaterol/glycopyrrolate inhalation powder for the treatment of moderate to severe COPD in the US.

BACKGROUND: Indacaterol 27.5 µg/glycopyrrolate 15.6 µg (IND/GLY 27.5/15.6 µg) inhalation powder, a twice-daily, fixed-dose combination of a long-acting beta2-agonist (LABA) and a long-acting antimuscarinic antagonist (LAMA), is indicated in the US for long-term maintenance treatment of airflow obstruction in patients with COPD. The safety and efficacy of IND/GLY 27.5/15.6 µg have been established, but cost-effectiveness is not yet known. This study compared the cost-effectiveness of IND/GLY 27.5/15.6 µg with other long-acting COPD maintenance therapies. METHODS: A Markov model was constructed from the US payer perspective. Health states were defined as mild (post-bronchodilator FEV1 ≥80% of predicted), moderate (50% ≤FEV1 <80% of predicted), severe (30% ≤FEV1 <50% of predicted), and very severe (FEV1 <30% of predicted) COPD. Patients entering the model transitioned through health states based on placebo-adjusted change from baseline in trough FEV1 for each comparator at week 12. Comparators included other US Food and Drug Administration-approved LABA/LAMA fixed-dose combinations as well as commonly prescribed LAMA and LABA/inhaled corticosteroid agents. One-way and probabilistic sensitivity analyses were conducted to test the model assumptions and the overall robustness of the results. RESULTS: Using the model, IND/GLY 27.5/15.6 µg treatment for 12 weeks resulted in total costs of US $23,375 vs US $9,365 for placebo. Compared with placebo, IND/GLY 27.5/15.6 treatment resulted in the highest improvement in FEV1 across all comparators and the lowest cost per decline in 100 mL FEV1. IND/GLY 27.5/15.6 µg was also among the most cost-effective treatment option as measured by St George's Respiratory Questionnaire response rate, at US $3,518 per additional responder at 12 weeks compared with placebo. In addition, IND/GLY 27.5/15.6 µg had the lowest cost per severe exacerbation avoided vs placebo across all comparators (US $87,686). CONCLUSION: This model, developed from the US payer perspective with a 5-year time horizon, found IND/GLY 27.5/15.6 µg to be a cost-effective treatment option for patients with moderate to severe COPD.

Cost-Effectiveness and Budget Impact of Lumacaftor/Ivacaftor in the Treatment of Cystic Fibrosis.

BACKGROUND: Cystic fibrosis (CF) is a chronic, progressive, genetic disease affecting more than 30,000 people in the United States and 70,000 people globally. The goals of treatment are to slow disease progression, reduce pulmonary exacerbations, relieve chronic symptoms, and improve the patient's quality of life. Lumacaftor/ivacaftor is a new therapy for CF that has demonstrated good clinical outcomes, including improved absolute percentage predicted forced expiratory volume in 1 second (FEV1%). However, given the high cost of therapy, there is a need to evaluate the overall value of lumacaftor/ivacaftor in CF management. OBJECTIVES: To (a) conduct a cost-effectiveness analysis (CEA) of lumacaftor/ivacaftor to understand the overall effectiveness of the drug compared with its costs and (b) conduct a budget impact analysis (BIA) to understand the potential financial effect of introducing a new drug in a health plan. METHODS: Two static decision models were developed using Microsoft Excel to evaluate the cost-effectiveness and budget impact of lumacaftor/ivacaftor over a 1-year time frame from a payer perspective. Model inputs included drug costs (wholesale acquisition costs), drug monitoring schedules (package inserts), drug monitoring costs (Centers for Medicare & Medicaid physician fee schedule and published literature), FEV1% predicted and pulmonary exacerbation values (clinical trials), and cost to treat pulmonary exacerbations (published literature). The outcomes in the CEA included total cost of therapy; average cost-effectiveness ratio (ACER), defined as cost per FEV1% predicted; and incremental cost-effectiveness ratio (ICER), defined as the difference in the ratio of cost per FEV1% predicted of lumacaftor/ivacaftor and placebo. Outcomes in the BIA included total budget impact; cost per member per month (PMPM), defined as total budget impact per hypothetical plan population; and cost per treated member per month (PTMPM), defined as total budget impact per target CF population. All costs were adjusted to 2016 dollars, and one-way sensitivity analyses were conducted to test the model robustness given uncertainty in model inputs and study assumptions. RESULTS: The annual cost of therapy per patient for lumacaftor/ivacaftor was $379,780. The ACER for lumacaftor/ivacaftor was $151,912, while the ICER for lumacaftor/ivacaftor compared with placebo was $95,016 per FEV1% predicted. The annual total budget impact due to the inclusion of lumacaftor/ivacaftor on the health plan formulary was $266,046. The PMPM cost was $0.02 and the PTMPM cost was $6.21. CONCLUSIONS: In patients with CF, lumacaftor/ivacaftor has demonstrated better clinical effectiveness compared with placebo alongside an increased drug acquisition cost. However, the therapy may be a viable alternative to existing standard therapy over a short time horizon. Health care payers, both private and public, need to evaluate the cost-effectiveness and the financial effect when considering expansion of new drug coverage in CF management. DISCLOSURES: No outside funding supported this study. Covvey and Kamal have received research funding from Novartis Pharmaceuticals. Covvey, Giannetti, and Kamal have received research funding from the College of Psychiatric and Neurologic Pharmacists. Kamal serves as a consultant to the Lynx Group (Cranbury, NJ) and Manticore Consulting Group (Scottsdale, AZ). Mukherjee has nothing to disclose. A related poster abstract was presented at the AMCP Managed Care & Specialty Pharmacy Annual Meeting; March 27-30, 2017; Denver, CO.

Enumerating the economic cost of antimicrobial resistance per antibiotic consumed to inform the evaluation of interventions affecting their use.

Background: Antimicrobial resistance (AMR) poses a colossal threat to global health and incurs high economic costs to society. Economic evaluations of antimicrobials and interventions such as diagnostics and vaccines that affect their consumption rarely include the costs of AMR, resulting in sub-optimal policy recommendations. We estimate the economic cost of AMR per antibiotic consumed, stratified by drug class and national income level. Methods: The model is comprised of three components: correlation coefficients between human antibiotic consumption and subsequent resistance; the economic costs of AMR for five key pathogens; and consumption data for antibiotic classes driving resistance in these organisms. These were used to calculate the economic cost of AMR per antibiotic consumed for different drug classes, using data from Thailand and the United States (US) to represent low/middle and high-income countries. Results: The correlation coefficients between consumption of antibiotics that drive resistance in S. aureus, E. coli, K. pneumoniae, A. baumanii, and P. aeruginosa and resistance rates were 0.37, 0.27, 0.35, 0.45, and 0.52, respectively. The total economic cost of AMR due to resistance in these five pathogens was $0.5 billion and $2.9 billion in Thailand and the US, respectively. The cost of AMR associated with the consumption of one standard unit (SU) of antibiotics ranged from $0.1 for macrolides to $0.7 for quinolones, cephalosporins and broad-spectrum penicillins in the Thai context. In the US context, the cost of AMR per SU of antibiotic consumed ranged from $0.1 for carbapenems to $0.6 for quinolones, cephalosporins and broad spectrum penicillins. Conclusion: The economic costs of AMR per antibiotic consumed were considerable, often exceeding their purchase cost. Differences between Thailand and the US were apparent, corresponding with variation in the overall burden of AMR and relative prevalence of different pathogens. Notwithstanding their limitations, use of these estimates in economic evaluations can make better-informed policy recommendations regarding interventions that affect antimicrobial consumption and those aimed specifically at reducing the burden of AMR.

Cost-effectiveness analysis of a fixed-dose combination of indacaterol and glycopyrronium as maintenance treatment for COPD.

OBJECTIVE: The aim of this study was to evaluate the cost-effectiveness of the long-acting beta-2 agonist (LABA)/long-acting muscarinic antagonist (LAMA) dual bronchodilator indacaterol/glycopyrronium (IND/GLY) as a maintenance treatment for COPD patients from the perspective of health care payer in Taiwan. PATIENTS AND METHODS: We adopted a patient-level simulation model, which included a cohort of COPD patients aged ≥40 years. The intervention used in the study was the treatment using IND/GLY, and comparators were tiotropium or salmeterol/fluticasone combination (SFC). Data related to the efficacy of drugs, incidence of exacerbation, and utility were obtained from clinical studies. Direct costs were estimated from claims data based on the severity of COPD. The cycle length was 6 months (to match forced expiratory volume in 1 second [FEV1] data), and the time horizons included 1, 3, 5, 10 years, and lifetime. Deterministic and probabilistic sensitivity analyses were conducted to test the robustness of the model results. Costs were expressed in US dollars with a discount rate of 3.0%. RESULTS: Compared to tiotropium and SFC, the incremental cost-effectiveness ratios (ICERs) per quality-adjusted life year (QALY) gained of patients treated with IND/GLY were US$5,987 and US$14,990, respectively. One-way sensitivity analysis revealed that the improvement in FEV1 provided by IND/GLY, the distribution of patients with regard to the severity of COPD, and acute exacerbation rate ratio were the key drivers behind cost-effectiveness. Adopting a willingness to pay of US$60,000 per QALY gained as the threshold, there was a 98.7% probability that IND/GLY was cost-effective compared to tiotropium. Similarly, there was a 99.9% probability that IND/GLY was cost-effective compared to SFC. CONCLUSION: As a maintenance treatment for COPD, we consider the dual bronchodilator IND/GLY as a cost-effective strategy when compared to either tiotropium or SFC.

Cost-effectiveness of indacaterol/glycopyrronium in comparison with salmeterol/fluticasone combination for patients with moderate-to-severe chronic obstructive pulmonary disease: a LANTERN population analysis from Singapore.

INTRODUCTION: In light of the growing evidence base for better clinical results with the use of the dual bronchodilator indacaterol/glycopyrronium (IND/GLY) over inhaled corticosteroid-containing salmeterol/fluticasone combination (SFC), this study aimed to evaluate the cost-effectiveness of IND/GLY over SFC in patients with moderate-to-severe chronic obstructive pulmonary disease (COPD) who are at low risk of exacerbations, in the Singapore healthcare setting. METHODS: A previously published patient-level simulation model was adapted for use in Singapore by applying local unit costs. The model was populated with clinical data from the LANTERN and ECLIPSE studies. Both costs and health outcomes were predicted for the lifetime horizon from a payer's perspective and were discounted at 3% per annum. Costs were expressed in 2015 USD exchange rates. Uncertainty was assessed through probabilistic sensitivity analysis. RESULTS: Compared to SFC, use of IND/GLY increased mean life expectancy by 0.316 years and mean quality-adjusted life years (QALYs) by 0.246 years, and decreased mean total treatment costs (drug costs and management of associated events) by USD 1,474 over the entire lifetime horizon. IND/GLY was considered to be 100% cost-effective at a threshold of 1 × gross domestic product per capita. The cost-effectiveness acceptability curve showed that IND/GLY was 100% cost-effective at a willingness-to-pay threshold of USD 0 (additional cost) when compared to SFC. CONCLUSION: IND/GLY was estimated to be highly cost-effective compared to SFC in patients with moderate-to-severe COPD who are not at high risk of exacerbations in the Singapore healthcare setting.

Forecasting the Long-Term Clinical and Economic Outcomes of Lumacaftor/Ivacaftor in Cystic Fibrosis Patients with Homozygous phe508del Mutation.

OBJECTIVES: To forecast lifetime outcomes and cost of lumacaftor/ivacaftor combination therapy in patients with cystic fibrosis (CF) with homozygous phe508del mutation from the US payer perspective. METHODS: A lifetime Markov model was developed from a US payer perspective. The model included five health states: 1) mild lung disease (percent predicted forced expiratory volume in 1 second [FEV1] >70%), 2) moderate lung disease (40% ≤ FEV1 ≤ 70%), 3) severe lung disease (FEV1 < 40%), 4) lung transplantation, and 5) death. All inputs were derived from published literature. We estimated lumacaftor/ivacaftor's improvement in outcomes compared with a non-CF referent population as well as CF-specific mortality estimates. RESULTS: Lumacaftor/ivacaftor was associated with additional 2.91 life-years (95% credible interval 2.55-3.56) and additional 2.42 quality-adjusted life-years (QALYs) (95% credible interval 2.10-2.98). Lumacaftor/ivacaftor was associated with improvements in survival and QALYs equivalent to 27.6% and 20.7%, respectively, for the survival and QALY gaps between CF usual care and their non-CF peers. The incremental lifetime cost was $2,632,249. CONCLUSIONS: Lumacaftor/ivacaftor increased life-years and QALYs in CF patients with the homozygous phe508del mutation and moved morbidity and mortality closer to that of their non-CF peers but it came with higher cost.

Indacaterol/glycopyrronium is cost-effective compared to salmeterol/fluticasone in COPD: FLAME-based modelling in a Swedish population.

BACKGROUND: This study assessed the cost-effectiveness of indacaterol/glycopyrronium (IND/GLY) versus salmeterol/fluticasone (SFC) in chronic obstructive pulmonary disease (COPD) patients with moderate to very severe airflow limitation and ≥1 exacerbation in the preceding year. METHODS: A previously published and validated patient-level simulation model was adapted using clinical data from the FLAME trial and real-world cost data from the ARCTIC study. Costs (total monetary costs comprising drug, maintenance, exacerbation, and pneumonia costs) and health outcomes (life-years (LYs), quality-adjusted life-years (QALYs)) were projected over various time horizons (1, 5, 10 years, and lifetime) from the Swedish payer's perspective and were discounted at 3% annually. Uncertainty in model input values was studied through one-way and probabilistic sensitivity analyses. Subgroup analyses were also performed. RESULTS: IND/GLY was associated with lower costs and better outcomes compared with SFC over all the analysed time horizons. Use of IND/GLY resulted in additional 0.192 LYs and 0.134 QALYs with cost savings of €1211 compared with SFC over lifetime. The net monetary benefit (NMB) was estimated to be €8560 based on a willingness-to-pay threshold of €55,000/QALY. The NMB was higher in the following subgroups: severe (GOLD 3), high risk and more symptoms (GOLD D), females, and current smokers. CONCLUSION: IND/GLY is a cost-effective treatment compared with SFC in COPD patients with mMRC dyspnea grade ≥ 2, moderate to very severe airflow limitation, and ≥1 exacerbation in the preceding year.

Ivacaftor for cystic fibrosis: An evaluation of real world utilisation and expenditure in the Irish Healthcare Setting.

In Ireland, Ivacaftor is reimbursed, on the High-Tech Drug Scheme, for the treatment of cystic fibrosis in patients age 6 years and older who have the G551D mutation. The aim of this study was to analyse the utilisation and expenditure of Ivacaftor on this scheme in the 12 month period post-reimbursement. All patients who had received Ivacaftor (regardless of General Medical Services Scheme eligibility/ineligibility) were included. A total of 140 individuals (male=74; 53%) received Ivacaftor over the defined 12 month study period (from January 2015 to December 2015 inclusive). The cohort ranged in age from 6 years to 61 years. The mean age was 22 years; a positive skew in age distribution indicated that a greater number of the cohort were in the younger age groups. No statistically significant difference was detected in the mean ages of the male and female subgroups. Drug acquisition expenditure by the Health Services Executive on Ivacaftor over the 12 month study period was €29.81 million.

The pharmacokinetic interaction between ivacaftor and ritonavir in healthy volunteers.

AIMS: The aim of this study was to determine the pharmacokinetic interaction between ivacaftor and ritonavir. METHODS: A liquid chromatography mass spectrometry (LC-MS) method was developed for the measurement of ivacaftor in plasma. An open-label, sequential, cross-over study was conducted with 12 healthy volunteers. Three pharmacokinetic profiles were assessed for each volunteer: ivacaftor 150 mg alone (study A), ivacaftor 150 mg plus ritonavir 50 mg daily (study B), and ivacaftor 150 mg plus ritonavir 50 mg daily after two weeks of ritonavir 50 mg daily (study C). RESULTS: Addition of ritonavir 50 mg daily to ivacaftor 150 mg resulted in significant inhibition of the metabolism of ivacaftor. Area under the plasma concentration-time curve from time 0 to infinity (AUC0-inf obv ) increased significantly in both studies B and C compared to study A (GMR [95% CI] 19.71 [13.18-31.33] and 19.77 [14.0-27.93] respectively). Elimination half-life (t1/2 ) was significantly longer in both studies B and C compared to study A (GMR [95% CI] 11.14 [8.72-13.62] and 9.72 [6.68-12.85] respectively). There was no significant difference in any of the pharmacokinetic parameters between study B and study C. CONCLUSION: Ritonavir resulted in significant inhibition of the metabolism of ivacaftor. These data suggest that ritonavir may be used to inhibit the metabolism of ivacaftor in patients with cystic fibrosis (CF). Such an approach may increase the effectiveness of ivacaftor in 'poor responders' by maintaining higher plasma concentrations. It also has the potential to significantly reduce the cost of ivacaftor therapy.