School of Pharmacy
Cystic Fibrosis, Database Analysis, Economic burden, Specialty Pharmacy, Retrospective, Medication Adherence, CFTR Modulator Therapies
Background: Cystic fibrosis (CF) is a progressive, genetic disorder caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Patients with CF experience excessive mucus build up and infections leading to complications in the pancreas, lungs, and other organs. There has been a paradigm shift in the treatment of CF with the introduction of CFTR modulator therapies and given their high acquisition cost, assessing their economic burden along with the adherence rate of patients is imperative. Objective: (i) To assess the utilization of CFTR modulator therapies in a specialty pharmacy CF patient population and (ii) to calculate the economic burden of CFTR modulator therapies and medications utilized for other comorbidities in the CF population.
Methods: A retrospective data analysis was conducted using refill and patient assessment data for CF Patients using CFTR modulator therapies from AllianceRx Walgreens specialty pharmacy. The study was conducted in two phases. In Phase I adherence was calculated using Proportion of Days Covered (PDC) measurement and data from the specialty pharmacy patient assessments focusing on discontinuations, missed doses, and medication-related adverse events were extracted and analyzed. In Phase II economic burden was assessed by calculating the spending of the specialty pharmacy on CFTR modulator therapies, average co-pay of the patients for CFTR modulator therapies and the cost of other medications reported by the patients (except CFTR modulator therapies) related to symptom management of CF as well as unrelated to CF. All statistical analyses were conducted using Statistical Analysis System University Edition (SAS Institute; Cary, NC).
Result: A total of 4,444 patients contributed to 57,960 refills of CFTR modulator therapies from January 2015 to August 2018. The overall PDC calculated for the entire study period for all CFTR modulator therapies was 0.83. Based on the patient assessment data, majority of the patients reported not missing a dose (n=38,428, 93%), switching as the most common reason for discontinuing therapy (n=185, 74.9%), and no adverse events for all three CFTR modulator therapies (n=23,888, 85-95%). A non-linear trend was observed in patient co-pays with a high of $312.70 (2018) and a low of $182.05 (2016). Patients on primary government insurance had a lower co-pay ($0-$40) compared to those on commercial insurance ($20-$310). The annual spending of the specialty pharmacy increased from 2015 to 2018 for all three CFTR modulator therapies. The most widely reported therapeutic classes for other medications included anti-infectives (n=2472, 22.81%), respiratory (n=2192, 20.23%), and electrolytes and dietary supplements (n=1701, 15.69%). The costs ranged from $0.2-$98,175 for all the other medications reported by the patients.
Conclusion: Patients with CF demonstrated good adherence to CFTR modulator therapies. Additionally, patients reported low missing doses or adverse events, all of which could be attributed to the specialty CF pharmacy program. Also, there seems to be a substantial economic burden associated with CFTR modulator therapies and other medications.
Mehta, Z. (2020). Cystic Fibrosis Transmembrane Conductance Regulator Modulator Therapies in Cystic Fibrosis: A Retrospective Evaluation of a Nationwide Specialty Pharmacy Database (Master's thesis, Duquesne University). Retrieved from https://dsc.duq.edu/etd/1866