OBJECTIVES: The introduction of novel CFTR modulator therapies (ivacaftor, lumacaftor/ivacaftor and tezacaftor/ivacaftor) is associated with a significant economic burden as the annual wholesale acquisition costs (WAC) per patient range from $270,000- $310,000. The study objectives were to analyze the trends associated with the utilization of CFTR modulator therapies in terms of: (i) patient co-pay based on the insurance characteristics, and (ii) the annual spending of the specialty pharmacy.

METHODS: A retrospective study was conducted using prescription refill data from a national specialty pharmacy database. The number of prescriptions, insurance characteristics, and patient co-pays were extracted from January 2015 till August 2018. The drug costs from 2018 Red Book (WAC per package) and the number of prescriptions from the database were utilized to calculate the total spending of the specialty pharmacy. Patient co-pays were extracted and adjusted to 2018 dollar value. Statistical analyses were conducted using Statistical Analysis System University Edition (SAS Institute; Cary, NC).

RESULTS: A total of 4,444 patients contributed to 57,960 refills of CFTR modulator therapies from 2015 to 2018. A majority of the refills (62.95%) were for patients with only primary insurance whereas 37.05% of refills were for patients with both primary and secondary insurances. There was a non-linear trend 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 from 2015 to 2018 for ivacaftor/lumacaftor increased from $67.42 million (n=3,223) to $183.31 million (n=8,763) and for ivacaftor from $103.87 million (n=4,347) to $114.55 million (n=4,794). The 2018 spending for tezacaftor/ivacaftor was $86.06 million (n=3,842).

CONCLUSIONS: There seems to be a substantial economic burden of CFTR modulator therapies on patients and an increasing trend in the spending of the specialty pharmacy for these novel drug therapies.