Adherence to cystic fibrosis transmembrane conductance regulator (CFTR) modulators: analysis of a national specialty pharmacy database

Figures & data

Table 1. Cystic fibrosis transmembrane conductance regulator (CFTR) modulators.

	Year approved	Indication	Mutation	Target CF population (%)	Annual cost^a
Ivacaftor	2012	Age ≥ 6 months	Effective for gating mutation and some residue function and conduction mutations	3–5	$311,501
Lumacaftor /ivacaftor	2015	Age ≥ 2 years	F508del homozygous	45–50	$272,694
Tezacaftor /ivacaftor & ivacaftor	2018	Age ≥ 6 years	F508del homozygous, heterozygous, other mutations	45–50	$292,000
Elexacaftor /tezacaftor /ivacaftor & ivacaftor	2019	Age ≥ 12 years	One copy of F508del mutation	85–90	$311,501

^aWholesale Acquisition Cost from IBM Micromedex RED BOOK Online (as of April 10, 2020).

Abbreviation: CF, Cystic Fibrosis.

Table 2. Demographic, medication utilization, and insurance characteristics of patients on CFTR modulators.

Variables	Overall	Children/adolescents	Adults
	n = 2,548	n = 1,075	n = 1,473
Age in years
Mean ± SD	23.05 ± 13.68	11.40 ± 3.84	31.55 ± 11.90
Median	20	11	29
Sex (n, %)
Female	1,161, 45.57%	515, 47.91%	646, 43.86%
Male	1,387, 54.43%	560, 52.09%	827, 56.14%
Patient Residence (n, %)
Northeast	472, 18.52%	185, 17.21%	287, 19.48%
Midwest	698, 27.39%	306, 28.47%	392, 26.21%
South	967, 37.95%	432, 40.19%	535, 36.32%
West	411, 16.13%	152, 14.14%	259, 17.58%
CFTR Modulators (n, %)
Ivacaftor	784, 30.77%	329, 30.60%	455, 30.89%
Lumacaftor/ivacaftor	1,289, 50.59%	661, 61.49%	628, 42.63%
Tezacaftor/ivacaftor & ivacaftor	475, 18.64%	85, 7.91%	390, 26.48%
Insurance type
Only primary insurance	1,564, 61.38%	701, 65.21%	863, 58.59%
Government/charitable	756, 48.34%	404, 57.63%	352, 40.79%
Commercial	808, 51.66%	297, 42.37%	511, 59.21%
Primary/secondary insurance	984, 39.62%	374, 34.79%	610, 41.41%

Data collected based on the last refill (most recent).

Abbreviation: CFTR, Cystic fibrosis transmembrane conductance regulator.

Table 3. PDC calculated using fill dates from September 2017 to August 2018.

	Overall PDC
	n	Mean ± SD
Total	2,548	0.86 ± 0.15
Ivacaftor	789	0.84 ± 0.16
Lumacaftor/ivacaftor	1,361	0.84 ± 0.15
Tezacaftor/ivacaftor & ivacaftor	398	0.92 ± 0.11
	PDC categorized according to age
	Children/Adolescents		Adults		p-value^a
	n	Mean ± SD	n	Mean ± SD
Total	1,075	0.86 ± 0.14	1,473	0.85 ± 0.15	0.0876
Ivacaftor	330	0.85 ± 0.15	459	0.84 ± 0.16	0.3744
Lumacaftor/ivacaftor	684	0.86 ± 0.14	677	0.83 ± 0.15	0.0001
Tezacaftor/ivacaftor & ivacaftor	61	0.96 ± 0.10	337	0.91 ± 0.11	0.001
	PDC categorized according to insurance characteristics
	Individuals with only primary insurance		Individuals with primary and secondary insurances		p-value^a
	n	Mean ± SD	n	Mean ± SD
Total	1,564	0.86 ± 0.15	984	0.86 ± 0.15	1.00
Ivacaftor	455	0.84 ± 0.16	334	0.84 ± 0.16	1.00
Lumacaftor/ivacaftor	869	0.85 ± 0.15	492	0.84 ± 0.15	0.24
Tezacaftor/ivacaftor & ivacaftor	240	0.92 ± 0.12	158	0.92 ± 0.11	1.00

^aIndependent t-test.

Significance p ≤ 0.05.

Abbreviation: PDC, proportion of days covered.