Patients Adhere Well to CFTR Therapies But High Costs Could Undermine Use, Pharmacy Study Says
People with cystic fibrosis (CF) show a “high adherence” to CFTR modulators, but these newer medications are costly and could undermine compliance to treatment over time, according to a joint studies by AllianceRx Walgreens Prime and Duquesne University School of Pharmacy.
These findings were presented at the recent Academy of Managed Care Pharmacists (AMCP) Nexus in Maryland and ISPOR Europe 2019 in Copenhagen.
Their goal was to better understand whether patients took their medications as prescribed, and the degree of burden these medications’ cost posed to patients and health insurance programs.
Since they were first approved in 2012, CFTR modulators have significantly advanced CF care. These medications are specialized therapies that tackle the root cause of CF, a defect in the CFTR gene that leads to the abnormal production or workings of a protein channel called the cystic fibrosis transmembrane conductance regulator (CFTR).
“CFTR modulator therapies are relatively new in the treatment of CF and address the underlying cause of the disease,” Richard T. Miller, MSPharm, MBA, vice president of clinical and professional services at AllianceRx Walgreens Prime and one of the study’s authors, said in a press release.
“As such, they have the potential to change the treatment of CF. It is important to understand how patients are adhering to these newer therapies,” Miller added.
Four oral CFTR modulators are approved in the U.S. to treat CF, all from Vertex Pharmaceuticals: Kalydeco (ivacaftor), Orkambi (ivacaftor/lumacaftor), Symdeko (ivacaftor/tezacaftor), and Trikafta (elexacaftor/tezacaftor/ ivacaftor), approved in October and expected to be able to treat 90% of all people with CF.
Researchers analyzed prescription refill and assessment data from 3,482 CF patients using Kalydeco, Orkambi, or Symdeko between September 2017 and August 2018.
Medication adherence was measured by the proportion of days covered (PDC) — the days each individual had the medication to take, based on prescription fill and supply dates. These data were obtained from AllianceRx Walgreens Prime, a U.S. specialty pharmacy.
Results showed that half of these patients (50.8%) were taking Orkambi, followed by Symdeko (24.8%), and Kalydeco (24.4%). Days covered (PDC)Â were above 80%, indicating a positive adherence to medications. With Symdeko, the newest of these Vertex therapies at the time, compliance was more than 91%.
“Compared to PDC values reported for patients with CF in the literature, the PDC values of the CFTR modulator therapy regimen calculated for the specialty pharmacy population demonstrated good adherence,” the researchers wrote.
“This data indicates patients are maintaining a high level of adherence to the CFTR modulators,” Miller said. “Better adherence may help patients control their CF symptoms, as well as potential disease progression and future healthcare costs.”
Such overall high adherence could, in part, “be attributed to the specialty pharmacy CF program, which provides regular reminders for refilling CFTR modulator therapies, and counselling on medication adherence. Future studies are required to validate these assumptions,” the study noted.
To understand the therapies’ financial impact on both patients and payers, the team analyzed trends in the use of CFTR modulators and estimated medication copays by patients.
“To understand the trends associated with the utilization of CFTR modulator therapies, we need to estimate drug copays borne by the patients. This will help us understand the association with outcomes such as medication adherence,” said Khalid M. Kamal, PhD, a professor at Duquesne University School of Pharmacy in Pittsburgh, and a study co-author.
Prescription refills, insurance characteristics, and patient copays were examined from January 2015 to August 2018, covering a total of 4,444 patients and 57,960 refills of CFTR modulators.
Results here showed that most medication refills (62.95%) were for patients with primary insurance only (one payer, whether public or private), whereas nearly 37.05% of the refills were for  patients with both primary and secondary insurance (a secondary insurer covers some or all of what the first does not).
Average monthly copays (out-of-pocket payments) made by patients rose to $312.70 in 2018, from $182.05 in 2016.
“Evidence shows higher copays are associated with lower patient adherence and adverse clinical outcomes,” Kamal said. “Thus, there is a need to monitor these characteristics in CF, as well to understand the impact of copays across different insurances and patient outcomes.”
Annual total spending on Orkambi for these patients also rose sharply, to $281 million in 2017 from $67 million in 2015, while spending on Kalydeco remained fairly constant, $119 million in 2017 and $103 million in 2015, the study found.
“[T]here is a need to conduct real-world studies to assess the economic burden of CFTR modulator therapies on both the patients and the specialty pharmacy,” the researchers wrote.
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