Adherence and Persistence to Antifibrotic Treatments for Idiopathic Pulmonary Fibrosis

Abstract

SESSION TITLE: Diffuse Lung Disease 1 SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, November 1, 2017 at 01:30 PM - 02:30 PM PURPOSE: To describe real-world treatment patterns with pirfenidone and nintedanib for the treatment of idiopathic pulmonary fibrosis (IPF). METHODS: This analysis was conducted using Truven Health MarketScan Commercial and Medicare Supplemental claims data from 1/1/2014 through 10/31/2016. We included patients age ≥40 years old with a diagnosis of IPF (ICD-9-CM 515, 516.31), ≥1 outpatient pharmacy claim for pirfenidone or nintedanib (antifibrotic) and ≥6 months of continuous enrollment prior to antifibrotic initiation. Adherence was assessed with the proportion of days covered (PDC) calculated by dividing the number of days on which medication was available by the total days of follow up. Days of supply for the first pirfenidone claim was modified to account for the on label dose titration (207 pills in the first 30 days vs 270 pills for the following 30-day periods). Discontinuation was defined as a treatment gap of ≥60 days after the run out of days’ supply, and time to discontinuation was defined as the time in days from the index date until discontinuation. Re-initiation was defined as a claim for the initiated drug after a ≥60 day gap. RESULTS: The study population included 1,069 patients initiating an antifibrotic medication (pirfenidone: n=608; nintedanib: n = 461). The mean age of patients in the pirfenidone and nintedanib cohort was 69.5 (SD: 9.1) and 70.3 (SD: 9.5), respectively. Adherence to both therapies was high (mean PDC: 0.7 for both therapies). In the pirfenidone cohort 34.9% of patients discontinued treatment, while 37.5% of patients in the nintedanib cohort discontinued (p: N/S). The mean total number of days on therapy was higher for pirfenidone (222.3 days [SD: 174.1]) compared to nintedanib (183.3 days [167.4]), p<0.001. The proportion of patients re-initiating the index drug after discontinuation was also higher for pirfenidone (23.1%) compared to nintedanib (12.7%), p=0.009. CONCLUSIONS: Adherence to antifibrotic therapies for the treatment of IPF is high. The majority of patients stayed on index therapy during the study follow-up. The mean time on therapy was longer for patients on pirfenidone compared to nintedanib, possibly due to a higher re-initiation rate. CLINICAL IMPLICATIONS: IPF is an incurable disease, and antifibrotic therapy is the only FDA-approved pharmacologic approach to slow the decline in lung function, hence the importance of high adherence and persistence to IPF therapy. DISCLOSURE: Karina Raimundo: Employee: Employee of Genentech, Inc. Amanda Kong: Other: Contractor, paid by Genentech to perform work Stephani Gray: Other: Contractor, paid by Genentech to perform work Slim Benloucif: Other: Contractor, paid by Genentech to perform work Susan Limb: Employee: Employee of Genentech, Inc. No Product/Research Disclosure Information