The incidence of fibrosing colonopathy (FC) among patients with cystic fibrosis (CF) is very low since publication of current treatment guidelines and more stringent quality standards for pancreatic enzyme replacement therapy (PERT) products, investigators reported in the Journal of Cystic Fibrosis.
The prospective Fibrosing Colonopathy in Cystic Fibrosis (CF-FC) study used data from the CFF Patient Registry (CFFPR) to quantify the incidence of FC after publication of the Cystic Fibrosis Foundation’s (CFF) dosing guidelines and reformulation of PERT products.
Participants had a diagnosis of CF and received medical care from a CFF-accredited care center providing data to the CFFPR and were enrolled from July 31, 2012, to July 30, 2014.
Person-time for each patient was calculated until confirmed FC, patient or site discontinuation from the CFFPR, patient inactivity defined as no encounter for 2 years, date of death, or end of follow-up on April 10, 2020, whichever came first.
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[T]he incidence of FC in patients with CF in the era of the current treatment guidelines and reformulated PERT products is very low and may help to better inform the benefit-risk decision-making about using PERT.
A total of 26,025 patients were included in the base study population, of whom 91.1% (23,719) were active at the end of follow-up. The total person-time was 155,814 person-years, and each patient was part of the study for a mean (SD) 6.0 (2.0) years and a maximum of 7.8 years. Of the cohort, 2303 (8.8 %) patients died from any cause. The patients had a mean age of 19.5 years, 50.6 % were male, and 90.6 % were White.
Among 29 patients with suspected FC, it was confirmed by adjudication for 3 cases, confirmed not to be FC for 22 cases, and was indeterminate for 4 cases.
The “any PERT” group included 22,161 patients, with 123,719 person-years of current PERT use, 5438 person-years of former use, and 9137 person-years of nonuse. The “never PERT” group had 3864 patients with 17,520 person-years, for a an overall 26,657 person-years of non-PERT use time. The “other PERT” group had 3014 patients (7427 person-years).
The 3 confirmed and 4 indeterminate cases of FC occurred during current use of any PERT. The incidence rates of confirmed FC per 1000 person-years were 0.0242 (95% CI, 0.0050-0.0709) for current use and 0.0232 (95% CI, 0.0048-0.0679) for combined current and former use. In a sensitivity analysis, the incidence rates of indeterminate or confirmed FC (n=7) per 1000 person-years were 0.0566 (95% CI, 0.0227-0.1166) for current use and 0.0542 (95% CI, 0.0218-0.1117) for combined current and former use.
The mean daily dose of PERT was 8328 (4345) LU/kg per day in the overall cohort.
“Based on the results of this prospective study, the observed incidence
rate of FC among [people with] CF exposed to “Any PERT” was approximately one eighth the expected incidence rate of 0.17 per 1000 patient-years estimated based on prior studies,” the study authors noted. They added that “After almost 8 years of observation … the incidence of FC in patients with CF in the era of the current treatment guidelines and reformulated PERT products is very low and may help to better inform the benefit-risk decision-making about using PERT.”
Disclosure: Funding for this research was provided by AbbVie Inc, Janssen LLC, Vivus Inc, Digestive Care Inc, Allergan, and Nestle. Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
