The rate of decline in lung function in patients with idiopathic pulmonary fibrosis (IPF) before they are treated with Genentech‘s Esbriet (pirfenidone) influences the effects of the medication, researchers have found.
Patients classified as rapid progressors, who experience accelerated declines in lung function, benefited more from Esbriet than those considered slow progressors.
The study with these findings, “Pretreatment rate of decay in forced vital capacity predicts long-term response to pirfenidone in patients with idiopathic pulmonary fibrosis,” was published recently in the journal Scientific Reports.
Lung function in the patients was measured by forced vital capacity (FVC), the amount of air which can be forcibly exhaled from the lungs after taking the deepest breath possible. It drops in patients with pulmonary fibrosis, and Esbriet is used to slow the rate of this decline.
The Italian study included 56 IPF patients. They were categorized as either rapid progressors or slow progressors, based on whether their FVC decline in the year before treatment with Esbriet was greater than 10 percent of predicted FVC in rapid progressors, or less than or equal to 10 percent of predicted FVC in slow progressors.
Once treatment began, patients were assessed every six months for 24 months. For all patients in the study, Esbriet caused the rate in decline of FVC at six months to drop from a pre-treatment value of 231 ml/year to 49 ml/year — a result that was maintained through the 24 months of the study.
The effect of Esbriet was found to be excellent among rapid progressors, where the decline in FVC before treatment was 706 ml/year, and dropped to 36 ml/year after six months of treatment. This effect continued, though to a lesser degree, every six months through 24 months.
Esbriet also was beneficial for slow progressors. Although the rate of FVC decline was found not to be significant in these patients after they started taking Esbriet, the therapy seemed to stabilize the disease.
The study found the rate of discontinuation of Esbriet due to adverse events was 3.5 percent, confirming the safety and tolerability of the treatment in clinical practice. The discontinuation rate was lower than that observed in clinical trials, where it was around 14 percent.
“The study confirms that [Esbriet] treatment reduces significantly the rate of FVC decline in patients with IPF, an effect that is significantly more pronounced in patients with rapidly progressive disease,” researchers wrote.
“Additional studies are required to identify more precisely the underlying differences in disease behavior and treatment response of the slow and rapid decliners in IPF,” they added. “This will greatly benefit clinical research and daily clinical practice alike.”
Esbriet reduces FVC decline in IPF patients, investigators wrote. “However, its beneficial effect is more pronounced in patients with rapidly progressive disease,” they said.