Wrong endpoint?
In an accompanying editorial, Marco Sebastiani and Andreina Manfredi, MD, said that the choice of the primary outcome of an FVC decline from a baseline of 10% or more could have negatively influenced results because an FVC decline of 10% or more was probably too challenging to show a difference between the two groups. Indeed, the updated 2022 guidelines proposed a decline of 5% or more in FVC as a “significant threshold” for disease progression in patients with progressive pulmonary fibrosis, as the editorialists pointed out.
Nevertheless, the editorialists felt that the effect of pirfenidone on the decline in FVC seems to be significant, particularly when patients with usual interstitial pneumonia are considered. ”The magnitude of the effect of pirfenidone in patients with usual interstitial pneumonia-rheumatoid arthritis-interstitial lung disease and idiopathic pulmonary fibrosis [enrolled in a different study] was very similar,” they noted, “suggesting that a careful identification of usual interstitial pneumonia pattern at HRCT [high resolution CT] could be relevant in patients with RA-ILD. Moreover, given that pirfenidone did not modify its safety in these patients, the fact that pirfenidone can be safely used with DMARD therapy is important in clinical practice.
Dr. Solomon had no conflicts of interest to declare. Dr. Sebastiani disclosed ties with Bristol Myers Squibb, Pfizer, Boehringer-Ingelheim, Lilly, Amgen, Janssen, and Celltrion. Dr. Manfredi disclosed ties with Bristol Myers Squibb, Lilly, and Boehringer-Ingelheim. The study was funded by Genentech.