Abstract
BACKGROUND: Although antifibrotic drugs, including nintedanib and pirfenidone, slow the progression of idiopathic pulmonary fibrosis (IPF), there is little data about the timing of start of antifibrotic treatment in real-world clinical practice. The present study aimed to clarify the efficacy of nintedanib and pirfenidone in patients with early-stage IPF. METHODS: We compared survival and disease progression between patients with IPF with Japanese Respiratory Society (JRS) disease severity system stage I with and without oxygen desaturation on the 6-min walk test (6MWT) and increased the gender-age-physiology (GAP) staging. We examined the efficacy of antifibrotic drugs in patients with early-stage IPF. RESULTS: The severity of stage I IPF (n = 179) according to the JRS criteria consisted of the following GAP staging criteria: stage I, 111 cases; stage II, 58 cases; stage III, 10 cases. The duration from the initial visit to disease progression and survival time was significantly shorter in JRS stage I patients with oxygen desaturation on the 6MWT or with increased GAP staging (unfavorable group) compared with patients without those factors. In the unfavorable group, the relative decline in percentage predicted forced vital capacity (%FVC) over 6 months was significantly lower in patients undergoing antifibrotic treatment compared with non-treated patients. CONCLUSION: Antifibrotic drugs have a beneficial effect on the decline in %FVC in Japanese patients with early-stage IPF who have oxygen desaturation on the 6MWT or increased GAP staging.