Abstract
The present study aimed to clarify the efficacy of nintedanib and pirfenidone in patients with early-stage IPF. We compared survival, disease progression, and efficacy of antifibrotics between patients with IPF with Japanese Respiratory Society (JRS) disease severity system stage I with and without oxygen desaturation on the 6-minute walk test (6MWT) and increased the gender–age–physiology (GAP) staging. 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 forced vital capacity (FVC) decline and relative decline in percentage predicted FVC over 6 months was significantly lower in patients undergoing antifibrotic treatment compared with non-treated patients. Antifibrotics 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.