Accordingly, patients with a deterioration after initiation of treatment showed a massive and highly significant ( p < 0.001) worsening in the FVC slope (right panel, right part), as compared to the similarly significant ( p < 0.001) slight improvement in the FVC decline in those patients stable upon initiation of pirfenidone treatment (left panel, right part).
In response to treatment with pirfenidone, GAP I patients ( n = 26) did not show a meaningful change in the FVC slopes, whereas GAP II patients ( n = 51) showed a weakly significant reduction in FVC decline ( p = 0.04), and GAP III patients ( n = 26) showed a highly significant reduction in FVC decline ( p < 0.001).
In never smoking IPF subjects the slope change was less prominent and it did not reach statistical significance ( p = 0.056, right part of left panel).