The incidence of IPF-related deaths during treatment was also lower among patients treated with pirfenidone . IPF-related deaths occurred during the treatment period in 4.1 % of patients in the pirfenidone group and 8.1 % of patients in the placebo group in CAPACITY 1 . IPF-related deaths occurred during the treatment period in 2.9 % of pirfenidone group and 6.3 % of patients in the placebo group in CAPACITY 2 .