Hermansky-Pudlak Syndrome (HPS) is a rare autosomal recessive disease consisting of oculocutaneous albinism and a platelet storage pool defect. The most serious complication of this disorder, which is common in Puerto Rico, is pulmonary fibrosis, generally fatal in the fourth or fifth decade. There is no treatment for the pulmonary disease of HPS, which resembles idiopathic pulmonary fibrosis. However, a drug called pirfenidone has antifibrotic effects in animal models of lung fibrosis. Pirfenidone is an IND drug initially provided by Marnac, Inc.; InterMune, Inc., now holds the license. Pirfenidone inhibits cytokine-induced inflammation. Reported side effects include gastrointestinal upset, a photosensitivity rash, and palpitations. Between 1997 and 2001, we performed a randomized, placebo-controlled trial under this protocol that found pirfenidone to be safe and efficacious when analyzed using a repeated measures model. Using a random coefficients model, however, the data were definitive only in the restricted group of subjects whose initial forced vital capacity was greater than 50% of predicted. Because the repeated measures analysis had been chosen a priori as the optimal model, the DSMB stopped the study and directed that all patients receive pirfenidone. (Of the 23 original patients, 3 are still receiving pirfenidone under this protocol.)