A phase II trial of pirfenidone (5-methyl-1-phenyl-2-[1H]-pyridone), a novel anti-fibrosing agent, in myelofibrosis with myeloid metaplasia

The anti-fibrotic and cytokine modulatory properties of pirfenidone suggest its usefulness in the treatment of myelofibrosis with myeloid metaplasia ( MMM). In a prospective study, 28 patients with MMM were treated with oral p irfenidone. Twelve patients completed 1 year of therapy; 13 were withdrawn because of disease progression and three because of drug intolerance. Only one patient experienced a clinically relevant benefit with respect to anaem ia and splenomegaly. The overall lack of clinical benefit correlated with n o significant improvement in the bone marrow morphological features of the disease. We conclude that pirfenidone has no significant clinical or biolog ical activity in MMM.