Phase1/-2 study of pomalidomide in myelofibrosis

We conducted a dose-escalation study to see if higher doses of Pomalidomide (previously shown to be safe and effective for myelofibrosis-associated anemia at 0.5 mg/day [with prednisone] or 2.0 mg/day) increased anemia responses. 3.0 mg/d given for 21 of 28 consecutive days was the maximum-tolerated dose (MTD), with myelosuppression being dose limiting. Nonresponders at the MTD had their dose decreased and the therapy interval increased to daily. Seven of 19 subjects had an anemia-response and two had a spleen response. Most responses occurred after dose-reduction to 0.5 mg/d, suggesting higher doses are associated with increasing myelosuppression without increasing (or possibly decreasing) efficacy.