Hb change from baseline to last observation (≥90 days): responder analysis for ≥1 g/dL. *Day 15 presented due to a protocol-specified dose reduction on day 17 (because of a 2.7 g/dL increase in Hb). †Day 150 presented because this is the last time point collected for Hb while the patient was receiving study drug. ‡Concurrent hydroxyurea. §Documented nonadherence with study drug regimen.