Study design. Patients in the MAD2 cohort could directly rollover into the OL cohort at the time of their EOS visit whether they tolerated the 2-week treatment period and continued to meet eligibility criteria. Patients from other cohorts and the study sites could also enroll in the OL cohort. In the OL cohort, protocol amendment 7.0 allowed etavopivat dosing to extend from 2 days to up to 2 weeks beyond day 84, allowing a stepwise dose decrease in patients with a >2.0 g/dL increase in Hb over baseline or if clinically indicated. MAD, multiple ascending dose; OL, open-label.