Global Blood Therapeutics, Inc. announced enrollment of the first patient in the HOPE (Hemoglobin Oxygen Affinity Modulation to Inhibit HbS PolymErization) Study, a pivotal Phase 3 clinical trial of GBT440 in people with sickle cell disease (SCD). The HOPE Study will be conducted at SCD sites globally and is expected to enroll up to 400 adults and adolescents with SCD who have had at least one episode of vaso-occlusive crisis (VOC) in the previous year. The randomized, double-blind, placebo-controlled, multi-national trial will enroll patients age 12 and older with SCD who have had at least one episode of VOC in the previous year. The study will be conducted in two parts: Part A will compare GBT440 administered at doses of 900 or 1,500 mg per day vs. placebo in up to 150 patients treated for at least 12 weeks, and Part B will include 250 patients randomized to placebo or a dose of GBT440 selected from Part A. The main objectives of Part A are to select the optimal dose, define the final secondary endpoints for Part B, and qualify the patient-reported outcome (PRO) instrument. The primary efficacy endpoint of the HOPE Study is the proportion of patients who achieve a greater than 1 g/dL increase in hemoglobin at 24 weeks of treatment compared with baseline. Key secondary efficacy endpoints include the effect of GBT440 on SCD symptom exacerbation (as measured by the HOPE PRO instrument), overall SCD symptoms, traditionally defined VOCs, hospitalizations and red blood cell transfusions.