Effects of HQK-1001 in Patients With Sickle Cell Disease

Inclusion Criteria: * Males and females between 12 and 60 years of age * Diagnosis of SCD, type Hb SS or Hb S-B0 Thalassemia * At least 1 episode of SCD pain crisis, acute chest syndrome, other acute SCD complications, or leg ulcers in the 12 months prior to screening * Not being treated with Hydroxyurea (HU); if HU treatment has been previously administered and then discontinued, at least 3 months must have elapsed since last dose of HU * If subject has been transfused in the 3 months prior to screening, then Hb A level \< 20% at screening * Baseline Hb F level obtained within 14 days prior to randomization * Able to swallow tablets * Able and willing to give informed consent and/or assent * If subject is a woman of child-bearing potential (WCBP), she must have a negative serum pregnancy test within 14 days of first dose of HQK-1001 and a negative urine pregnancy test prior to dosing on Day 1 * If a subject is a WCBP, she must agree to use an effective form of contraception starting at screening and for one month after HQK-1001 discontinuation * Sexually active male subjects who have not had a vasectomy must agree to use latex condoms with WCBP partners or ensure that their partner(s) use an effective form of contraception starting at screening and for one month after HQK-1001 discontinuation. Exclusion Criteria: * Assigned to a regular transfusion program * Use of erythropoiesis stimulating agents within 90 days prior to screening * An SCD pain crisis or SCD-related acute complication within 3 weeks prior to randomization * More than 5 SCD pain crisis or SCD-related acute complications within 12 months prior to screening * Pulmonary hypertension requiring therapy * ALT or AST \> 3x ULN * Serum creatinine \> 1.5x ULN * Serum amylase levels \> 1.5x ULN * Serum lipase level \> 1.5x ULN * A serious, concurrent illness that would limit ability to complete or comply with the study requirements * An acute illness (e.g., febrile, GI, respiratory) within 72 hours prior to screening * History of syncope, clinically significant dysrhythmias or resuscitation from sudden death due to SCD-related complication * Symptomatic peptic ulcer, hiatus hernia, or gastroesophageal reflux disease (GERD) * History of pancreatitis * Chronic opiate use, which, in the view of the investigator, could confound evaluation of an investigational drug * Current abuse of alcohol or drugs * Use of another investigational agent within 4 weeks or 5 half-lives, whichever is longer, prior to screening * Currently pregnant or breast feeding a child * Known infection with HIV-1 * Infection with hepatitis B or hepatitis C, such that subjects are currently on anti-viral therapy or will be placed on therapy