Phase 1/2 Study to Evaluate the Safety, Tolerability and Pharmacokinetics of HQK-1001 Administered Daily in Patients With Sickle Cell Disease

Inclusion Criteria: * Diagnosis of SCD or sickle beta thalassemia (excluding Hemoglobin C) * Between 12 and 60 years of age, inclusive * At least one episode of a SCD-related crisis or complication (e.g., vaso-occlusive crisis, acute chest syndrome, priapism) per year for an average of 3 years or one episode of acute chest syndrome over the prior 5 years * Screening (untransfused) HbF level \>/= 2% as analyzed by a central laboratory * If receiving hydroxyurea therapy, must be receiving a stable dose for at least 6 months * Able and willing to give informed consent * If female, must have a negative serum pregnancy test within 7 days of dosing * If female, must not be of childbearing potential defined as post-menopausal by at least 2 years or surgically sterile, or must agree to use a medically accepted form of contraception throughout the study * If the sexual partner of a male subject is a WCBP, she must agree to use a medically accepted form of birth control for themselves or their partner throughout the study * In the view of the Investigator, able to comply with necessary study procedures Exclusion Criteria: * Red blood cell (RBC) transfusion within 3 months prior to beginning study medication * Participation in a regular blood transfusion program * More than 4 hospitalizations for acute sickle cell-related events in the previous 12 months * An acute vaso-occlusive event within 3 weeks prior to receiving first dose of study medication * Pulmonary hypertension requiring oxygen * QTc \> 450 msec on screening * Alanine transaminase (ALT) \> 3X upper limit of normal (ULN) * Creatinine phosphokinase (CPK) \> 20% above the ULN * Serum creatinine \>1.2 mg/dL * An acute illness (e.g., febrile, gastrointestinal \[GI\], respiratory) within 72 hours prior to receiving first dose of study medication * History of syncope, clinically significant dysrhythmias or resuscitation from sudden death * Chronic opiate use which, in the view of the Investigator, could confound evaluation of an investigational drug * Current abuse of alcohol or drugs * Received another investigational agent within 4 weeks, or 5 half-lives, whichever is longer, prior to administration of study medication * Currently pregnant or breast feeding a child * Known infection with HIV-1 * Infection with hepatitis B or hepatitis C such that patients are currently on therapy or will be placed on therapy during the trial