Patient description: The patient is a 34-year-old African American man with the known history of Sickle cell disease comes to the clinic with severe bone pain. The patient had severe pain in his lower back that radiated to both thighs scored 9 out of 10. The patient has had positive history of sickle cell crises since childhood. He also had the same symptoms in past two weeks treated with oxycodone which was not beneficial to his pain. His PCP sent him to the emergency department to receive intra venous pain modulators. The patient is afebrile within the normal blood pressure. No splenomegaly was detected in the physical exam. He has no positive history of drug allergy. He won't smoke or uses any illicit drugs. The lab study is as bellow: Hgb: 8 g/dl WBC: 10000 /mm3 Plt: 300000 /ml MCV: 106 fL Hemoglobine electrophoresis: 91% HbS 6%HbF 3%HbA2 AST: 22 U/L ALT: 43 U/L Alk P: 53 U/L Ferritin: 1200 ng/ml

Clinical trial eligibility criteria: eligible ages (years): 18.0-60.0,  Anemia Healthy adult male or female subjects. Female subjects must be of non-childbearing potential. 2. Age 18 to 60 years inclusive at time of consent. 3. Body mass index (BMI) of ≥18.5 to ≤32.0 kg/m2 or, if outside the range, considered not clinically significant by the investigator. 4. Good state of health (mentally and physically) as indicated by a comprehensive clinical assessment (detailed medical history and a complete physical examination), ECG and laboratory investigations. 5. Subjects who are actively non-smokers and have not used other nicotine-containing products for at least 12 months prior to the screening assessment. 6. Must be willing and able to communicate and participate in the whole study. 7. Must provide written informed consent. 8. Must agree to use an adequate method of contraception. 9. Japanese subjects enrolled in Part 4 must be first generation: born in Japan, not having lived outside Japan for 5 to 10 years, able to trace maternal and paternal Japanese ancestry, with no significant change in lifestyle, including diet (at least one Japanese meal consumed per day), since leaving Japan  Participation in a clinical research study within the previous 3 months. 2. Subjects who are study site employees, or immediate family members of a study site or sponsor employee. 3. Subjects who have previously been enrolled in this study. 4. History of any drug or alcohol abuse in the past 2 years. 5. Regular alcohol consumption in males >21 units per week and females >14 units per week (1 unit = ½ pint beer, 25 mL of 40% spirit or a 125 mL glass of wine). 6. Current smokers and those who have smoked within the last 12 months. A breath carbon monoxide reading of greater than 10 ppm at screening. 7. Any females of childbearing potential. 8. Subjects who do not have suitable veins for multiple venepunctures/cannulation as assessed by the investigator at screening. 9. Subjects who, after 10 min of supine rest, have a systolic blood pressure (BP) ≥140 mmHg (≥150 mmHg in subjects >45 years of age) or a diastolic BP of ≥90 mmHg. 10. Male subjects with QTcF interval (Fridericia's correction factor) ECG >450 msec, or female subjects with QTcF interval ECG >470 msec on screening or Day 1 (pre dose) ECG. 11. Subjects with a history of serious mental illness, that includes, but is not limited to schizophrenia, bipolar disorder, and major depression. 12. Subjects with glucose-6-phosphate-dehydrogenase (G6PD) deficiency. 13. Subjects with a history of any primary malignancy, including a history of melanoma or suspicious undiagnosed skin lesions. 14. Subjects with any other medical or psychological condition, deemed by the investigator to be likely to interfere with a subject's ability to sign informed consent, cooperate, or participate in the study. 15. Subjects who have undergone major surgery within 6 months prior to screening. 16. Clinically significant abnormal biochemistry, hematology or urinalysis as judged by the investigator. 17. Positive drugs of abuse test result at screening or admission. 18. Positive hepatitis B surface antigen (HBsAg), hepatitis C virus antibody (HCV Ab) or human immunodeficiency virus (HIV) results. 19. Subjects who are taking, or have taken, any prescribed or over-the-counter drug. 20. Subjects who have used St. John's Wort within 28 days before the first dose of study drug. 21. History of cardiovascular, renal, hepatic, chronic respiratory or GI disease, or hematologic, lymphatic, neurolologic, endocrine, psychiatric, musculoskeletal, genitourinary, immunologic, dermatologic or connective tissue disease or disorders, as judged by the investigator. 22. Serious adverse reaction or serious hypersensitivity to any drug or the formulation excipients, including history of allergy to sulfonamides. 23. Presence or history of clinically significant allergy requiring treatment, as judged by the investigator. 24. Donation or loss of greater than 400 mL of blood within the previous 3 months. 25. Failure to satisfy the investigator of fitness to participate for any other reason