Patient description: The patient is a 23-year-old man who came to the hospital with high blood pressure (175/95 mmHg) and signs of septicemia. He developed respiratory failure requiring mechanical ventilation and renal failure requiring hemodialysis. His blood smear showed microangiopathic hemolytic anemia and thrombocytopenia. His blood tests revealed elevated lactate dehydrogenase and reduced human complement C3 levels with a normal coagulation profile. He was diagnosed with atypical hemolytic uremic syndrome. He was treated with plasma exchange and corticosteroids. He has been previously vaccinated with meningococcal group ACWY conjugate vaccine and meningococcal group B vaccine. The genetic survey revealed ADAMTS13 >10%.

Clinical trial eligibility criteria: eligible ages (years): 18.0-70.0,  Sickle Cell Disease For enrollment, subjects must meet all of the following during the screening period: 1. Have provided signed written informed consent prior to performing any study procedure, including screening procedures. 2. Age between 18-70 years 3. Unequivocal diagnosis of HbSS confirmed by hemoglobin electrophoresis performed on patients at least 90 days after a blood transfusion if previously transfused, or DNA genotyping 4. No transfusion in the 90 days prior to the first dose of study drug or absence of HbA on hemoglobin analysis (by high-performance liquid chromatography; HPLC) 5. Have adequate organ function, as defined by: 1. Serum aspartate aminotransferase (AST) less than or equal to 2.5 (SqrRoot) Upper Limit of Normal (ULN) (unless the increased AST is assessed by the Investigator as due to hemolysis and/or hepatic iron deposition) and alanine aminotransferase (ALT) less than or equal to 2.5 (SqrRoot) ULN (unless the increased ALT is assessed by the Investigator as due to hepatic iron deposition). 2. Serum creatinine less than or equal to 1.25 (SqrRoot) ULN. If serum creatinine is >1.25 (SqrRoot) ULN, then glomerular filtration rate (based on creatinine) must be greater than or equal to 60 mL/min. 3. Absolute neutrophil count greater than or equal to 1.0 (SqrRoot) 109/L. 4. Hemoglobin greater than or equal to 7 g/dL 5. Platelet count greater than or equal to 100 (SqrRoot) 109/L. 6. Activated partial thromboplastin time and international normalized ratio less than or equal to 1.5 (SqrRoot) ULN, unless the subject is receiving therapeutic anticoagulants. 6. For women of reproductive potential, have a negative serum or urine pregnancy test during the screening period. Women of reproductive potential are defined as sexually mature women who have not undergone a hysterectomy, bilateral oophorectomy, or tubal occlusion; or who have not been naturally postmenopausal (i.e., who have not menstruated at all for at least the preceding 12 months prior to signing informed consent and have an elevated folliclestimulating hormone level indicative of menopause during the screening period). 7. For women of reproductive potential as well as men and their partners who are women of reproductive potential, be abstinent as part of their usual lifestyle, or agree to use 2 effective forms of contraception from the time of giving informed consent, during the study, and for 28 days for women and 90 days for men following the last dose of study treatment. An effective form of contraception is defined as hormonal oral contraceptives, injectables, patches, and barrier methods. 8. Be willing to comply with all study procedures for the duration of the study  Subjects who meet any of the following during screening will not receive AG348 and will not be counted toward the final enrollment count for statistical purposes: 1. Documented pyruvate kinase deficiency 2. Have a significant medical condition that confers an unacceptable risk to participating in the study, and/or that could confound the interpretation of the study data. Such significant medical conditions but are not limited to the following: 1. Poorly controlled hypertension (defined as systolic blood pressure [BP] >150 mmHg or diastolic BP >90 mmHg) refractory to medical management. 2. History of recent (within 6 months prior to signing informed consent) congestive heart failure; myocardial infarction or unstable angina pectoris; hemorrhagic, embolic, or thrombotic stroke; deep venous thrombosis; or pulmonary or arterial embolism. 3. Cardiac dysrhythmias judged as clinically significant by the Investigator. 4. Heart-rate corrected QT interval-Fredericia's method (QTcF) >480 msec with the exception of subjects with right or left bundle branch block. 5. Clinically symptomatic cholelithiasis or cholecystitis. Prior cholecystectomy is not exclusionary. Subjects with symptomatic cholelithiasis or cholecystitis may be rescreened once the disorder has been treated and clinical symptoms have resolved. 6. History of drug-induced cholestatic hepatitis. 7. Iron overload sufficiently severe to result in a clinical diagnosis by the Investigator of cardiac (e.g., clinically significant impaired left ventricular ejection fraction), hepatic (e.g., fibrosis, cirrhosis), or pancreatic (e.g., diabetes) dysfunction. 8. Have a diagnosis of any other congenital or acquired blood disorder, or any other hemolytic process as defined by a positive direct antiglobulin test (DAT), except mild allo-immunization as a consequence of transfusion therapy. 9. Positive test for hepatitis B surface antigen or hepatitis C virus (HCV) antibody (Ab) with signs of active hepatitis B or C virus infection. If the subject is positive for HCV Ab, a reverse transcriptase-polymerase chain reaction test will be conducted. Subjects with hepatitis C may be rescreened after receiving appropriate hepatitis C treatment. 10. Positive test for human immunodeficiency virus 1 or 2 Ab. 11. Active infection requiring any use of systemic antimicrobial agents (parenteral or oral) or Grade greater than or equal to 3 in severity (per National Cancer Institute Common Terminology for Adverse Events) within 2 months prior to signing informed consent. 12. Diabetes mellitus judged to be under poor control by the Investigator or requiring >3 antidiabetic agents, including insulin (all insulins are considered 1 agent); use of insulin per se is not exclusionary. 13. History of any primary malignancy, with the exception of: curatively treated nonmelanomatous skin cancer; curatively treated cervical or breast carcinoma in situ; or other primary tumor treated with curative intent, no known active disease present, and no treatment administered during the last 3 years. 14. Unstable extramedullary hematopoiesis that could pose a risk of imminent neurologic compromise. 15. Current or recent history of psychiatric disorder that, in the opinion of the Investigator or Medical Monitor, could compromise the ability of the subject to cooperate with study visits and procedures. 16. Are currently enrolled in another therapeutic clinical trial involving ongoing therapy with any investigational or marketed product or placebo. Sickle cell anemia subjects on hydroxyurea or L-glutamine will also be considered, provided that they have been on an unchanged dose of hydroxyurea or L-Glutamine for three months prior to enrollment. 17. Have exposure to any investigational drug, device, or invasive procedure within 3 months prior to the first dose of study treatment. All noninvestigational invasive procedures within 3 months of starting study treatment may be considered as a potential per the PI s discretion. 18. Have had any prior treatment with a pyruvate kinase activator. 19. Have received crizanlizumab or voxelotor in the 12 weeks prior to signing consent 20. Have a prior bone marrow or stem cell transplant. 21. Are currently pregnant or breastfeeding. 22. Are currently receiving medications that are strong inhibitors of cytochrome P450 (CYP)3A4 or strong inducers of CYP3A4 that have not been stopped for a duration of at least 5 days or a timeframe equivalent to 5 half-lives (whichever is longer) prior to the first dose of AG-348. 23. Are currently receiving hematopoietic stimulating agents (e.g., erythropoietins, granulocyte colony stimulating factors, thrombopoietins) that have not been stopped for a duration of at least 28 days prior to the first dose of study treatment. 24. Have a history of allergy to sulfonamides if characterized by acute hemolytic anemia, drug-induced liver injury, anaphylaxis, rash of erythema multiforme type or Stevens-Johnson syndrome, cholestatic hepatitis, or other serious clinical manifestations