Patients taking Voxelotor 1500 mg were shown to have a rapid improvement in Hb concentration and a potential reduction in morbidity related to hemolytic anemia in SCD 72 weeks after starting the drug, without significant side effects compared to placebo.68 L-glutamine has also been approved by the FDA to treat SCD. This evidence concerns the gene GSTM1 and Schnyder corneal dystrophy.