Pharmacologic Therapies in Beta Hemoglobinopathies: Fetal Globin Gene Induction in the First Molecular Diseases
Article Sidebar
Published
Mar 30, 2024
Downloads
Download data is not yet available.
Submit your own article
Register as an author to reserve your spot in the next issue of the Medical Research Archives.
Author RegistrationJoin the Society
The European Society of Medicine is more than a professional association. We are a community. Our members work in countries across the globe, yet are united by a common goal: to promote health and health equity, around the world.
Join Europe’s leading medical society and discover the many advantages of membership, including free article publication.
MembershipMain Article Content
Abstract
Beta hemoglobinopathies and thalassemias are caused by diverse molecular mutations of the βA globin chains and modulated by polymorphisms. These are important disorders in medical history, as they became prevalent globally in regions where P. falciparum malaria was endemic. Heterozygous or carrier states conferred a survival advantage; however, doubly heterozygous or homozygous states cause severe hemolytic anemia and multi-organ complications.
These disorders are somewhat unique in that all humans have alternate genes for fetal globin chains, which are expressed in fetal life but are silenced on a developmental clock in infancy. An established approach to ameliorating conditions of abnormal adult globin genes is to reactivate, or increase expression, of the endogenous fetal globin genes to replace the missing protein chains in beta thalassemias or inhibit polymerization of hemoglobin S and reduce the red cell abnormalities.
This review provides a high-level overview of cell and molecular mechanisms that mediate fetal to adult globin gene switching and pharmacologic therapies that can reactivate fetal globin through different actions. Intermittent or metronomic dosing regimens have overcome challenges of undesirable off-target effects by agents that cause erythroid cell growth arrest.
Multiple pharmacologic candidates reactivate or increase the expression of fetal globin protein and proportions of red blood cells containing HbF (F-cells). Hydroxyurea maintains high levels of HbF if begun in infancy, with some decline in mid-childhood. It elicits lower responses in HbF in adult patients, but still has broad clinical benefit in reducing many complications. However, many adult patients do not tolerate optimal hydroxyurea dosing due to cytopenias. Parenterally administered therapies with differing molecular actions, such as demethylating agents and histone deacetylase inhibitors, have shown proof-of-principle in reactivating HbF. Orally bioavailable candidates with complementary molecular mechanisms are in trials.
Combining fetal globin-inducing agents with other therapies with complementary mechanisms, such as recombinant erythropoietin that promotes the survival of red blood cells and therapeutics that promote erythroid cell metabolism, should have additive effects. These pharmaceutical candidates offer great clinical potential and global feasibility for ameliorating these serious diseases.
Article Details
How to Cite
KUO, Kevin H.M. et al.
Pharmacologic Therapies in Beta Hemoglobinopathies: Fetal Globin Gene Induction in the First Molecular Diseases.
Medical Research Archives, [S.l.], v. 12, n. 3, mar. 2024.
ISSN 2375-1924.
Available at: <https://esmed.org/MRA/mra/article/view/5130>. Date accessed: 30 apr. 2024.
doi: https://doi.org/10.18103/mra.v12i3.5130.
Section
Research Articles
The Medical Research Archives grants authors the right to publish and reproduce the unrevised contribution in whole or in part at any time and in any form for any scholarly non-commercial purpose with the condition that all publications of the contribution include a full citation to the journal as published by the Medical Research Archives.
References
1. Conley C. Sickle cell anemia-The first molecular disease. In: Wintrobe MM, ed. Blood, pure and eloquent: A story of discovery, of people, and of ideas. McGraw-Hill, Inc; 1980.
2. Weatherall DJ, Miller LH, Baruch DI, et al. Malaria and the red cell. Hematology Am Soc Hematol Educ Program. 2002:35-57. Doi:10.1182/asheducation-2002.1.35
3. Schechter AN. Hemoglobin research and the origins of molecular medicine. Blood. 2008;112(10):3927-38. Doi:10.1182/blood-2008-04-078188
4. Bunn HF. Pathogenesis and treatment of sickle cell disease. N Engl J Med. 1997;337(11):762-9. Doi:10.1056/nejm199709113371107
5. Weatherall DJ. The inherited diseases of hemoglobin are an emerging global health burden. Blood. 2010;115(22):4331-6. Doi:10.1182/blood-2010-01-251348
6. Kan YW, Dozy AM. Polymorphism of DNA sequence adjacent to human beta-globin structural gene: relationship to sickle mutation. Proc Natl Acad Sci U S A. 1978;75(11):5631-5. Doi:10.1073/pnas.75.11.5631
7. Yuan J, Angelucci E, Lucarelli G, et al. Accelerated programmed cell death (apoptosis) in erythroid precursors of patients with severe beta-thalassemia (Cooley's anemia). Blood. 1993;82(2):374-7.
8. Rund D, Rachmilewitz E. Beta-thalassemia. N Engl J Med. 2005;353(11):1135-46. Doi:10.1056/NEJMra050436
9. Bauer DE, Orkin SH. Update on fetal hemoglobin gene regulation in hemoglobinopathies. Curr Opin Pediatr. 2011;23(1):1-8. Doi:10.1097/MOP.0b013e3283420fd0
10. Galanello R, Origa R. Beta-thalassemia. Orphanet J Rare Dis. 2010;5:11. Doi:10.1186/1750-1172-5-11
11. GBD 2021 Sickle Cell Disease Collaborators. Global, regional, and national prevalence and mortality burden of sickle cell disease, 2000-2021: a systematic analysis from the Global Burden of Disease Study 2021. Lancet Haematol. 2023;10(8):e585-e599. Doi:10.1016/s2352-3026(23)00118-7
12. Stamatoyannopoulos G. Control of globin gene expression during development and erythroid differentiation. Exp Hematol. 2005;33(3):259-71. Doi:10.1016/j.exphem.2004.11.007
13. Lavelle D, Engel JD, Saunthararajah Y. Fetal hemoglobin induction by epigenetic drugs. Semin Hematol. 2018;55(2):60-67. Doi:10.1053/j.seminhematol.2018.04.008
14. Charache S, Terrin ML, Moore RD, et al. Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. Investigators of the Multicenter Study of Hydroxyurea in Sickle Cell Anemia. N Engl J Med. 1995;332(20):1317-22. Doi:10.1056/nejm199505183322001
15. Joseph JJ, Abraham AA, Fitzhugh CD. When there is no match, the game is not over: alternative donor options for hematopoietic stem cell transplantation in sickle cell disease. Semin Hematol. 2018;55(2):94-101. Doi:10.1053/j.seminhematol.2018.04.013
16. Leonard A, Tisdale JF. A pause in gene therapy: Reflecting on the unique challenges of sickle cell disease. Mol Ther. 2021;29(4):1355-1356. Doi:10.1016/j.ymthe.2021.03.010
17. Nienhuis AW. Development of gene therapy for blood disorders. Blood. 2008;111(9):4431-44. Doi:10.1182/blood-2007-11-078121
18. Wood WG, Bunch C, Kelly S, Gunn Y, Breckon G. Control of haemoglobin switching by a developmental clock? Nature. 1985;313(6000):320-3. Doi:10.1038/313320a0
19. Perrine SP, Rudolph A, Faller DV, et al. Butyrate infusions in the ovine fetus delay the biologic clock for globin gene switching. Proc Natl Acad Sci U S A. 1988;85(22):8540-2. Doi:10.1073/pnas.85.22.8540
20. Perrine SP, Greene MF, Faller DV. Delay in the fetal globin switch in infants of diabetic mothers. N Engl J Med. 1985;312(6):334-8. Doi:10.1056/nejm198502073120602
21. Watson J. The significance of the paucity of sickle cells in newborn Negro infants. Am J Med Sci. 1948;215(4):419-23. Doi:10.1097/00000441-194804000-00008
22. Steinberg MH, Rodgers GP. Pharmacologic modulation of fetal hemoglobin. Medicine (Baltimore). 2001;80 (5):328-44. Doi:10.1097/00005792-200109000-00007
23. Perrine RP, Brown MJ, Clegg JB, Weatherall DJ, May A. Benign sickle-cell anaemia. Lancet. 1972;2(7788):1163-7. Doi:10.1016/s0140-6736(72)92592-5
24. Franco RS, Yasin Z, Palascak MB, Ciraolo P, Joiner CH, Rucknagel DL. The effect of fetal hemoglobin on the survival characteristics of sickle cells. Blood. 2006;108(3):1073-6. Doi:10.1182/blood-2005-09-008318
25. Papayannopoulou T, Vichinsky E, Stamatoyannopoulos G. Fetal Hb production during acute erythroid expansion. I. Observations in patients with transient erythroblastopenia and post-phlebotomy. Br J Haematol. 1980;44(4):535-46. Doi:10.1111/j.1365-2141.1980.tb08707.x
26. Mabaera R, West RJ, Conine SJ, et al. A cell stress signaling model of fetal hemoglobin induction: what doesn't kill red blood cells may make them stronger. Exp Hematol. 2008;36(9):1057-72. Doi:10.1016/j.exphem.2008.06.014
27. Chen JJ, Perrine S. Stressing HbF synthesis: role of translation? Blood. 2013;122(4):467-8. Doi:10.1182/blood-2013-06-506139
28. Chen JJ. HRI stress signaling and HbF production. Blood. 2020;135(24):2113-2114. Doi:10.1182/blood.2020006300
29. Thein SL. Genetic modifiers of beta-thalassemia. Haematologica. 2005;90(5):649-60.
30. Sedgewick AE, Timofeev N, Sebastiani P, et al. BCL11A is a major HbF quantitative trait locus in three different populations with beta-hemoglobinopathies. Blood Cells Mol Dis. 2008;41(3):255-258. Doi:10.1016/j.bcmd.2008.06.007
31. Uda M, Galanello R, Sanna S, et al. Genome-wide association study shows BCL11A associated with persistent fetal hemoglobin and amelioration of the phenotype of beta-thalassemia. Proc Natl Acad Sci U S A. 2008;105(5):1620-5. Doi:10.1073/pnas.0711566105
32. Bieker JJ. Putting a finger on the switch. Nat Genet. 2010;42(9):733-4. Doi:10.1038/ng0910-733
33. Borg J, Papadopoulos P, Georgitsi M, et al. Haploinsufficiency for the erythroid transcription factor KLF1 causes hereditary persistence of fetal hemoglobin. Nat Genet. 2010;42(9):801-5. Doi:10.1038/ng.630
34. Thein SL. Molecular basis of β thalassemia and potential therapeutic targets. Blood Cells Mol Dis. 2018;70:54-65. Doi:10.1016/j.bcmd.2017.06.001
35. Platt OS, Brambilla DJ, Rosse WF, et al. Mortality in sickle cell disease. Life expectancy and risk factors for early death. N Engl J Med. 1994;330(23):1639-44. Doi:10.1056/nejm199406093302303
36. Steinberg MH. Fetal hemoglobin in sickle cell anemia. Blood. 2020;136(21):2392-2400. Doi:10.1182/blood.2020007645
37. Calvet D, Tuilier T, Mélé N, et al. Low fetal hemoglobin percentage is associated with silent brain lesions in adults with homozygous sickle cell disease. Blood Adv. 2017;1(26):2503-2509. Doi:10.1182/bloodadvances.2017005504
38. Bunn HF. Reversing ontogeny. N Engl J Med. 1993;328(2):129-31. Doi:10.1056/nejm199301143280210
39. Atweh GF, Sutton M, Nassif I, et al. Sustained induction of fetal hemoglobin by pulse butyrate therapy in sickle cell disease. Blood. 1999;93(6):1790-7.
40. Cao H, Stamatoyannopoulos G, Jung M. Induction of human gamma globin gene expression by histone deacetylase inhibitors. Blood. 2004;103(2):701-9. Doi:10.1182/blood-2003-02-0478
41. Dover GJ, Charache S, Nora R, Boyer SH. Progress toward increasing fetal hemoglobin production in man: experience with 5-azacytidine and hydroxyurea. Ann N Y Acad Sci. 1985;445:218-24. Doi:10.1111/j.1749-6632.1985.tb17191.x
42. Fucharoen S, Inati A, Siritanaratku N, et al. A randomized phase I/II trial of HQK-1001, an oral fetal globin gene inducer, in β-thalassaemia intermedia and HbE/β-thalassaemia. Br J Haematol. 2013;161(4):587-93. Doi:10.1111/bjh.12304
43. Shi L, Cui S, Engel JD, Tanabe O. Lysine-specific demethylase 1 is a therapeutic target for fetal hemoglobin induction. Nat Med. 2013;19(3):291-4. Doi:10.1038/nm.3101
44. Kutlar A, Meiler S, Swerdlow P, Knight R. Thalidomide and its analogs for hemoglobinopathies: two birds with one stone? Expert Rev Hematol. 2012;5(1):9-11. Doi:10.1586/ehm.11.77
45. Engel JD, Tanimoto K. Looping, linking, and chromatin activity: new insights into beta-globin locus regulation. Cell. 2000;100(5):499-502. Doi:10.1016/s0092-8674(00)80686-8
46. Kanter J, Walters MC, Krishnamurti L, et al. Biologic and clinical efficacy of LentiGlobin for sickle cell disease. N Engl J Med. 2022;386(7):617-628. Doi:10.1056/NEJMoa2117175
47. US Food and Drug Administration. FDA approves first gene therapies to treat patients with sickle cell disease. December 8, 2023. https://www.fda.gov/news-events/press-announcements/fda-approves-first-gene-therapies-treat-patients-sickle-cell-disease
48. Fontana L, Alahouzou Z, Miccio A, Antoniou P. Epigenetic regulation of β-globin genes and the potential to treat hemoglobinopathies through epigenome editing. Genes (Basel). 2023;14(3)Doi:10.3390/genes14030577
49. Wood WG, Stamatoyannopoulos G, Lim G, Nute PE. F-cells in the adult: normal values and levels in individuals with hereditary and acquired elevations of Hb F. Blood. 1975;46(5):671-82.
50. Dover GJ, Boyer SH, Charache S, Heintzelman K. Individual variation in the production and survival of F cells in sickle-cell disease. N Engl J Med. 1978;299(26):1428-35. Doi:10.1056/nejm197812282992603
51. Ansari SH, Shamsi TS, Munzir S, et al. Gγ-Xmn I polymorphism: a significant determinant of β-thalassemia treatment without blood transfusion. J Pediatr Hematol Oncol. 2013;35(4):e153-6. Doi:10.1097/MPH.0b013e31827e8662
52. Winichagoon P, Thonglairoam V, Fucharoen S, Wilairat P, Fukumaki Y, Wasi P. Severity differences in beta-thalassaemia/haemoglobin E syndromes: implication of genetic factors. Br J Haematol. 1993;83(4):633-9. Doi:10.1111/j.1365-2141.1993.tb04702.x
53. Gong Y, Zhang X, Zhang Q, et al. A natural DNMT1 mutation elevates the fetal hemoglobin level via epigenetic derepression of the γ-globin gene in β-thalassemia. Blood. 2021;137(12):1652-1657. Doi:10.1182/blood.2020006425
54. Manwani D, Bieker JJ. KLF1: when less is more. Blood. 2014;124(5):672-3. Doi:10.1182/blood-2014-05-576967
55. Charache S, Barton FB, Moore RD, et al. Hydroxyurea and sickle cell anemia. Clinical utility of a myelosuppressive "switching" agent. The Multicenter Study of Hydroxyurea in Sickle Cell Anemia. Medicine (Baltimore). 1996;75(6):300-26. Doi:10.1097/00005792-199611000-00002
56. Ware RE, Eggleston B, Redding-Lallinger R, et al. Predictors of fetal hemoglobin response in children with sickle cell anemia receiving hydroxyurea therapy. Blood. 2002;99(1):10-4. Doi:10.1182/blood.v99.1.10
57. Gladwin MT, Shelhamer JH, Ognibene FP, et al. Nitric oxide donor properties of hydroxyurea in patients with sickle cell disease. Br J Haematol. 2002;116(2):436-44. Doi:10.1046/j.1365-2141.2002.03274.x
58. de Franceschi L, Rouyer-Fessard P, Alper SL, Jouault H, Brugnara C, Beuzard Y. Combination therapy of erythropoietin, hydroxyurea, and clotrimazole in a beta thalassemic mouse: a model for human therapy. Blood. 1996;87(3):1188-95.
59. Goldberg MA, Brugnara C, Dover GJ, Schapira L, Charache S, Bunn HF. Treatment of sickle cell anemia with hydroxyurea and erythropoietin. N Engl J Med. 1990;323(6):366-72. Doi:10.1056/nejm199008093230602
60. Little JA, McGowan VR, Kato GJ, et al. Combination erythropoietin-hydroxyurea therapy in sickle cell disease: experience from the National Institutes of Health and a literature review. Haematologica. 2006;91(8):1076-83.
61. Rodgers GP, Dover GJ, Uyesaka N, Noguchi CT, Schechter AN, Nienhuis AW. Augmentation by erythropoietin of the fetal-hemoglobin response to hydroxyurea in sickle cell disease. N Engl J Med. 1993;328(2):73-80. Doi:10.1056/nejm199301143280201
62. Steinberg MH, Lu ZH, Barton FB, Terrin ML, Charache S, Dover GJ. Fetal hemoglobin in sickle cell anemia: determinants of response to hydroxyurea. Multicenter Study of Hydroxyurea. Blood. 1997;89(3):1078-88.
63. Ballas SK, Marcolina MJ, Dover GJ, Barton FB. Erythropoietic activity in patients with sickle cell anaemia before and after treatment with hydroxyurea. Br J Haematol. 1999;105(2):491-6.
64. Sanchez Ventura LM, Adimora I, Elliot EC, Fasipe T, Flanagan JM. Clinical and hematopoietic profiles associated with sustained hydroxyurea response for patients with sickle cell disease. Blood. 2023;142(Supplement 1):17-17. Doi:10.1182/blood-2023-187335
65. Wang WC, Ware RE, Miller ST, et al. Hydroxycarbamide in very young children with sickle-cell anaemia: a multicentre, randomised, controlled trial (BABY HUG). Lancet. 2011;377(9778):1663-72. Doi:10.1016/s0140-6736(11)60355-3
66. Ware RE, Schultz WH, Yovetich N, et al. Stroke With Transfusions Changing to Hydroxyurea (SWiTCH): a phase III randomized clinical trial for treatment of children with sickle cell anemia, stroke, and iron overload. Pediatr Blood Cancer. 2011;57(6):1011-7. Doi:10.1002/pbc.23145
67. Thornburg CD, Files BA, Luo Z, et al. Impact of hydroxyurea on clinical events in the BABY HUG trial. Blood. 2012;120(22):4304-10; quiz 4448. Doi:10.1182/blood-2012-03-419879
68. Alvarez O, Yovetich NA, Scott JP, et al. Pain and other non-neurological adverse events in children with sickle cell anemia and previous stroke who received hydroxyurea and phlebotomy or chronic transfusions and chelation: results from the SWiTCH clinical trial. Am J Hematol. 2013;88(11):932-8. Doi:10.1002/ajh.23547
69. Aygun B, Lane AC, Smart LR, et al. Hydroxyurea dose optimization is safe and improves outcomes for children with sickle cell anemia living in sub-Saharan Africa: the Reach experience. Blood. 2023;142(Supplement 1):6-6. Doi:10.1182/blood-2023-172919
70. DeBaun MR, Jordan LC, King AA, et al. American Society of Hematology 2020 guidelines for sickle cell disease: prevention, diagnosis, and treatment of cerebrovascular disease in children and adults. Blood Adv. 2020;4(8):1554-1588. Doi:10.1182/bloodadvances.2019001142
71. Cronin RM, Lin CJ, Chiang C, MacEwan SR, DeBaun MR, Hyer JM. The use of FDA-approved medications for preventing vaso-occlusive events in sickle cell disease. Blood Adv. 2023;7(13):3114-3116. Doi:10.1182/bloodadvances.2022008965
72. Saraf S, Farooqui M, Infusino G, et al. Standard clinical practice underestimates the role and significance of erythropoietin deficiency in sickle cell disease. Br J Haematol. 2011;153(3):386-92. Doi:10.1111/j.1365-2141.2010.08479.x
73. Fucharoen S, Siritanaratkul N, Winichagoon P, et al. Hydroxyurea increases hemoglobin F levels and improves the effectiveness of erythropoiesis in beta-thalassemia/hemoglobin E disease. Blood. 1996;87(3):887-92.
74. Singer ST, Kuypers FA, Olivieri NF, et al. Fetal haemoglobin augmentation in E/beta(0) thalassaemia: clinical and haematological outcome. Br J Haematol. 2005;131(3):378-88. Doi:10.1111/j.1365-2141.2005.05768.x
75. Algiraigri AH, Wright NAM, Paolucci EO, Kassam A. Hydroxyurea for nontransfusion-dependent β-thalassemia: A systematic review and meta-analysis. Hematol Oncol Stem Cell Ther. 2017;10(3):116-125. Doi:10.1016/j.hemonc.2017.02.002
76. Hatamleh MI, Chenna VSH, Contractor H, et al. Efficacy of hydroxyurea in transfusion-dependent major β-thalassemia patients: a meta-analysis. Cureus. 2023;15(4):e38135. Doi:10.7759/cureus.38135
77. Zeng YT, Huang SZ, Ren ZR, et al. Hydroxyurea therapy in beta-thalassaemia intermedia: improvement in haematological parameters due to enhanced beta-globin synthesis. Br J Haematol. 1995;90(3):557-63. Doi:10.1111/j.1365-2141.1995.tb05584.x
78. Banan M, Bayat H, Azarkeivan A, et al. The XmnI and BCL11A single nucleotide polymorphisms may help predict hydroxyurea response in Iranian β-thalassemia patients. Hemoglobin. 2012;36(4):371-80. Doi:10.3109/03630269.2012.691147
79. Goren A, Simchen G, Fibach E, et al. Fine tuning of globin gene expression by DNA methylation. PLoS One. 2006;1(1):e46. Doi:10.1371/journal.pone.0000046
80. DeSimone J, Heller P, Hall L, Zwiers D. 5-Azacytidine stimulates fetal hemoglobin synthesis in anemic baboons. Proc Natl Acad Sci U S A. 1982;79(14):4428-31. Doi:10.1073/pnas.79.14.4428
81. Ginder GD. Epigenetic regulation of fetal globin gene expression in adult erythroid cells. Transl Res. 2015;165(1):115-25. Doi:10.1016/j.trsl.2014.05.002
82. Ley TJ, DeSimone J, Anagnou NP, et al. 5-azacytidine selectively increases gamma-globin synthesis in a patient with beta+ thalassemia. N Engl J Med. 1982;307(24):1469-75. Doi:10.1056/nejm198212093072401
83. Lowrey CH, Nienhuis AW. Brief report: treatment with azacitidine of patients with end-stage beta-thalassemia. N Engl J Med. 1993;329(12):845-8. Doi:10.1056/nejm199309163291205
84. Koshy M, Dorn L, Bressler L, et al. 2-deoxy 5-azacytidine and fetal hemoglobin induction in sickle cell anemia. Blood. 2000;96(7):2379-84.
85. DeSimone J, Koshy M, Dorn L, et al. Maintenance of elevated fetal hemoglobin levels by decitabine during dose interval treatment of sickle cell anemia. Blood. 2002;99(11):3905-8. Doi:10.1182/blood.v99.11.3905
86. Saunthararajah Y, Hillery CA, Lavelle D, et al. Effects of 5-aza-2'-deoxycytidine on fetal hemoglobin levels, red cell adhesion, and hematopoietic differentiation in patients with sickle cell disease. Blood. 2003;102(12):3865-70. Doi:10.1182/blood-2003-05-1738
87. Olivieri NF, Saunthararajah Y, Thayalasuthan V, et al. A pilot study of subcutaneous decitabine in β-thalassemia intermedia. Blood. 2011;118(10):2708-11. Doi:10.1182/blood-2011-03-341909
88. Lavelle D, Vaitkus K, Ling Y, et al. Effects of tetrahydrouridine on pharmacokinetics and pharmacodynamics of oral decitabine. Blood. 2012;119(5):1240-7. Doi:10.1182/blood-2011-08-371690
89. Molokie R, Lavelle D, Gowhari M, et al. Oral tetrahydrouridine and decitabine for non-cytotoxic epigenetic gene regulation in sickle cell disease: A randomized phase 1 study. PLoS Med. 2017;14(9):e1002382. Doi:10.1371/journal.pmed.1002382
90. Molokie R, Saraf SL, Krauz L, et al. Translating an HPFH-mechanism into oral small molecule therapy for beta-hemoglobinopathies: clinical proof-of-principle. Blood. 2023;142(Supplement 1):2524-2524. Doi:10.1182/blood-2023-186228
91. Perrine SP, Miller BA, Faller DV, et al. Sodium butyrate enhances fetal globin gene expression in erythroid progenitors of patients with Hb SS and beta thalassemia. Blood. 1989;74(1):454-9.
92. Bank A. Regulation of human fetal hemoglobin: new players, new complexities. Blood. 2006;107(2):435-43. Doi:10.1182/blood-2005-05-2113
93. Steliou K, Boosalis MS, Perrine SP, Sangerman J, Faller DV. Butyrate histone deacetylase inhibitors. Biores Open Access. 2012;1(4):192-8. Doi:10.1089/biores.2012.0223
94. Boosalis MS, Bandyopadhyay R, Bresnick EH, Pace BS, Van DeMark K, Faller DV, Perrine SP. Short chain fatty acid derivatives stimulate cell proliferation and induce STAT-5 activation. Blood 2001;97:3259-3264.
95. Boosalis MS, Bandyopadhyay R, Bresnick EH, Pace BS, Van DeMark K, Faller DV, Perrine SP. S Pace PS, White GL, Dover GJ, Boosalis MS, Faller DV, Perrine SP. Short-chain fatty acid derivatives induce fetal globin expression and erythropoiesis in vivo. Blood 2002; 100:4640-4648.96.
96 Perrine SP, Ginder GD, Faller DV, et al. A short-term trial of butyrate to stimulate fetal-globin-gene expression in the beta-globin disorders. N Engl J Med. 1993;328(2):81-6. Doi:10.1056/nejm199301143280202
97. Weinberg RS, Ji X, Sutton M, et al. Butyrate increases the efficiency of translation of gamma-globin mRNA. Blood. 2005;105(4):1807-9. Doi:10.1182/blood-2004-02-0454
98. Centis F, Tabellini L, Lucarelli G, et al. The importance of erythroid expansion in determining the extent of apoptosis in erythroid precursors in patients with beta-thalassemia major. Blood. 2000;96(10):3624-9.
99. Mathias LA, Fisher TC, Zeng L, et al. Ineffective erythropoiesis in beta-thalassemia major is due to apoptosis at the polychromatophilic normoblast stage. Exp Hematol. 2000;28(12):1343-53. Doi:10.1016/s0301-472x(00)00555-5
100. Pootrakul P, Sirankapracha P, Hemsorach S, et al. A correlation of erythrokinetics, ineffective erythropoiesis, and erythroid precursor apoptosis in thai patients with thalassemia. Blood. 2000;96(7):2606-12.
101. Perrine SP, Castaneda SA, Boosalis MS, White GL, Jones BM, Bohacek R. Induction of fetal globin in beta-thalassemia: Cellular obstacles and molecular progress. Ann N Y Acad Sci. 2005;1054:257-65. Doi:10.1196/annals.1345.033
102. Schaeffer EK, West RJ, Conine SJ, Lowrey CH. Multiple physical stresses induce γ-globin gene expression and fetal hemoglobin production in erythroid cells. Blood Cells Mol Dis. 2014;52(4):214-24. Doi:10.1016/j.bcmd.2013.10.007
103. Bohacek R, Boosalis MS, McMartin C, Faller DV, Perrine SP. Identification of novel small-molecule inducers of fetal hemoglobin using pharmacophore and 'PSEUDO' receptor models. Chem Biol Drug Des. 2006;67(5):318-28. Doi:10.1111/j.1747-0285.2006.00386.x
104. Boosalis MS, Castaneda SA, Trudel M, et al. Novel therapeutic candidates, identified by molecular modeling, induce γ-globin gene expression in vivo. Blood Cells Mol Dis. 2011;47(2):107-16. Doi:10.1016/j.bcmd.2011.04.008
105. Boosalis MS, Sangerman JI, White GL, et al. Novel inducers of fetal globin identified through high throughput screening (HTS) are active in vivo in anemic baboons and transgenic mice. PLoS One. 2015;10(12):e0144660. Doi:10.1371/journal.pone.0144660
106. Perrine SP, Wargin WA, Boosalis MS, et al. Evaluation of safety and pharmacokinetics of sodium 2,2 dimethylbutyrate, a novel short chain fatty acid derivative, in a phase 1, double-blind, placebo-controlled, single-dose, and repeat-dose studies in healthy volunteers. J Clin Pharmacol. 2011;51(8):1186-94. Doi:10.1177/0091270010379810
107. Kutlar A, Reid ME, Inati A, et al. A dose-escalation phase IIa study of 2,2-dimethylbutyrate (HQK-1001), an oral fetal globin inducer, in sickle cell disease. Am J Hematol. 2013;88(11):E255-60. Doi:10.1002/ajh.23533
108. Patthamalai P, Fuchareon S, Chaneiam N, et al. A phase 2 trial of HQK-1001 in HbE-β thalassemia demonstrates HbF induction and reduced anemia. Blood. 2014;123(12):1956-7. Doi:10.1182/blood-2013-11-538470
109. Inati A, Kahale M, Perrine SP, et al. A phase 2 study of HQK-1001, an oral fetal haemoglobin inducer, in β-thalassaemia intermedia. Br J Haematol. 2014;164(3):456-8. Doi:10.1111/bjh.12635
110. Domenica Cappellini M, Graziadei G, Ciceri L, et al. Oral isobutyramide therapy in patients with thalassemia intermedia: results of a phase II open study. Blood Cells Mol Dis. 2000;26(1):105-11. Doi:10.1006/bcmd.2000.0283
111. Reich S, Bührer C, Henze G, et al. Oral isobutyramide reduces transfusion requirements in some patients with homozygous beta-thalassemia. Blood. 2000;96(10):3357-63.
112. Dai Y, Sangerman J, Luo HY, et al. Therapeutic fetal-globin inducers reduce transcriptional repression in hemoglobinopathy erythroid progenitors through distinct mechanisms. Blood Cells Mol Dis. 2016;56(1):62-9. Doi:10.1016/j.bcmd.2015.10.004
113. Mankidy R, Faller DV, Mabaera R, et al. Short-chain fatty acids induce gamma-globin gene expression by displacement of a HDAC3-NCoR repressor complex. Blood. 2006;108(9):3179-86. Doi:10.1182/blood-2005-12-010934
114. Perrine SP, Mankidy R, Boosalis MS, Bieker JJ, Faller DV. Erythroid Kruppel-like factor (EKLF) is recruited to the gamma-globin gene promoter as a co-activator and is required for gamma-globin gene induction by short-chain fatty acid derivatives. Eur J Haematol. 2009;82(6):466-76. Doi:10.1111/j.1600-0609.2009.01234.x
115. Sarkar S, Abujamra AL, Loew JE, Forman LW, Perrine SP, Faller DV. Histone deacetylase inhibitors reverse CpG methylation by regulating DNMT1 through ERK signaling. Anticancer Res. 2011;31(9):2723-32.
116. Ibanez V, Vaitkus K, Rivers A, et al. Efficacy and safety of long-term RN-1 treatment to increase HbF in baboons. Blood. 2017;129(2):260-263. Doi:10.1182/blood-2016-10-746727
117. Rivers A, Vaitkus K, Ibanez V, et al. The LSD1 inhibitor RN-1 recapitulates the fetal pattern of hemoglobin synthesis in baboons (P. anubis). Haematologica. 2016;101(6):688-97. Doi:10.3324/haematol.2015.140749
118. Rivers A, Vaitkus K, Ruiz MA, et al. RN-1, a potent and selective lysine-specific demethylase 1 inhibitor, increases γ-globin expression, F reticulocytes, and F cells in a sickle cell disease mouse model. Exp Hematol. 2015;43(7):546-53.e1-3. Doi:10.1016/j.exphem.2015.04.005
119. Cui S, Lim KC, Shi L, et al. The LSD1 inhibitor RN-1 induces fetal hemoglobin synthesis and reduces disease pathology in sickle cell mice. Blood. 2015;126(3):386-96. Doi:10.1182/blood-2015-02-626259
120. Rivers A, Vaitkus K, Jagadeeswaran R, et al. Oral administration of the LSD1 inhibitor ORY-3001 increases fetal hemoglobin in sickle cell mice and baboons. Exp Hematol. 2018;67:60-64.e2. Doi:10.1016/j.exphem.2018.08.003
121. Ibanez V, Vaitkus K, Zhang X, et al. Combinatorial targeting of epigenome-modifying enzymes with decitabine and RN-1 synergistically increases HbF. Blood Adv. 2023;7(15):3891-3902. Doi:10.1182/bloodadvances.2022009558
122. Krivega I, Byrnes C, de Vasconcellos JF, et al. Inhibition of G9a methyltransferase stimulates fetal hemoglobin production by facilitating LCR/γ-globin looping. Blood. 2015;126(5):665-72. Doi:10.1182/blood-2015-02-629972
123. Dai Y, Sangerman J, Nouraie M, et al. Effects of hydroxyurea on F-cells in sickle cell disease and potential impact of a second fetal globin inducer. Am J Hematol. 2017;92(1):E10-e11. Doi:10.1002/ajh.24590
124. Pace BS, Perrine S, Li B, et al. Benserazide racemate and enantiomers induce fetal globin gene expression in vivo: Studies to guide clinical development for beta thalassemia and sickle cell disease. Blood Cells Mol Dis. 2021;89:102561. Doi:10.1016/j.bcmd.2021.102561
125. Kuo KHM, Singer ST, Blyden GT, et al. Initial results in a phase 1b trial of PB-04 in sickle cell disease demonstrate fetal hemoglobin induction, additive activity with hydroxyurea, and improved red blood cell sickling parameters. Blood. 2023;142(Supplement 1):1148-1148. Doi:10.1182/blood-2023-184627
126. Bou-Fakhredin R, De Franceschi L, Motta I, Cappellini MD, Taher AT. Pharmacological induction of fetal hemoglobin in β-thalassemia and sickle cell disease: an updated perspective. Pharmaceuticals (Basel). 2022;15(6)Doi:10.3390/ph15060753
127. Ferraresi M, Panzieri DL, Leoni S, Cappellini MD, Kattamis A, Motta I. Therapeutic perspective for children and young adults living with thalassemia and sickle cell disease. Eur J Pediatr. 2023;182(6):2509-2519. Doi:10.1007/s00431-023-04900-w
128. Steinberg MH. Clinical trials in sickle cell disease: adopting the combination chemotherapy paradigm. Am J Hematol. 2008;83(1):1-3. Doi:10.1002/ajh.21033
129. Minniti CP. l-glutamine and the dawn of combination therapy for sickle cell disease. N Engl J Med. 2018;379(3):292-294. Doi:10.1056/NEJMe1800976
130. Pauling L, Itano HA, et al. Sickle cell anemia, a molecular disease. Science. 1949;109(2835):443.
131. Martyn G, Winert B, Yang L, et al. Natural regulatory mutations elevate fetal globin gene via disruption of BCL11A or ZBTB7A binding. Nature Genetics 2018; 498-503.
2. Weatherall DJ, Miller LH, Baruch DI, et al. Malaria and the red cell. Hematology Am Soc Hematol Educ Program. 2002:35-57. Doi:10.1182/asheducation-2002.1.35
3. Schechter AN. Hemoglobin research and the origins of molecular medicine. Blood. 2008;112(10):3927-38. Doi:10.1182/blood-2008-04-078188
4. Bunn HF. Pathogenesis and treatment of sickle cell disease. N Engl J Med. 1997;337(11):762-9. Doi:10.1056/nejm199709113371107
5. Weatherall DJ. The inherited diseases of hemoglobin are an emerging global health burden. Blood. 2010;115(22):4331-6. Doi:10.1182/blood-2010-01-251348
6. Kan YW, Dozy AM. Polymorphism of DNA sequence adjacent to human beta-globin structural gene: relationship to sickle mutation. Proc Natl Acad Sci U S A. 1978;75(11):5631-5. Doi:10.1073/pnas.75.11.5631
7. Yuan J, Angelucci E, Lucarelli G, et al. Accelerated programmed cell death (apoptosis) in erythroid precursors of patients with severe beta-thalassemia (Cooley's anemia). Blood. 1993;82(2):374-7.
8. Rund D, Rachmilewitz E. Beta-thalassemia. N Engl J Med. 2005;353(11):1135-46. Doi:10.1056/NEJMra050436
9. Bauer DE, Orkin SH. Update on fetal hemoglobin gene regulation in hemoglobinopathies. Curr Opin Pediatr. 2011;23(1):1-8. Doi:10.1097/MOP.0b013e3283420fd0
10. Galanello R, Origa R. Beta-thalassemia. Orphanet J Rare Dis. 2010;5:11. Doi:10.1186/1750-1172-5-11
11. GBD 2021 Sickle Cell Disease Collaborators. Global, regional, and national prevalence and mortality burden of sickle cell disease, 2000-2021: a systematic analysis from the Global Burden of Disease Study 2021. Lancet Haematol. 2023;10(8):e585-e599. Doi:10.1016/s2352-3026(23)00118-7
12. Stamatoyannopoulos G. Control of globin gene expression during development and erythroid differentiation. Exp Hematol. 2005;33(3):259-71. Doi:10.1016/j.exphem.2004.11.007
13. Lavelle D, Engel JD, Saunthararajah Y. Fetal hemoglobin induction by epigenetic drugs. Semin Hematol. 2018;55(2):60-67. Doi:10.1053/j.seminhematol.2018.04.008
14. Charache S, Terrin ML, Moore RD, et al. Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. Investigators of the Multicenter Study of Hydroxyurea in Sickle Cell Anemia. N Engl J Med. 1995;332(20):1317-22. Doi:10.1056/nejm199505183322001
15. Joseph JJ, Abraham AA, Fitzhugh CD. When there is no match, the game is not over: alternative donor options for hematopoietic stem cell transplantation in sickle cell disease. Semin Hematol. 2018;55(2):94-101. Doi:10.1053/j.seminhematol.2018.04.013
16. Leonard A, Tisdale JF. A pause in gene therapy: Reflecting on the unique challenges of sickle cell disease. Mol Ther. 2021;29(4):1355-1356. Doi:10.1016/j.ymthe.2021.03.010
17. Nienhuis AW. Development of gene therapy for blood disorders. Blood. 2008;111(9):4431-44. Doi:10.1182/blood-2007-11-078121
18. Wood WG, Bunch C, Kelly S, Gunn Y, Breckon G. Control of haemoglobin switching by a developmental clock? Nature. 1985;313(6000):320-3. Doi:10.1038/313320a0
19. Perrine SP, Rudolph A, Faller DV, et al. Butyrate infusions in the ovine fetus delay the biologic clock for globin gene switching. Proc Natl Acad Sci U S A. 1988;85(22):8540-2. Doi:10.1073/pnas.85.22.8540
20. Perrine SP, Greene MF, Faller DV. Delay in the fetal globin switch in infants of diabetic mothers. N Engl J Med. 1985;312(6):334-8. Doi:10.1056/nejm198502073120602
21. Watson J. The significance of the paucity of sickle cells in newborn Negro infants. Am J Med Sci. 1948;215(4):419-23. Doi:10.1097/00000441-194804000-00008
22. Steinberg MH, Rodgers GP. Pharmacologic modulation of fetal hemoglobin. Medicine (Baltimore). 2001;80 (5):328-44. Doi:10.1097/00005792-200109000-00007
23. Perrine RP, Brown MJ, Clegg JB, Weatherall DJ, May A. Benign sickle-cell anaemia. Lancet. 1972;2(7788):1163-7. Doi:10.1016/s0140-6736(72)92592-5
24. Franco RS, Yasin Z, Palascak MB, Ciraolo P, Joiner CH, Rucknagel DL. The effect of fetal hemoglobin on the survival characteristics of sickle cells. Blood. 2006;108(3):1073-6. Doi:10.1182/blood-2005-09-008318
25. Papayannopoulou T, Vichinsky E, Stamatoyannopoulos G. Fetal Hb production during acute erythroid expansion. I. Observations in patients with transient erythroblastopenia and post-phlebotomy. Br J Haematol. 1980;44(4):535-46. Doi:10.1111/j.1365-2141.1980.tb08707.x
26. Mabaera R, West RJ, Conine SJ, et al. A cell stress signaling model of fetal hemoglobin induction: what doesn't kill red blood cells may make them stronger. Exp Hematol. 2008;36(9):1057-72. Doi:10.1016/j.exphem.2008.06.014
27. Chen JJ, Perrine S. Stressing HbF synthesis: role of translation? Blood. 2013;122(4):467-8. Doi:10.1182/blood-2013-06-506139
28. Chen JJ. HRI stress signaling and HbF production. Blood. 2020;135(24):2113-2114. Doi:10.1182/blood.2020006300
29. Thein SL. Genetic modifiers of beta-thalassemia. Haematologica. 2005;90(5):649-60.
30. Sedgewick AE, Timofeev N, Sebastiani P, et al. BCL11A is a major HbF quantitative trait locus in three different populations with beta-hemoglobinopathies. Blood Cells Mol Dis. 2008;41(3):255-258. Doi:10.1016/j.bcmd.2008.06.007
31. Uda M, Galanello R, Sanna S, et al. Genome-wide association study shows BCL11A associated with persistent fetal hemoglobin and amelioration of the phenotype of beta-thalassemia. Proc Natl Acad Sci U S A. 2008;105(5):1620-5. Doi:10.1073/pnas.0711566105
32. Bieker JJ. Putting a finger on the switch. Nat Genet. 2010;42(9):733-4. Doi:10.1038/ng0910-733
33. Borg J, Papadopoulos P, Georgitsi M, et al. Haploinsufficiency for the erythroid transcription factor KLF1 causes hereditary persistence of fetal hemoglobin. Nat Genet. 2010;42(9):801-5. Doi:10.1038/ng.630
34. Thein SL. Molecular basis of β thalassemia and potential therapeutic targets. Blood Cells Mol Dis. 2018;70:54-65. Doi:10.1016/j.bcmd.2017.06.001
35. Platt OS, Brambilla DJ, Rosse WF, et al. Mortality in sickle cell disease. Life expectancy and risk factors for early death. N Engl J Med. 1994;330(23):1639-44. Doi:10.1056/nejm199406093302303
36. Steinberg MH. Fetal hemoglobin in sickle cell anemia. Blood. 2020;136(21):2392-2400. Doi:10.1182/blood.2020007645
37. Calvet D, Tuilier T, Mélé N, et al. Low fetal hemoglobin percentage is associated with silent brain lesions in adults with homozygous sickle cell disease. Blood Adv. 2017;1(26):2503-2509. Doi:10.1182/bloodadvances.2017005504
38. Bunn HF. Reversing ontogeny. N Engl J Med. 1993;328(2):129-31. Doi:10.1056/nejm199301143280210
39. Atweh GF, Sutton M, Nassif I, et al. Sustained induction of fetal hemoglobin by pulse butyrate therapy in sickle cell disease. Blood. 1999;93(6):1790-7.
40. Cao H, Stamatoyannopoulos G, Jung M. Induction of human gamma globin gene expression by histone deacetylase inhibitors. Blood. 2004;103(2):701-9. Doi:10.1182/blood-2003-02-0478
41. Dover GJ, Charache S, Nora R, Boyer SH. Progress toward increasing fetal hemoglobin production in man: experience with 5-azacytidine and hydroxyurea. Ann N Y Acad Sci. 1985;445:218-24. Doi:10.1111/j.1749-6632.1985.tb17191.x
42. Fucharoen S, Inati A, Siritanaratku N, et al. A randomized phase I/II trial of HQK-1001, an oral fetal globin gene inducer, in β-thalassaemia intermedia and HbE/β-thalassaemia. Br J Haematol. 2013;161(4):587-93. Doi:10.1111/bjh.12304
43. Shi L, Cui S, Engel JD, Tanabe O. Lysine-specific demethylase 1 is a therapeutic target for fetal hemoglobin induction. Nat Med. 2013;19(3):291-4. Doi:10.1038/nm.3101
44. Kutlar A, Meiler S, Swerdlow P, Knight R. Thalidomide and its analogs for hemoglobinopathies: two birds with one stone? Expert Rev Hematol. 2012;5(1):9-11. Doi:10.1586/ehm.11.77
45. Engel JD, Tanimoto K. Looping, linking, and chromatin activity: new insights into beta-globin locus regulation. Cell. 2000;100(5):499-502. Doi:10.1016/s0092-8674(00)80686-8
46. Kanter J, Walters MC, Krishnamurti L, et al. Biologic and clinical efficacy of LentiGlobin for sickle cell disease. N Engl J Med. 2022;386(7):617-628. Doi:10.1056/NEJMoa2117175
47. US Food and Drug Administration. FDA approves first gene therapies to treat patients with sickle cell disease. December 8, 2023. https://www.fda.gov/news-events/press-announcements/fda-approves-first-gene-therapies-treat-patients-sickle-cell-disease
48. Fontana L, Alahouzou Z, Miccio A, Antoniou P. Epigenetic regulation of β-globin genes and the potential to treat hemoglobinopathies through epigenome editing. Genes (Basel). 2023;14(3)Doi:10.3390/genes14030577
49. Wood WG, Stamatoyannopoulos G, Lim G, Nute PE. F-cells in the adult: normal values and levels in individuals with hereditary and acquired elevations of Hb F. Blood. 1975;46(5):671-82.
50. Dover GJ, Boyer SH, Charache S, Heintzelman K. Individual variation in the production and survival of F cells in sickle-cell disease. N Engl J Med. 1978;299(26):1428-35. Doi:10.1056/nejm197812282992603
51. Ansari SH, Shamsi TS, Munzir S, et al. Gγ-Xmn I polymorphism: a significant determinant of β-thalassemia treatment without blood transfusion. J Pediatr Hematol Oncol. 2013;35(4):e153-6. Doi:10.1097/MPH.0b013e31827e8662
52. Winichagoon P, Thonglairoam V, Fucharoen S, Wilairat P, Fukumaki Y, Wasi P. Severity differences in beta-thalassaemia/haemoglobin E syndromes: implication of genetic factors. Br J Haematol. 1993;83(4):633-9. Doi:10.1111/j.1365-2141.1993.tb04702.x
53. Gong Y, Zhang X, Zhang Q, et al. A natural DNMT1 mutation elevates the fetal hemoglobin level via epigenetic derepression of the γ-globin gene in β-thalassemia. Blood. 2021;137(12):1652-1657. Doi:10.1182/blood.2020006425
54. Manwani D, Bieker JJ. KLF1: when less is more. Blood. 2014;124(5):672-3. Doi:10.1182/blood-2014-05-576967
55. Charache S, Barton FB, Moore RD, et al. Hydroxyurea and sickle cell anemia. Clinical utility of a myelosuppressive "switching" agent. The Multicenter Study of Hydroxyurea in Sickle Cell Anemia. Medicine (Baltimore). 1996;75(6):300-26. Doi:10.1097/00005792-199611000-00002
56. Ware RE, Eggleston B, Redding-Lallinger R, et al. Predictors of fetal hemoglobin response in children with sickle cell anemia receiving hydroxyurea therapy. Blood. 2002;99(1):10-4. Doi:10.1182/blood.v99.1.10
57. Gladwin MT, Shelhamer JH, Ognibene FP, et al. Nitric oxide donor properties of hydroxyurea in patients with sickle cell disease. Br J Haematol. 2002;116(2):436-44. Doi:10.1046/j.1365-2141.2002.03274.x
58. de Franceschi L, Rouyer-Fessard P, Alper SL, Jouault H, Brugnara C, Beuzard Y. Combination therapy of erythropoietin, hydroxyurea, and clotrimazole in a beta thalassemic mouse: a model for human therapy. Blood. 1996;87(3):1188-95.
59. Goldberg MA, Brugnara C, Dover GJ, Schapira L, Charache S, Bunn HF. Treatment of sickle cell anemia with hydroxyurea and erythropoietin. N Engl J Med. 1990;323(6):366-72. Doi:10.1056/nejm199008093230602
60. Little JA, McGowan VR, Kato GJ, et al. Combination erythropoietin-hydroxyurea therapy in sickle cell disease: experience from the National Institutes of Health and a literature review. Haematologica. 2006;91(8):1076-83.
61. Rodgers GP, Dover GJ, Uyesaka N, Noguchi CT, Schechter AN, Nienhuis AW. Augmentation by erythropoietin of the fetal-hemoglobin response to hydroxyurea in sickle cell disease. N Engl J Med. 1993;328(2):73-80. Doi:10.1056/nejm199301143280201
62. Steinberg MH, Lu ZH, Barton FB, Terrin ML, Charache S, Dover GJ. Fetal hemoglobin in sickle cell anemia: determinants of response to hydroxyurea. Multicenter Study of Hydroxyurea. Blood. 1997;89(3):1078-88.
63. Ballas SK, Marcolina MJ, Dover GJ, Barton FB. Erythropoietic activity in patients with sickle cell anaemia before and after treatment with hydroxyurea. Br J Haematol. 1999;105(2):491-6.
64. Sanchez Ventura LM, Adimora I, Elliot EC, Fasipe T, Flanagan JM. Clinical and hematopoietic profiles associated with sustained hydroxyurea response for patients with sickle cell disease. Blood. 2023;142(Supplement 1):17-17. Doi:10.1182/blood-2023-187335
65. Wang WC, Ware RE, Miller ST, et al. Hydroxycarbamide in very young children with sickle-cell anaemia: a multicentre, randomised, controlled trial (BABY HUG). Lancet. 2011;377(9778):1663-72. Doi:10.1016/s0140-6736(11)60355-3
66. Ware RE, Schultz WH, Yovetich N, et al. Stroke With Transfusions Changing to Hydroxyurea (SWiTCH): a phase III randomized clinical trial for treatment of children with sickle cell anemia, stroke, and iron overload. Pediatr Blood Cancer. 2011;57(6):1011-7. Doi:10.1002/pbc.23145
67. Thornburg CD, Files BA, Luo Z, et al. Impact of hydroxyurea on clinical events in the BABY HUG trial. Blood. 2012;120(22):4304-10; quiz 4448. Doi:10.1182/blood-2012-03-419879
68. Alvarez O, Yovetich NA, Scott JP, et al. Pain and other non-neurological adverse events in children with sickle cell anemia and previous stroke who received hydroxyurea and phlebotomy or chronic transfusions and chelation: results from the SWiTCH clinical trial. Am J Hematol. 2013;88(11):932-8. Doi:10.1002/ajh.23547
69. Aygun B, Lane AC, Smart LR, et al. Hydroxyurea dose optimization is safe and improves outcomes for children with sickle cell anemia living in sub-Saharan Africa: the Reach experience. Blood. 2023;142(Supplement 1):6-6. Doi:10.1182/blood-2023-172919
70. DeBaun MR, Jordan LC, King AA, et al. American Society of Hematology 2020 guidelines for sickle cell disease: prevention, diagnosis, and treatment of cerebrovascular disease in children and adults. Blood Adv. 2020;4(8):1554-1588. Doi:10.1182/bloodadvances.2019001142
71. Cronin RM, Lin CJ, Chiang C, MacEwan SR, DeBaun MR, Hyer JM. The use of FDA-approved medications for preventing vaso-occlusive events in sickle cell disease. Blood Adv. 2023;7(13):3114-3116. Doi:10.1182/bloodadvances.2022008965
72. Saraf S, Farooqui M, Infusino G, et al. Standard clinical practice underestimates the role and significance of erythropoietin deficiency in sickle cell disease. Br J Haematol. 2011;153(3):386-92. Doi:10.1111/j.1365-2141.2010.08479.x
73. Fucharoen S, Siritanaratkul N, Winichagoon P, et al. Hydroxyurea increases hemoglobin F levels and improves the effectiveness of erythropoiesis in beta-thalassemia/hemoglobin E disease. Blood. 1996;87(3):887-92.
74. Singer ST, Kuypers FA, Olivieri NF, et al. Fetal haemoglobin augmentation in E/beta(0) thalassaemia: clinical and haematological outcome. Br J Haematol. 2005;131(3):378-88. Doi:10.1111/j.1365-2141.2005.05768.x
75. Algiraigri AH, Wright NAM, Paolucci EO, Kassam A. Hydroxyurea for nontransfusion-dependent β-thalassemia: A systematic review and meta-analysis. Hematol Oncol Stem Cell Ther. 2017;10(3):116-125. Doi:10.1016/j.hemonc.2017.02.002
76. Hatamleh MI, Chenna VSH, Contractor H, et al. Efficacy of hydroxyurea in transfusion-dependent major β-thalassemia patients: a meta-analysis. Cureus. 2023;15(4):e38135. Doi:10.7759/cureus.38135
77. Zeng YT, Huang SZ, Ren ZR, et al. Hydroxyurea therapy in beta-thalassaemia intermedia: improvement in haematological parameters due to enhanced beta-globin synthesis. Br J Haematol. 1995;90(3):557-63. Doi:10.1111/j.1365-2141.1995.tb05584.x
78. Banan M, Bayat H, Azarkeivan A, et al. The XmnI and BCL11A single nucleotide polymorphisms may help predict hydroxyurea response in Iranian β-thalassemia patients. Hemoglobin. 2012;36(4):371-80. Doi:10.3109/03630269.2012.691147
79. Goren A, Simchen G, Fibach E, et al. Fine tuning of globin gene expression by DNA methylation. PLoS One. 2006;1(1):e46. Doi:10.1371/journal.pone.0000046
80. DeSimone J, Heller P, Hall L, Zwiers D. 5-Azacytidine stimulates fetal hemoglobin synthesis in anemic baboons. Proc Natl Acad Sci U S A. 1982;79(14):4428-31. Doi:10.1073/pnas.79.14.4428
81. Ginder GD. Epigenetic regulation of fetal globin gene expression in adult erythroid cells. Transl Res. 2015;165(1):115-25. Doi:10.1016/j.trsl.2014.05.002
82. Ley TJ, DeSimone J, Anagnou NP, et al. 5-azacytidine selectively increases gamma-globin synthesis in a patient with beta+ thalassemia. N Engl J Med. 1982;307(24):1469-75. Doi:10.1056/nejm198212093072401
83. Lowrey CH, Nienhuis AW. Brief report: treatment with azacitidine of patients with end-stage beta-thalassemia. N Engl J Med. 1993;329(12):845-8. Doi:10.1056/nejm199309163291205
84. Koshy M, Dorn L, Bressler L, et al. 2-deoxy 5-azacytidine and fetal hemoglobin induction in sickle cell anemia. Blood. 2000;96(7):2379-84.
85. DeSimone J, Koshy M, Dorn L, et al. Maintenance of elevated fetal hemoglobin levels by decitabine during dose interval treatment of sickle cell anemia. Blood. 2002;99(11):3905-8. Doi:10.1182/blood.v99.11.3905
86. Saunthararajah Y, Hillery CA, Lavelle D, et al. Effects of 5-aza-2'-deoxycytidine on fetal hemoglobin levels, red cell adhesion, and hematopoietic differentiation in patients with sickle cell disease. Blood. 2003;102(12):3865-70. Doi:10.1182/blood-2003-05-1738
87. Olivieri NF, Saunthararajah Y, Thayalasuthan V, et al. A pilot study of subcutaneous decitabine in β-thalassemia intermedia. Blood. 2011;118(10):2708-11. Doi:10.1182/blood-2011-03-341909
88. Lavelle D, Vaitkus K, Ling Y, et al. Effects of tetrahydrouridine on pharmacokinetics and pharmacodynamics of oral decitabine. Blood. 2012;119(5):1240-7. Doi:10.1182/blood-2011-08-371690
89. Molokie R, Lavelle D, Gowhari M, et al. Oral tetrahydrouridine and decitabine for non-cytotoxic epigenetic gene regulation in sickle cell disease: A randomized phase 1 study. PLoS Med. 2017;14(9):e1002382. Doi:10.1371/journal.pmed.1002382
90. Molokie R, Saraf SL, Krauz L, et al. Translating an HPFH-mechanism into oral small molecule therapy for beta-hemoglobinopathies: clinical proof-of-principle. Blood. 2023;142(Supplement 1):2524-2524. Doi:10.1182/blood-2023-186228
91. Perrine SP, Miller BA, Faller DV, et al. Sodium butyrate enhances fetal globin gene expression in erythroid progenitors of patients with Hb SS and beta thalassemia. Blood. 1989;74(1):454-9.
92. Bank A. Regulation of human fetal hemoglobin: new players, new complexities. Blood. 2006;107(2):435-43. Doi:10.1182/blood-2005-05-2113
93. Steliou K, Boosalis MS, Perrine SP, Sangerman J, Faller DV. Butyrate histone deacetylase inhibitors. Biores Open Access. 2012;1(4):192-8. Doi:10.1089/biores.2012.0223
94. Boosalis MS, Bandyopadhyay R, Bresnick EH, Pace BS, Van DeMark K, Faller DV, Perrine SP. Short chain fatty acid derivatives stimulate cell proliferation and induce STAT-5 activation. Blood 2001;97:3259-3264.
95. Boosalis MS, Bandyopadhyay R, Bresnick EH, Pace BS, Van DeMark K, Faller DV, Perrine SP. S Pace PS, White GL, Dover GJ, Boosalis MS, Faller DV, Perrine SP. Short-chain fatty acid derivatives induce fetal globin expression and erythropoiesis in vivo. Blood 2002; 100:4640-4648.96.
96 Perrine SP, Ginder GD, Faller DV, et al. A short-term trial of butyrate to stimulate fetal-globin-gene expression in the beta-globin disorders. N Engl J Med. 1993;328(2):81-6. Doi:10.1056/nejm199301143280202
97. Weinberg RS, Ji X, Sutton M, et al. Butyrate increases the efficiency of translation of gamma-globin mRNA. Blood. 2005;105(4):1807-9. Doi:10.1182/blood-2004-02-0454
98. Centis F, Tabellini L, Lucarelli G, et al. The importance of erythroid expansion in determining the extent of apoptosis in erythroid precursors in patients with beta-thalassemia major. Blood. 2000;96(10):3624-9.
99. Mathias LA, Fisher TC, Zeng L, et al. Ineffective erythropoiesis in beta-thalassemia major is due to apoptosis at the polychromatophilic normoblast stage. Exp Hematol. 2000;28(12):1343-53. Doi:10.1016/s0301-472x(00)00555-5
100. Pootrakul P, Sirankapracha P, Hemsorach S, et al. A correlation of erythrokinetics, ineffective erythropoiesis, and erythroid precursor apoptosis in thai patients with thalassemia. Blood. 2000;96(7):2606-12.
101. Perrine SP, Castaneda SA, Boosalis MS, White GL, Jones BM, Bohacek R. Induction of fetal globin in beta-thalassemia: Cellular obstacles and molecular progress. Ann N Y Acad Sci. 2005;1054:257-65. Doi:10.1196/annals.1345.033
102. Schaeffer EK, West RJ, Conine SJ, Lowrey CH. Multiple physical stresses induce γ-globin gene expression and fetal hemoglobin production in erythroid cells. Blood Cells Mol Dis. 2014;52(4):214-24. Doi:10.1016/j.bcmd.2013.10.007
103. Bohacek R, Boosalis MS, McMartin C, Faller DV, Perrine SP. Identification of novel small-molecule inducers of fetal hemoglobin using pharmacophore and 'PSEUDO' receptor models. Chem Biol Drug Des. 2006;67(5):318-28. Doi:10.1111/j.1747-0285.2006.00386.x
104. Boosalis MS, Castaneda SA, Trudel M, et al. Novel therapeutic candidates, identified by molecular modeling, induce γ-globin gene expression in vivo. Blood Cells Mol Dis. 2011;47(2):107-16. Doi:10.1016/j.bcmd.2011.04.008
105. Boosalis MS, Sangerman JI, White GL, et al. Novel inducers of fetal globin identified through high throughput screening (HTS) are active in vivo in anemic baboons and transgenic mice. PLoS One. 2015;10(12):e0144660. Doi:10.1371/journal.pone.0144660
106. Perrine SP, Wargin WA, Boosalis MS, et al. Evaluation of safety and pharmacokinetics of sodium 2,2 dimethylbutyrate, a novel short chain fatty acid derivative, in a phase 1, double-blind, placebo-controlled, single-dose, and repeat-dose studies in healthy volunteers. J Clin Pharmacol. 2011;51(8):1186-94. Doi:10.1177/0091270010379810
107. Kutlar A, Reid ME, Inati A, et al. A dose-escalation phase IIa study of 2,2-dimethylbutyrate (HQK-1001), an oral fetal globin inducer, in sickle cell disease. Am J Hematol. 2013;88(11):E255-60. Doi:10.1002/ajh.23533
108. Patthamalai P, Fuchareon S, Chaneiam N, et al. A phase 2 trial of HQK-1001 in HbE-β thalassemia demonstrates HbF induction and reduced anemia. Blood. 2014;123(12):1956-7. Doi:10.1182/blood-2013-11-538470
109. Inati A, Kahale M, Perrine SP, et al. A phase 2 study of HQK-1001, an oral fetal haemoglobin inducer, in β-thalassaemia intermedia. Br J Haematol. 2014;164(3):456-8. Doi:10.1111/bjh.12635
110. Domenica Cappellini M, Graziadei G, Ciceri L, et al. Oral isobutyramide therapy in patients with thalassemia intermedia: results of a phase II open study. Blood Cells Mol Dis. 2000;26(1):105-11. Doi:10.1006/bcmd.2000.0283
111. Reich S, Bührer C, Henze G, et al. Oral isobutyramide reduces transfusion requirements in some patients with homozygous beta-thalassemia. Blood. 2000;96(10):3357-63.
112. Dai Y, Sangerman J, Luo HY, et al. Therapeutic fetal-globin inducers reduce transcriptional repression in hemoglobinopathy erythroid progenitors through distinct mechanisms. Blood Cells Mol Dis. 2016;56(1):62-9. Doi:10.1016/j.bcmd.2015.10.004
113. Mankidy R, Faller DV, Mabaera R, et al. Short-chain fatty acids induce gamma-globin gene expression by displacement of a HDAC3-NCoR repressor complex. Blood. 2006;108(9):3179-86. Doi:10.1182/blood-2005-12-010934
114. Perrine SP, Mankidy R, Boosalis MS, Bieker JJ, Faller DV. Erythroid Kruppel-like factor (EKLF) is recruited to the gamma-globin gene promoter as a co-activator and is required for gamma-globin gene induction by short-chain fatty acid derivatives. Eur J Haematol. 2009;82(6):466-76. Doi:10.1111/j.1600-0609.2009.01234.x
115. Sarkar S, Abujamra AL, Loew JE, Forman LW, Perrine SP, Faller DV. Histone deacetylase inhibitors reverse CpG methylation by regulating DNMT1 through ERK signaling. Anticancer Res. 2011;31(9):2723-32.
116. Ibanez V, Vaitkus K, Rivers A, et al. Efficacy and safety of long-term RN-1 treatment to increase HbF in baboons. Blood. 2017;129(2):260-263. Doi:10.1182/blood-2016-10-746727
117. Rivers A, Vaitkus K, Ibanez V, et al. The LSD1 inhibitor RN-1 recapitulates the fetal pattern of hemoglobin synthesis in baboons (P. anubis). Haematologica. 2016;101(6):688-97. Doi:10.3324/haematol.2015.140749
118. Rivers A, Vaitkus K, Ruiz MA, et al. RN-1, a potent and selective lysine-specific demethylase 1 inhibitor, increases γ-globin expression, F reticulocytes, and F cells in a sickle cell disease mouse model. Exp Hematol. 2015;43(7):546-53.e1-3. Doi:10.1016/j.exphem.2015.04.005
119. Cui S, Lim KC, Shi L, et al. The LSD1 inhibitor RN-1 induces fetal hemoglobin synthesis and reduces disease pathology in sickle cell mice. Blood. 2015;126(3):386-96. Doi:10.1182/blood-2015-02-626259
120. Rivers A, Vaitkus K, Jagadeeswaran R, et al. Oral administration of the LSD1 inhibitor ORY-3001 increases fetal hemoglobin in sickle cell mice and baboons. Exp Hematol. 2018;67:60-64.e2. Doi:10.1016/j.exphem.2018.08.003
121. Ibanez V, Vaitkus K, Zhang X, et al. Combinatorial targeting of epigenome-modifying enzymes with decitabine and RN-1 synergistically increases HbF. Blood Adv. 2023;7(15):3891-3902. Doi:10.1182/bloodadvances.2022009558
122. Krivega I, Byrnes C, de Vasconcellos JF, et al. Inhibition of G9a methyltransferase stimulates fetal hemoglobin production by facilitating LCR/γ-globin looping. Blood. 2015;126(5):665-72. Doi:10.1182/blood-2015-02-629972
123. Dai Y, Sangerman J, Nouraie M, et al. Effects of hydroxyurea on F-cells in sickle cell disease and potential impact of a second fetal globin inducer. Am J Hematol. 2017;92(1):E10-e11. Doi:10.1002/ajh.24590
124. Pace BS, Perrine S, Li B, et al. Benserazide racemate and enantiomers induce fetal globin gene expression in vivo: Studies to guide clinical development for beta thalassemia and sickle cell disease. Blood Cells Mol Dis. 2021;89:102561. Doi:10.1016/j.bcmd.2021.102561
125. Kuo KHM, Singer ST, Blyden GT, et al. Initial results in a phase 1b trial of PB-04 in sickle cell disease demonstrate fetal hemoglobin induction, additive activity with hydroxyurea, and improved red blood cell sickling parameters. Blood. 2023;142(Supplement 1):1148-1148. Doi:10.1182/blood-2023-184627
126. Bou-Fakhredin R, De Franceschi L, Motta I, Cappellini MD, Taher AT. Pharmacological induction of fetal hemoglobin in β-thalassemia and sickle cell disease: an updated perspective. Pharmaceuticals (Basel). 2022;15(6)Doi:10.3390/ph15060753
127. Ferraresi M, Panzieri DL, Leoni S, Cappellini MD, Kattamis A, Motta I. Therapeutic perspective for children and young adults living with thalassemia and sickle cell disease. Eur J Pediatr. 2023;182(6):2509-2519. Doi:10.1007/s00431-023-04900-w
128. Steinberg MH. Clinical trials in sickle cell disease: adopting the combination chemotherapy paradigm. Am J Hematol. 2008;83(1):1-3. Doi:10.1002/ajh.21033
129. Minniti CP. l-glutamine and the dawn of combination therapy for sickle cell disease. N Engl J Med. 2018;379(3):292-294. Doi:10.1056/NEJMe1800976
130. Pauling L, Itano HA, et al. Sickle cell anemia, a molecular disease. Science. 1949;109(2835):443.
131. Martyn G, Winert B, Yang L, et al. Natural regulatory mutations elevate fetal globin gene via disruption of BCL11A or ZBTB7A binding. Nature Genetics 2018; 498-503.