Inherited disorders which decrease production or alter structure of the 2-chain of hemoglobin A (2-thalassemias or sickle cell disease) are among the most common monogenic diseases in the world, afflicting millions worldwide, and are designated by WHO as a global health burden. Fetal hemoglobin (HbF: 12, 32) is another type of hemoglobin which is present in all humans, but is normally suppressed in infancy to levels below 2%. Decades of biochemical, clinical, and epidemiologic research have shown that any incremental increase in HbF reduces the severity of sickle cell disease, or reduces the life-threatening anemia of 2-thalassemia. Pharmacologic augmentation of fetal hemoglobin (3-globin chain) production, to replace the defective or missing 2-globin chains, is established as a therapeutic modality. A small panel of therapeutic agents of different chemical classes can induce HbF experimentally, and a few have been tested clinically. Classes of agents shown to induce HbF in sickle cell disease and beta-thalassemia include: cytotoxic chemotherapeutic agents (such as hydroxyurea (HU), 5-azacytidine, and decitabine), short chain fatty acids (SCFAs) and derivatives (SCFADs), and some HDAC inhibitors. Some have shown proof-of-principle in reducing hospitalizations and transfusion dependency, but, except for HU, require parenteral administration or large doses, or are cytotoxic and mutagenic, and have not proven suitable for broad application. Further, any new chemical entities require costly toxicology and development costs for FDA approval. We recently developed and utilized a novel high-throughput screening program to interrogate a chemical library of drugs which are already FDA-approved for other conditions, and identified a select panel of novel, and previously unrecognized potent HbF-inducing drugs some of which have benign safety profiles. The activity was validated in a secondary gene assays, erythroid cell culture, and in a pilot study in baboons. This proposal is to confirm and compare the efficacy of 3 candidate HbF-inducers in a nonhuman primate model which has been predictive of subsequent human responses for other drugs. This will allow selection of a therapeutic for rapid clinical application.
Our Aims i nclude:
Aim I : To determine comparative in vivo activity of the candidate therapeutics in anemic nonhuman primates.
Aim II : To prepare a medicinal formulation of the selected therapeutic
This proposal will evaluate three therapeutics for a new medical use in an animal model that simulates sickle cell disease and beta thalassemia, serious blood diseases worldwide. The therapeutics are already approved for other conditions. Upon completion of the proposed studies, the most potent agent can be tested in the patient populations, and a new therapy can be rapidly applied to patient care.
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|Perrine, Susan P; Pace, Betty S; Faller, Douglas V (2014) Targeted fetal hemoglobin induction for treatment of beta hemoglobinopathies. Hematol Oncol Clin North Am 28:233-48|
|Kutlar, Abdullah; Ataga, Kenneth; Reid, Marvin et al. (2012) A phase 1/2 trial of HQK-1001, an oral fetal globin inducer, in sickle cell disease. Am J Hematol 87:1017-21|