Disease category Disorder S2 Protein augmentation therapies for inherited 1 Augmented protein 2 Source of therapeutic protein / peptide Outcome References 3 Membrane transport Coagulation Cystic fibrosis Pancreatic enzymes Porcine and bovine pancreas Gastrointestinal phenotype Hemophilia A Factor VIII Recombinant factor VIII Bleeding episodes Hemophilia B Factor IX Recombinant factor IX Bleeding episodes 1,2 3,4 3,4 Von Willebrand Disease Von Willebrand factor Pooled human plasma Bleeding episodes 5-7 Emphysema α1-antitrypsin deficiency α1-antitrypsin Pooled human plasma Decreased mortality from emphysema 8,9 Immune deficiency Severe combined immune deficiency Adenosine deaminase Bovine adenosine deaminase coated with polyethylene glycol Reduced incidence of infections 10 Endocrine Growth hormone deficiency Growth hormone Recombinant growth hormone Normal growth 11 Congenital leptin deficiency Leptin Recombinant leptin Normalization of hyperphagia; reduction in body mass 12 Congenital neurogenic diabetes insipidus Anti-diuretic hormone Recombinant anti-diuretic hormone Abolishment of polyuria and polydipsia 13
Disease category Disorder Augmented protein 2 Source of therapeutic protein / peptide Outcome References 3 Lysosomal storage Gaucher disease type I Acid β-glucosidase Recombinant acid β- glucosidase Reduced hepatosplenomegaly, thrombocytopenia, anemia and bone crises; CNS and lung pathologies persist 14 Fabry disease α-galactosidase A Recombinant α-galactosidase A Improvement in renal function and peripheral nervous system pathology 15 Mucopolysaccharidosis I α-l-iduronidase Recombinant α-l-iduronidase Reduced hepatosplenomegaly, improved range of motion and lung function; bone deficiencies persist Mucopolysaccharidosis II α-iduronate 2-sulfatase Recombinant α-iduronate 2- sulfatase Reduced hepatosplenomegaly Mucopolysaccharidosis VI Arylsulfatase Recombinant arylsulfatase Improved lung function, endurance and range of motion 6 17 18 Pompe disease Acid α-glucosidase Recombinant acid α- glucosidase Improved heart, lung, and skeletal muscle function 19
1 2 3 The concept of protein augmentation therapy is simple: purify the missing protein and give it back. Protein augmentation therapy is most applicable to treat hereditary where the deficient protein functions in the extracellular milieu. If the therapeutic protein has to reach sites where there is a barrier against diffusion of proteins (e.g., the brain), systemic protein augmentation therapy will not be effective. When the phenotype involves an intracellular protein, protein augmentation therapy can be effective only if there is a mechanism to import the protein into a compartment of the cell relevant to the abnormal phenotype, such as protein augmentation therapy for the lysosomal storage. Other challenges for treating hereditary with protein augmentation therapy include maintaining venous access to administer the protein, infection, shortages, cost, requirement of frequent, repeated administrations, and allergic, inflammatory and immune responses to the infused proteins. This list is representative, but not exhaustive. For further details, several general reviews are available detailing strategies of protein augmentation therapies for hereditary 20, 21, 22. Almost all protein augmentation therapy is administered intravenously; exceptions include pancreatic enzymes for the gastrointestinal manifestations of cystic fibrosis (oral) and anti-diuretic therapy for diabetes insipidus (intranasal). Specific references in this column of the table are numbered according to the literature cited below. References 1. Walters, M.P. and Littlewood, J.M. Pancreatin preparations used in the treatment of cystic fibrosis--lipase content and in vitro release. Aliment. Pharmacol. Ther. 10, 433-440 (1996). 2. Littlewood, J.M. and Wolfe, S.P. Control of malabsorption in cystic fibrosis. Paediatr. Drugs 2, 205-222 (2000). 3. Srivastava, A. Dose and response in haemophilia--optimization of factor replacement therapy. Br. J. Haematol. 127, 12-25 (2004). 4. Carcao, M.D. and Aledort, L. Prophylactic factor replacement in hemophilia. Blood Rev. 18, 101-113 (2004). 5. Hambleton, J. Advances in the treatment of von Willebrand disease. Semin. Hematol. 38, 7-10 (2001). 6. Cox, G.J. Diagnosis and treatment of von Willebrand disease. Hematol. Oncol. Clin. North Am. 18, 1277-99, viii (2004). 7. Mannucci, P.M. Treatment of von Willebrand's Disease. N. Engl. J. Med. 351, 683-694 (2004).
8. Crystal, R.G. Alpha 1-antitrypsin deficiency, emphysema, and liver disease. Genetic basis and strategies for therapy. J. Clin. Invest. 85, 1343-1352 (1990). 9. Stoller, J.K. and Aboussouan, L.S. alpha1-antitrypsin deficiency: intravenous augmentation therapy: current understanding. Thorax 59, 708-712 (2004). 10. Chan, B., et al. Long-term efficacy of enzyme replacement therapy for Adenosine deaminase (ADA)-deficient Severe Combined Immunodeficiency (SCID). Clin. Immunol. 117, 133-143 (2005). 11. Bierich, J.R. Therapy with growth hormone--old and new indications. Horm. Res. 32, 153-165 (1989). 12. Farooqi, I.S. and O'Rahilly, S. Monogenic obesity in humans. Annu. Rev. Med. 56, 443-458 (2005). 13. D. G. Bichet and T. M. Fujiwara, "Nephropgenic Diabetes Inipidus,"in The Metabolic & Molecular Bases of Inherited Disease, Eighth ed. edited by C. R. Scriver, et al. (McGraw-Hill, New York, 2001), pp.4181-4204. 14. Charrow, J., et al. Enzyme replacement therapy and monitoring for children with type 1 Gaucher disease: consensus recommendations. J. Pediatr. 144, 112-120 (2004). 15. Wilcox, W.R., et al. Long-term safety and efficacy of enzyme replacement therapy for Fabry disease. Am. J. Hum. Genet. 75, 65-74 (2004). 16. Wraith, J.E., et al. Enzyme replacement therapy for mucopolysaccharidosis I: a randomized, double-blinded, placebo-controlled, multinational study of recombinant human alpha-l-iduronidase (laronidase). J. Pediatr. 144, 581-588 (2004). 17. Muenzer, J., et al. Enzyme replacement therapy in mucopolysaccharidosis type II (Hunter syndrome): a preliminary report. Acta. Paediatr. Suppl. 91, 98-99 (2002). 18. Harmatz, P., et al. Enzyme replacement therapy in mucopolysaccharidosis VI (Maroteaux-Lamy syndrome). J. Pediatr. 144, 574-580 (2004).
19. Winkel, L.P., et al. Enzyme replacement therapy in late-onset Pompe's disease: a three-year follow-up. Ann. Neurol. 55, 495-502 (2004). 20. E. P. Treacy, D. Valle, and C. R. Scriver, "Treatment of Genetic Disease,"in The Metabolic & Molecular Bases of Inherited Disease, Eighth ed. edited by C. R. Scriver, et al. (McGraw-Hill, New York, 2001), pp.175-192 21. Desnick, R.J. Enzyme replacement and enhancement therapies for lysosomal diseases. J. Inherit. Metab. Dis. 27, 385-410 (2004). 22. Brady, R.O. Enzyme replacement therapy: conception, chaos and culmination. Philos. Trans. R. Soc. Lond. B. Biol. Sci. 358, 915-919 (2003).