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Gene therapy for hemophilia
Author(s) -
Chuah Marinee K. L.,
Collen Desire,
VandenDriessche Thierry
Publication year - 2001
Publication title -
the journal of gene medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.689
H-Index - 91
eISSN - 1521-2254
pISSN - 1099-498X
DOI - 10.1002/1521-2254(200101/02)3:1<3::aid-jgm167>3.0.co;2-h
Subject(s) - genetic enhancement , factor ix , medicine , viral vector , clotting factor , vector (molecular biology) , adverse effect , gene delivery , immunology , gene , bioinformatics , biology , genetics , recombinant dna
Hemophilia A and B are X‐chromosome linked recessive bleeding disorders that result from a deficiency in factor VIII (FVIII) and factor IX (FIX) respectively. Though factor substitution therapy has greatly improved the lives of hemophiliac patients, there are still limitations to the current treatment that have triggered interest in alternative treatments by gene therapy. Significant progress has recently been made in the development of gene therapy for the treatment of hemophilia A and B. These advances parallel the technical improvements of existing vector systems including MoMLV‐based retroviral, adenoviral and AAV vectors, and the development of new delivery methods such as lentiviral vectors, helper‐dependent adenoviral vectors and improved non‐viral gene delivery methods. Therapeutic and physiologic levels of FVIII and FIX could be achieved in FVIII‐ and FIX‐deficient mice and hemophilia dogs by different gene therapy approaches. Long‐term correction of the bleeding disorders and in some cases a permanent cure has been realized in these preclinical studies. However, the induction of neutralizing antibodies often precludes stable phenotypic correction. Another complication is that certain promoters are prone to transcriptional inactivation in vivo , precluding long‐term FVIII or FIX expression. Several gene therapy phase I clinical trials are currently ongoing in patients suffering from severe hemophilia A or B. No significant adverse side‐effects were reported, and semen samples were negative for vector sequences by sensitive PCR assays. Most importantly, some subjects report fewer bleeding episodes and occasionally have very low levels of clotting factor activity detected. The results from the extensive preclinical studies in normal and hemophilic animal models and encouraging preliminary clinical data indicate that the simultaneous development of different strategies is likely to bring a permanent cure for hemophilia one step closer to reality. Copyright © 2001 John Wiley & Sons, Ltd.