Biopharmaceuticals and gene therapy

Biopharmaceuticals and gene therapy

Biopharmaceuticals

• These are therapeutic agents produced through biotechnological means, but not by conventional laboratory (chemical) synthesis.
• Biopharmaceuticals have their origin from the advancement in the knowledge of biotechnology and molecular cell biology.
• Biopharmaceuticals popularly called as “Designer Proteins” are the promising therapeutic tolls of the future.
• Examples are functional human peptides such as: 
  • ADH, oxytocin, GnRH, ACTH, TSH/TRH, Calcitonin, Insulin,  Somatostatin, Growth Hormone, Cyclosporin etc., and
  • Enzymes / proteins (Streptokinase, Asparaginase, DNAase, glucocerebrosidase, erythropoietin, clotting factors, interferons, Monoclonal Antibodies, Vaccines etc) Daclizumab(Zenopox).
• Genetically engineered human IgG (immunosuppressant monoclonal antibody binds specifically to a-chain of IL₂ receptor) used to lower the rate of rejection phenomenon in kidney transplant recipients.
• Through DNA recombinant technology, bacteria are induced to produce hormones like insulin and growth hormone and enzymes like L – asparaginase.

Gene therapy

• Gene therapy means prevention or treatment of diseases through manipulation of gene function. It is done by insertion of specific genes (therapeutic genes) exogenously into the animal cells.
• It involves replacing the defective gene or supplementation to a nonfunctional gene or suppression of an abnormal gene.
• Recombination DNA technology forms the basis of synthesis of therapeutic genes.
• Gene delivery into host is highly complicated and different from that of conventional drug delivery systems.
• The process involves inserting a therapeutic gene first into a vector (Viral vectors: Retro – or Adenoviruses or Nonviral Vectors: Liposomes, microspheres and plasmid DNA).
• A vector with the gene is then introduced into the patient through either in vivo or ex vivo means.
• The in vivo method involves injecting the suspension of the vector having the therapeutic gene intravenously or into the target tissue/ organ.
• The ex vivo method involves first inserting the therapeutic gene into stem cells obtained from the patient ( blood or bone marrow) and inject the same into the patient.
• Gene therapy is currently aimed at treatment of diseases not responding to conventional drug therapy, such as inherited metabolic diseases through either correction of a deficiency or blockade of an abnormal metabolic reaction.
• It is also applied to induce synthesis of a deficient protein in the host’s cells and treatment of a variety of cancers (melanoma, renal carcinoma, lung cancer, cystic fibrosis etc) certain immune deficiencies and infectious diseases ( like HIV).