Gene Therapy For Haemophilia A (FVIII Deficiency)

Context: 

Recently, the Union Science and Technology Minister announced that India has conducted the first human clinical trial of gene therapy for haemophilia A at Christian Medical College – Vellore.  

India Conducts Clinical Trials For Haemophilia A

The trials involved deploying a novel technology of using a lentiviral vector to express a FVIII transgene in the patient’s own haematopoietic stem cell which will then express FVIII from specific differentiated blood cells.

About Haemophilia A

• A Rare Bleeding Disorder: Hemophilia A, also known as classical haemophilia, is a rare and genetic bleeding disorder caused by insufficient levels of a blood protein called factor VIII. 
  • Factor VIII is a clotting factor (an essential protein required for blood to clot and stop bleeding).
• Caused by: Hemophilia A is caused by disruptions or changes (variants or mutations) to the F8 gene located on the X chromosome. 
• Susceptibles: Hemophilia A is mostly expressed in males but some females who carry the gene variant may have mild or, rarely, severe symptoms of bleeding. 
• World Haemophilia Day: April 17 

About Haemophilia

• Caused by: Hemophilia is caused by a defect in the X chromosome. 
• A Royal Disease: Britain’s Queen Victoria (1819-1901) is the world’s most widely known carrier of haemophilia.
  • From her, the condition spread among a number of European royal families, which is why haemophilia was once known as the “royal disease”. 
• An Inherited Disease: Haemophilia is a medical condition, mostly inherited, in which the ability of blood to clot is severely reduced so that even a minor injury can cause severe bleeding. 
• Types: The most common type of Haemophilia is called Haemophilia A. Here, the person does not have enough clotting factor VIII.
• Haemophilia B is less common. Here, a person does not have enough factor IX.
• Statistics In India: Haemophilia A, occurs in about 1 in 5,000 births, while Haemophilia B is even rarer at about 1 in about 20,000 births.

About Gene Therapy For Haemophilia

• It is based on the transfer of a non-pathogenic and non-replicating recombinant adeno-associated virus (AAV), the viral DNA of which has been replaced by a bioengineered gene cassette, with a tissue-specific promoter and other regulatory elements.
• Roctavian is the first gene therapy to treat haemophilia A. The active substance in Roctavian, valoctocogene roxaparvovec, is based on a virus (adeno-associated virus or AAV) which has been modified to not cause disease in humans.

News Source: PIB

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