Potent dengue antibody in three years lifts treatment hopes

PUNE: What dengue patients need is a single fast-acting antibody that instantly deactivates any of the four strains of the virus. Such a drug will be ready by 2018.

Pune-based Serum Institute of India (SII) has entered into a licence agreement with US-based biotech company Visterra to develop, manufacture and make commercially available the drug, anti-dengue human monoclonal antibody (VIS513) that can neutralize all four serotypes of the dengue virus found in the Indian subcontinent.

During pre-clinical studies, the candidate drug was found successful in protecting animals exposed to a lethal amount of the virus.

"We have tied up with Visterra to use their human monoclonal antibody to treat dengue . It will be launched after two- three years as we have to carry out multi-centric trials to make sure that the antibody works against all four serotypes of dengue virus," Adar Poonawalla, executive director and chief executive officer of Serum Institute of India Ltd (SII) told TOI on Friday.

The antibody provides immediate protection against all the four serotypes as against those which have so far been found effective against either one or two serotypes.

"The monoclonal antibody provides cure in dengue infection caused by any one of the four serotypes . Researchers have succeeded in developing fast-acting antibody but they have been found effective in curing either one or two serotypes whereas the antibody developed by Visterra is effective in all the four," Poonawalla said.

SII plans to conduct clinical trials for 1,000 people to assess the drug's therapeutic potency.

Under the terms of the agreement, SII receives an exclusive licence to manufacture Visterra's antibody (VIS513) for the Indian subcontinent.

"We have to pay royalties and millions of dollars to Visterra for using their clone which has proven to work and cure patients diagnosed with dengue. It is an exclusive agreement for India and some countries at the moment with the option to expand it to 140 countries in which SII currently sells its products," Poonawalla said.

Dengue fever, which can cause death, infects an estimated one lakh people a year, mostly in the tropics. The only treatment is alleviating the symptoms, which can include intense joint and muscle pain, nausea, vomiting and high fever. The potentially fatal virus can cause plasma to leak from the circulatory system.

Paediatrician Sanjay Lalwani (IMA), executive member of Indian Academy of Paediatrics (IAP), Pune branch said, "We are administering only symptomatic treatment to patients down with dengue. Many have complications that involve organs. Sometimes, the dengue fever can become dengue hemorrhagic fever which has higher morbidity and mortality rate. If we encounter an epidemic of severe dengue hemorrhagic fever it will lead to many deaths. If the fast-acting human monoclonal antibody against dengue is available, it will decrease fatalities associated with the mosquito-borne infection."

Dengue antibody

  • As of now, disease prevention is solely dependent on limiting or eradicating mosquitoes that transmit the virus
  • Fast-acting antibody to deactivate any of the four serotypes likely by 2018
  • Serum Institute of India will fund and be responsible for clinical development of VIS513
  • SII and Visterra will establish a committee to coordinate VIS513 development activities for the subcontinent
  • Following regulatory approval, Serum Institute will be responsible for commercializing the antibody in the licensed territories

Infection from serotypes

  • Dengue has four different serotypes, dengue types 1, 2, 3, and 4, different from each other at the genomic level, but they are clubbed together because of similarity at the immunological level. There is similarity in the body's immune response when it is infected by any of these strains
  • Infection through one serotype endows lifelong protection against it, but does not protect against infection from a different serotype
  • A person who has suffered from dengue once can get dengue again, which is called secondary infection.
  • Severe dengue, characterised by haemorrhage and sometimes shock, is associated more with secondary infections
  • The immune response recognises the second infection, but instead of inhibiting the virus it enhances its growth and causes inflammatory response

Source: The Times of India