The Belgian vaccine maker GSK Biologicals’ rotaviral diarrhoea vaccine, Rotarix, is likely to miss the first-mover advantage in India. The company, which has already completed clinical studies in the country, has not yet presented the trial data to the Indian drug regulator even as two local vaccines are expected to hit the market by the year-end.

A senior official from the office of Drug Controller General of India, who did not want to be identified, said GSK has not presented the trial data though its application for the product is pending approval.

A file picture of a child undergoing treatment for diarrhoea at Safdarjung Hospital in New Delhi. GSK Biologicals was expected to launch its rotaviral diarrhoea vaccine, Rotarix, in India this year

Rotarix, which was developed by GSK Biologicals in 1997, has been one of the promising new vaccines in its parent GlaxoSmithKline’s pipeline for India, as it would have been the first diarrhoea vaccine to be launched in the country. Rotarix is the first human rotavirus vaccine available in the market as the US drug maker Merck & Co. Inc.’s Rotateq, which is currently undergoing trials in Africa and a few other Asian countries, is based on a bovine strain.

Though questions are being raised among the global scientist community whether vaccines designed to combat viruses should be introduced in different countries without trials specific to that region’s patient population, Sundar Rajan, a GSK spokesman, said the firm was not aware of any reports that shows its vaccine is not suitable for India.

“Although there are viruses with different genotypes moving in India, publication of surveillance done in India indicates that the majority of severe rota virus disease causing hospitalization is due to genotypes G1, G2, G3, G4 and G9. For these genotypes, Rotarix has demonstrated significant efficacies of up to 100%," Rajan said, adding that the vaccine—which is given orally—confers significant protection against rotavirus diarrhoea.

GSK has not presented clinical data to the regulator, “but (that) is not likely to delay the launch as it is part of a regulatory procedure", Rajan said. The British company has a vaccine manufacturing facility operational in Nashik since 2005.

Meanwhile, the first two rotaviral diarrhoea vaccines—116 E and I321—specific to India have completed human clinical trials in the country and has just entered so-called Phase III trials, which will likely be completed in three months’ time, said Krishna Ella, chairman and managing director, Bharat Biotech International Ltd.

“The Phase I clinical trials dealing with the safety and immunogenicity studies have been completed in adults, children and infants. The infant trials showed both vaccines to be well tolerated and safe," Ella added.

According to medical reports available with the drug controller’s office, results show the 116E-based vaccine candidate is more promising and provides up to 70% protection with a single dose in infants, which may increase to complete protection with two or three doses.

The Hyderabad-based Bharat Biotech International has produced prototype vaccine 116E to ensure its sufficient stock for the phase II and III clinical trials. Rotavirus is the most common cause of severe dehydrating diarrhoea in infants and children. Among children under five years of age, it is estimated to be responsible for an estimated two million hospitalization cases. Two out of five instances of diarrhoea disease in children can be traced to the rotavirus. Deaths due to diarrhoea in India top 150,000 a year.