In June this year, the Pune-based Serum Institute of India Pvt. Limited will begin a Phase II/III vaccine trial for tuberculosis using a novel, recombinant BCG (bacillus Calmette-Guérin) vaccine.
The double-blind, placebo-controlled, randomised trial will be carried out on 2,000 adults who have been successfully treated (and cured) for TB. While 1,000 adults will receive the vaccine, the remaining volunteers will receive a placebo. A single dose of the vaccine will be administered, and the volunteers will be followed up for a year. The trial will be conducted in 15-17 centres across the country.
The new TB vaccine (VPM1002), which will be tested, is based on the BCG vaccine that is in use. However, it is more powerful and efficacious as it contains a gene, better recognised by the immune system.
Safety test
“Adults who have completed TB treatment will be first screened and enrolled if found eligible 2-4 weeks after completion of TB treatment,” says Dr. Prasad S. Kulkarni, Medical Director at Serum Institute.
“Traces of the drugs may be present in the body for two weeks after completion of the treatment. Since the vaccine contains live, weakened bacteria, the drugs can kill them if given earlier than two weeks after completing the treatment.”
The vaccine will be first administered in 200 volunteers to test its safety, and safety of the vaccine will be tested. “If there are no safety concerns, the trial will continue in the remaining 1,800 volunteers,” he says.
The safety of the vaccine has already been tested in two Phase I trials — 80 adults in Germany (2009) and 24 in South Africa (2010) — and one Phase 2a trial in South Africa in 2012 in 48 newborns who have not been exposed to HIV. “These trials have confirmed the safety of the vaccine and sufficient strengthening of the immune system against TB,” says Umesh Shaligram, Director-R&D, Serum Institute.
The results of the Phase 2a trial in newborns in South Africa, published in February this year in Clinical and Vaccine Immunology, has confirmed the safety of the vaccine.
“The VPM1002 is a safe, well-tolerated, and immunogenic vaccine in newborn infants, confirming the results from the previous trials in adults,” the paper says.
A Phase 2b trial on 416 newborns who have either been exposed or not to HIV is under way in South Africa. “The results of the Phase 2b trial will be known in August-September this year. So far, there have been no safety concerns,” he says.
While the currently used BCG vaccine causes BCG-related disease in HIV-positive babies (due to reduced immunity), the recombinant version is expected to be safe in babies exposed to HIV.
Serum Institute is also planning to start next year a Phase III trial on newborns in India.
