Bharat Biotech starts TB vaccine’s trials in adults

The only related vaccine in use today, BCG (Bacillus, Calmette and Guérin), is an attenuated variant of the bovine TB pathogen

Bharat Biotech has begun clinical trials of the Spanish anti-tuberculosis vaccine among adults in India, the Hydreabad-based pharmaceutical company announced on Sunday. The vaccine candidate called MTBVAC is the first live attenuated vaccine of mycobacterium tuberculosis isolated from a human.

Tuberculosis, which is transmitted through the respiratory tract, kills at least 1.6 million people and infects at least 10 million worldwide each year (AP)

“The trials are carried out by Bharat Biotech in close collaboration with Biofabri,” the company said in a statement. “Trials to evaluate the safety and immunogenicity of MTBVAC have started with a pivotal safety, immunogenicity and efficacy trial planned to start in 2025.”

“It is a giant step to test in adults and adolescents in the country where 28% of the world’s TB cases accumulate,” said Esteban Rodriguez, CEO of Biofabri. “More effort and funding is needed to combat TB, which remains one of the world’s leading infectious causes of death, especially in India.”

The only related vaccine in use today, BCG (Bacillus, Calmette and Guérin), is an attenuated variant of the bovine TB pathogen. It is at least a 100 years old and has a limited effect on pulmonary tuberculosis, which is responsible for the transmission of the disease.

“Our quest for a more effective vaccine against tuberculosis received a big boost today with clinical trials in India,” said Krishna Ella, executive chairman of Bharat Biotech. “Our goal to develop TB vaccines to prevent disease in adults and adolescents has taken a big step today.”

Tuberculosis, which is transmitted through the respiratory tract, kills at least 1.6 million people and infects at least 10 million worldwide each year. In 90% of infections, the immune system recognises and controls the bacillus without causing disease. However, in 5-10% of infected people, the bacillus develops tuberculosis, which is fatal in half of patients without treatment. If the infection is in the lungs, it can find a free path to progress, multiply and spread the disease.

Although there are antibiotics that can kill the bacilli at a higher rate than they reproduce, the tuberculosis bacteria have a coat that protects them from the immune system and makes it difficult for many of these drugs to penetrate, and multi-drug resistant strains have emerged in recent decades, making it crucial to get an effective vaccine against the disease

After the recent completion of a phase II dose- finding trial, a double-blind, controlled phase III clinical trial in newborns has started in 2023, comparing the vaccine with the current BCG vaccine. Seven thousand newborns from South Africa, 60 from Madagascar and 60 from Senegal will be vaccinated, Bharat Biotech said. More than 1,900 babies have been vaccinated till now.

The aim is to assess the immunogenicity and efficacy of MTBVAC, which is administered intradermally to infants on the first day of life.

“Vaccination began at a time of setback in the global fight against TB. Health restrictions imposed during the COVID-19 pandemic led to an increase in infections and a decrease in diagnosis and treatment. As a result, annual TB deaths have risen to over 1.6 million,” the company said.

This phase III neonatal project, partially funded by the European Union through its European and Development Countries Clinical Trial Partnership programme, is being coordinated by Biofabri, as part of a consortium that also includes the University of Zaragoza, Tuberculosis Vaccine Initiative , University of Cape Town, Wits VIDA Health Consortium, Stellenbosch University, Enhancing Care Foundation, Center de Recherche Biomedicale Espoir Pour La Santé in Senegal and Institut Pasteur de Madagascar.

After completing a dose escalation trial in HIV uninfected adults, a phase II study in HIV infected adults has started in 2024 to determine whether MTBVAC is safe in this population cohort. This ongoing trial at 16 sites in South Africa, involving the vaccination of 276 adults, is evaluating safety and immunogenicity in HIV-negative and HIV-positive adults and adolescents vaccinated with MTBVAC.

A phase IIb efficacy study in adolescents and adults is planned to start in the second half of 2024 in sub-Saharan Africa, the company said. The study in adolescents and adults in sub-Saharan Africa is led by the American institution IAVI. The Phase II HIV safety study is carried out by HIV Vaccine Trials Network and is funded by the Division of AIDS, National Institute of Allergy and Infectious Diseases, National Institutes of Health and Department of Health and Human Services. The phase IIb efficacy study will be carried out by IAVI and will be funded by the Bill and Melinda Gates Foundation and Open Philanthropy.

“MTBVAC is the only vaccine against tuberculosis in clinical trials based on a genetically modified form of the pathogen isolated from humans mycobacterium tuberculosis which, unlike BCG, contains all the antigens present in strains that infect humans,” Bharat Biotech said.