TB vaccine candidate shows excellent safety and promising immunogenicity

Lausanne / Zaragoza / Madrid / Porriño / Lelystad, 17 November 2015 – For the first time, a live-attenuated tuberculosis vaccine – MTBVAC – has been evaluated in humans. MTBVAC – evaluated in 36 human volunteers with no signs of previous exposure to M. tuberculosis – showed excellent safety and promising immunogenicity profiles. The results of this clinical trial, conducted in Lausanne, were published yesterday in the journal THE LANCET Respiratory Medicine. Following this promising evaluation, a subsequent study that will evaluate safety and immunogenicity in humans in an endemic setting has recently started in South Africa.

Tuberculosis remains one of the world’s deadliest transmissible diseases, killing 1.5 million lives per year. Currently there is only one vaccine against tuberculosis available worldwide: Bacille Calmette-Guérin (BCG). This vaccine, used since 1921, can protect children from severe forms of tuberculosis. However, BCG has little to no efficacy in preventing pulmonary TB in (young) adults, the most common and most infectious form of tuberculosis. Therefore new, lifesaving vaccines are urgently needed. MTBVAC is considered to be the most promising vaccine candidate in the portfolio of vaccines in the global pipeline.

Study results
The Phase I study – sponsored by the Spanish Biopharmaceutical Company Biofabri and carried out in collaboration with TuBerculosis Vaccine Initiative (TBVI) – was conducted at the Centre Hospitalier Universitaire Vaudois (CHUV) in Lausanne, Switzerland. The new vaccine candidate MTBVAC was compared to BCG, and did not show any signs of disease and only mild side effects in 36 volunteers. ‘In my experience, it is one of the safest vaccines I have ever tested,’ says Professor François Spertini of CHUV, the Principal Investigator of the trial.
The immune response of the subjects vaccinated with MTBVAC showed promising results, including a strong immunological memory post-vaccination. Overall, MTBVAC was at least as immunogenic as BCG. Combined with an excellent safety profile, these data support its further advanced clinical development in high-burden tuberculosis endemic countries.

MTBVAC: made harmless in the laboratory
Present vaccine BCG is based on attenuated strain of Mycobacterium bovis isolated from cows. MTBVAC, developed by Professor Carlos Martin of the University of Zaragoza in collaboration with Professor Brigitte Gicquel at Pasteur Institute, is a live vaccine based on attenuated M. tuberculosis isolated from humans; a strongly weakened version of the bacterium that causes TB and the first candidate of this kind ever tested in humans. Made harmless in the laboratory, the vaccine stimulates the human immune system to prevent, TB disease. ‘Pre-clinical studies showed great promise, as well as the now held phase I study. If MTBVAC successfully runs through all phases of clinical evaluation and shows efficacy, potentially stronger, it could replace BCG and protect millions of children and adults from getting tuberculosis,’ Carlos Martin says.

Follow up trial already started
The development of MTBVAC so far has been made possible through a unique European collaboration within the TBVI consortium and was financed by TBVI and the Spanish biopharmaceutical company Biofabri. Throughout the process, TBVI’s Product and Clinical Development Team has provided scientific support and developmental expertise.
The promising results of the Phase I study will be followed by a new clinical study in South Africa, where TB is endemic. This study – started in September – will be conducted by the South African Tuberculosis Vaccine Initiative (SATVI) over the coming two year period. This clinical trial is designed to evaluate the safety and immunogenicity of MTBVAC vaccine in new-borns. Biofabri plays an important role in the search for a new vaccine against TB worldwide, because it is responsible for the development and optimisation of the industrial process of the MTBVAC vaccine and together with TBVI (through Aeras/DFID and Norad) continue to financially support the developments.
‘In 2008 Biofabri committed to MTBVAC project and more and more the encouraging expectations of this new vaccine are being confirmed. Since then, Biofabri has contributed to MTBVAC making a huge technical and investment effort’ Biofabri CEO Esteban Rodríguez says.