Tuberculosis Vaccine Initiative Announces Encouraging Preliminary Results

Armen Hareyan's picture

Crucell presents a progress update and immunology data from a Phase I Ad35 tuberculosis vaccine study. The study, conducted in Worcester, South Africa and launched in May 2007, is the second phase I study in a current series of three and has revealed promising results.

Highest CD8 immune responses ever in a TB vaccine study

Preliminary data show both critical arms of the cellular immune system, CD4 and CD8 immune T-cells were induced and that in those participants who responded, CD8 immune responses are considerably higher than has ever previously been seen in a TB vaccine study.

The trial of AERAS-402/Crucell Ad35, which began in May 2007, is being conducted as a double-blind, randomized, placebo-controlled dose escalation study in four groups of healthy adults vaccinated at birth with BCG (Bacille Calmette-Guerin) vaccine. A total of 40 healthy adult volunteers are enrolled.

"While preliminary, these results are promising. We are pleased that Crucell's technologies are playing a key role in the search and development of a much-needed TB vaccine," said Dr. Jaap Goudsmit, Chief Scientific Officer at Crucell. "We highly value the collaboration with Aeras and SATVI on this important mission."


Third key clinical phase I study in progress

Aeras and Crucell began jointly developing this vaccine candidate in 2004 using Crucell's AdVac vaccine technology and PER.C6 manufacturing technology. A first Phase I clinical trial launched in October 2006 in Kansas, USA indicated that the vaccine candidate is safe in healthy adults in the US. The results of a second study, launched in May 2007, are presented in Atlanta at the "TB Vaccines for the World" conference. A third phase I study in healthy adults in St. Louis, Missouri, USA was launched in December 2007 and focuses on the immunogenicity and safety of two AERAS-402/Crucell Ad35 boost doses administered at three to six month intervals after BCG priming in healthy adults.

"The world urgently needs a new TB vaccine, and although we are still in the early stages of clinical trials, the preliminary data of this second phase I study are promising," said Dr. Jerald C. Sadoff, President and CEO of Aeras. "Aeras is delighted to be working with the excellent researchers at Crucell and SATVI. We are grateful to the Bill & Melinda Gates Foundation, the Netherlands Ministry of Foreign Affairs, and our other donors for their financial support of this trial and our vaccine development efforts."

This trial was conducted in the Boland-Overberg region of Western Cape Province in South Africa, which has one of the world's highest TB burdens.

"SATVI is proud to be playing such an important role in the global effort to develop new vaccines to combat TB, which are needed in South Africa and worldwide," said Dr. Gregory Hussey, Director of SATVI and Principal Investigator for the trial. "By conducting this trial, we have advanced the development of a new TB vaccine, expanded scientific capacity, and built awareness of the need for new TB vaccines."

About Tuberculosis

Tuberculosis is the world's second deadliest infectious disease, with over 9 million new cases diagnosed in 2006. According to the World Health Organization (WHO), an estimated 1.7 million people died from TB in 2006. One third of the world's population has been infected with the TB bacillus and current treatment takes 6-9 months. The current TB vaccine Bacille Calmette-Guerin (BCG), developed over 85 years ago, reduces the risk of severe forms of TB in early childhood, but is not very effective in preventing pulmonary TB in adolescents and adults - the populations with the highest rates of TB disease. TB is changing and evolving, making new vaccines more crucial to controlling the pandemic. Tuberculosis is now the leading cause of death for people living with HIV/AIDS, particularly in Africa. Multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) are hampering treatment and control efforts.