Hopes of new drugs, vaccines for tuberculosis

December 6, 2009

CANCUN, Mexico (Reuters) - In Uganda, health experts are getting laboratories ready and preparing villagers in two districts for a large clinical trial to test the world's first experimental tuberculosis vaccine in nearly a century.

For Anne Wajja, a doctor who heads TB vaccine studies in Uganda, this could be the start of a turning point.

"New TB drugs and vaccines will be important, they will change the lives of ordinary people, it is definitely important to have a new vaccine," said Wajja, who spoke at a conference on lung health in Cancun, Mexico, Sunday.

Over a thousand scientists and researchers were gathered in Cancun over the weekend to discuss experimental drugs and vaccines to fight TB, which killed 1.8 million people in 2008, or one person every 20 seconds.

One of the oldest diseases known to mankind, TB afflicts mostly the poor in developing places such as sub-Saharan Africa, India and China.

For decades, it was forgotten by richer and scientifically more advanced nations until people infected with HIV started falling ill and dying from TB because of the damage done to their immune systems by AIDS.

"It was only in the 80s and 90s when TB resurged in the west and north that everyone woke up and the U.S. Congress asked 'this (TB) exists?' New York City had to spend US$1 billion in 1990 just to get the TB epidemic in New York City under control," said Ann Ginsberg, chief medical officer of the TB Alliance.

TB Alliance is a U.S.-based non-profit scientific group that pulls together partners to develop new drugs to fight TB.

"So there is renewed attention to the problem, and awakening and rebuilding again after many years of lying fallow," Ginsberg said in an interview.

HOPES IN THE PIPELINE

Although TB has plagued humankind for thousands of years, there is only one vaccine -- the Bacille Calmette-Guerin (BCG) developed around 1920 -- which isn't very good.

It gives only some measure of protection to young children and none at all to adults.

With the exception of rifabutin, there has been no new drug for TB for more than 40 years.

Currently, patients need to take a combination of four drugs daily for six to nine months and compliance is poor, leading often to drug resistance. These patients then become harder to treat because there are only very few second-line drugs.

One in every two patients with the worst form of drug resistant TB dies.

There are now nine experimental vaccines in clinical trials and experts in the field are confident that the world will see a new and better vaccine by 2016.

The U.S.-based non-profit Aeras Global TB Vaccine Foundation, which is working on four of the nine vaccines, hopes to launch a product that will not only prevent TB infection in all age groups, but also stop the TB bacteria from becoming active in people infected with HIV.

"We think that eventually we could prevent enough people from having the disease and acquiring (the bacteria) that the transmission rate will be so low that the disease will go away," said Aeras president Jerald Sadoff, a medical doctor.

TB Alliance is involved in developing three of the eight experimental drugs in clinical trials, one of which is moxifloxacin, which it hopes will be ready in five years.

"We are very hopeful that moxifloxacin will be able to shorten treatment from six months to four months," Ginsberg said.

Researchers are considering using some of these experimental drugs in combination to prevent drug resistance.

"We think some of these novel combinations can bring treatment down to about three months because they are completely new," Ginsberg said, adding that these new regimens can be used for all TB patients, including those with drug resistant TB.