Vancouver, BC, Canada (PRWEB) September 23, 2013
One-month Phase II trial was conducted in sputum smear-positive patients with pulmonary tuberculosis randomized into treatment (n=22) and placebo (n=21) arms to investigate the safety and efficacy of an orally-administered therapeutic TB vaccine (V7 Immunitor) containing a small dose of heat-killed Mycobacterium vaccae supplied by Chinese biotech company Anhui Longcom. The injectable version of M. vaccae, VACCAE™, manufactured by Longcom has been approved by Chinese FDA for adjunct treatment of TB. The goal of Immunitor study was to develop and test an easier-to-administer TB vaccine that could be more appealing to patients averse to needle injections.
Patients comprised 8 newly diagnosed (18.6%), 6 re-treated (14%), and 29 multidrug-resistant (MDR-TB; 67.4%) TB cases equally distributed between two treatment arms. Both groups received conventional TB drugs. The outcome of "imm02" study indicates that V7 vaccine was safe, has not produced any adverse effects or reactivation of TB. The mycobacterial clearance in sputum smears was observed in 31.8% versus 9.5% of patients on V7 and placebo, respectively. Sputum conversion occurred fast – only one month of treatment was needed. No difference was seen when drug-sensitive, easy-to-treat TB was compared to treatment-failed TB or MDR-TB – the proportion of converted patients and time to conversion were identical.
Globally AIDS, malaria and tuberculosis are most common causes of death in developing world, with 9.4 million new cases of TB and 1.7 million people dying each year. Current TB drugs are not fully effective, particularly against multi-drug resistant TB (MDR-TB) and TB with HIV and strenuous and often-toxic treatment regimens lasting for up to 2 years are required. Despite that only about half of patients can be cured. Lengthy and difficult treatment prompts high rate of non-compliance, which increases the risk of emergence of drug-resistant bacteria.
"The main implication of this trial is that conventional TB chemotherapy can be shortened to as little as one month. We are confident that we can do better. Indeed, we have second trial of V7, which will be published next month with even better outcome. These promising findings need to be confirmed in expanded studies," said Dr. Dmytro Butov, the Principal Investigator of this study.
Killed M. vaccae preparation is the only therapeutic TB vaccine that has been ever approved by regulatory authorities. VACCAE™ preparation is currently sold in China for TB indication. Except small, ten-patient trial, conducted in Argentina in 2010 by John Stanford and colleagues, all prior studies conducted during past two decades in over 20 countries were based on injectable formulation. The proprietary oral vaccine technology developed by Immunitor has obvious advantages and potential to address current challenges – offering faster, more efficacious and safer solution with high compliance rate. In addition, M. vaccae is inexpensive, made from readily available source, does not require cold-chain storage – all these advantages suit ideally developing countries where TB has become the major healthcare problem.