Pune: 2nd phase of AIDS vaccine trials halted

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Pune: 2nd phase of AIDS vaccine trials halted

22 Nov 2007, 0332 hrs IST , TNN

PUNE: Plans for the second phase human trials of an AIDS vaccine

candidate at the National AIDS Research Institute (Nari) here have

been finally dropped because the vaccine candidate — tgAAC09

(recombinant adeno-associated virus vector) — has not been able to

induce the desired immune response.

The deputy director at Nari, and principal investigator of the phase

I clinical trials, Dr Sanjay Mehendale, told TOI that the decision to

drop plans for the next phase of clinical trials was based on the

cumulative results on the immunogenecity capacity of the vaccine

candidate from the three trial sites — Pune, Germany and Belgium.

" Although the vaccine was well tolerated by the volunteers and no

safety concerns were identified, it was not enough to proceed on to

the next phase of clinical trials, which would involve a much bigger

group of volunteers, " he said. " Only 20% of the volunteers at the

three sites responded positively. "

The phase I clinical trials for the AIDS vaccine began on February 8,

2005 at Nari. In February this year, Nari scientists announced that

the " whole exercise went off smoothly without any safety concern. "

The trials were aimed at evaluating the safety and tolerability of

the vaccine at escalating dose levels as well as immune responses in

healthy adult volunteers not infected by HIV.

Thirty healthy adult volunteers, who had enrolled for the ambitious

programme, were administered with the injectible vaccine called

tgAAC09 (recombinant adenoassociated virus (AAV) vector, expressing

HIV-1 subtype C genes.

The vaccine candidate was developed by Pune researcher Dr Pervin

Anklesaria at the Seattle-based Targeted Genetics Corporation, a

biotechnology company developing gene therapy products for the

treatment of acquired and inherited diseases, and Columbus Children's

Research Institute in partnership with IAVI (International AIDS

Vaccine Initiative).

A senior official from the Indian Council of Medical Research (ICMR),

who attended the planning meeting on September 12 in New Delhi to

discuss the trials, told TOI the decision was taken after analysing

the results of the phase I clinical trials. Similar results on the

immune response have been reported from Belgium and Germany, " the

official said.

Although disappointed, Nari scientists said the conduct of the first

ever phase I trials in India was itself a big achievement. We are now

eagerly awaiting the results of a similar phase I human trials —

currently under way at the Tuberculosis Research Centre (TRC) in

Chennai — with another vaccine candidate, the Modified Vaccinia

Ankara (MVA), they said.

http://timesofindia.indiatimes.com/Pune/2nd_phase_of_AIDS_vaccine_tria

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