Results from clinical trial of TA-NIC, therapeutic vaccine for the treatment of nicotine addiction

Xenova Group has announced initial results from the second clinical trial of TA-NIC, the Company's therapeutic vaccine being developed for the treatment of nicotine addiction.

60 smokers, divided into three cohorts of 20 subjects, have been recruited into this double-blind, randomised, placebo-controlled study. The objectives of this second Phase I clinical study were to explore the safety, tolerability and level of anti-nicotine antibody response to increasing doses of the vaccine TA-NIC, and to select a dose for Phase II/III evaluation.

Key findings from the study were:

• No drug-related serious adverse events were seen in any cohort
• Minimal injection-site effects were seen at the dose selected for Phase II/III studies
• Anti-nicotine antibody responses were dose dependent
• The selected dose showed an improved anti-nicotine antibody response profile compared to the lowest dose tested:
  • Approximately twice the level of anti-nicotine antibodies were observed
  • Faster and more rapid onset of anti-nicotine antibody response was achieved
• Although not designed to test the effect of the TA-NIC vaccine on smoker's quit rates, there was a clear reduction across all groups receiving TA-NIC compared to those with the placebo group, in terms of those smokers who voluntarily quit during the 12-week period or self-reported a reduction in smoking pleasure
  • At week six, 19 out of the 44 (43%) subjects receiving TA-NIC voluntarily gave up smoking or reported reduced pleasure when smoking compared to only 1 out of 11 (9%) receiving the placebo

On the basis of these results, a Phase II/III dose has been selected for further clinical evaluation. The final data from this Phase I study is expected at the end of this year (2004) with Phase II trials commencing shortly thereafter.

David Oxlade, Chief Executive Officer of Xenova said, "We are most encouraged by these results. The next stage of trials will test TA-NIC's ability to help smokers break the habit and thereby reduce the serious consequences to health caused by smoking."