Xenova Group PLC
9 July 2001
FOR IMMEDIATE RELEASE
Xenova Group plc
Anti-Cocaine Addiction Vaccine Released from Clinical Hold
Phase IIa Study Results Announced
Slough, UK, 9th July 2001 - Xenova Group plc (Nasdaq NM: XNVA; London Stock
Exchange: XEN) today announces that, following a US Food and Drug
Administration (FDA) review of the Company's recently submitted toxicology and
clinical study results, the FDA has notified Xenova that its TA-CD
(anti-cocaine addiction vaccine) product candidate has been released from
clinical hold with immediate effect.
The TA-CD Phase IIa study had been placed on precautionary hold in August 2000
following the observation that a related product caused eye irritation in
preclinical studies. No such effects were observed with TA-CD in man and
extensive further testing of the related product has shown no safety
implications. These results were submitted to the FDA in May 2001 and,
following FDA review, the clinical hold on the TA-CD IND has been removed.
TA-CD is designed to work by generating antibodies in the bloodstream, thus
preventing cocaine from crossing from the bloodstream into the brain and
stopping cocaine from blocking dopamine uptake, which is the cause of the '
high' that addicts obtain. Patients may therefore be expected to benefit most
from the support offered by TA-CD during the approximately 9 month period
which it takes for the addiction craving for cocaine to be lost.
Phase IIa trial results - It is also announced today that the successful
results of this Phase IIa trial have been presented at the 63rd Annual
Scientific Meeting of the College on Problems of Drug Dependence, in Arizona,
USA. The nine-patient study, in outpatient cocaine addicts, was conducted by
Dr Thomas Kosten, Professor of Psychiatry, Yale University School of Medicine
and was designed to evaluate the safety and immunogenicity of TA-CD using a
four-dose accelerated vaccination schedule.
TA-CD was shown to be well tolerated systemically and locally and was able to
generate higher and earlier antibody titres than those seen in a Phase I
34-patient trial using a three-dose vaccination schedule, potentially
benefiting the patient by establishing a more rapid therapeutic effect.
Cocaine specific antibodies persisted throughout the 12 weeks of the study.
No cocaine metabolites were detected in the urine of 5 out of the 8 evaluable
patients involved in the study, indicating no further cocaine use. An
attenuation of the usual euphoric effects of cocaine was reported amongst
patients who relapsed during the study, providing anecdotal evidence of the
benefit TA-CD may provide.
Dr Kosten commented: 'We are delighted by the progress to date of this
potentially valuable product. TA-CD was well tolerated in this trial and has
shown encouraging indications of efficacy. It is very hard for cocaine
addicts to quit and TA-CD shows promise as a potential therapy. TA-CD
certainly warrants further clinical investigation.'
Xenova expects to begin a new Phase II cocaine challenge study in the US in
the near future. Addicts will be given cocaine under controlled conditions
before and after vaccination with TA-CD and their behaviour monitored. Blood
samples will be taken for the measurement of antibody titres. The purpose of
the study is to provide an assessment of the efficacy of TA-CD, as determined
by quantitative behavioural and other measurements.
This study is being funded in part by the US National Institute on Drug Abuse
(NIDA). NIDA have also supported earlier Phase l/lla work as part of this
David Oxlade, Chief Executive of Xenova, commented: 'There is a real societal
need for a solution to the problems of drug abuse and addiction, with an
estimated 900,000 people seeking treatment for cocaine addiction every year in
the US alone. Following the encouraging results of this trial we will now be
evaluating the efficacy of TA-CD in cocaine addicts.'
Xenova Group plc Financial Dynamics
Tel: +44 (0) 1753 706600 Tel: +44(0) 207 831 3113
David Oxlade: Chief Executive Officer David Yates/Fiona Noblet
Daniel Abrams: Finance Director
Hilary Reid Evans: Corporate Communications
Notes to Editors
Xenova Group plc's product pipeline focuses principally on the therapeutic
areas of cancer, infectious diseases and addiction. The Group has a
well-established track record in the identification, development and
partnering of innovative products and technologies. The Group has
partnerships with a number of major pharmaceutical companies including Glaxo
SmithKline, Lilly, Pfizer and Celltech.
For further information about Xenova and its products please visit the Xenova
website at www.xenova.co.uk