Csl Demonstrates Robust Immune Response From Single (15mcg) Dose Of Monovalent Pandemic (h1n1) 2009

For immediate release
September 11, 2009


CSL DEMONSTRATES ROBUST IMMUNE RESPONSE FROM
SINGLE (15mcg) DOSE OF MONOVALENT PANDEMIC (H1N1)
2009 INFLUENZA A VACCINE IN HEALTHY ADULTS


CSL Limited, Australia's leading biopharmaceutical company, announced today
that preliminary data from the first study of its candidate pandemic H1N1
vaccine demonstrated a robust immune response in healthy adults after a single
unadjuvanted15mcg dose.

The preliminary data, published today as an original article in the New England
Journal of Medicine, showed that over 95% of participants receiving the single
15mcg dose of the vaccine achieved antibody levels that correlate with the
prevention of influenza infection.1

The study also shows that the vaccine has a tolerability profile consistent with
seasonal influenza vaccines.

In this single-centre observer-blind study, 240 healthy adults aged 18 to 64 were
randomised into two dose groups. Each participant received an initial
vaccination followed by a second vaccination three weeks later. The first group
received 15mcg of vaccine, the standard dose used for a single strain in the
trivalent seasonal influenza vaccine, and the second group received 30mcg of
vaccine. Blood samples were taken three weeks after each dose.

Preliminary data after the first vaccination demonstrated that post-vaccination
antibody titres of 1:40 or greater were achieved in 96.7% of participants
receiving the 15mcg dose and in 93.3% of participants receiving the 30mcg
dose. This immune response remains consistently strong irrespective of age.
No deaths, serious adverse events or adverse events of special interest were
reported. The most commonly reported solicited adverse events were injection
site tenderness, headache and injection site pain.





1 de Jong J C Haemaggutination -Inhibiting Antibody to Influenza Virus. Dev Biol 2003 vol 115, 63-73.


Page 2 September 11, 2009

`The preliminary data obtained from this initial study show a promising result
which gives us confidence that a vaccination program can be successfully
carried out in adults using a single standard dose of the H1N1 vaccine. CSL
currently has other studies underway that are examining the vaccine in children
and older adults. We look forward to sharing these data when they become
available' CSL Chief Scientific Officer Dr Andrew Cuthbertson said today.

`The results of our initial study provide critical information given that vaccine
yields have been much lower than expected around the world. Knowledge of the
likely effective dose will enable the available vaccine to go further'.

`CSL can also offer reassurance that no safety signals have been noted so far in
any of our current studies We will, of course, continue to monitor safety through
the clinical study process and with post-marketing surveillance', he said.

CSL has worked quickly to make the preliminary dose response and safety data
available to public health and regulatory authorities around the world in order to
inform policy decisions about how immunisation programs against pandemic
H1N1 2009 influenza should be implemented.

The article is available at http://content.nejm.org/cgi/content/full/NEJMoa0907413

For more information about CSL Limited, visit www.csl.com.au


Dr Rachel David Australia and ROW
Director of Public Affairs
CSL Limited
Ph 61 3 9389 1821 Mob 0401 775 779
[email protected]

Dr Daniella Goldberg Australia and ROW
Ph 0416 211 067
[email protected]

Sheila A. Burke
Director, Public Relations & Communications
CSL Biotherapies US
484-919-2618 (mobile) 610-878-4209 (office)
[email protected]