CSL Ltd. — Regulatory Filings 2003

Sep 2, 2003

ASX ANNOUNCEMENT 3 September 2003

CSL OBTAINS US HUMAN PAPILLOMAVIRUS PATENT

CSL Limited today announced that the US Patent and Trade Mark Office (PTO) has issued an important patent to the Company and its academic partner, the University of Queensland, which relates to the HPV 16 serotype of the multiple-serotype human papillomavirus (HPV) vaccine being developed by its exclusive licensee, Merck & Co., Inc. The Company confirmed that Merck are currently in a worldwide Phase III clinical trial with a vaccine that contains virus like particles (VLPs) prepared from the four major HPV serotypes (which includes HPV16).

The Company advised that the main claim granted by the US PTO is a claim to the sequence of the surface protein (known as L1) of the HPV16 serotype necessary for VLP formation.

The Company advised that the grant of this patent will secure royalty revenue to CSL if the Merck vaccine is launched in the US. CSL also confirmed that it had exclusive distribution rights for the product in Australia and New Zealand.

In addition, the Company has advised that in Europe, a patent related to VLPs of HPV6 and 11, two additional components of the Merck vaccine has also recently been granted.

Andrew Cuthbertson DIRECTOR, R&D

For further information, please contact: Mr Mark Dehring General Manager Investor Relations

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