London, UK; Brentwood, TN, US; 8 January 2007 - Protherics PLC (“Protherics” or the “Company”), the international biopharmaceutical company focused on critical care and cancer, announces that notification was received today from Aviva plc that, following the purchase of 3,738,187 Ordinary 2p shares in Protherics on 4 January 2007 (1.10% of the Company’s issued share capital), Aviva plc and its subsidiaries hold an interest in 40,095,830 Ordinary Shares (11.83%).