CeNeS Announces Phase II Drug Deal with Addex Pharmaceuticals

Geneva, Switzerland, 18 December 2002 - CeNeS Pharmaceuticals plc (LSE: CEN) announced today that it had signed an agreement to partner CEE 03–310, its selective antagonist of dopamine D1 receptors, which CeNeS had been developing for the potential treatment of sleep disorders and substance abuse. The compound has been acquired by Addex Pharmaceuticals, a biopharmaceutical company committed to the discovery, development and marketing of novel therapeutic compounds for the treatment of addiction and other neuropsychiatric conditions. Addex will focus on the development of the compound in the treatment of drug abuse. Under the terms of the agreement, Addex will acquire CeNeS' rights relating to CEE 03-310 and in return, CeNeS will receive up to $4.5m in upfront and milestone payments. CeNeS will also receive royalties on any product sales.

Neil Clark, Chief Operating Officer of CeNeS Pharmaceuticals plc, commented, "As part of our restructuring plan we are divesting certain non-core assets and are very pleased to have reached this agreement with Addex. We maintain a carried interest in the program and believe that Addex is uniquely positioned to exploit this asset to its maximum potential. Under our divestment programme we have built up an interesting portfolio of carried interests in non-core assets which has the potential to deliver considerable upside. Meanwhile, we continue to focus on our core business, drugs for pain control and associated conditions."

CeNeS has been developing CEE 03-310 for the treatment of sleep disorders and for the treatment of substance abuse, with an initial focus on alcohol abuse to establish proof of principle. CeNeS acquired rights to CEE 03-310 from Novo Nordisk in 1999, together with associated know-how, which comprised all of Novo Nordisk's clinical and pre-clinical trial information. The results of a Phase II clinical trial in healthy volunteers were announced in May 2000 and described CEE 03-310's significant effect on human sleep patterns. CeNeS has an IND granted to begin Phase II clinical trials in the USA with the aim of determining whether CEE 03-310 can decrease craving for alcohol. CEE 03-310 may have a broad application within substance abuse including addiction to nicotine and cocaine as well as alcohol.

This news release contains forward-looking statements that reflect the Company's current expectation regarding future events. Forward-looking statements involve risks and uncertainties. Actual events could differ materially from those projected herein and depend on a number of factors including the success of the Company's research strategy, the applicability of the discoveries made therein, the successful and timely completion of clinical studies and the uncertainties related to the regulatory process.

About CeNeS Pharmaceuticals

CeNeS is a biopharmaceutical company specialising in the development and commercialisation of drugs for CNS disorders and pain control. The company currently markets four products, and has research and development assets targeting pain and schizophrenia. CeNeS is based in Cambridge, England. For further information please visit www.cenes.co.uk .