PRESS RELEASE: A COLLABORATIVE AGREEMENT BETWEEN THE DNDi FOUNDATION AND SANOFI-AVENTIS TO DEVELOP A NEW, EASY-TO-USE MALARIA DRUG AT TARGET PRICE BELOW ONE DOLLAR

Paris, April 7, 2005 A collaborative agreement has just been concluded between the Drugs for Neglected Diseases Initiative (DNDi) Foundation and sanofi-aventis to develop a new medicine against malaria. This is a fixed-dose combination (FDC) of artesunate and amodiaquine (AS/AQ) which is easier to use and cheaper than other combos currently available. This drug is expected to become available to patients in 2006.

Contacts Sanofi-aventis: Robert SEBBAG +33 (0)1 53 77 40 76 +33 (0)6 08 17 21 83 DNDi : Jean-Francois ALESANDRINI +41 79 596 5066 Samantha BOLTON +41 22 906 9230 +41 79 239 2366 THE AGREEMENT Because of increasing parasite resistance to animalarials, particularly chloroquine, the World Health Organisation (WHO) recommends a new treatment combining two antimalarials, one being a derivative of artemisinin. This treatment is known as “ACT” or artemisinin combination therapy. In line with WHO experts’ recommendations, DNDi and sanofi-aventis have initiated the development of an artesunate + amodiaquine co-formulation or FDC. In particular, the DNDi Foundation and its partners developed an original formulation combining two active ingredients in a single tablet and carried out the pharmaceutical and clinical development. The two parties then decided to join forces and signed an agreement to speed up the development of this FDC, which will become the indispensable treatment to control malaria. In keeping with the provisions of the agreement and building on the studies conducted by DNDi, sanofi-aventis will be responsible for the development of the product, notably at industrial level, for the filing of the dossier with the regulatory authorities in the countries concerned and for WHO prequalification. The first applications should be filed by the end of 2005 or early 2006. In agreement with DNDi, sanofi-aventis commits to sell the product at cost to the public health structures of countries affected, to international organisations and NGOs, thus facilitating access to the medicine for malaria sufferers. THE PRODUCT This combination is one of the first line treatments recommended by WHO and it has already been adopted by various African countries and Indonesia. Easier to use To improve patient compliance and to reduce the risks of resistance, the use of the drug should be as simple as possible. The new formulation is so designed that adult treatment is limited to 2 tablets per day for three days, instead of 8 tablets per day. The paediatric formulation for infants will also be simplified: one tablet a day for three days. An innovative feature of the paediatric formulation is that it can be dispersed in water, which considerably facilitates drug administration. In addition, the dosage may easily be adjusted for children and teenagers simply by giving either one or two tablets a day. Finally, the fixed-dose combination avoids the risk for patients to take one active ingredient only. Compared with the presently available co-blisters the fixed dose combination is a real step forward, because the number of tablets is reduced. Cheaper This new co-formulation will be less expensive than all other combinations containing artemisinin derivatives, as it combines two well-known active ingredients that are widely used in single-drug- therapy and as combinations of two separate tablets in the same blister pack. Furthermore, this new co-formulation is not covered by any patent. Based upon WHO projections for the years to come and in line with sanofi-aventis at-cost strategy, the target price envisaged should be below one dollar for adults and 50 cents for children. This target price will only be achievable if international organisations provide adequate financial assistance to the countries concerned, thus enabling them to undertake the necessary therapeutic switch and contributing to the stabilization of raw materials markets. This price will dramatically lower the budgetary impact of the malaria treatment cost at international level. Dr Bernard Pecoul, DNDi Foundation Executive Director, noted: “One of the key goals of the DNDi’s development strategy was to create a drug that is simple to use, at a cost below a dollar. This objective can now be met thanks to the determination of sanofi-aventis to bring this drug into the public sector at cost price”. Jean-François Dehecq, Chairman and CEO of sanofi-aventis, said: “This highly innovative partnership between DNDi and sanofi-aventis will ensure that this new product is rapidly made available to the poorest among the poor and that it is tailored to their needs”. Malaria in figures WHO has designated Malaria, as well as HIV/AIDS and TB, as one of the major public health challenges undermining development in the poorest countries in the world. - Malaria kills between one and two million people every year, and affects some 500 million. - A child dies of malaria every 30 seconds in Africa. - An estimated 40% of the world population, mostly living in the world poorest countries, is at risk of malaria - Malaria is the leading cause of death among the under-five children in sub-Saharan Africa. To date, over twelve national protocols in Africa and Indonesia have recommended combining artesunate and amodiaquine in a first-line treatment. This drug combination can, however, only be used in endemic zones and regions where the resistance rate for amodiaquine is below 25%. It is estimated that dozens of millions of people could benefit from this treatment each year. DNDi: This is the first drug developed by DNDi since its inception in 2003. DNDi intends to re-launch the research and development of new drugs against neglected diseases (trypanosomiasis, leishmaniasis, Chagas disease etc). It’s FACT antimalaria programme – Fixed-Dose Artesunate Combination Therapy – received financial support from Médecins Sans Frontières, WHO/Tropical Diseases Research and the European Union International Cooperation programme (INCO/DEV). The success of the project fulfils DNDi’ s ambition to bring together the skills and know-how of various scientific, academic, public and private partners in the North and in the South. This success was made possible thanks to the participation of the WHO/TDR programme, TropiVal, Université de Bordeaux 2, Sains University in Malaysia, the University of Oxford, and Burkina Faso’s National Malaria Research and Training Centre. Sanofi-Aventis: Sanofi-aventis is the world's third largest pharmaceutical company, ranking number one in Europe. Backed by a world-class R&D organization, sanofi-aventis is developing leading positions in seven major therapeutic areas: cardiovascular, thrombosis, oncology, metabolic diseases, central nervous system, internal medicine and vaccines. The sanofi-aventis Group is listed in Paris (EURONEXT: SAN) and in New York (NYSE: SNY). Through its Impact Malaria programme, Sanofi-Aventis reiterates its historic involvement in the fight against malaria, through its Impact Malaria programme and its medicines, with the derivatives of quinine and chloroquine ,then with the first derivative of arteminisin, Arsumax, being made available in Africa in 1996 and wich received WHO prequalification, and with the marketing of Arsucam co-blister artenusate+amodiaquine (deparate tablets put together in the same package). The Impact Malaria programme was created in 2001 and is sanofi-aventis contribution to the fight against malaria . The four major axes are: - 1/ to try and discover new antimalarial drugs - 2/ to develop new combinations or formulations from existing drugs, particularly ACT’s - 3/ to inform, educate and communicate about malaria, to reach out to remote healthcare facilities, communities and families - 4/ to distribute antimalarial drugs which are vital to the poorest populations, at special “no profit-no loss” cost. These actions are carried out with public and private healthcare organisations and the health authorities in most of the countries concerned, notably through national malaria control programmes in liaison with the WHO, Roll Back Malaria Partnership and leading international institutions. Forward Looking Statements This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995. Forward-looking statements are statements that are not historical facts. These statements include financial projections and estimates and their underlying assumptions, statements regarding plans, objectives and expectations with respect to future operations, products and services, and statements regarding future performance. Forward-looking statements are generally identified by the words “expect,” “anticipates,” “believes,” “intends,” “estimates,” “plans” and similar expressions. Although sanofi-aventis’ management believes that the expectations reflected in such forward-looking statements are reasonable, investors are cautioned that forward-looking information and statements are subject to various risks and uncertainties, many of which are difficult to predict and generally beyond the control of sanofi-aventis, that could cause actual results and developments to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. 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