Taxotere (docetaxel) regimen Significantly improves survival in women with node positive early stage breast cancer

Sequential Taxotere following epirubicin-based regimen demonstrates survival advantage Aventis, part of the sanofi-aventis Group announced today that the results of a large phase III study demonstrated that sequential TAXOTERE (docetaxel) Injection Concentrate-based regimen significantly improved overall survival of women with operable, node-positive early stage breast cancer compared to a standard regimen of 5-fluorouracil, epirubicin, and cyclophosphamide (FEC-100). These data were disclosed today during an oral presentation at the 27th Charles A. Coltman, Jr. San Antonio Breast Cancer Symposium (SABCS). The trial, PACS 01, conducted by investigators from the Federation Nationale des Centres de Lutte contre le Cancer (FNCLCC) in France - French Federation of Cancer Centers - showed that women with operable, node-positive, early stage breast cancer who received 3 cycles of TAXOTERE after 3 cycles of FEC-100 experienced a significant 17 percent reduction in the risk of relapse as compared to women treated with 6 cycles of FEC-100. Investigators also reported that women receiving TAXOTERE following FEC regimen experienced a 23 percent reduction in the risk of death at five-years of follow-up. These results were observed regardless of the hormone receptor status. PACS01 is the first trial to show a survival benefit with TAXOTERE in a sequential regimen containing epirubicin. Moreover, this is the second1 phase III study to demonstrate a long term survival advantage for a TAXOTERE containing regimen in the adjuvant treatment of operable, node-positive breast cancer. “These results offer greater chance for cure for women with node-positive, early stage breast cancer; women aged 50 years or older seem to particularly benefit from this regimen” said Henri Roché, MD, Institut Claudius Regaud- Toulouse, France, member of the Federation Nationale des Centres de Lutte contre le Cancer (FNCLCC), and principal investigator of the trial. “This study represents the first long-term outcomes of the sequential use of TAXOTERE with epirubicin, in early stage breast cancer.” It is estimated that worldwide more than 300,000 women per year will be diagnosed with node-positive, early stage breast cancer. Most patients with early stage breast cancer (cancer localized to the breast with or without invasion of the lymph nodes under the arm) undergo surgery to remove the tumor. After surgery, most patients receive additional treatments, which may include chemotherapy to reduce the probability of tumor recurrence. Earlier diagnosis of breast cancer results in earlier treatment and may offer a better chance for cure. PACS 01 Study Protocol The primary endpoint of this study was to compare the disease-free survival. Secondary endpoints included overall survival, safety, cost-effectiveness and quality of life. The study enrolled 1,999 pre- and post-menopausal women with operable, node-positive, early stage breast cancer from 85 sites in France and Belgium between June 1997 and March 2000. Patients were randomized to receive as adjuvant treatment either three cycles of TAXOTERE following three cycles of a standard regimen of 5-fluorouracil, epirubicin and cyclophosphamide (FEC 100) or six cycles of FEC 100. Patients in both arms received radiation therapy within four weeks of their last week of chemotherapy. In addition, patients with hormone receptor positive tumors were administered tamoxifen daily for five years. The median age of patients was 50 years old. The study demonstrated an improvement in the primary endpoint, disease-free survival, for patients treated with TAXOTERE containing sequence as compared to FEC-100: 78.3 percent versus 73.2 percent respectively (p=0.014). These benefit translated in an improvement of overall survival after 60 months follow-up, with 90.7 percent and 86.7 percent of patients alive in the arm with TAXOTERE and the control arm respectively (p=0.017). Five-year follow-up of women in the study did not identify any unexpected safety concerns. Patients receiving TAXOTERE following FEC experienced a higher rate of febrile neutropenia (low white blood cell count combined with fever) (11.2 percent versus 8.4 percent) and nail disorders compared with FEC-100 alone. However patients receiving FEC-100 alone had higher rates of neutropenia, anemia, nausea/vomiting, and higher decreased and subnormal Left Ventricular Ejection Fraction (LVEF) at the end of their chemotherapy treatment. Four cases of acute leukemia occurred (three patients receiving FEC-100 alone and one patient receiving TAXOTERE following FEC-100). Breast Cancer Breast cancer is the most common cancer among women. It is the second-leading cause of cancer death after lung cancer -- and is the leading cause of cancer death among women aged 40 to 59. More than 1,000,000 new cases of breast cancer are reported worldwide annually and more than 400,000 women die each year from the disease. The risk of a woman developing breast cancer during her lifetime is approximately 11 percent (about one in nine of all women worldwide). In the European Union, 191,000 new cases will be diagnosed, and more than 60,000 European women will die of the disease. In the United States, more than 215,000 American women will be diagnosed with breast cancer this year, and 40,000 will die of the disease. About Taxotere® TAXOTERE (docetaxel) a drug in the taxoid class of chemotherapeutic agents, inhibits cell division by essentially “freezing” the cell’s internal skeleton, which is comprised of microtubules. Microtubules assemble and disassemble during a cell cycle. TAXOTERE promotes their assembly and blocks their disassembly, thereby preventing many cells from dividing and resulting in cell death. TAXOTERE is indicated for the treatment of metastatic breast cancer, non-small cell lung cancer, and androgen-independent (hormone-refractory) metastatic prostate cancer. TAXOTERE is being studied extensively in clinical trials for safety and efficacy in early-stage breast , Head and Neck and gastric cancers. On August 18, 2004, the FDA approved TAXOTERE for use in combination with doxorubicin and cyclophosphamide (TAC regimen) for the adjuvant (post surgery) treatment of patients with operable, node-positive breast cancer. In 2003, TAXOTERE generated worldwide sales of over € 1.3 billion. Important safety information WARNING: Taxotere® treatment can cause serious, physically limiting, and potentially life-threatening side effects, such as infection, low blood-cell counts, allergic reaction, and retention of excess fluid (edema). Taxotere® should not be given to patients with low white–blood-cell counts, abnormal liver function, or a history of allergic reactions to Taxotere® or any of the ingredients in Taxotere®. Before each Taxotere® treatment, all patients treated with Taxotere® must receive another medicine called dexamethasone. This drug can help reduce the risk of fluid retention (edema) and allergic reactions. Taxotere® should be administered only under the supervision of a qualified physician experienced in the use of anticancer treatments. Appropriate management of complications is possible only when adequate diagnostic and treatment facilities are readily available. Treatment-related acute myeloid leukemia (AML) has occurred in patients given anthracyclines and/or cyclophosphamide, including use with Taxotere® in adjuvant therapy for breast cancer. The most common severe side effects are low white–blood-cell count, anemia, fatigue, diarrhea, and mouth and throat irritation. Low white–blood-cell count can lead to life-threatening infections. The earliest sign of infection may be fever, so tell your doctor right away if you have a fever. Other common side effects from Taxotere® include nausea, vomiting, hair loss, rash, infusion-site reactions, odd sensations (such as numbness, tingling, or burning) or weakness in the hands and feet, nail changes, muscle and/or bone pain, or excessive tearing. Patients 65 years of age or older may experience some side effects more frequently than younger patients. Because of the potential risk of fetal harm, pregnant women should not receive Taxotere®. Women of childbearing potential should avoid becoming pregnant during treatment with Taxotere®. Before receiving Taxotere®, tell your doctor if You have any allergies You are taking any other medicines — including nonprescription (over-the-counter) drugs, vitamins, and dietary or herbal supplements When taking Taxotere®, contact your doctor if: You have symptoms of an allergic reaction (warm sensation, tightness in your chest, itching/hives, or shortness of breath) You experience any other side effects For more information about Taxotere®, visit www.taxotere.com or see full prescribing information including boxed WARNING. For more information about ongoing clinical trials, please call 1-800-RxTrial or visit www.aventisoncology.com. About sanofi-aventis The sanofi-aventis Group is the world’s 3rd largest pharmaceutical company, ranking number 1 in Europe. Backed by a world-class R&D organization, sanofi-aventis is developing leading positions in seven major therapeutic areas: cardiovascular disease, thrombosis, oncology, diabetes, central nervous system, internal medicine, vaccines. The sanofi-aventis Group is listed in Paris (EURONEXT : SAN) and in New York (NYSE : SNY). Forward Looking Statement 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” 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. These risks and uncertainties include those discussed or identified in the public filings with the SEC and the AMF made by Sanofi-aventis and Aventis, including those listed under “Forward-Looking Statements” and “Risk Factors” in sanofi-aventis’s annual report on Form 20-F for the year ended December 31, 2003 and those listed under “Cautionary Statement Regarding Forward-Looking Statements” and “Risk Factors” in Aventis’s annual report on Form 20-F for the year ended December 31, 2003. Other than as required by applicable law, sanofi-aventis does not undertake any obligation to update or revise any forward-looking information or statements. 1 M.Martin et al, TAC improves disease free survival and overall survival over FAC in node positive early breast cancer patients, BCIRG 001, SABCS 2003 (Abs# 43)- Oral presentation. 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