News Release

Two landmark studies show Taxotere (R) significantly improves survival in men with prostate cancer

Taxotere-based regimen is first and only treatment with proven significant survival benefit for men with androgen-independent (hormone-refractory) metastatic prostate cancer

Peer-Reviewed Publication

Porter Novelli

BRIDGEWATER, NJ - June 7, 2004 - Aventis (NYSE: AVE) announced today that the results of two landmark phase III trials using Taxotere® (docetaxel) Injection Concentrate based regimens in the treatment of androgen-independent (hormone-refractory) metastatic prostate cancer have been presented at the plenary session of the annual meeting of the American Society of Clinical Oncology (ASCO) in New Orleans, LA.

The clinical trials TAX 327 and SWOG 9916, were led by investigators from the Johns Hopkins Kimmel Cancer Center and NewYork-Presbyterian Hospital/Columbia University Medical Center and the Southwest Oncology Group (SWOG). The trials involved nearly 1,800 patients and demonstrated that Taxotere®-based regimens significantly reduced the risk of death by 24 percent and 20 percent, respectively. Investigators in the TAX 327 trial also reported that Taxotere® significantly improved patients' PSA responses by 43 percent (p=0.0005) and improved pain responses by 59 percent (p=0.0107), relative to mitoxantrone response rates.

The SWOG trial investigators reported a 27 percent increase in disease-progression-free survival and a 55 percent increase in objective response rate in the Taxotere®-containing arm. In addition, the majority of patients had a PSA decline of more than 50 percent.

"These studies are the first to show that a chemotherapy agent, Taxotere®, can deliver a significant survival benefit in androgen-independent (hormone-refractory) metastatic prostate cancer patients, giving hope to thousands of men worldwide," said Daniel Petrylak, MD, Associate Professor of Medicine at Columbia University College of Physicians & Surgeons, Director of the Genitourinary Oncology Program at NewYork-Presbyterian Hospital. "These data represent an important new treatment option for men with prostate cancer because it can help some patients live longer."

Prostate cancer ranks third worldwide in cancer incidence and sixth in cancer mortality among men. In the United States, more than 230,000 men will be diagnosed with prostate cancer this year, and more than 29,900 will die of the disease.

"The results of these studies mark a significant milestone in cancer care. Taxotere® is the only drug approved for patients with breast, lung and prostate cancer, three of the most prevalent cancers in the world today," said Frank Douglas, MD, PhD, Executive Vice President of Drug Innovation and Approval and a Member of the Board of Management at Aventis.

TAX 327/SWOG 9916 Study Protocol

The TAX 327 study reported by Mario Eisenberger, MD, Dale Hughes Professor of Oncology and Urology at the Johns Hopkins Kimmel Cancer Center, enrolled patients at 240 sites in 24 countries. One thousand six (1,006) eligible patients were randomized to receive one of three treatment regimens. Taxotere® 75mg/m2 once every three weeks plus daily prednisone, or Taxotere® 30 mg/m² every week for five out of six weeks plus daily prednisone, or mitoxantrone 12mg/m2 every three weeks plus daily prednisone, the established standard of care. The majority of the patients were over the age of 65.

The SWOG 9916 study reported by Dr. Petrylak randomized 770 patients in the United States to one of two treatment arms: Taxotere® 60 mg/m2 every three weeks and estramustine 280 mg three times daily for 5 days or mitoxantrone 12 mg/m2 every three weeks and prednisone 5 mg twice daily.

Taxotere® was well tolerated and had a generally predictable and manageable safety profile in both studies. The most commonly observed adverse events in TAX 327 were alopecia, fatigue, and nausea, but the rates were comparable to mitoxantrone. Hematological events seen in the trial were consistent with the expected safety profile for both treatments, with grade 3-4 neutropenia reported more frequently in the Taxotere® group than the mitoxantrone group (32 percent vs 21.7 percent, p=0.004). However, complications of neutropenia appeared comparable in both groups.

In the SWOG 9916 study, gastrointestinal and cardiovascular events occurred more frequently in men treated with Taxotere® plus estramustine than those treated with mitoxantrone.

About Taxotere®

Taxotere®, a drug in the taxoid class of chemotherapeutic agents, inhibits cancer 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 cancer cells from dividing and resulting in cancer cell death.

Taxotere® is currently approved in the United States to treat patients with locally advanced or metastatic breast cancer after failure of prior chemotherapy, and patients with unresectable locally advanced or metastatic non-small cell lung cancer (NSCLC) in combination with cisplatin, who had not received prior chemotherapy. It also is approved for patients with unresectable locally advanced or metastatic NSCLC after failure of prior platinum-based chemotherapy. On May 19, 2004, the U.S. Food and Drug Administration granted approval of Taxotere® for use in combination with prednisone as a treatment for men with androgen-independent (hormone-refractory) metastatic prostate cancer.

Among patients receiving Taxotere® the most common severe adverse events were low blood cell count, fatigue, diarrhea, and mouth and throat irritation.

The most common non-severe side effects include hair loss, numbness, a tingling and/or burning sensation, rash, nail changes, nausea, vomiting, and muscle pain. Less common severe or potentially life threatening side effects include fluid retention, infections, and allergic reactions.

Patients 65 years of age or older may experience some side effects more frequently. For more information about Taxotere®, visit www.taxotere.com or see full prescribing information including boxed WARNINGS. For more information about ongoing clinical trials, please call 1-800-RxTrial or visit www.aventisoncology.com.

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About Aventis

Aventis is dedicated to treating and preventing disease by discovering and developing innovative prescription drugs and human vaccines. In 2003, Aventis generated sales of € 16.79 billion (US $18.99), invested € 2.86 billion (US $3.24) in research and development and employed approximately 69,000 people in its core business. Aventis corporate headquarters are in Strasbourg, France. The company's prescription drugs business is conducted in the U.S. by Aventis Pharmaceuticals Inc., which is headquartered in Bridgewater, New Jersey. For more information, please visit: www.aventis-us.com.

Statements in this news release containing projections or estimates of revenues, income, earnings per share, capital expenditures, capital structure, or other financial items; plans and objectives relating to future operations, products, or services; future economic performance; or assumptions underlying or relating to any such statements, are forward-looking statements subject to risks and uncertainties. Actual results could differ materially depending on factors such as the timing and effects of regulatory actions, the results of clinical trials, the company's relative success developing and gaining market acceptance for new products, the outcome of significant litigation, and the effectiveness of patent protection. Additional information regarding risks and uncertainties is set forth in the current Annual Report on Form 20-F of Aventis on file with the Securities and Exchange Commission and in the current Annual Report -"Document de Référence"- on file with the "Commission des Opérations de Bourse" in France, recently renamed "Autorité des marchés financiers".

Additional Contact:
Marisol Peron, US Product Communications, 908-243-7592, marisol.peron@aventis.com
ASCO Presentations: #3 and #4


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