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BÂRRX Medical, Inc. Initiates Landmark Study Comparing Two Treatment Options for Barrett's Esophagus

AstraZeneca (NYSE: AZN), makers of NEXIUM® (esomeprazole magnesium), co-sponsors first study of radio frequency ablation therapy vs. standard of care for Barrett's

Sunnyvale, Calif. - March 20, 2006 - BÂRRX Medical, Inc. today announced the initiation of a landmark human study titled "Ablation of Intestinal Metaplasia Containing Dysplasia: a Multi- Center, Randomized, Sham-Controlled Trial." The AIM Dysplasia Trial will compare the effectiveness of the HALO³⁶⁰ System against the current standard of care for Barrett's esophagus, which includes regular endoscopic biopsy surveillance and appropriate medical management of associated acid reflux disease (also called GERD). Barrett's esophagus, often caused by chronic GERD, is a pre-cancerous change to the lining of the esophagus that affects approximately three million U.S. adults. Barrett's sufferers are at increased risk for developing a dangerous type of cancer called esophageal adenocarcinoma, currently the fastest growing cancer in the U.S. The study is the first to compare radio frequency (RF) ablation therapy against the current standard of care for the treatment of Barrett's esophagus.

The study has a planned enrollment of 120 patients diagnosed with Barrett's esophagus with dysplasia (abnormal cells) - either low-grade or high-grade - at 16 U.S. medical centers. The randomized, sham-controlled trial will assign patients in a 2:1 ratio to receive either an endoscopic ablation procedure using the HALO³⁶⁰ System or a similar procedure in which no ablation is delivered (sham). Patients will not be aware of which procedure they receive and will undergo follow-up with endoscopy and biopsy over the ensuing 12 months with comparison of the treatment results at each time interval. All patients will receive esomeprazole magnesium (NEXIUM) as therapy for acid reflux disease as part of the study protocol. The study hypothesis, based on available data from other trials, is that a significantly greater proportion of treatment patients versus sham-control patients will be completely free of Barrett's esophagus at follow-up. After one year, patients who received ablation therapy continue their follow-up for two full years, while patients who received the sham-control procedure will undergo a "real" ablation procedure and will be followed for two additional years.

Barrett's esophagus occurs when chronic acid reflux disease causes the cells lining the esophagus to transform and undergo genetic changes that can set the stage for cancer development. Barrett's has traditionally been managed with frequent endoscopic biopsy surveillance to detect progression to cancer. However, many physicians have long recognized the need to more proactively treat Barrett's esophagus as opposed to watching and waiting for cancer to develop. Ablation, the use of energy to remove the diseased layer of cells from the esophagus, offers treatment for the disease before it has the opportunity to progress to cancer. New healthy tissue replaces the ablated Barrett's tissue in three to four weeks for most patients. "Barrett's esophagus is a serious disease that can lead to esophageal adenocarcinoma, which has one of the poorest prognoses of any human cancer," said Bergein F. Overholt, M.D., gastroenterologist at Gastrointestinal Associates in Knoxville, Tennessee, and principle investigator in the AIM Dysplasia Trial. "We have participated in several trials using the HALO³⁶⁰ System, and have successfully treated numerous patients. We are optimistic that this trial will provide additional rigorous evidence that this device is a valid intervention for this disease state." Dr. Overholt was the first physician to enroll patients in the AIM Dysplasia Trial earlier this month.

About BÂRRX Medical, Inc.

BÂRRX Medical, Inc. develops treatment solutions for Barrett's esophagus, a precancerous condition of the lining of the esophagus (swallowing tube) caused by gastroesophageal reflux disease, or GERD. Its flagship product, the HALO³⁶⁰ System, provides uniform and controlled therapy at a consistent depth, which can remove Barrett's esophagus and allow the regrowth of normal cells. In the largest study conducted (AIM-II Trial), 70% of patients were Barrett'sfree (at one year follow-up). The system used in the clinical trials was cleared by the U.S. Food and Drug Administration in 2001 and has been commercially available since January 2005. Based in Sunnyvale, Calif., BÂRRX Medical, Inc. was founded in 2000 and is privately-held. Additional information about BÂRRX Medical, Inc. and the HALO³⁶⁰ System is available at www.barrx.com.

About the HALO³⁶⁰ System

The BÂRRX Medical HALO³⁶⁰ System is the first of a new generation of ablation tools that provides uniform and controlled ablative therapy at a consistent depth to remove the layer of the diseased esophageal tissue allowing replacement by normal cells. The procedure, which in clinical studies had a median procedure time of 26 minutes, is performed without incisions using conscious sedation in an out-patient setting. First, a physician uses a HALO³⁶⁰ sizing balloon catheter to dilate the esophagus and determine its inner diameter. A correctly sized ablation catheter is then inflated within the diseased area of the esophagus. The HALO³⁶⁰ energy BÂRRX Medical, Inc. Initiates Study Comparing Two Treatment Options for Barrett's Esophagus generator is activated to deliver a rapid (less than one second) burst of ablative energy, which removes a very thin (less than one millimeter) layer of the diseased esophagus. Controlled delivery of energy avoids injury to normal, healthy underlying tissues. New healthy tissue replaces the ablated Barrett's tissue in three to four weeks for most patients, according to trial results. Minor discomfort, which may be experienced by some patients, has been managed in the trials with medication. Following ablation therapy, patients resume acid suppression therapy.

About NEXIUM (esomeprazole magnesium)

NEXIUM is indicated for treating frequent, persistent heartburn and other symptoms associated with acid reflux disease. NEXIUM is approved for healing and maintenance of erosive esophagitis. Most erosions heal in 4 to 8 weeks. Individual results may vary, and only a doctor can determine if erosions to the esophagus have occurred. Symptom relief does not rule out the existence of other serious stomach conditions. NEXIUM is also indicated for reducing the risk of gastric (stomach) ulcers developing among at-risk patients on continuous NSAID therapy. Patients are considered to be at risk if they are 60 and over, or if they have a history of previous stomach ulcer. The most frequently reported adverse events with NEXIUM include headache, diarrhea, and abdominal pain. For full prescribing information for NEXIUM please visit www.purplepill.com.

About AstraZeneca

AstraZeneca is a major international healthcare business engaged in the research, development, manufacture and marketing of prescription pharmaceuticals and the supply of healthcare services. It is one of the world's leading pharmaceutical companies with healthcare sales of $23.95 billion and leading positions in sales of gastrointestinal, cardiovascular, neuroscience, respiratory, oncology and infection products. In the United States, AstraZeneca is a $10.77 billion healthcare business with more than 12,000 employees. AstraZeneca is listed in the Dow Jones Sustainability Index (Global) as well as the FTSE4Good Index.

For more information about AstraZeneca, please visit: www.astrazeneca-us.com

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