Otsuka Pharmaceutical Co., Ltd. (OPC; Head Office: Chiyoda-ku, Tokyo, Japan; President: Tatsuo Higuchi; Phone: +81-3-3292-0021) announces the launch of an atypical antipsychotic agent, Abilify^® (development code: OPC-14597, nonproprietary name: aripiprazole), on June 8.

Abilify is an antipsychotic medication with a new mechanism of action that was discovered in 1988 and developed by OPC. Abilify was approved for marketing in the United States as a treatment for schizophrenia in November 2002 and is currently marketed in more than 45 countries and regions including Europe^*1.

Dr. Kunitoshi Kamijima, professor of the International University of Health and Welfare, commented about the approval of Abilify, saying that "For the first time in five years, a promising new drug has appeared. For more than half a century, antipsychotics have provided an effective means for the treatment of schizophrenia. However, both patients and physicians have continued to be distressed by adverse reactions such as muscle rigidity, finger tremors and mask-like facial expressions that are due to extrapyramidal symptoms. These adverse reactions can disturb living activities, make returning to society difficult and affect patients' quality of life. Clinicians have high expectations for Abilify, with dopamine partial agonist action, which broadens the options for the treatment of schizophrenia."

Mr. Masayasu Komatsu, chairman of the National Federation of Families with the Mentally Ill in Japan, is hopeful about the launch of Abilify in Japan. "We have actively promoted the early introduction of drugs which have been used overseas and have shown valid evidence of effectiveness, but are not yet available in Japan," he said. "Our only wish is that the patients get relief from the pain of schizophrenia. Since the effectiveness of antipsychotic drugs differs from person to person, we welcome the introduction of Abilify, which represents a new option for the treatment of schizophrenia."

President Higuchi commented, "We are proud that Otsuka discovered Abilify and developed it as a drug that has made important advances in the treatment of schizophrenia. To date, Abilify has been strategically marketed as an international product around the world, and we are very pleased that Abilify is now available to patients in Japan, the country of its birth. Abilify may help people in Japan who suffer from schizophrenia lead more productive lives. It is expected to become a valuable new treatment option."

Abilify is an antipsychotic drug with a new mechanism of action; it works as a partial agonist against dopamine D₂ receptors and differs from other antipsychotics in this respect. It shows inhibitory action when large amounts of dopamine are released in the brain and stimulatory action when only small amounts of dopamine are released. Because of this mechanism of action, Abilify is known as a dopamine system stabilizer (DSS). Therefore, it improves both positive and negative symptoms of schizophrenia considered to be caused by dopamine abnormalities. It is expected that this drug can be used for long periods since it is considered that this drug is less likely to cause sleepiness or weight gain.

Schizophrenia is the most chronic and debilitating psychiatric disease, with a lifetime prevalence in approximately 1% of the population. Schizophrenia causes disturbances in social functions of the patients, including clear thinking, emotional control, decisiveness and interpersonal relations. The disease often appears in early adulthood and is characterized by positive symptoms such as hallucinations and delusions, and negative symptoms such as apathy, lack of interpersonal communications, and lack of drive.

• *1: Otsuka (including its affiliates) has exclusive marketing rights for Abilify in Japan, China, Taiwan, Korea, the Philippines, Thailand, Indonesia, Pakistan and Egypt, and marketing has already started in Taiwan, Korea, the Philippines, Thailand, Indonesia and Egypt. In the United States and Europe, Otsuka holds approval and marketing rights for Abilify, and in the United States and 4 EU countries (UK, France, Germany and Spain), Abilify is co-marketed by the local subsidiaries of OPC and Bristol-Myers Squibb Company. In other countries where Abilify has received approval, it is marketed by Bristol-Myers Squibb.

Founded in 1964, Otsuka Pharmaceutical Co., Ltd. is a healthcare company with the mission statement: "Otsuka - people creating new products for better health worldwide." Otsuka researches, develops, manufactures and markets innovative, original products, focusing its core businesses on pharmaceutical products for the treatment of disease and consumer products for the maintenance of everyday health.

The Otsuka Pharmaceutical Group comprises 87 companies and employs approximately 27,000 people in 17 countries and regions worldwide. Otsuka and its consolidated subsidiaries earned US$6.8 billion in annual revenues in fiscal 2005.

Product summary of Abilify (for Japan only)