Japan’s biggest drug maker, Takeda Pharmaceutical Co. Ltd, said on Monday it is on track to release a sleeping pill as early as September in the United States and may extend its use to treat Alzheimer’s disease and other illnesses.

The Osaka-based drug maker plans to launch its insomnia drug Ramelteon in the U.S. market in September or October, marking its entry into the central nervous system disease segment, Takeda President Yasuchika Hasegawa told an analysts’ meeting.

To be marketed as Rozerem, it will be Takeda’s first new drug in the United States in six years, and will compete with existing drugs such as Sanofi-Aventis’s Ambien and Sepracor’s Lunesta.

Ramelteon, which is under phase III clinical trials in Japan and Europe, has a new mechanism that specifically targets the MT1 and MT2 receptors in the brain, which are critical in regulating the body’s sleep-wake cycle, and induces what is very similar to natural sleep, the drug maker said.

The drug has fewer side effects than existing drugs, it added.

Takeda, which filed for U.S. approval for the drug in September 2004, expects to gain approval as early as this month with “non-scheduled drug” status, which means that no restrictions will be placed on how physicians prescribe the drug.

Kazuaki Ikeya, general manager at Takeda’s strategic product planning department, said he is “fairly confident” of winning the status.

Some analysts estimate sales of the sleeping pill could reach 60-100 billion yen ($535-$890 million) if the drug is approved as a non-scheduled drug, but sales could be only half such estimates if some restrictions are imposed.

“Since Takeda’s shares have risen in anticipation that the drug will be approved as a non-scheduled drug, the shares will come under pressure if the scenario is upset,” said Kumi Miyauchi, senior analyst at Daiwa Institute of Research.

Shares in Takeda, which closed up 2.6 percent at 5,600 yen on Monday, have gained 8.5 percent so far this year, outperforming a 3.9 percent rise in the pharmaceutical sector sub-index.

Takeda’s Ikeya also said the company is considering extending the drug’s use to other illnesses such as Alzheimer’s disease or depression, and may start clinical development for these purposes after the launch of the sleeping pill. In a bid to fill its sparse drug cabinet, Takeda has sealed four licensing deals with U.S. and British biotech companies since last October, and it bought U.S. biotech venture Syrrx in March.

Thanks to these efforts, Takeda now plans to launch one new drug a year in the United States between this year and 2007. “We are making continuous efforts to keep the flow of new drugs after 2008. We may be able to announce a new deal before long,” Hasegawa said, without elaborating.