Asthma treatment maker Asthmatx Inc. may raise up to $75 million in an initial public offering, according to a regulatory filing on Monday.

Terms have not been set for the offering expected to be led by underwriters Piper Jaffray and Bear, Stearns & Co., according to the filing with the U.S. Securities and Exchange Commission.

The company's products are currently in clinical trials. It intends to file an application for premarket approval with U.S. regulators in 2007, the filing said.

The company's only revenue to date comes from research grants.

The Mountain View, California-based company has applied for a Nasdaq listing under the symbol \"AZMA\" (AZMA.O: Quote, Profile, Research).