By Mary Welch

Esperion Therapeutics Inc., which has three products for the treatment of cardiovascular diseases expected in clinical trials within the next 18 months, filed for an initial public offering (IPO) to raise $138 million.

The Ann Arbor, Mich., company did not reveal how many shares would be offered or at what price. FleetBoston Robertson Stephens Inc. and Chase H&Q, both of New York, are co-lead underwriters. U.S. Bancorp Piper Jaffray Inc., of Minneapolis, is co-manager.

Esperion's goal is to exploit the high-density lipoprotein (HDL) pathway to remove excessive, disease-causing lipids, a process called reverse cholesterol transport. Lipoproteins are blood-borne particles that transport lipids throughout the body and contain a blend of cholesterol, proteins, triglycerides and phospholipids.

High levels of HDL reduce the risk of heart disease by countering the body's level of low-density liproprotein (LDL) and the very low-density lipoproteins. The company wants to reverse vascular disease by removing lipids from potentially unstable plaques in blood vessels called atherosclerotic lesions.

Slated for clinical trials in the first half of 2001 is ApoA-I Milano (AIM), a component of HDL, for the treatment of acute coronary syndromes and restenosis. AIM, a natural variant of normal apolipoprotein A-L, was discovered by researchers who studied the local Milan, Italy, population, which despite other risk factors, has a low incidence of cardiovascular disease.

The company believes that AIM removes and transports cholesterol and other lipids from arteries.

Third-party clinical studies have indicated that an intravenous infusion of AIM can limit the progression and promote regression of atherosclerosis, as well as inhibit restenosis following balloon angioplasty.

Esperion is developing ProApoA-I, a precursor of ApoA-I, for the treatment of life-threatening acute coronary syndromes, including heart attacks. Preliminary human clinical studies of ProApo-I done by a third party suggest that when it is infused into people with high blood cholesterol levels, elimination of cholesterol from the body is increased. Clinical trials with ProApoA-I are expected to start in the second half of this year.

Founded in May 1998, the company also is developing large unilamellar vesicles (LUVs) for the treatment of acute coronary syndromes. LUVs are made of naturally occurring lipids that enhance the reverse lipid transport (RLT) pathway. When injected into the bloodstream, the company believes that LUVs will be able to accept cholesterol and deliver it to the liver for elimination from the body. Clinical trials with LUVs are expected to start in the second half of this year.

Two other product candidates are being developed. The first, an RLT peptide, is designed to remove cholesterol from arteries and activate specific steps in the RLT pathway. The second, an HDL elevator, is an orally active small molecule for the sustained elevation of HDL, which will increase the efficiency of the RLT pathway, the company said.

The company had no revenues for 1999, and posted a net loss of $12.8 million. As of Dec. 31, the company had $5.9 million in cash.

Earlier this year, Esperion raised $22 million in a private financing aimed at advancing its cardiovascular therapies into clinical trials. The company, co-founded by Oak Investment Partners, of Westport, Conn., and Scheer & Co. Inc., of Branford, Conn., raised $15.5 million shortly after its founding. (See BioWorld Today, Jan. 14, 2000, p. 1; and July 17, 1998, p. 1.)

TL Ventures III and IV, of Wayne, Pa., is the leading shareholder with 6.72 million shares. Oak Investment Partners currently owns a little more than 6.1 million shares. It was unclear how many shares would be outstanding after the offering.

Esperion's intended NASDAQ ticker symbol is ESPR.