Pfizer Inc announced it has entered into an agreement to acquire Esperion Therapeutics, Inc., a biopharmaceutical company focused on the development of high-density lipoprotein (HDL) targeted therapies for the treatment of cardiovascular disease.

Pursuant to this agreement, Pfizer will commence a cash tender offer to acquire the shares of Esperion stock for $1.3 billion at a price of $35 per share, subject to certain conditions. This price represents a 54 per cent premium over Esperion's average closing share price during the last 20 trading days.

"By acquiring Esperion, we can bring our research capabilities to bear on an emerging new area which has potentially significant beneficial impact on patients", said Hank McKinnell, chairman and CEO of Pfizer. "Epidemiologic data and drug intervention trials support a strong correlation between higher HDL levels and improvements in morbidity and mortality."

"The acquisition will enable us to utilize Pfizer's skills and apply the resources needed to develop our pipeline of compounds to benefit patients with atherosclerosis", said Roger Newton, president and CEO of Esperion. "We are pleased to have the opportunity to work with the world leader in cardiovascular medicines to develop HDL-focused therapies."

Pfizer’s Lipitor is the world's most prescribed agent for reducing low-density lipoprotein (LDL). Pfizer is also developing Lipitor/torcetrapib, which works by combining Lipitor with an agent that inhibits the action of cholesteryl ester transfer protein or CETP. Results of Phase II studies indicate that this combination may represent a significant advance in preventive cardiovascular medicine by enhancing the LDL-lowering effect of Lipitor while also increasing HDL or "good" cholesterol.

While both Lipitor and Lipitor/torcetrapib are chronic therapies, Esperion has three clinical compounds that are being developed as acute, hospital-based treatments to regress arterial plaque and thereby reduce morbidity and mortality in patients who have had a cardiovascular event.

Atherosclerosis, which is a leading cause of death from heart attack and stroke, occurs when there is a build-up of cholesterol-rich fatty areas called plaques in the arteries. It accounts for more than 75 per cent of all deaths from cardiovascular disease. The break-up and dispersal of these plaques can block the blood flow throughout the body, which can be fatal.

"Pfizer is clearly committed to long-term cardiovascular research", said Dr. McKinnell. "We recognize that HDL control is an emerging area, and that early-stage development brings risk. However, we are confident that the rigorous and long-term clinical trials we plan to conduct will further scientific and medical understanding in this area, which will ultimately benefit patients."

Based in Ann Arbor, MI, Esperion was founded by a group of scientists who worked on the discovery and development of Lipitor. Esperion will operate as a division of the Pfizer Global Research and Development organization, and remain in Ann Arbor.