Apparent increases in systolic blood pressure caused by Pfizer's torcetrapib/ Lipitor (atorvastatin) combination will be investigated in further clinical studies, the firm said.

In Phase II trials reported at the American Heart Association annual meeting Nov. 15 in Dallas, patients taking the combination cholesterol therapy demonstrated a rise in systolic blood pressure of approximately 2 mm Hg, which Pfizer said "will be further defined in ongoing Phase III studies."

Overall, the adverse effects observed in the two Phase II trials were similar to those linked to the statin alone, the company noted.

Lipitor labeling says that hypertension is a cardiovascular system side effect that occurred in clinical trials in less than 2% of patients. An increase in systolic or diastolic blood pressure could lead to a higher incidence of hypertension - a counterproductive result for a cholesterol-lowering agent.

On a positive note, data from a 500-patient Phase II study demonstrated that torcetrapib/atorvastatin increased HDL cholesterol 44%-66% and lowered LDL cholesterol by 41%-60%; patients received torcetrapib 60 mg combined with atorvastatin 10 mg, 20 mg, 40 mg and 80 mg.

Torcetrapib blocks cholesterol-ester transfer protein (CETP), a protein that transfers cholesterol from HDL to LDL, resulting in arterial plaque build-up.

A separate 40-patient study tested whether torcetrapib allows HDL particles to maintain their ability to transport cholesterol away from cells.

Patients receiving 120 mg torcetrapib had 40%-60% increases in HDL cholesterol compared to placebo. Additionally, torcetrapib subjects showed a greater ability to carry cholesterol from cells, much as occurs in people with naturally high levels of HDL cholesterol.

The Phase II results mark the most recent milestone in Pfizer's 40-study, 25,000-patient, $800 mil. development program for torcetrapib/atorvastatin (¹ Also see "Pfizer Torcetrapib Phase III Program Will Cost $800 Mil." - Pink Sheet, 6 December, 2004., p. 7). The effort includes five components: imaging studies to evaluate atherosclerosis; lipid studies to support dyslipidemia claims; head-to-head comparisons; scientific development; and a comorbidity and mortality study.

Pfizer’s Torcetrapib/Lipitor Raises HDL Cholesterol, But Blood Pressure Too

More from Archive

More from Pink Sheet