skidded Tuesday after the pharmaceutical company issued mixed test results for a new drug to improve heart health.
The experimental drug lowers bad cholesterol and raises good cholesterol, but it also elevates blood pressure, according to preliminary results of a late-stage clinical trial.
By mid-afternoon, Pfizer's stock was off 74 cents, or 2.7%, to $26.45 on trading that was 50% higher than the average daily volume for the past three months.
The experimental drug combines Lipitor with the investigational compound torcetrapib. Pfizer is counting heavily on this combination pill, which features the bad-cholesterol-lowering power of Lipitor and the good-cholesterol-raising ability of torcetrapib.
Pfizer tested the combination pill vs. Lipitor in patients with heterozygous familial hypercholesterolemia -- a high level of bad cholesterol and a high risk of early heart disease. The combination pill raised good cholesterol by 56% and lowered bad cholesterol by 27% vs. patients taking only Lipitor. The study will be presented Nov. 15 at the American Heart Association's annual scientific convention in Chicago.
However, the combination pill also raised blood pressure by an average of about two millimeters vs. patients taking Lipitor. Systolic blood pressure, the upper number in a blood-pressure reading, reflects pressure of blood in arteries when the heart contracts. The lower number -- diastolic blood pressure -- measures pressure in arteries when the heart relaxes between beats.
Pfizer's chief medical officer, Dr. Joseph Feczko, praised the cholesterol results while noting that the phase III results are "incomplete and must be rigorously analyzed when all ... trials are finished." Feczko said the early phase III results cover less than 25% of patients being tested, adding that "we want to ensure that these results are put in the appropriate perspective." Phase III represents the final round of human testing before a drug application is submitted to regulators.
Pfizer believes the elevated blood-pressure results "will not alter the favorable clinical profile of
the drug in the treatment of cardiovascular disease," Feczko said in a prepared statement.
Pfizer is conducting several phase III tests. The company said overall phase III data show patients taking the combination pill had an average gain in systolic blood pressure of roughly one millimeter above the two- to three-millimeter increase found in phase II studies.
Studies that have been completed so far "vary in duration and size, and preliminary data at this stage may not represent the final results when phase III is completed," Feczko said. "No final conclusions" on safety and efficacy can be made until Pfizer completes other studies and runs a statistical analysis, he added.
The Lipitor Defense
The combination pill is essential to Pfizer's protecting sales from Lipitor, which accounted for
27% of corporate revenue in the third quarter. If the Food and Drug Administration approves a drug that offers extra benefits to Lipitor, Pfizer will compete effectively against other good-cholesterol drugs and have time to switch Lipitor patients to the combination pill.
Timing is crucial. Depending on
patent-challenge disputes, the key Lipitor patent in the U.S. will expire in March 2010. Another Lipitor patent has been overturned in court. Pfizer is appealing the decision to the U.S. Patent and Trademark Office. If Pfizer wins, that patent will remain in effect until June 2011.
It's not clear when the FDA might act on the combination pill, and several analysts are worried that Pfizer might be forced to push back its launch of the combination pill.
"We felt the company's tone
during an Oct. 19 teleconference pertaining to Lipitor-torcetrapib was more cautionary, though this could well be a reflection of greater conservatism on the part of Pfizer's new leadership," UBS analyst Roopesh Patel wrote in a Oct. 24 report. He cut his rating to neutral from buy.
Patel had predicted Pfizer would file an application during the second half of 2007, receive an accelerated six-month review from the FDA and launch the drug in 2008. Based on Pfizer executives' recent comments, Patel now predicts the drug will reach the market in 2009. If the FDA requires more test data, the drug might be delayed until 2011, he says. Patel doesn't own shares; his firm has had a recent investment banking relationship with the company.