Just two days after an upbeat analysts meeting, Pfizer’s pipeline has suffered a serious setback on the news that the firm has stopped all clinical trials of the cholesterol-lowerer torcetrapib due to safety concerns.

Pfizer took the decision after the independent Data Safety Monitoring Board which was monitoring the morbidity and mortality study for torcetrapib, called ILLUMINATE, recommended terminating trials “because of an imbalance of mortality and cardiovascular events.” The company noted that patient participants have been told to stop taking the drug immediately and the entire development programme for the compound has been axed.

Dr Philip Barter, chairman of the steering committee overseeing the ILLUMINATE study and director of the Heart Research Institute in Australia could not hide his amazement, saying that “based on all the evidence we have seen regarding torcetrapib and in light of prior study results, we were very surprised by the information received from the DSMB, the only body with access to the unblinded safety data.” He added that “this new information was totally unexpected and disappointing, given the potential benefits of this drug.”

Pfizer’s chief executive Jeffrey Kindler said the news was “both

surprising and disappointing,” and “we understand the challenge that this

represents and we will respond quickly and aggressively to it.” However,

in reference to the company’s business as a whole, he claimed “it is

important to put this information in the context of both our commitment to

transform Pfizer and our overall product and financial strength.”

He was referring to the aforementioned analysts' day which saw Pfizer raise

its earnings estimates and highlight a pipeline that should produce six

new products a year starting in 2010.

Launch had been scheduled for '07

Nevertheless, there is no disguising the negative impact that the

termination of torcetrapib will have, given that Pfizer had been hoping to

launch the product next year. The drug, which raises protective

high-density lipoprotein cholesterol, was to be launched on its own and in

combination with blockbuster Lipitor (atorvastatin).

Over $800 million has already been spent developing torcetrapib, which was supposed to take the place of Lipitor when the latter faces patent expiry in 2010 or 2011, though earlier clinical trials showed that it may raise blood pressure levels.

It also comes at the time when the company is looking to soften the blow

of patent expiries on other blockbusters such as the antidepressant Zoloft

(sertraline), the epilepsy drug Neurontin (gabapentin) and the

hypertension treatment Norvasc (amlodipine).

The US Food and Drug Administration said it “fully supports Pfizer’s

decision to suspend this trial” and added that will continue to work with

the company and “other sponsors developing molecules in this class of

drugs (cholesteryl-ester-transfer-protein inhibitors) to ensure that

appropriate protections are in place.”

The bad news about torcetrapib came out on Saturday, so the effect this

will have on Pfizer’s shares will not become clear until later today. Some

observers have predicted a 5% decline, with others plumping for a much worse fall.