Pfizer aces another pair of PCSK9 inhibitor trials

Pfizer ($PFE) has posted positive data from two more trials for its new experimental anticholesterol drug bococizumab as the three-way dual for the PCSK9 inhibitor market heats up.

The U.S. pharma giant said two more Phase III bococizumab trials met their primary endpoints in patients who are at high risk of heart problems and those with genetically high cholesterol levels after besting placebo at 12 weeks.

Pfizer is hoping to shore up lost revenue from its major blockbuster statin Lipitor, which was making around $13 billion at peak, before generic competition decimated its sales.

“These positive results add to the growing body of scientific evidence in support of bococizumab for lowering LDL-cholesterol in patients at high risk for cardiovascular events,” said James Rusnak, chief development officer, CV and metabolic disease at Pfizer.

“The high burden of cardiovascular disease suggests that more treatment options are needed to help lower cholesterol and reduce cardiovascular risk in these patients. Our goal with the extensive SPIRE clinical program is to evaluate whether bococizumab not only reduces cholesterol, but also reduces the risk of cardiovascular events in a broad range of high-risk patients, including those without a history of heart disease.”

These latest data--full details of which are expected to be revealed later this year--build on another positive set of trial data published back in April, which also met their testing goals.

The SPIRE-HR and SPIRE-FH studies are now the third and fourth of 6 SPIRE lipid-lowering studies to be completed, all of which will be used for a regulatory filing.

PCSK9 inhibitors work by reducing the number of receptors on the liver that remove LDL cholesterol from the blood. By blocking PCSK9’s ability to work, more receptors are available to get rid of LDL cholesterol from the blood and, as a result, lower LDL cholesterol levels. The company is also reported to be working on a pill version and a vaccine in this franchise area.

But Pfizer is not on its own in developing this next-gen statin, and is in a race for market share with Amgen ($AMGN) and Regeneron ($REGN)/Sanofi ($SNY), which have both already gained marketing approvals with their injectable PCSK9 inhibitors in Repatha (evolocumab) and Praluent (alirocumab, respectively.

Repatha has an effectively second-line FDA license for patients who can’t get their low-density lipoprotein (LDL) cholesterol under control with current treatment options as well as for HeFH and HoFH, while Praluent is used to treat heterozygous familial hypercholesterolemia (hereditary high cholesterol) alongside other statins, or those with CV disease.

But these two do not yet have licenses to lower CV events, although all three are now testing for this. Helping CV outcomes is where the real potential of these drugs are, and Pfizer will hope to produce better data to make up for coming to market third.

Current projections see Pfizer completing its round of CV outcome trials by April 2018, just four months after Sanofi/Regeneron and 6 months after Amgen.

Analysts figure each PCSK9 antibody will top out at $3 billion a year in sales.

- check out the release

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