Pfizer's cooking up a PCSK9-blocking pill

SAN FRANCISCO--Keeping up the rear in a three-way race to commercialize the first of a new class of anticholesterol antibodies, Pfizer ($PFE) is at work on a pill that attacks the same target, planning to build a franchise in what is expected to be a blockbuster new therapeutic area.

Pfizer R&D chief Mikael Dolsten

At the JP Morgan Healthcare Conference in San Francisco, Pfizer R&D chief Mikael Dolsten told Reuters that the company is developing a small-molecule inhibitor of the protein PCSK9, which stands in the way of the body's ability to clear LDL, or "bad," cholesterol from the blood. As it stands, Amgen ($AMGN) and a team of Sanofi ($SNY) and Regeneron ($REGN) lead the race to commercialize injectable therapies that block PCSK9, with Pfizer bringing up the rear with a Phase III program of its own.

The company expects to begin a human trial of its anti-PCSK9 pill later this year, Dolsten told the news service, touting "a substantial reduction" in cholesterol in preclinical animal studies.

Pfizer's antibody, bococizumab, is likely to hit the market after its two main rivals, but Dolsten is taking the long view on PCSK9. Looking beyond first-generation therapies, Pfizer's approach to cholesterol includes the aforementioned pill and an early-stage vaccine candidate--which would block the protein's expression through an annual injection--that could enter Phase I next year.

A pill that inhibits PCSK9 is "a Holy Grail" in the world of lowering LDL cholesterol, according to Esperion ($ESPR) CEO Tim Mayleben, whose company is at work on a small-molecule cardio treatment that taps a different pathway. And if Pfizer can pull off such a feat, its third-place finish in the blockbuster race in PCSK9 antibodies could eventually be lost to history.

Meanwhile, Amgen, long the leader in PCSK9 inhibitors, is expecting to win FDA approval for its treatment no later than Aug. 27. That would have given it months of market exclusivity, but, over the summer, Sanofi and Regeneron paid $67.5 million for an FDA voucher that will cut the review time for their alirocumab down from 10 months to 6 months. Assuming the pair files its drug by year's end as planned, alirocumab will likely be up for approval at the same time if not before Amgen's contender. Further complicating matters, Amgen is suing its rivals over alleged patent infringement.

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

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