Amgen ($AMGN) won the support of FDA advisers with its potentially game-changing new cardiovascular treatment, but the agency panel cautioned against widespread use of the injection until its long-term safety is better understood.
The FDA's cardio drugs committee, made up of outside experts, voted in favor of approval for Amgen's evolocumab, noting that it led to significant reductions in LDL, or bad, cholesterol compared to standard statin therapy. But many panelists urged the FDA to be choosey with which patients it allows Amgen to target, expressing concern that evolocumab may have little to no effect on preventing heart attacks and extending lives.
The panel voted 15-0 in favor of approving the treatment for homozygous familial hypercholesterolemia (HoFH), a genetic disorder that results in sky-high LDL cholesterol levels, but split 11-4 in favor of approval in any other indication. The group's recommendation now goes to the FDA, which is not required to obey its panels' recommendations but typically does so. The agency has promised to rule on evolocumab by Aug. 27.
Amgen's treatment, to be marketed as Repatha, is an antibody that blocks the protein PCSK9 to help the body clear LDL cholesterol from the blood. Like a rival contender from Sanofi ($SNY) and Regeneron ($REGN)--which won a 13-3 endorsement from the same panel Tuesday--Amgen's antibody is considered to be a potential blockbuster, with peak sales estimates reaching as high as $3 billion a year. And while both candidates are expected to win approval later this summer, the potential of the whole PCSK9 class will depend heavily on the contents of each treatment's indication.
Echoing their discussion the day before, panelists reviewing evolocumab supported approving it for FH and for patients who can't get down to healthy levels on statin therapy alone. But Amgen, like Sanofi and Regeneron, is also seeking a nod for patients who cannot or will not take the likes of Lipitor and its cheap generics, and most of the panelists were unenthusiastic about that idea, worrying that it would lead to widespread adoption of a treatment whose long-term profile is not yet known.
Amgen is working through an outcomes study on more than 20,000 patients to determine exactly how well evolocumab works over time, but data from that trial won't be available until 2017. Most of the panelists agreed that the FDA should hold out on clearing evolocumab for patients with less severe high cholesterol until those outcomes results are published.
Furthermore, the group again voiced concerns about the potential of PCSK9 therapies to send patients' LDL cholesterol levels down too low. And those worries could be a net negative for Amgen in the likely head-to-head race between evolocumab and alirocumab, as Regeneron and Sanofi plan to start patients on a 75-mg dose, where low LDL levels are likely to be of less concern, and then move up to 150 mg when necessary. Amgen, in contrast, plans to initiate therapy on a 140-mg biweekly jab with a monthly 420-mg dose also available.
In the meantime, the two leading PCSK9 factions are preparing for a near-term fight to differentiate themselves as they march toward the market. Express Scripts ($ESRX), the pharmacy benefit manager that successfully spurred a price war among competing hepatitis C therapies last year, has identified PCSK9 blockers as its next target, figuring it can squeeze some savings by pitting fairly comparable drugs against one another.