Amgen, Inc (AMGN +0.00%) was a big winner coming out of the American College of Cardiology Conference, where it presented five new phase 3 studies on evolocumab, part of the likely next generation of cholesterol drugs.
Most cholesterol medications – statins, fibrates, niacin – have been around for decades, and Pfizer's (PFE +0.09%) blockbuster statin Lipitor was the best selling drug in history. Its patent expired in late 2011, but not before racking up over $100 billion in cumulative sales.
High cholesterol unfortunately effects over 70 million Americans, providing a ready potential market for these drugs. High LDL cholesterol is widely recognized and proven to be a major risk factor in heart disease. LDL is the cholesterol associated with heart disease; HDL cholesterol is cardioprotective.
This new class of drugs, known as PCSK9 blockers,are expected to generate total peak sales of $10 billion.
What's the data say?
As compared to placebo, Amgen's evolocumab lowered LDL cholesterol by 55-66%. Similar results were shown in comparison to Merck & Co.'s (MRK +0.44%) non-statin cholesterol medication Zetia, and the combination of evolocumab with a statin lowered LDL cholesterol by 75%. Safety data showed improvement over Zetia, and there were no significant neurological side effects, a concern that had arisen from rival PCSK9 blocker developer Sanofi (SNY +0.87%).
These were the first studies presented on this class of medications, targeted to lower LDL cholesterol on patients who are either unable to tolerate or unresponsive to statins. The studies spanned over 4,000 patients and looked at both patients who could not tolerate statins and well as patients in which evolocumab was used in combination with a statin.
Approval on its way?
Amgen plans to file for approval this year, but it may be premature. While the studies it presented shows that the drugs do indeed lower LDL cholesterol, there are not yet results from studies looking at if this lowered cholesterol will help prevent heart attacks or heart disease.
In the case of Zetia, Merck won approval in 2002 but sales declined following the famous 2008 ENHANCE trial showered that despite lowering cholesterol, Zetia did nothing to combat arterial plaque formation. These plaques are the mechanism behind cholesterol's association with heart disease; as such, the ENHANCE trial called into question the cholesterol-lowering abilities of Zetia to combat heart disease, which defeated the entire purpose of lowering cholesterol in the first place. Following that trial, sales dropped significantly.
Statins already have scientific proof of combating heart disease through their cholesterol-lowering mechanism of minimizing cholesterol production. Merck's Zetia worked on minimizing cholesterol absorption, which apparently does not help prevent heart disease.
Evolocumab works on an entirely different mechanism that assists in the liver's ability to remove cholesterol. As such, however, the proof of improved patient morbidity and mortality will be lacking – while this may not hold up approval (it didn't with Merck's Zetia), it may significantly affect adoption by physicians, patients and payers. Amgen does, however, already have studies looking at the drug's effects on heart disease.
Even if the drug is approved, Amgen will have to battle other factors in clinical adoption. The drug is in shot-form only, as opposed to the easy-to-take pills that statins come in. And given that most cholesterol medications are age-old and widely available as generics, this new class of medications will inevitably be the most expensive ones on the market. Quickly, the targeted population shrinks from 70 million to the smaller group comprised of those that cannot take statins or need additional therapy.
Meanwhile, Amgen faces serious competition not lagging far behind. Sanofi is developing a similar drug alirocumab, which showed significant improvement in cholesterol levels over Zetia, and Pfizer's bococizumab also showed efficacy in LDL levels.
Nonetheless, Amgen leads the field and may enjoy 6-12 months without having to share the market. It may not be the $13 billion peak annual sales of Lipitor (peak sales for evolocumab estimates seem to hover closer to $2.5 billion annually), but it should be enough to make Amgen a stock to watch closely this year.
