FDA Advisory Panel Backs Amgen's Repatha

On June 10, 2015, an FDA advisory panel backed the approval of Amgen’s Repatha (evolocumab) after a 11-4 vote, one day after a 12-3 vote backing approval for Sanofi and Regeneron’s PCSK9 inhibitor Praluent (alirocumab). Repatha has a target action date of August 27.

As pointed out by Evercore ISI analyst Mark Schoenebaum in an email, of the four panelists who voted "no" on approval, three also voted "no" on Praluent. The fourth "no" for Repatha was reportedly from an endocrinologist named Abraham Thomas, MD, who voted "yes" to Praluent a day prior. The endocrinologist was concerned that Amgen's 12-week blinded trials (vs. 24 weeks for Praluent) and one 52-week blinded trial were too short to adequately assess the safety of the medication, a concern which, according to Schoenebaum, was shared by at least one other panelist.

Many of the panelists, though they thought the drug would be useful to treat heterozygous familial hypercholesterolemia and homozygous familial hypercholesterolemia, expressed uncertainty that low-density lipoprotein (LDL) should be used as a surrogate endpoint for PCSK9 inhibitors, a new class of drugs. In other words, many of the panelists were unsure if Repatha’s and Praluent’s ability to lower cholesterol alone would be sufficient grounds for approval, as some were not adequately convinced that the lowering of LDL alone would translate into a cardiovascular benefit.

Many of the estimations that predict PCSK9 inhibitors to cost the US healthcare system billions of dollars have been calculated based on the assumption of use of this class of drugs to lower LDL, which represents a larger patient population than the population diagnosed with hypercholesterolemia. Ultimately, if drugs in this class are not approved by FDA for their capacity to lower LDL, the cost burden may not be as significant as previously imagined.

Sources:
Forbes 
Evercore ISI