FDA Approves Amgen’s PCSK9 Inhibitor Repatha

FDA announced on Aug. 27, 2015 that it approved Repatha (evolocumab), Amgen’s PCSK9 inhibitor for the treatment of heterozygous familial hypercholesterolemia (HeFH), homozygous familial hypercholesterolemia (HoFH), and clinical atherosclerotic cardiovascular disease. PCSK9 inhibitors represent a brand new class of drugs.

The approval comes just one month after the approval of the first PCSK9 inhibitor in the US-Sanofi and Regeneron’s Praluent (alirocumab).  Compared with placebo, Repatha reduced low-density lipoprotein (LDL) by approximately 60%, while trial participants taking Praluent had an average reduction in LDL cholesterol ranging from 36–59%. Unlike Praluent, Repatha was approved for HoFH, an additional indication. Both drugs were not approved for their ability to lower low-density lipoprotein (LDL) alone in patients (i.e., primary prevention in statin-intolerant patients). In the EU, however, Repatha was approved for a more broad indication; the European Commission accepted the lowering of LDL as a surrogate endpoint in those trials.

Repatha is rumored to have a slightly lower price than Praluent ($14,100 per year vs. $14,600, respectively). Regeneron has said that the pricing of Praluent is consistent with the pricing of most other monoclonal antibody (mAb)-based drugs currently on the market. Praluent dosing is 75 mg or 150 mg (depending on patient response) once every two weeks, while Repatha is administered as a 140-mg injection every other week or a 420-mg injection once a month.

Both drugs are antibodies that facilitate the removal of low-density lipoprotein from the blood by blocking the protein PCSK9. PCSK9 normally reduces the number of receptors available to remove LDL from the blood, so blocking PCSK9’s function allows more receptors to work within the liver to remove cholesterol. The drugs will compete with Genzyme's Kynamro (mipomersen) for the treatment of HeFH and HoFH and Aegerion's Juxtapid (lomitapide) for HoFH.

Source: FDA