Familial Hypercholesterolemia (FH) is a genetic disorder that causes abnormally high levels of low-density lipoprotein cholesterol (LDL-C), a risk factor for early onset cardiovascular diseases such as stroke or heart attack. FH is often caused by dysfunctional LDL-C receptors, preventing effective removal of circulating LDL-C, but may also arise through other mutations.
1 in 500 people are heterozygous, having one allele for FH, while 1 in 1,000,000 people are homozygous, having two alleles. Untreated, most homozygous FH patients develop cardiovascular disease by 20 and die by 30. Heterozygous FH is fortunately less severe, but still dramatically increases the risk of cardiovascular disease.
Clearly, FH requires aggressive cholesterol lowering therapy. Statins, which have traditionally been used to lower LDL-C levels, are often insufficient. In fact, Pijlman et al. found that only 21% of FH patients on statins reach target LDL-C goals set by doctors. In cases where statins are inadequate, patients are forced to combine therapies or undergo invasive procedures. A new class of drugs to enter the market, PCSK9 inhibitors, are much more powerful than statins. PCSK9 breaks down LDL-C receptors, preventing their ability to remove LDL-C from the blood. Thus, PCSK9 inhibitors prolong the lifespan of LDL-C receptors and allow for increased removal of LDL-C. Shown to lower LDL-C by 30-40%, PCSK9 inhibitors are very effective at treating FH patients. PCSK9 inhibitors present an exciting opportunity to improve FH management, and with time may have a significant impact on the pharmaceutical industry at large due to their increased effectiveness compared to statins. Currently, however, PCSK9 inhibitors are not cost effective at the price of $503,000 per quality-adjusted-life-year gained.
Written By Kelvin Ng
References may be found in the journal.