Both mipomersen and lomitapide have been FDA approved for the treatment of HoFH and are currently under investigation for use in HeFH (38, 39) A third agent that is still under investigation is inclisiran, a small interfering RNA (siRNA) that inhibits PCSK9 production by selectively silencing the translation of the messenger RNAs for PCSK9 (40–42). Here, PCSK9 is linked to homozygous familial hypercholesterolemia.