Dangers of Untreated HoFH and Current Treatment Options
Seth J. Baum, MD, Chief Medical Officer of Flourish Research and the Vice Chair of the Board of the Family Heart Foundation, discusses the potential consequences of untreated homozygous familial hypercholesterolemia (HoFH) and how evinacumab is a “game changer” treatment.
In the final video in this series, hear Dr. Baum explain the importance of early detection of HoFH.
Question:
What are the potential consequences of untreated HoFH on cardiovascular health?
Seth J. Baum, MD:
The consequences of untreated HoFH are terrible. LDL, we know, causes plaque formation. This is very well established; it’s no longer hypothetical. It’s the LDL truth or the LDL reality. It does so more aggressively if LDL is higher and the longer a patient has had a high LDL. Since this is a genetic disorder, we’re talking about HoFH, even in utero babies have very high LDL levels, so in utero they have it so their entire life they’re bathed in super high LDL cholesterol and plaque forms, and kids as young as 5 years old can die of heart attacks or require bypass surgery. We want to get to these children really, really early, as soon as we can. Those are obviously our most severe cases. They can develop supravalvular aortic stenosis and, in fact, markedly elevated LDL plus supravalvular aortic stenosis is truly pathognomonic for homozygous FH, that’s all you need and you make the diagnosis.
They can develop, obviously, xanthomas and there are some classic xanthomas that are pathognomonic for HoFH, intertrigenous ones, the ones in the webs of the fingers. Those are pathognomonic for HoFH so if you see that the patient has HoFH. Obviously, the most severe adverse consequence is going to be vascular, plus aortic stenosis is pretty bad too, but is going to be vascular. I mentioned the most severe cases. Patients can have problems before they’re 10 but in the less severe cases … and when I say less severe you have to understand we’re talking about an LDL of 700, 800 versus an LDL of 500, 600, right? They’re pretty severe. They can develop events in their teens or 20s, also terrible, so the idea is time is plaque and you want to get to these patients. You want to identify these patients as early as possible and you want to treat the patients as aggressively as possible to reduce LDL as low as you can and try to, to the best of our ability, normalize the patient to get closer to a normal level. In the olden days I would have said it’s impossible, you can never get an LDL down to close to normal. But I have patients now who have homozygous FH who have LDLs in the 115, 120 range from a top of 700-something. To be able to do that, and that’s with the help of the medicines I just mentioned, it’s remarkable that we can achieve that.
Question:
What are the current treatment options available for HoFH and how effective are they in managing LDL cholesterol levels?
Seth J. Baum, MD:
We’ve had some great advances in the management of homozygous FH for LDL reduction, obviously is the key here. As I stated earlier, our typical medications for managing LDL, so the statins, ezetimibe, PCSK9 inhibitors, all rely on up-regulating the LDL receptor in order to be effective. The problem in HoFH is the receptors are either defective or null, meaning that they’re just either poorly functioning or not functioning at all so you can up-regulate those receptors all day long, doesn’t matter, they’re not going to do anything. You need an LDL receptor independent therapy, and lomitapide and evinacumab are the 2 that are our most important ones, evinacumab being the most recent development and, in my view, an absolute game changer because to get a 50% reduction in LDL on top of other therapies is just remarkable.
