Editing Cholesterol Genes - The New Code to Preventing Heart Attacks?
Can you imagine being able to walk into a clinic and take a jab for preventing heart disease? Now, that is the kind of vaccine-led future that we all want to dream of.
We hear/read about thousands of innovations in the longevity/health-tech space every single day, but few excite us in the way of being potentially ‘‘life-changing’’ as Verve Therapeutics’ novel gene-editing therapy that is aiming to permanently lower levels of ‘’bad’’ LDL cholesterol that the liver produces with a single jab.
If Verve’s experiment works, it could potentially save millions of people from cardiovascular disease and prevent heart attacks.
Twice the number of people that die of all cancers combined, die or suffer from cardiovascular diseases across the world. Yet, treatments for these end points remain expensive and inaccessible. Much of the issue is connected to chronically high levels of potentially damaging LDL (Low Density Lipoprotein) cholesterol across large swathes of the world population, which at excessive levels can contribute to damaged and blocked arteries and untimely death. Regular interventions such as hard-to-follow diets, exercise and prescribed medication have only been able to create a small dent in LDL levels at a population level. Statins are the most commonly prescribed preventive medicine for reducing LDL levels, but daily adherence is notoriously difficult. They have also been found to increase long term risk of diabetes, which itself is a strong risk factor for cardiovascular diseases.
As an alternative to statin therapy, an enzyme called ‘Proprotein convertase subtilisin/kexin type 9’ (or PCSK9) aims to lower LDL without the potential downsides of statins. PCSK9 is an enzyme produced in most tissues in the body that locks on to LDL particles and ingests the fats they carry. The first two PCSK9 inhibitors, alirocumab and evolocumab, were approved by the FDA in 2015 as injections that could be taken once every two weeks. They were known to lower LDL-particle concentrations when statins and other drugs were ineffective or could not be taken. However these drugs which block PCSK9 consist of difficult and expensive to produce ‘proteins’ which need to be injected similarly to insulin. Most of the world simply can’t afford this. Moreover we don’t yet know all the lifelong downsides of PCSK9 inhibitors.
Therefore, it comes as no surprise that one gene responsible for high LDL cholesterol and cardiovascular diseases is the PCSK9 gene. 2-3% of the human population is lucky enough to have a mutation in the PCSK9 gene which is responsible for lowering or switching off this enzyme completely. One study of 3,336 participants noted distinct differences among participants of different racial backgrounds in prevalence of the PCSK9 mutation, resulting in lowering of LDL cholesterol, and decreased instances of cardiovascular disease. For instance, 2.6% of the black people in the study had the mutation, and on average they had 28% less LDL cholesterol, and thus an 88% reduction in the risk of developing cardiovascular disease over the course of the study. Whereas, amongst white people in the same study, 3.2% had the variation in PCK9. On average they had 15% less LDL cholesterol, and thus a 47% reduction in the risk of developing cardiovascular disease. In comparison, the Verve therapy reduces LDL cholesterol by 60% in non-human primate studies from a single injection for months or more.
A 60% reduction in LDL from a new therapy sounds extremely promising in theory, especially when people born with dramatically lower risks of cardiovascular disease only need a 20% reduction in LDL. But it is very important to know that if you have been enjoying the cardiovascular benefits of 20% lower LDL your whole life due to a gene mutation from birth, it may well require 60% reduction from a therapy when you start lowering your LDL at age 50. This reinforces the criticality of lifelong disease risk reduction and health optimization not just treating health issues once the damage is done.
Until now this technology has only been tried as part of exploratory trials on people suffering from rare diseases like sickle-cell anemia.
Interestingly, one of the reasons as to why Verve’s base-editing technique and pipeline is moving forward so fast is because the technology is vastly similar to mRNA vaccines that were developed for COVID-19. Just like the vaccines, Verve’s treatment is not the injection of actual base-editing CRISPR, but rather consists of RNA genetic instructions wrapped in a nanoparticle, which then ferries everything into a cell. These instructions help the cells build the therapy of an otherwise impossibly expensive and hard to administer CRISPR machine. Much like the COVID vaccine, which instructs cells to make a component of the SARS-CoV-2 virus, the particles in the Verve treatment serum carry RNA instructions for a cell to assemble a base-editing protein.
The Verve trial addresses several access and scalability issues (prevalent in developing nations) in the existing standard-of-care model, namely the requirement of rigorous patient adherence, regular access to care, and availability of healthcare infrastructure. ‘’VERVE-101 has the potential to change the way cardiovascular disease is cared for by lowering LDL-C as low as possible for as long as possible after a single treatment.”, said Andrew Bellinger, M.D., Ph.D., chief scientific and medical officer at Verve.
So what’s next?
In their experiment on monkeys, Verve has already found that the treatment lowered bad cholesterol by 60%. The effect lasted for more than a year in the animals. Verve will now enroll approximately 40 adult patients with heterozygous familial hypercholesterolemia (HefH). Patients with HefH is a genetic disorder that causes patients to inherit the mutated gene that causes high cholesterol levels. HefH impacts as many as 31 million people globally. This next stage trial will be conducted to evaluate the safety and tolerability of the injection.
If this round of testing goes well and Verve is able to make their treatment accessible to large groups of the world’s population, we may be at the cusp of preventing heart disease and making its treatment accessible and affordable.