Two new drugs for cholesterol

PEOPLE with high cholesterol levels who cannot tolerate stat ins, or find it does not work for them, now have new drugs that may help.

About 70 per cent of patients admitted to National Heart Centre Singapore ( NHCS) with heart attacks have unhealthy low- density lipoprotein ( LDL) or bad cholesterol levels.

After a heart attack, doctors typically start them on high doses of statins. These are drugs proven to save lives and prevent deaths by reducing both inflammation in coronary arteries and recurrent heart attacks.

However, after a year on statins following a heart attack, one in two on the medication still cannot each target cholesterol levels, said Dr Jack Tan, Deputy Head and Senior Consultant, Department of Cardiology, NHCS.

This led Dr Tan to start giving two new drugs – alirocumab or evolocumab – to patients. The drugs were approved by the Health Sciences Authority last year for use on people who have had a heart attack, or are at a high risk of one. These are patients who cannot reach their target levels while on conventional treatment, or cannot tolerate the usual highintensity statins.

The drugs have had positive data from a worldwide study that also included participants from Singapore. Alirocumab was found to be much more effective in reducing LDL levels than high- dose statins, while having barely any side effects, said Dr Tan, who is also Adjunct Assistant Professor, Duke-NUS Medical School.

Made by different companies, both alirocumab and evolocumab act similarly. They target and inhibit a protein called PCSK9, which prevents the breakdown of LDL receptors in the liver. These receptors remove harmful LDL cholesterol from the blood. Who are these drugs for?

Currently, NHCS has 20 patients on either one of the two new drugs. They are those at high risk of a heart attack, who cannot tolerate high- dose statins, or have not been able to reach target levels.

Alirocumab is prescribed in two doses (no difference in price), and evolocumab in a standard dose. Both are taken once a fortnight through subcutaneous injections.

Except for patients who cannot tolerate statins, Dr Tan said the preferred way to use both drugs is in combination with a statin, because they complement statins and produce better results when paired up. He said they complement statins in treating patients who are at a high risk of a heart attack but cannot reach target LDL cholesterol levels with statins alone.

The drugs are also given to people with an inherited condition called homozygous familial hypercholesterolemia, where the bad cholesterol is so high that even the strongest doses of statins cannot reduce it to target levels.

One in 300 to 500 people have this condition in the milder heterozygous form. “From young, their baseline cholesterol is very high. So they have heart attacks earlier in life. If their condition is more severe, they can have heart attacks as young as in their 20s because their cholesterol is sky-high,” said Dr Tan.

Patients have two considerations regarding the drugs: cost, and that the drugs have to be injected, which some fi nd off-putting, although the jabs are convenient and almost painless.

One month’s treatment with alirocumab or evolocumab is about $ 600 at NHCS, as subsidies are not available for these non- standard drugs. Comparatively, the high dose of the generic statin, torvastatin, costs $ 18 per month before subsidy, and $ 4.50 on a 75 per cent subsidy. • This story was first published in Singapore Health, May - June 2018 issue.