Inclisiran

Inclisiran is a cholesterol-lowering medicine belonging to a class of therapies known as small interfering RNA (siRNA) medicines. It is designed to reduce the production of proprotein convertase subtilisin/kexin type 9 (PCSK9), a protein produced mainly in the liver that influences the number of low-density lipoprotein (LDL) receptors available to remove cholesterol from the bloodstream. Inclisiran works by directing the breakdown of PCSK9 messenger RNA inside liver cells. This increases the availability of LDL receptors and helps the liver remove more LDL cholesterol from circulation. Elevated LDL cholesterol is an important risk factor for atherosclerotic cardiovascular disease, including heart attack and stroke. Inclisiran is administered as a subcutaneous injection by a healthcare professional and offers a long dosing interval after the initial doses. It is generally used alongside dietary measures and may be prescribed with statins or other lipid-lowering medicines when additional LDL cholesterol reduction is required, depending on the applicable approved indication. Inclisiran can also be considered for certain patients who cannot use statins, according to local prescribing guidance. Its effect is assessed through blood lipid measurements. Although it lowers LDL cholesterol, the degree to which it reduces cardiovascular events should be interpreted according to the available clinical evidence and current guidelines.

Inclisiran was developed as an RNA interference therapy targeting PCSK9, offering a different approach from medicines that block circulating PCSK9 protein. The European Commission granted marketing authorisation for Leqvio, the inclisiran-containing medicine, on 9 December 2020 for specified adults with primary hypercholesterolaemia or mixed dyslipidaemia. The United States Food and Drug Administration (FDA) initially approved inclisiran in December 2021 for certain adults requiring additional LDL cholesterol reduction. The US indication was subsequently expanded, including paediatric use for specified forms of familial hypercholesterolaemia in patients aged 12 years and older, as reflected in updated prescribing information. Clinical development included the ORION trial programme, which evaluated LDL cholesterol reduction in people with elevated cholesterol and different cardiovascular risk profiles. Regulatory indications and eligibility criteria differ between countries and may change as new evidence is reviewed. Prescribers should therefore follow the current product information and applicable local regulatory requirements.

Inclisiran is used to reduce LDL cholesterol in patients with hypercholesterolaemia and certain inherited cholesterol disorders, according to the locally approved indication. In the United States, it is indicated alongside diet and exercise for adults with hypercholesterolaemia, including heterozygous familial hypercholesterolaemia, and for specified patients aged 12 years and older with heterozygous or homozygous familial hypercholesterolaemia. In the European Union, its approved use includes adults with primary hypercholesterolaemia, whether familial or non-familial, or mixed dyslipidaemia, when LDL cholesterol targets are not achieved with the maximum tolerated statin dose or when statins cannot be used. Depending on the indication and local approval, inclisiran may be given with a statin, with other lipid-lowering therapies, or as an alternative for statin-intolerant patients. It complements rather than replaces dietary changes, physical activity, and other cardiovascular risk-reduction measures. The exact approved use should be checked against the current prescribing information for the relevant country.

For the standard adult regimen, inclisiran is administered as a 284 mg subcutaneous injection by a healthcare professional. The first dose is followed by a second dose after three months and then by maintenance doses every six months. The injection is usually given into the abdomen, upper arm, or thigh, avoiding areas of active skin disease, irritation, or infection. The dosing schedule should be maintained to support sustained LDL cholesterol reduction. If a dose is missed, the healthcare professional should follow the instructions in the applicable product information to determine when treatment should resume. LDL cholesterol should be checked as clinically appropriate to assess response and guide any additional lipid-lowering treatment. Patients should continue prescribed dietary measures and other cholesterol medicines unless their clinician advises otherwise. Dosing for children and adolescents should follow the approved age-specific indication and current local prescribing guidance.

The most frequently reported adverse effects of inclisiran include reactions at the injection site, such as pain, redness, or rash. Joint pain and bronchitis have also been reported in clinical studies. Injection-site reactions are generally mild or moderate and may resolve without specific treatment. As with any medicine, individual responses vary, and new or persistent symptoms should be discussed with a healthcare professional. Patients should not stop other cholesterol-lowering medicines or alter their treatment schedule without medical advice.

Serious hypersensitivity reactions, including allergic reactions, are an important safety consideration. Inclisiran should not be used in patients with a known serious hypersensitivity to the active substance or any of its components. Patients should seek prompt medical attention if they develop symptoms suggestive of a severe allergic reaction, such as swelling of the face or throat, difficulty breathing, or widespread severe rash. Treatment should be assessed and discontinued when clinically indicated if a serious hypersensitivity reaction occurs. The current prescribing information should be consulted for the full safety profile and any updated warnings. Inclisiran is intended to lower LDL cholesterol; patients should not assume that cholesterol reduction alone replaces other measures needed to reduce cardiovascular risk.

Before treatment, the healthcare professional should review the patient's cholesterol levels, cardiovascular risk factors, previous lipid-lowering treatments, allergies, and relevant medical history. Pregnancy and breastfeeding require individual assessment because information about inclisiran use in these situations is limited; treatment decisions should be made with a qualified clinician. Patients with severe kidney or liver impairment may require particular clinical consideration, even though routine dose adjustment is generally not specified for many degrees of impairment in the product information. Inclisiran is not expected to have clinically significant interactions through common cytochrome P450 enzymes or drug transporters, and meaningful interactions with statins are not expected based on available data. However, the clinician should review all prescription medicines, non-prescription products, and supplements. Patients should also continue recommended lifestyle measures and have their lipid levels monitored during treatment.

Confirm that the patient meets the locally approved indication and that expected LDL cholesterol reduction aligns with the overall treatment plan. Review baseline lipid measurements, existing lipid-lowering therapy, cardiovascular risk factors, and any history of serious hypersensitivity. Explain that inclisiran reduces PCSK9 production in liver cells and is not a substitute for diet, exercise, or other prescribed cardiovascular preventive treatments. Ensure administration by a trained healthcare professional using the correct subcutaneous technique and the recommended injection sites. Record the date of each dose and arrange the next injection before the patient leaves the clinic, as the long interval between maintenance doses can make appointment tracking important. Monitor LDL cholesterol as clinically appropriate and assess whether additional treatment is needed to achieve the patient's target. Counsel patients to report severe allergic symptoms promptly and to discuss pregnancy, breastfeeding, or new medical conditions with their healthcare professional. Follow the latest local product information for storage, handling, missed doses, and any updated safety recommendations.