lenacapavir
Sunlenca (lenacapavir) is a first-in-class long-acting HIV-1 capsid inhibitor from Gilead for adults with multidrug-resistant HIV-1 infection who cannot otherwise build a suppressive regimen. It targets the virus's protective protein shell at multiple stages of the replication cycle and is given as a subcutaneous injection every six months.
This page is based on EMA assessment information for lenacapavir (Sunlenca), cross-checked with MedlinePlus; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
HIV carries its genetic material inside a protein shell shaped like a soccer ball. Lenacapavir is like superglue that stiffens the seams of that shell — the ball becomes too rigid to open when it needs to, and too fragile to hold together when it needs to stay intact, so the virus cannot complete its life cycle.
In simple terms
Lenacapavir targets the capsid, the protein shell protecting HIV's genetic material. The capsid must be strong enough to shield the virus as it enters a cell, but flexible enough to open at the right moment so the virus can release its genes. Lenacapavir interferes with both steps: it makes the capsid too stiff to disassemble when it needs to, and stops new capsids being built correctly when the virus tries to make copies of itself. Because it works on a part of HIV other medicines do not target, lenacapavir remains active even when the virus has become resistant to other drug classes. It is given by injection under the skin every six months after an initial oral loading dose.
In depth
Lenacapavir (GS-6207) is a first-in-class small molecule that binds at the interface between capsid protein (CA) monomers, modulating capsid function at multiple stages of the HIV-1 life cycle. It interferes with capsid uncoating by stabilising the assembled lattice, blocking release of the viral core into the cytoplasm, and it also disrupts capsid assembly during viral maturation by promoting mis-assembly of the new capsid. The compound shows low nanomolar antiviral activity against HIV-1 group M subtypes and retains activity against viruses resistant to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors, integrase inhibitors, and entry inhibitors. The long-acting subcutaneous formulation maintains therapeutic concentrations for approximately six months.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
HIV carries its genetic material inside a protein shell shaped like a soccer ball.
- Lenacapavir targets the capsid, the protein shell protecting HIV's genetic material.
- The capsid must be strong enough to shield the virus as it enters a cell, but flexible enough to open at the right moment so the virus can release its genes.
- Lenacapavir interferes with both steps: it makes the capsid too stiff to disassemble when it needs to, and stops new capsids being built correctly when the virus tries to make copies of itself.
- Because it works on a part of HIV other medicines do not target, lenacapavir remains active even when the virus has become resistant to other drug classes.
Target: HIV-1 capsid protein (CA)
The protein that forms the conical capsid shell enclosing the viral RNA genome; the capsid protects the genome during entry, assists reverse transcription, and controls the timed release of viral DNA into the nucleus.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in European Union
EMA- Sunlenca injection, in combination with other antiretroviral(s), is indicated for the treatment of adults with multidrug resistant HIV-1 infection for whom it is otherwise not possible to construct a suppressive antiviral regimen
- Sunlenca tablet, in combination with other antiretroviral(s), is indicated for the treatment of adults with multidrug resistant HIV-1 infection, for oral loading prior to administration of long-acting lenacapavir injection
Approved uses in United States
MedlinePlus- Used to treat human immunodeficiency virus (HIV) infection
- Also used along with practicing safer sex to reduce the risk of HIV infection
- Lenacapavir is in a class of medications called HIV capsid inhibitors; it works by decreasing the amount of HIV in the blood
Official sources
The statements on this page trace back to these records.
- Sunlenca (lenacapavir) — Summary of product characteristics and package leaflet, English version
European Medicines Agency
- MedlinePlus: lenacapavir
MedlinePlus, U.S. National Library of Medicine
- Emc SmPC: Lenacapavir (UK licensed product)
Medicines and Healthcare products Regulatory Agency (EMC)
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.