Dr. Mersad Alimoradi 02 Mar 2023

The human immunodeficiency virus (HIV) is a virus that impacts the body’s immune system. It can cause acquired immunodeficiency syndrome (AIDS) if left untreated.

Without treatment, AIDS can lead to opportunistic infections, tumors, and death in HIV patients.

Despite the antiretroviral treatments available for HIV, many patients cannot reduce the blood levels of the virus because of multidrug resistance, which decreases the efficacy of the current HIV medications.

Recently, the FDA approved a new HIV medication called Lenacapavir (Sunlenca) to treat patients with multidrug-resistant HIV. 

Lenacapavir (Sunlenca) is a capsid inhibitor that can block the replication of HIV. In clinical trials, this drug, in combination with other antiretroviral medicines, reduced the viral load to undetectable levels in more than 80% of patients with drug-resistant HIV after only 26 weeks.

Continue reading to learn more about HIV and Lenacapavir, the newest treatment for drug-resistant HIV infections that do not respond to traditional antiretroviral therapy drugs. 

What Is HIV?

The human immunodeficiency virus (HIV) is a virus that attacks the infection-fighting CD4 cells of the immune system, which reduces the body’s ability to fight off infections and diseases. 

HIV belongs to a class of viruses called retrovirus which use RNA rather than DNA to encode their genetic information.

HIV can be transmitted sexually with an infected person or by sharing contaminated needles or syringes while injecting drugs. Moreover, pregnancy, childbirth, and breastfeeding can transfer the human immunodeficiency virus from the mother to the baby.

Without treatment, HIV can progress and cause acquired immunodeficiency syndrome (AIDS), the most severe stage of HIV infection. People with AIDS have severely damaged immune systems, which makes them vulnerable to infections and serious illnesses. People with AIDS usually survive around three years without HIV treatment.

How Do You Treat HIV?

Currently, there is no cure for HIV. People who get it have it for life. However, there are effective antiviral treatments for HIV that can limit the progress of the disease, prevent AIDS, and help people with HIV live long, healthy lives without spreading the virus to their partners.

Antiretroviral therapy (ART) are medications that can control HIV and prevent associated complications. Anyone with HIV should begin treatment immediately after diagnosis, regardless of how healthy they are or how long they have had the virus.

HIV destroys immune cells called CD4 T lymphocytes, making it difficult for your body to fight off infections. When the body has a high viral load (a high blood level of HIV), it cannot produce enough CD4 cells to compensate for the ones the virus has destroyed.

Antiretroviral therapy involves a combination of anti-HIV drugs that can prevent the virus from replicating (making copies of itself). That helps reduce the levels of HIV in the body (the viral load).

The fewer copies of HIV you have, the more time your immune system has to recover and produce more CD4 cells. Although you would still have HIV, your immune system will be strong enough to protect your body against infections and keep you healthy.

ART therapy also reduces the risk of HIV transmission by reducing the amount of HIV in the body. The patient has no risk of transmitting HIV to their partners sexually when his or her level of HIV in the blood becomes so low that it cannot be detected by a viral load test (undetectable viral load).

There are three classes of antiretroviral therapy drugs, including:

  • Nucleoside reverse transcriptase inhibitors (NRTIs): These medications block an enzyme called nucleoside reverse transcriptase, which HIV needs to convert its RNA into DNA and replicate in the body.
  • Protease inhibitors (PIs): These drugs block another enzyme called protease, which helps HIV to make copies of itself inside the body.
  • Fusion inhibitors: These medicines block the fusion of the HIV envelope with your body’s CD4 cells. That prevents HIV from entering and destroying the body’s immune cells.

Antiretroviral therapy usually combines two or more medications from different drug classes.

What Is Multidrug Resistant HIV?

Multidrug-resistant (MDR) HIV is a strain of HIV that has become resistant to all three classes of antiretroviral therapy drugs. People with MDR HIV do not respond well to the usual ART medications.

People can develop resistance to antiretroviral drugs because HIV can have mutations (changes in its genetic structure) that reduce the medicine’s ability to block the enzymes responsible for the replication of the virus. 

HIV patients can have resistance mutations to one, two, or all three ART drug classes. 

The Latest Treatment For Multidrug-Resistant HIV

The capsid (CA) protein is a protein shell that protects the virus’s genetic material and enzymes needed for replication. A class of medications known as capsid inhibitors can bind to the HIV’s capsid, disrupt it, and stop the virus from replicating.

Capsid inhibitors are an excellent treatment choice for patients with multidrug-resistant HIV. Scientists believe that the virus cannot develop mutations that would cause resistance to capsid inhibitors without damaging the fitness of the virus itself.

Lenacapavir (Sunlenca) is a first-in-class capsid inhibitor HIV treatment manufactured by the biopharmaceutical company Gilead Sciences. In December 2022, the FDA approved Lenacapavir as a treatment option for adults with multidrug-resistant HIV.

It is the first drug belonging to a new class of capsid inhibitors to become FDA-approved for the treatment of HIV.

It is a treatment administered twice yearly (given every six months) combined with other antiretrovirals to control HIV levels in MDR patients.

What Scientific Evidence Supports Lenacapavir?

The FDA approval for Lenacapavir (Sunlenca) is supported by Phase 2/3 CAPELLA trial data.

72 patients with HIV infections who were resistant to several types of HIV medicines participated in the multicenter clinical trial.

The patients had a high viral load (high levels of HIV in their blood) despite undergoing antiretroviral therapy (ART). Patients received either a placebo or Lenacapavir (Sunlenca) while continuing their previous antiretroviral therapy regimen.

During the first two weeks, 87.5% of patients who took Lenacapavir had a significant decrease in their HIV viral load. On the other hand, only 16.7% of those who took the placebo achieved a similar reduction in HIV levels.

After 26 weeks, 81% of patients who received Lenacapavir (Sunlenca) with other antiretroviral drugs achieved undetectable levels of HIV. This percentage increased to 83% after 52 weeks, proving that the new capsid inhibitor Lenacapavir (Sunlenca) can effectively suppress the HIV RNA.

Additionally, these participants achieved a significant increase in the levels of CD4 immune cells.

The most commonly reported side effects of Lenacapavir (Sunlenca) were the following:

  • Reactions at the injection site (swelling, pain, or redness at the injection site)
  • Nausea

Patients should not take Lenacapavir (Sunlenca) if they also take medications that reduce the levels of this capsid inhibitor drug because that can decrease its efficacy and lead to viral resistance.

The promising results make Lenacapavir (Sunlenca) a breakthrough HIV medication for people living with multidrug-resistant HIV that no longer responds to conventional antiretroviral medications. The drug signifies a potentially significant milestone that could curb or even end the HIV epidemic in the future. 

The drug manufacturer Gilead is currently studying the safety and efficacy of Lenacapavir for HIV prevention in multiple ongoing clinical studies.

To search for the best doctors and healthcare providers worldwide, please use the Mya Care search engine.

About the Author:
Dr. Mersad is a medical doctor, author, and editor based in Germany. He's managed to publish several research papers early in his career. He is passionate about spreading medical knowledge. Thus, he spends a big portion of his time writing educational articles for everyone to learn.


Disclaimer: Please note that Mya Care does not provide medical advice, diagnosis, or treatment. The information provided is not intended to replace the care or advice of a qualified health care professional. The views expressed are personal views of the author and do not necessarily reflect the opinion of Mya Care. Always consult your doctor for all diagnoses, treatments, and cures for any diseases or conditions, as well as before changing your health care regimen. Do not reproduce, copy, reformat, publish, distribute, upload, post, transmit, transfer in any manner or sell any of the materials in this blog without prior written permission from