Sunlenca

Indications for Use

Sunlenca is used to treat human immunodeficiency virus type 1 (HIV-1) in adults. It is specifically intended for people who meet the following criteria:

• They have already tried several other HIV medications.
• Their HIV infection can no longer be successfully treated with other available medicines because the virus has developed resistance to them.

This medication belongs to a class of drugs called HIV-1 capsid inhibitors. It works by interfering with the HIV capsid, which is the protein shell that protects the virus's genetic material, thereby blocking several steps of the viral life cycle.

Combination Therapy

Sunlenca is not used alone. It must be prescribed as part of a complete treatment regimen that includes other antiretroviral medications. Using it in combination helps to:

• Reduce the amount of HIV in the body (viral load).
• Increase the count of CD4 (T) cells, which help the immune system fight infections.
• Reduce the risk of complications related to HIV.

It is important to note that while Sunlenca helps manage HIV, it is not a cure for HIV infection or AIDS.

Mechanism of Action

Sunlenca (lenacapavir) belongs to a class of medications called HIV-1 capsid inhibitors. It works differently than many other antiretroviral drugs by targeting the HIV-1 capsid, which is the protective protein shell that surrounds the virus's genetic material.

By binding to this capsid, Sunlenca disrupts the HIV lifecycle at several different stages:

• Nuclear Uptake: It blocks the virus from transporting its genetic material into the nucleus of the host cell, a step required for the virus to replicate.
• Virus Assembly: It interferes with the process of building new virus particles within the host cell.
• Capsid Maturation: It prevents the virus from forming a functional shell. This results in the production of immature, non-infectious virus particles that cannot spread to other cells.

Because Sunlenca targets the virus in a unique way, it can be effective for individuals whose HIV has developed resistance to other types of HIV medications. When used in combination with other antiretroviral therapies, it helps lower the amount of HIV in the blood (viral load) and supports the immune system.

Common Side Effects

The most frequently reported side effects of Sunlenca include:

• Nausea
• Diarrhea
• Injection site reactions, such as pain, swelling, redness, itching, or the formation of small lumps (nodules) or hard areas (induration)

Lumps or nodules at the injection site are common and may take several months to resolve. In some cases, these nodules may be permanent.

Serious Side Effects

While less common, some side effects can be serious. You should contact a healthcare provider if you experience:

• Immune Reconstitution Inflammatory Syndrome (IRIS): This occurs when the immune system becomes more active after starting HIV treatment and begins to fight hidden infections, which can cause new or worsening symptoms.
• Severe injection site reactions: Seek medical advice if injection site lumps become severe or do not improve.
• Allergic reactions: Symptoms may include skin rash, hives, or swelling of the face, lips, or tongue.

Drug Interactions

Sunlenca should not be used with certain medications known as strong CYP3A inducers. These drugs can significantly decrease the levels of Sunlenca in the blood, making it less effective and potentially leading to drug resistance. Examples of medications to avoid include:

• Certain anticonvulsants (such as carbamazepine, phenytoin, or phenobarbital)
• Rifampin
• St. John's wort

Because Sunlenca stays in the body for up to six months after the last injection, new drug interactions can occur even after treatment has stopped.

Immune Reconstitution Inflammatory Syndrome (IRIS)

Some patients with advanced HIV-1 infection may experience Immune Reconstitution Inflammatory Syndrome. This occurs when the immune system becomes more active and begins to fight hidden or slow-growing infections that were already present in the body. This can lead to a sudden onset of inflammatory symptoms shortly after starting HIV treatment.

Injection Site Reactions

When administered as an injection, Sunlenca can cause reactions at the site of the shot. These reactions may include pain, redness, swelling, or the formation of hard lumps (nodules). In some cases, these nodules or masses may be felt under the skin for several months or longer.

Long-Acting Medication

Sunlenca is a long-acting medication. If the treatment is discontinued, it is important to start an alternative HIV treatment regimen within two weeks of the last missed dose to prevent the virus from becoming resistant to medications.

Pregnancy

There are no adequate studies on the use of Sunlenca in pregnant individuals to determine if there is a drug-associated risk of birth defects or miscarriage. In animal studies, no significant developmental issues were observed at doses much higher than those used in humans. Because Sunlenca stays in the body for a long time after the last dose, its effects during pregnancy may persist even after treatment is stopped.

If you are pregnant or planning to become pregnant, discuss the potential risks and benefits of this medication with your healthcare provider.

Breastfeeding

It is not known whether Sunlenca passes into human breast milk or if it affects a nursing infant. However, health experts generally recommend that individuals with HIV do not breastfeed to avoid the risk of transmitting the virus to the baby. Additionally, there is a risk that the infant could develop viral resistance if the medication is present in breast milk.

Available Forms

Sunlenca is provided in the following forms:

• Oral Tablets: These are taken by mouth, typically during the initial phase of treatment.
• Subcutaneous Injection: This is a long-acting formulation administered by a healthcare professional under the skin.

FDA Approval Status

The U.S. Food and Drug Administration (FDA) approved Sunlenca in December 2022. It is the first medication in a class of drugs known as capsid inhibitors to be approved for the treatment of HIV-1.

Approved Indications

Sunlenca is specifically indicated for adults with HIV-1 infection who meet the following criteria:

• They are heavily treatment-experienced, meaning they have a history of taking multiple HIV medications.
• Their HIV-1 infection is multi-drug resistant, making it difficult to treat with standard regimens.
• Their current antiretroviral treatment is failing due to resistance, safety concerns, or intolerance.

This medication is not a standalone cure or treatment; it must be used as part of a combination regimen with other antiretroviral drugs.

Regulatory Considerations

The FDA approval was based on clinical evidence showing the drug's effectiveness in reducing viral loads in patients who had exhausted other treatment options. There are currently no boxed warnings or Risk Evaluation and Mitigation Strategies (REMS) associated with Sunlenca. During the regulatory process, the FDA previously addressed concerns regarding the compatibility of the injectable formulation with certain glass vials, which was resolved prior to the drug's final approval and release.

Insurance and Prior Authorization

Sunlenca is a specialty medication used for adults with multi-drug resistant HIV-1. Most insurance providers require prior authorization, a process where your doctor must prove the medical necessity of the drug before the plan agrees to cover it. Your out-of-pocket costs, such as copays or coinsurance, will vary based on your specific insurance plan.

Cost of Administration

The total cost of treatment includes both the medication and its administration. Sunlenca involves two different forms of the drug:

• Initial Dosing: A series of oral tablets taken at the start of treatment.
• Maintenance Dosing: Subcutaneous injections administered by a healthcare professional every six months.

Because the maintenance doses must be given by a healthcare provider, you may incur costs for the healthcare provider's time and the medical facility in addition to the price of the drug itself.

Financial Support Options

Financial assistance may be available through the manufacturer for eligible patients. These programs often include copay cards for those with private insurance or patient assistance programs for those who are uninsured or have limited coverage. You can ask your healthcare provider or pharmacist for help identifying these resources.