Common brand names

• Pegasys

How it is administered

Pegylated interferon alfa-2a is given as a subcutaneous injection, which means it is injected under the skin, usually in the thigh or abdomen. It is available in single-dose vials and prefilled syringes, with common adult doses being 180 micrograms once weekly. The medication is colorless to slightly yellowish and should be visually inspected before use. Patients may be trained to self-inject at home after proper instruction from a healthcare provider.

How it works

Pegylated interferon alfa-2a is a modified form of a naturally occurring protein called interferon, which is produced by the body in response to infections. The 'pegylated' part means the molecule has been attached to polyethylene glycol, which helps it stay in the body longer, allowing for once-weekly dosing.

This medication works by stimulating the immune system to fight viruses and abnormal cells, such as cancer cells. It binds to specific receptors on the surface of cells, activating pathways inside the cell that help control the growth of viruses and cancer. These pathways can also increase the production of proteins that help the immune system recognize and destroy infected or abnormal cells. While pegylated interferon alfa-2a is mainly approved for certain viral infections, its immune-stimulating effects have been explored in blood cancers, including some lymphomas and leukemias.

Who should take it

Pegylated interferon alfa-2a is FDA-approved for the treatment of chronic hepatitis B and C, but it has also been used off-label in some blood cancers, including certain types of leukemia and lymphoma. In the context of blood cancers, it may be considered for patients with specific disease characteristics or when other treatments are not suitable.

For Adult T-cell Leukemia/Lymphoma (ATLL), pegylated interferon alfa-2a may be considered in select cases, often as part of a clinical trial or specialized treatment plan. It is important to discuss with your healthcare provider whether this medication is appropriate for your specific condition.

Who should not take it

You should not take pegylated interferon alfa-2a if you have had a severe allergic reaction to interferons or any component of the medication. It is also contraindicated in people with autoimmune hepatitis, severe liver disease (hepatic decompensation), or in neonates and infants due to the risk of serious complications from one of its ingredients (benzyl alcohol).

Additionally, if you are pregnant or planning to become pregnant, this medication (especially when used with ribavirin) can cause serious birth defects and should not be used. People with certain psychiatric, heart, or autoimmune conditions should use caution and discuss risks with their doctor.

Commonly used with

Pegylated interferon alfa-2a is often used in combination with other antiviral medications, such as ribavirin, for the treatment of hepatitis C. In the context of blood cancers, it may be combined with other chemotherapy or immunotherapy agents, depending on the specific disease and treatment plan.

If you are being treated for a blood cancer, your doctor will determine if pegylated interferon alfa-2a should be used alone or in combination with other drugs.

Commonly tested with

In clinical studies, pegylated interferon alfa-2a has been tested with ribavirin and other antiviral agents for hepatitis C. In blood cancers, it may be studied in combination with chemotherapy drugs or other immune-modulating agents.

If you are participating in a clinical trial, you may receive pegylated interferon alfa-2a with other investigational or standard treatments.