Interferon Alfa-2b — Drug Monograph

Brand names: Intron A

Drug class: Immunomodulatory Agent

Mechanism of Action

Recombinant type I interferon that binds to type I interferon receptors, activating the JAK-STAT pathway and inducing expression of interferon-stimulated genes. Produces antiproliferative, antiviral, and immunomodulatory effects — enhancing NK-cell and T-cell activity, upregulating MHC expression, and modulating cytokine responses. In oncology it exerts direct antiproliferative effects on tumor cells and augments antitumor immune surveillance.

FDA Indications

• Malignant melanoma — adjuvant therapy in patients at high risk for recurrence after surgical resection
• Hairy cell leukemia
• Follicular non-Hodgkin lymphoma (in combination with chemotherapy)
• AIDS-related Kaposi sarcoma
• Condylomata acuminata, chronic hepatitis B and C (non-oncologic indications)

Common Side Effects

• Flu-like symptoms (fever, chills, myalgia, fatigue)
• Headache
• Anorexia/weight loss
• Nausea
• Depression and mood changes
• Injection-site reactions
• Elevated liver enzymes
• Neutropenia

Clinical Pearl

Once the backbone of adjuvant high-risk melanoma therapy, high-dose interferon alfa-2b has largely been supplanted by checkpoint inhibitors (e.g., pembrolizumab, nivolumab) and BRAF/MEK-targeted adjuvant therapy, which are better tolerated and more effective. Depression and flu-like symptoms are dose-limiting; screen for psychiatric history and pretreat with acetaminophen.

Related Therapies & Mechanisms

• Lenalidomide (Revlimid) — Immunomodulatory Agent
• Pomalidomide (Pomalyst) — Immunomodulatory Agent
• Thalidomide (Thalomid) — Immunomodulatory Agent
• Binimetinib (Mektovi) — Melanoma