IRX-2 + cyclophosphamide

IRX-2 + cyclophosphamide is a combination therapy used primarily in investigational settings for cancer immunotherapy. IRX-2 is a primary cell-derived biologic containing physiologic levels of multiple T-helper type 1 cytokines (notably IL-2, IL-1β, IFNγ, and TNFα), produced by stimulating peripheral blood mononuclear cells from healthy donors. It acts on various immune cells—including dendritic cells, T cells, and NK cells—to enhance antitumor immunity and counteract tumor-induced immunosuppression. Cyclophosphamide is an alkylating agent that suppresses regulatory T-cell activity at low doses and can potentiate immune responses when combined with immunotherapies like IRX-2. This combination has been studied as part of a 21-day neoadjuvant regimen in head and neck squamous cell carcinoma (HNSCC) as well as in other solid tumors. The regimen typically includes low-dose cyclophosphamide administered on day 1 followed by subcutaneous injections of IRX-2 over several days[1][6][9]. Clinical trials have shown that this approach increases lymphocyte infiltration into tumors and may improve event-free survival rates[6]. The mechanism involves both direct cytotoxic effects from cyclophosphamide on tumor or regulatory immune populations and broad activation of antitumor immunity via the cytokine mixture in IRX-2[8].

Other names

IRX-2 regimen (when referring to the combination with cyclophosphamide and other agents)