A human IgG1 monoclonal antibody directed against interleukin-1 alpha (IL1a) with potential antineoplastic activity. Anti-IL-1 alpha monoclonal antibody MABp1 binds to IL1a and may prevent IL 1a activity. In addition, this agent may induce antibody-dependent cellular cytotoxicity (ADCC) or complement-mediated killing (CMK). IL 1a, an inflammatory mediator, plays a key role in interleukin-mediated tumor cell activity such as metastasis and tumor cell invasion.