Biotherapy in clinical practice.

The interferons are the first of a new class of biologic response modifiers that include, among others, the interleukins, colony-stimulating factors, erythropoietin, additional growth factors, and monoclonal antibodies. Interferons have exhibited important clinical activity in hematologic malignancies, lymphomas, and solid tumors. Specific diseases responding to interferons include hairy-cell leukemia (HCL), chronic myelogenous leukemia (CML), low-grade non-Hodgkin's lymphoma, cutaneous T-cell lymphoma, multiple myeloma, superficial bladder carcinoma, malignant carcinoid, acquired immunodeficiency syndrome (AIDS)-related Kaposi's sarcoma, ovarian carcinoma, renal cell carcinoma, and malignant melanoma. The potentially antigenic nature of the recombinant interferons can result in the formation of antibodies. These antibodies have been associated with the abrogation of some of the clinical responsiveness of some patients treated with interferons. It is hoped that the controversy existing over the role of antibody formation in treatment efficacy can be resolved by prospective trials using standardized methodology in such areas as assay type, sampling time, route of drug administration, treatment schedule, cumulative dose, and duration of treatment.