ANTIBODIES TO INTERFERON-ALPHA IN TREATED CANCER-PATIENTS - INCIDENCEAND SIGNIFICANCE

Antibodies to interferon-alpha (IFN-alpha) are found in some patients being treated with this cytokine. In studies in which two recombinant IFN-alpha preparations were directly compared in cancer patients, thos e given IFN-alpha 2a were found to have neutralizing antibodies in the ir serum significantly more often than those given IFN-alpha 2b (p<0.0 01). Patients who develop neutralizing antibodies are more likely to h ave a clinical relapse and to become resistant to further treatment wi th at least the IFN preparation initially used for their treatment. In 10 studies in cancer patients, such an outcome was found in 63% of th ose who developed antibodies but in only 13% of those who did not. The se data are tabulated.