Use of interferon in the treatment of ovarian cancer as a single agent and in combination with cytotoxic drugs.

In vitro studies have shown that human ovarian cancers are sensitive to the antiproliferative effects of recombinant human alpha interferon. The degree of anticellular effect is related to the concentration of interferon achieved and to the duration of tumor cell exposure. In a clinical setting, the highest levels of interferon that can be achieved are seen when interferon is given by the intraperitoneal route. One Phase I clinical trial of intraperitoneally administered alpha interferon has shown complete (CR) and partial responses (PR) in 5 (45%) of 11 patients, each response determined by surgical re-exploration. The most favorable patient group for the tumor responses was the one having residual tumor bulk less than 5 mm in size. Combinations of interferon and standard cytotoxic drugs have been studied both in preclinical and clinical trials. One of the most active combinations is that of alpha interferon plus doxorubicin, which often shows an additive and occasionally synergistic combined effect. In a Phase II clinical trial of combined parenterally administered alpha interferon and doxorubicin, clinically determined CR and PR were seen in 7 (29%) of 24 patients with relapsing ovarian cancers. In this preliminary clinical trial, toxicity of the combination regimen was acceptable.