Rationale for and conduct of a phase I clinical trial with interferon alfa-2b plus doxorubicin.

A human tumor cloning system was utilized to screen for the antitumor activity of recombinant interferon alfa-2b (Intron A) alone and in combination with standard antineoplastic agents. These in vitro studies confirmed synergistic effects of alfa-2b plus doxorubicin against primary human tumors. Based on those in vitro findings, a phase I study has been conducted by Sarosy and colleagues that demonstrated that recombinant interferon alpha-2b and doxorubicin could be given together. Myelosuppression was the dose-limiting toxicity. Because responses were noted in the phase I trials with the combination, phase II trials of the combination are warranted. Additional phase I studies that should be pursued include recombinant interferon alpha-2b plus 5-fluorouracil, interferon plus cisplatinum, and interferon plus DTIC.