Viral oncolysates in patients with advanced ovarian cancer

Viral oncolysates (VO) derived from two cultured ovarian carcinoma cell lines infected with influenza A/PR8/34 were administered intraperitoneally (IP) to 40 patients with advanced ovarian carcinoma, including 31 with late-onset ascites and 5 with pleural effusions. PR8 virus-specific antigens and ovarian tumor-associated antigens have been demonstrated on two oncolysates designated OVO1 and OVO2. Thirty-five patients received 9 mg of a 1:1 mixture of OVO1 and OVO2, 5 patients received one or the other. During the first month three IP schedules were evaluated, i.e., single, biweekly, and weekly, which were followed by monthly injections. Intrapleural (IP1) injections of a 3.0-mg 1:1 mixture of OV1 and OV2 were administered to 3 patients concurrently with initial IP injections and to 2 patients following later development of pleural effusions. In 7 patients ascites disappeared; in 5 of these the number of cytologically detected malignant cells was markedly reduced, in 1 pleural effusion disappeared, and in 3 tumor masses were reduced. Tumor masses shrank also in 2 patients without ascites. Tumor reduction conformed to standard response criteria in 2 of the 5 patients. Response duration in the 9 responding patients lasted from 3 to 19 months and survival durations 4 to 42 months. Disease symptoms in 7 patients improved noticeably. Two of the 9 responders later developed unilateral pleural effusions that responded for 7 and 15+ months to a single IP1 injection. Seventeen patients experienced one or more treatment side effects including fever, nausea or anorexia, malaise, abdominal pain, and arthralgia, but in only 2 patients, both on the weekly schedule, was toxicity severe enough to require treatment withdrawal. Humoral responses to viral and tumor cell-surface antigens were frequently observed in patients demonstrating clinical activity.