Phase II trial of Serratia marcescens extract in recurrent malignant astrocytoma

Nineteen assessable patients with recurrent malignant astrocytomas who had failed standard therapy (surgery, radiation, and/or chemotherapy) were treated on a phase I-II trial with a biologic extract of Serratia marcescens (ImuVert; Cell Technology, Boulder, CO) a new biologic response modifier (BRM). Two complete responses (CRs) were seen, of 63 and 77 + weeks duration. One minor response (MR) occurred, of 6 weeks duration. There were four additional stable (S) patients, with durations of 58 +, 39, 12, and 7 weeks. Median time to progression and median survival in the CR plus MR patients were 63 and 129 + weeks, respectively. Overall, median time to progres-sion and median survival were 12 and 19 weeks, respectively. Three patients are alive ≥ 2.5 years from study entry. Common toxicities included transient (< 72 hours) tenderness, induration, and erythema at the injection sites. Systemic toxicities were less frequent and included fever, chills, nausea/vomiting, headache, arthralgia, and hypotension. The response rate (CR plus MR) to this new BRM is modest (16%). However, the observation of CRs in patients with advanced recurrent malignant astrocytomas, with acceptable overall toxicity, warrants further study of this agent.