SAN FRANCISCO—GVAX, an autologous cancer vaccine, demonstrated antitumor activity in non-small-cell lung cancer (NSCLC) patients in a phase I/II multicenter clinical trial. Interim data were presented at the 37th Annual Meeting of the American Society of Clinical Oncology (ASCO abstract 1019).

Metastatic tumors disappeared completely in 3 of 22 patients who had previously failed radiation therapy and/or chemotherapy for advanced-stage lung cancer. Another patient had a tumor reduction of more than 50%, for an overall response rate of 18%. Two patients had a mixed response, and four had stable disease at a median follow-up of 5 months.

Among eight early-stage lung cancer patients who received the vaccine after surgery, seven were disease free at a median follow-up of 7 months. The eighth patient died.

"It was a fairly substantial response rate, which surprised us all," said Kristen Hege, MD, senior director of clinical research for Cell Genesys, Inc., Foster City, California. John Nemunaitis, MD, of US Oncology, Dallas, was lead author of the study, which was presented at a poster session.

GVAX has already met the main objectives of the ongoing trial, Dr. Hege said. It has been shown to be feasible as an antitumor agent, and, so far, no dose-limiting toxicities have been observed.

The most common adverse events were flu-like symptoms in some patients and a vaccine-site reaction observed in 92% of patients. "These were typical vaccine-site reactions—redness, itching, swelling—similar to what you see with an insect bite," she said. "And that’s an encouraging side effect because it implies we are inducing an immune response at the vaccine site."

GVAX vaccines are also being evaluated for prostate cancer, myeloma, pancreatic cancer, and leukemia.