Introgen Therapeutics Inc announced the publication of data from its phase 2 study combining Advexin, an adenoviral vector containing the p53 tumor-suppressor gene, with radiation therapy. The study, treating patients with non-small cell lung cancer (NSCLC), showed that approximately 60% of patients' primary tumors regressed or disappeared after the combination therapy, as assessed by both biopsies and by CT scans three months after treatment. Moreover, Advexin administration did not appear to increase the side effects caused by radiation treatment. These data were published in the January 2003 issue of the journal Clinical Cancer Research.

The study was conducted at The University of Texas M.D. Anderson Cancer Center, under the direction of principal investigator Dr. Stephen Swisher, associate professor of thoracic and cardiovascular surgery.

"Locoregional control of lung cancer with radiation therapy alone is relatively poor," said Dr. Swisher. "These results suggest that Advexin may enhance the effect of radiation therapy at the local tumor site without significantly increasing toxicity. Further randomized trials are needed to follow-up on these observations," he continued.

The phase 2 clinical study enrolled non-metastatic patients with non-small cell lung cancer who were ineligible to receive surgery or combination therapy with radiation and cancer chemotherapy. Advexin was delivered via injection into the tumors, at a range of doses, over approximately one month. Radiation therapy began at the same time, but was completed over six weeks. Three months after treatment, examination of biopsies from the primary tumors showed no viable tumor cells in 63% of patients. Radiographic assessment of the primary tumor by CT scan likewise showed that 63% of patients had a major response (complete or partial response).