Vaccine Promising In Subset Of Lung Cancer Patients

VIENNA (Reuters Health) -A liposomal MUC1 cancer vaccine tested in non-small cell lung cancer appears to be most effective in patients with locally advanced/locoregional disease, a Canadian researcher reported Monday at the 29th European Society of Medical Oncology Congress.

That's the result of a subset analysis of a 17-center phase IIB trial involving 171 patients with stage III or IV disease, said Dr. Charles Butts, medical oncologist at the Cross Cancer Institute in Edmonton. Earlier results indicated an overall survival benefit of 4.4 months for patients in the trial receiving the vaccine.

Dr. Butts said 60% of the stage IIIB patients on vaccine were alive at 24 months compared with 36.7% of controls. "That seems to be where the big improvement is," he said. He described the findings as a "hypothesis generating result," that he hopes to test on a larger group of IIIB patients, where disease has not spread beyond the chest.

In the control arm, 83 patients with stable or responding stage IIIB or IV non-small-cell lung cancer after chemotherapy received the best available supportive care. Eighty-eight were also treated with the vaccine, called L-BLP25. The vaccine is given weekly subcutaneously for 8 weeks, followed by boosters every 6 weeks.

Overall, the median survival time was 17.4 months for those who received the vaccine, compared with 13 months for those who were treated with best supportive care. Among patients with locoregional disease, the median survival in the supportive care patients was 13.3 months. The median survival in patients receiving vaccine has not been reached. The longest a patient has been receiving vaccine in this trial is 43 months.

"These favorable results seen in the locoregional patients have encouraged us to proceed with plans for a more definitive phase III trial in this specific population of patients," Dr. Butts said.

The research was undertaken with Biomira Inc. of Edmonton, Canada, and Merck KGaA of Darmstadt, Germany. They plan to start the phase III trial next year.

In September 2004, the U.S. Food and Drug Administration granted the vaccine fast-track status, Merck reported.

If the results are confirmed, it would be the first vaccine to work in lung cancer, and the first to work in such a commonly occurring cancer. In theory at least, he said, the vaccine ought to work as well in stage I and II lung cancer, and all three stages represent about 50% of all lung cancer cases, which result in nearly 180,000 deaths in North American each year.

He said it would change the way lung cancer is treated. "There's no currently effective immunotherapy for lung cancer." Vaccine side effects are minimal, and include mild flu-like symptoms.

In particular, the vaccine was designed to induce an immune response to the abnormal MUC1 glycoprotein present on the surface of tumor cells. On tumor cells, the protein has truncated sugar side chains, which leave the underlying protein vulnerable to immune system activity. On normal cells, MUC1 sugar side chains are heavily branched, essentially shielding the protein component. So far, Dr. Butts said, there have been no reports of vaccine-stimulated autoimmune disease.

"The other thing that really has me excited, is if this is confirmed in non-small cell lung cancer, this MUC1 protein is present on a lot of cancer cells, not just lung cancer. It's present on cancers of the breast, colon, prostate, and multiple myeloma. It has potential applications for other tumors in general."

MeSH Headings: Behavioral Sciences : Clinical Trials : Congresses : Data Collection : Demography : Behavioral Disciplines and Activities : Health Care Economics and Organizations : Environment and Public Health : Epidemiologic Methods : Evaluation Studies : Health : Health Occupations : Health Services Administration : Information Science : Lung Neoplasms : Medicine : Investigative Techniques : Mortality : Neoplasms : Neoplasms by Site : Organizations : Population Characteristics : Preventive Medicine : Public Health : Quality of Health Care : Recombinant Proteins : Respiratory Tract Neoplasms : Social Sciences : Specialties, Medical : Thoracic Neoplasms : Vaccines, Synthetic : Vital Statistics : Epidemiologic Measurements : Survival Rate : Epidemiologic Study Characteristics : Clinical Trials, Phase II : Health Care Quality, Access, and Evaluation : Health Care Evaluation Mechanisms : Cancer Vaccines : Analytical, Diagnostic and Therapeutic Techniques and Equipment : Anthropology, Education, Sociology and Social Phenomena : Biological Sciences : Diseases : Health Care : Information Science : Psychiatry and Psychology