Nov. 9, 2011 -- A new approach to treating cancer appears to help certain patients with advanced lung cancer, and researchers say they think they may have a way of spotting those who will benefit.
The small study is generating big excitement in the world of cancer treatment because it demonstrates that so-called epigenetic drugs may work when traditional chemotherapy has failed.
Epigenetic drugs work by controlling gene expression -- the way information from genes is used to create products such as proteins.
The study is published in Cancer Discovery.
"This is a ... groundbreaking study, showing that by modifying the epigenetics of a cancer cell we can get real responses in lung cancer," said Jeffrey A. Engleman, MD, PhD, director of thoracic oncology at Massachusetts General Hospital, in Boston, in a news briefing. "And getting real responses in lung cancer is actually quite difficult, so we take special notice of therapies that can do this." He was not involved in the research.
All 45 patients recruited for the study had non-small-cell lung cancer, the leading cancer killer in the U.S.
All had tumors that had spread beyond their lungs despite treatment with an average of three other therapies.
"These are patients with very advanced disease" who have little chance of survival, says study researcher Charles Rudin, MD, PhD. He is professor of oncology and associate director for clinical research at Johns Hopkins University Kimmel Cancer Center in Baltimore.
Rudin says that he has consulted for Syndax Pharmaceuticals, the company that makes one of the drugs tested in the study.
Most patients with cancer this advanced are only expected to survive for about four months, the researchers note.
After treatment with a combination of the medications Vidaza, which is FDA approved to treat certain rare blood disorders, and the experimental pill entinostat, however, the average survival for the entire group was 6.4 months.
Doctors who wrote an editorial on the study note that this result was just shy of the same average survival (6.7 months) seen in patients treated with Tarceva, the only medication that's approved to treat patients with non-small-cell lung cancer that has spread to other organs.
The figure from the new study, however, included 11 patients who dropped out of the study before finishing a single cycle of treatment.
Among patients who finished at least one full treatment cycle, the average survival was even higher, about 8.6 months.
What's more, four of 19 patients who got chemotherapy after the experimental drug combo had dramatic responses to those treatments, "raising the hypothesis that maybe the epigenetic therapy is in some way priming the tumor for response to chemotherapy," Rudin says.
In total, seven patients who took part in the trial are still alive; two have survived for more than four years.