The death of Houston neurosurgeon Samuel Hassenbusch from the brain cancer he treated has been one of 2008's sadder stories. But there's good news about the experimental treatment that he pioneered.
In study results to be presented next week at an annual meeting of cancer doctors, Hassenbusch's treatment — chemotherapy and a new vaccine — significantly prolonged survival of patients with glioblastoma, the most common and aggressive brain cancer.
Sen. Edward Kennedy was diagnosed with the disease last week.
"I'm biased, but this is some of the best data we've ever seen," said Dr. John Sampson, a Duke University neurosurgeon and the principal investigator of the study, conducted at the University of Texas M.D. Anderson Cancer Center and Duke. "It appears very promising for a cancer where there's been little hope."
The trial's big surprise was that the chemotherapy didn't stop the vaccine from prompting a strong immune response and instead enhanced it. Because chemotherapy kills patients' white blood cells, it is usually considered incompatible with vaccines or, as they're also known, immunotherapy.
Glioblastoma kills nearly 10,000 Americans annually, a majority within the first 15 months after diagnosis, largely because of tentacle-like cells that creep into the brain from the main mass.
Hassenbusch, an M.D. Anderson professor of neurosurgery and a pain control expert who treated more than 500 brain cancer patients, was diagnosed with the disease in 2005. After surgery and follow-up radiation, he and his doctors decided to combine Temodar, the now-standard chemotherapy, and the vaccine, until then only used alone.
Hassenbusch became the first patient in the M.D. Anderson-Duke trial.
In all, the study enrolled 23 patients between 2005 and 2007. It was only open to those with a particular protein — present in one-third to two-thirds of glioblastomas — and those who were tumor free after surgery and radiation.
Kennedy's tumor is thought to be inoperable.
The study found the average time for recurrence of the tumor was 16.6 months, up from the previous six months. The time of survival was also up significantly from the previous average of 14 months, said Sampson, who declined to reveal the exact number until he presents the data June 2 at the American Society of Clinical Oncology meeting in Chicago.
Under the trial protocol, some patients received Temodar for the first five days of the month, and some received it for the first 21 days. On the 21st, all received the vaccine, which signals the immune system to destroy the cancer. Without the vaccine, the immune system doesn't recognize glioblastoma.
Almost all the patients mounted an immune response. The response was better with the highest dose of Temodar.
"I think Sam would be pretty excited about these results," said Dr. Mark Gilbert, an M.D. Anderson professor of neuro-oncology whose study of Temodar enrolled some 1,150 patients, the most ever in a brain cancer trial.
Gilbert cautioned that the study results are preliminary. He noted the impressive results could be the result of cherry-picking patients, accepting only those whose tumors had been excised by surgery and radiation.
To resolve that possibility, a new trial is under way at 20 cancer centers, including M.D. Anderson, dividing such patients into a group that gets just Temodor and a group that gets the combination therapy.
Also on tap is a trial adding a third drug — Avastin, a targeted therapy that starves tumors by stopping them from building blood vessels that supply them with nutrients — to the regimen.
For one patient in the study, the Temodar-vaccine combination by itself has worked fine.
"Doctors originally gave me six to eight months to live when I was diagnosed with glioblastoma," said Barbara Derenowski, 69, of Surprise, Ariz., a retirement community northwest of Phoenix. "But two years later, I'm in good shape, living a normal life and still returning cancer-free scans every month, thanks to this trial. I hope it becomes available to more people."
Hassenbusch lived almost three years after his diagnosis. He appeared to be beating the cancer with the combination therapy. But in May 2007, the cancer returned and this February claimed his life.