Can a vaccine treat cancer?
That’s the question behind new clinical tests, soon to begin at Buffalo’s Roswell Park Cancer Institute.
The medicine in question is not your average vaccine: Each dose is customized for each cancer patient.
Researchers will draw healthy cells from each study participant, attach a specialized protein in a sterile lab environment and then inject the mixture, now known as a dendritic cell vaccine, back into the body.
“You can see that these cells now come back. They have memory. They’re able to remember that cancer cells are bad. They need to be destroyed. They need to be killed,” says Kunle Odunsi, chair of the Department of Gynecologic Oncology.
Gatekeepers
Dendritic cells are the “gatekeepers of the human immune system, defending against invaders like bacteria, viruses and cancer,” Odunsi explained at a press conference at Roswell Tuesday.
While some vaccines pairing dendritic cells with medicines are already under development, Roswell’s clinical trials are the first to use rapamycin, traditionally used to prevent donated organ rejection.
Early pre-clinical trials have shown promise that the dendritic/rapamycin mixture can eradicate cancer and prevent relapses. While initial tests are limited, the results are prompting researchers to dream big in terms of the many different varieties of cancer the vaccine could treat.
“Types such as ovarian, breast, bladder, kidney, melanoma, lungs, gastrointestinal cancers and so on will all be potentially eligible,” Odunsi says.
“Several steps forward”
About 20 cancer patients will participate in the FDA-approved Phase I trials over the next few years, which will primarily look for safety issues. If those tests pass muster with the FDA, then it’s on to Phase II, which will look at how effectively the medicine achieves what it sets out to do. In this case, that’s cure cancer.
“Of course the hope is a complete cure. But right now we’re looking at safety and efficacy is,” says Chris Choi, director of Roswell’s Therapeutic Cell Production Facility. “We’re not saying that this is the end all. This is just one road for us.”
A similar cancer fighting approach employing dendritic cells has worked well with prostate cancer. The drug Provenge uses a patient’s own immune system to prolong life in terminally ill prostate cancer sufferers.
“[Provenge] clearly improves survival. But there’s a long way to go to optimizing that approach. The proof of principle has been established in human beings,” says Donald Trump, CEO of Roswell Park. “And this trial will be several steps forward in advancing treatment of established disease, high risk patients and conceivably in the future, a preventive strategy.”
Completing Phase I clinical trials of the yet-unnamed cancer vaccine could take years.
