A pilot study published in the journal Science Translational Medicine shows promising results for a personalized vaccine designed to treat ovarian cancer, almost doubling the number of patients who survived to the two-year mark.
Every year, roughly 22,000 women in the US are diagnosed with ovarian cancer; a type of cancer that is notoriously difficult to detect and treat because it is so often symptomless in the early stages.
Medics usually recommend a combination of surgery and chemotherapy, but while patients often notice a positive response to begin with, the majority of patients relapse and develop a resistance to chemotherapy. Of those 22,000 women diagnosed with cancer, 14,000 (64 percent) will probably die as a direct result of the disease.
So researchers at the Ludwig Institute for Cancer Research turned to an innovative new solution: personalized vaccines.
The custom-made vaccine is produced from a piece of the patient's tumor and a sample of the patient's immune cells. The immune cells are first extracted from a blood sample. Then they are trained to attack and "gobble up" any strange-looking organic matter and deliver these toxins to the T cells to stimulate an immune response.
The vaccine has been tested in an (admittedly small) clinical trial consisting of 25 women. While larger, randomized, and placebo-controlled trials will have to take place before it can be made available to members of the public, the results so far are extremely encouraging.
One year after treatment, 100 percent of patients given the vaccine in tangent with traditional immunotherapy drugs (bevacizumab and cyclophosphamide) were still alive compared to 60 percent of those who had received the drugs only. The following year, women who had been given the vaccine were almost two times more likely to have survived than those who had not – 78 percent versus 44 percent.
"This is the first time ever that a personalized vaccine made from the contents of whole cancer cells has been shown to produce immune responses against neoantigens [randomly mutated proteins not yet detected by the immune system]," Lana Kandalaft, an adjunct researcher at Ludwig Lausanne, said in a statement. "We've also shown that these immune responses are not just any responses, but the type that kill tumor cells, and that they correlate with better progression-free survival and better overall survival of patients."
The researchers add the vaccine is well tolerated by patients, easy and safe to administer, and can be produced in sizable enough quantities.
"We aren't giving patients any completely new drugs in combination with this personalized vaccine," Kandalaft added. "Bevacizumab and cyclophosphamide are routinely used to treat recurrent ovarian cancer. All we did was add the vaccine. This means that we should be able to easily integrate this personalized immunotherapy into the current standard of care for recurrent ovarian cancer [once it passes larger clinical trials]."
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