Personalized Immunotherapy Packs a Punch

In a recent clinical trial, more than half of the terminal cancer patients participating have experienced significant shrinking of their tumors, and in some cases, their complete disappearance. The new class of immunotherapy drugs appears likely to be a game changer for cancer sufferers. The research was announced at the recent annual conference of the American Society of Clinical Oncology where it was described as "spectacular."

The researchers believe that this immunotherapy can help even terminally ill patients with common, deadly forms of cancer like bowel, lung, ovarian and uterine-saving them from the pain and discomfort of chemotherapy, and perhaps even curing them.

Peter Johnson, a Cancer Research UK Professor of Medical Oncology, said these therapies function by by "re-educating" the immune system. "The evidence emerging from clinical trials suggests that we are at the beginning of a whole new era for cancer treatments," Johnson says, characterizing the treatments as among the greatest cancer treatment breakthroughs in forty years.

"Some of the most common types of cancer seem to be treatable with immunotherapy. Overall, cancers of the lung, kidney, bladder, head and neck, and melanoma cause about 50,000 deaths a year, or around one third of cancer deaths."

In one British study, 58 per cent of advanced melanoma patients experienced significant reduction of their tumors under treatment with immunotherapy drugs nivolumab and ipilimumab in new combinations. For example, the combined results of both were three times more effective than those of iplimumab alone.

More than ten percent of those studied saw tumors disappear entirely. Compared to the nine months these patients would typically have undergoing standard treatments, about half of them would be disease-free after immunotherapy.

Roy Herbst, Yale Cancer Center chief of medical oncology, comments on the results. "I think it's huge," Herbst says. "I think we are seeing a paradigm shift in the way oncology is being treated."

"I'm seeing this work in almost every cancer. The potential for long-term survival, effective cure, is definitely there."

Lead author Dr James Larkin, consultant medical oncologist at the Royal Marsden Hospital, said he was excited about the prospects of the new treatments.

"We've seen these drugs working in a wide range of cancers and I think we are at the beginning of a new era of treating cancer," Larkin says.

Scientists believe that these new treatments may soon take the role as the mainstream for cancer treatment. One of the reasons they are so successful is that they assist the natural immune response of the body.

"Cancers develop because they manage to hide from the immune system and disguise the danger they pose. Immunotherapy works by making the cancer visible again and alerting the body's immune system to the danger," Johnson says.

The immune system is your body's first line of defense against infections, but our bodies protect themselves by preventing the system from attacking the body's own tissues. Cancer exploits this, getting around the body's natural immune responses.

"By giving these drugs together you are effectively taking two brakes off the immune system rather than one so the immune system is able to recognize tumors it wasn't previously recognizing and react to that and destroy them" Larkin says. "For immunotherapies, we've never seen tumor shrinkage rates over 50 percent so that's very significant to see."

Although all the investigators involved with the results are very optimistic, Dr. Larkin adds, "We hope these early responses will turn out to be durable, but at the moment we can't say."

Side-effects with the medications can be significant for some patients, and thus far researchers are not sure why some people see far more impressive benefits from the treatments than others.

Dr. Alan Worsley, senior science research officer for Cancer Research UK, commented to BBC: "This research suggests that we could give a powerful one-two punch against advanced melanoma by combining immunotherapy treatments.. . .But combining these treatments also increases the likelihood of potentially quite severe side effects. Identifying which patients are most likely to benefit will be key to bringing our best weapons to bear against the disease."