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Novel vaccine approach halts disease after 23 years of breast cancer



A woman who had breast cancer for 23 years, and who had gone through 12 different lines of therapy, has shown a dramatic response to a novel cancer vaccine in a clinical trial.

A recent 6-month follow-up showed no evidence of new or recurrent disease, and scans showed regression of a distant bulky left adrenal metastasis, as well as at other sites.

A small site of residual hypermetabolism remains in the sternum, but this is thought to be related to scar tissue.

The patient, Stephanie Gangi, told Medscape Medical News that, before she entered into the trial for the novel cancer vaccine, she was “mentally and physically exhausted.” She had benefited from being diagnosed with hormone-positive breast cancer just as its treatment was evolving and progressing, which meant that, every time a treatment failed, “there was the next thing to try, which was great and kept me going.”

“But I will admit that, by age 66, and more than 20 years of cancer treatments, I was exhausted.”

Ms. Gangi, a New York City-based poet, essayist, and fiction writer, said she was “cautiously optimistic” about the cancer vaccine, but the “overriding thought was I wanted to avoid chemotherapy.”

“I was not really signing on for great outcomes, I was signing on for something that might keep chemo at bay. The biggest impact so far for me has been that, for the first time in more than a decade, I am not on any medication. That’s really amazing…and that means no side effects,” she said.

Ms. Gangi stopped the vaccine treatment this past July, and just over 3 months later, she is still “wrapping her head around” the fact that her cancer has regressed. “I’ve had breast cancer a long time,” she said, “and you can’t just snap your fingers and be fine.”

Although the two scans that she has had since the trial ended have been “astonishing,” she underlined that this is not about a ‘cure,’ but rather “clearing tumors for the first time in many years.”

“Cancer is sneaky and sinister, and it figures out how to circumvent all kinds of treatments,” she said, adding nevertheless that she is “happy and hopeful, and my family is thrilled, of course.”

Ms. Gangi was classed as having had a partial response to the cancer vaccine, one of a few in a small phase 1/2 trial at the Icahn School of Medicine at Mount Sinai in New York. One other patient also had a partial response, and one patient had a complete response.

However, six patients have progressive disease, and one has stable disease.

These results come from an interim analysis of 10 patients from the trial, and show a 30% response rate. They were presented at the recent annual meeting of the Society for Immunotherapy of Cancer.

The vaccine that was being tested combines local low-dose radiation, intramural Flt3L, which stimulates dendritic cells, and intravenous poly-ICLC, an immune stimulating factor, with the PD-1 inhibitor pembrolizumab (Keytruda).

The result is that, instead of making a vaccine in a laboratory and administering it, “we’re actually formulating it within the body,” lead author Thomas Marron, MD, PhD, professor of medicine (hematology and medical oncology) at Mount Sinai, said in an interview.

“What people don’t realize,” he said, is that bulky tumor sites contain “a lot of dead tumor, because they grow so fast and in a haphazard way.” This means that the immune system can be recruited to recognize the dead tumor and “gobble up the dead stuff that’s already there,” he added.

The hope is that the immune system will then kill not only “the tumor you are injecting into, but also tumors elsewhere in the body,” Dr. Marron said. “So you’re basically using your body’s own immune system and on and off switches to vaccinate the patient against their cancer.”

Another patient in the trial who had a complete response to the vaccine was William Morrison, with non-Hodgkin lymphoma (NHL).

Mr. Morrison was diagnosed in 2017, at which time he was enrolled onto a phase 1 trial of an earlier version of this novel vaccine treatment regimen. “Basically, they didn’t get the results they were hoping for, and I still had the lymphoma,” he said. In 2018, his indolent follicular lymphoma transformed into an aggressive diffuse large B-cell lymphoma, for which Mr. Morrison was given six cycles of chemotherapy. This put him into remission and cleared his lymphoma.

“But the remission lasted for maybe a little over a year,” he said.

The cancer came back, and at that point he was given the opportunity to enroll in the Mount Sinai trial. At the end of the treatment, “everything was clear.”

“I’ve been for PET scans every 6 months, and I just had a scan done the other week, and everything has been fine…I’ve been pretty excited. I was pretty lucky.”

“This recent one really has worked wonders,” he said, “When they gave me the good news the other day. I felt like a big weight had been lifted.”

Mr. Morrison also said that he did not experience any serious adverse events while being treated with the vaccine. “Other than a few minor things, I tolerated it pretty well,” he said.

In contrast, Ms. Gangi said she experienced “intense” flu-like symptoms that started in the first few days after the treatment and lasted for a couple of days.


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