The way doctors typically approach kidney cancer treatment could be evolving.
Two separate studies published Saturday in the New England Journal of Medicine showed that renal cell cancer patients had significantly better outcomes when their treatment combined the targeted therapy drug axitinib, or Inlyta, with an immunotherapy -- one study used pembrolizumab, or Keytruda, and the other used avelumab, or Bavencio.
"This is a proof of principle that we can do this if the drugs are in the same class and tolerated when combined," said Dr. Toni Choueiri, director of the Lank Center for Genitourinary Oncology at Dana-Farber Cancer Institute/Brigham and Women's Hospital and a professor of medicine at Harvard Medical School in Boston, who was senior author of the avelumab study. He was involved in earlier pembrolizumab research but not the new pembrolizumab study.
New immunotherapies overall "have made a revolution in many, many tumors," he said.
Targeted cancer therapies are drugs or other substances that block cancer growth by interfering with specific molecules that are involved in the growth, progression and spread of cancer, according to the National Cancer Institute.
Immunotherapy is a treatment approach that harnesses certain parts of the body's own immune system to target and attack a disease, such as cancer. This approach can come in many forms -- vaccines, antibody or cellular therapies, or drugs -- and can be administrated through injections, pills or capsules, topical ointments or creams, or a catheter.
An immunotherapy can also be combined with another therapy as a form of treatment, as seen in the two new studies.
The avelumab-axitinib study involved 886 renal cell cancer patients. Among them, 442 received avelumab plus axitinib as treatment, and 444 received the chemotherapy drug sunitinib, or Sutent, a first-line treatment for advanced renal cell cancer.
The study showed that average progression-free survival was 13.8 additional months of life among patients treated with avelumab plus axitinib, compared with 7.2 months among those treated with sunitinib.
The pembrolizumab-axitinib study involved 861 renal cell cancer patients. Among them, 432 received pembrolizumab intravenously plus axitinib as treatment, and 429 received sunitinib.
The study showed that average progression-free survival was 15.1 months in the pembrolizumab-axitinib group and 11.1 months in the sunitinib group. Patients who received the combination treatment had a 47% lower risk of death and a 31% lower risk of disease progression or death than those who received sunitinib.
The percentage of patients who were alive 12 months into the treatment was 89.9% in the pembrolizumab-axitinib group, compared with 78.3% in the sunitinib group.
Those study results "will absolutely change the standard of care in this disease. What was seen is really unprecedented results in terms of both an overall survival benefit with the lowest hazard ratio, meaning the most benefit that's ever seen in kidney cancer," said Dr. Brian Rini, an oncologist at the Cleveland Clinic and a professor of medicine at Case Western Reserve University in Cleveland, who was first author of the pembrolizumab study.
"We measure efficacy of cancer drugs in many different ways -- patients living longer, first and foremost -- but other measures as well, and across all these measures, this combination was superior to sunitinib," he said. These other measures include response to treatment and disease progression.
In both studies, the limitations and side effects of the combination treatment were what would be expected if either the immunotherapy or targeted therapy were administered individually. Side effects with immunotherapy can include flu-like symptoms, diarrhea or risk of infection. Side effects with targeted cancer therapies can include diarrhea, high blood pressure, thyroid issues or liver problems, such as hepatitis and elevated liver enzymes.
"These are not easy treatments to tolerate," said Dr. J. Leonard Lichtenfeld, interim chief medical officer at the American Cancer Society, who was not involved in either of the two studies.
"We learned from other studies, not in kidney cancer but in other studies, when we start combining some of these treatments, the side effects can be substantial, and that in itself can be a problem. Having said that, the reality is that the addition of the immunotherapy drug did prolong survival more than the standard treatment," he said.
"Some will say that was just a matter of a couple of months, and is that really an improvement, given the cost and side effects of the immunotherapy drugs? But by the same token, it's also very possible that we haven't followed these patients long enough," he said. "So we may see some patients who have remarkable improvement as a result of this treatment."
The combination treatments investigated in both studies are not yet approved by the US Food and Drug Administration for renal cell cancer, and the costs of the treatments are not known.
Yet the question remains: "Is this going to change the standard of care? Well, I think whether or not this changes the standard of care is going to be a matter of discussion among experts," Lichtenfeld said.
"I don't think that this study is going to make an immediate difference overnight, but I do suspect that over time, it will become a more standard treatment for metastatic or recurrent renal cell carcinoma -- kidney cancer."
Dr. Bernard Escudier, former chair of the genitourinary group of the Institut Gustave Roussy in Villejuif, France, wrote an editorial that accompanied the two studies in the New England Journal of Medicine.
He noted that sunitinib became the standard of care for renal cell cancer in 2007. Last year, the combination of two immunotherapies -- nivolumab, or Opdivo, and ipilimumab, or Yervoy -- were shown to have better efficacy than sunitinib and became the new standard.
Now, "it is noteworthy that these two trials had positive outcomes and showed superiority over sunitinib in terms of progression-free survival and the objective response rate. The pembrolizumab trial also showed a benefit with respect to overall survival," Escudier wrote. "Both combinations are expected to become new standards of care and to be incorporated into future guidelines."
Experts in the field continue to take a close look not only at the new studies but at how immunotherapies overall are influencing treatment approaches.
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