PARIS – (PFS) in advanced renal cell carcinoma (aRCC), particularly in intermediate-risk patients, suggest results from the COSMIC-313 trial.
At present, dual checkpoint inhibition with nivolumab and ipilimumab is a standard of care for first-line treatment of aRCC that is deemed to be of intermediate or poor risk on the International Metastatic RCC Database Consortium (IMDC) risk score.
Cabozantinib, a tyrosine kinase inhibitor (TKI), is also a standard of care in aRCC, both as a single agent and in combination with nivolumab.
The new study investigated the use of the three drugs together as upfront first-line treatment and suggests that this triplet may become a new standard of care, especially in patients with intermediate-risk disease.
The research was presented at the European Society for Medical Oncology Congress in Paris.
The trial involved 855 previously untreated patients with aRCC, all of whom received dual immunotherapy with nivolumab and ipilimumab, who were randomly assigned to also receive either cabozantinib or matched placebo.
Patients given the triplet therapy had a significant 27% reduction in the risk for progression versus the doublet in the overall patient population.
The difference increased to 37% in patients with intermediate-risk disease on the IMDC risk score.
However, patients with poor-risk disease appeared not to derive any benefit from adding cabozantinib to nivolumab plus ipilimumab.
In addition, grade 3 or 4 treatment-related adverse events were more common with the triplet therapy.
The results suggest that adding cabozantinib results in a “statistically significant and clinically meaningful” PFS benefit, study presenter Toni Choueiri, MD, director of the Lank Center for Genitourinary Oncology at the Dana-Farber Cancer Institute, Boston, told a press conference.
He added that the safety profile of the triplet therapy was “generally manageable” and “consistent with the profiles of the treatment components.”
“The study will continue to the next analysis of overall survival, as this secondary endpoint was not met at first interim analysis,” Dr. Choueiri commented.
He told this news organization that, based on the current results, the triplet combination “may end up in intermediate-risk” patients, although it is not clear why there is a difference in response between risk groups, and the finding is “quite intriguing.”
Asked which therapy to choose now for first-line treatment of aRCC, given that there are now so many options, he said that there is now such “an embarrassment of riches of trials in the first-line” that it is perhaps easier to talk about which therapies “not to use.”
“We cannot use single TKIs anymore, so you have to use doublets and possibly now triplets,” he said.
“In my practice, patients that are progressing rapidly ... need a VEGF [vascular endothelial growth factor]–based combination. In patients that can wait and ... do not have a heavy disease burden, I still believe in nivolumab and ipilimumab, which has the longest follow-up, and the responses are durable.”
Approached for comment, Dominik Berthold, MD, Centre hospitalier universitaire vaudois, Lausanne, Switzerland, said that this is a “really important study” because it has a “modern” study comparator in the control arm.
He said in an interview, however, that the question now is “obviously” how much treatment should be escalated to triple therapy “upfront versus the sequencing of active drugs.” The answer, he said, is currently unclear, and overall survival data are awaited.
Alongside the potential “challenge” of the toxicity to patients of the triplet therapy, Dr. Berthold also highlighted that it is “currently a challenge for health systems to imagine giving such expensive combinations.”
So though it is “really interesting data” and potentially represents a “step forward” in the field, the combination of cabozantinib and nivolumab plus ipilimumab is “not for everybody.”
Dr. Choueiri said that he does “agree” that adding a third drug to an already expensive doublet therapy can mean that the costs end up being “exorbitant.”
However, he noted that in aRCC, “the paradigm is sequential, so if we’re able to delay the second line, and give drugs later, especially if there is some quality of life [benefit], I’m not sure it is more expensive” to give the three-drug combination.
Commenting for ESMO, Viktor Grünwald, MD, West German Cancer Center, University Hospital Essen, Germany, noted that this is the “first study” to report “successful treatment intensification” in metastatic RCC through the use of triple therapy.
“However, treatment intensification is rarely seen without additional risks. Patients experienced the benefit of superior disease control but also additional toxicities, treatment pauses and discontinuations,” he pointed out.
“The triplet may compete in the clinical landscape with recommended life-prolonging immune doublets but mature overall survival data is needed for it to become a novel standard of care,” Dr. Grünwald commented.
