NIVO/IPI Combo Demonstrates Long-Term Efficacy in NSCLC

Long-term follow-up from the CheckMate 227 study has revealed lasting benefit from the combination of the CTLA-4 inhibitor ipilimumab (IPI) and the PD-1 inhibitor nivolumab (NIVO) in non-small cell lung cancer. After 6 years, previous tumor response, tumor burden reduction, and baseline health-related quality of life all correlated with overall survival, according to the latest analysis from the study.

“Patients treated with NIVO-IPI versus chemotherapy continue to derive long term durable efficacy benefit in CheckMate 227, regardless of PD-L1 expression. This represents the longest ever reported follow-up across phase three studies of frontline immunotherapy in patients with metastatic non–small cell lung cancer, and this further highlights the clinical benefit of frontline NIVO-IPI as a treatment in these patients with metastatic non–small cell lung cancer, regardless of the PD-L1 expression,” said Solange Peters, MD, PhD, during a presentation of the latest analysis at the annual World Conference on Lung Cancer. Dr. Peters is a professor of oncology at Lausanne (Switzerland) University Hospital.

The combination of nivolumab and ipilimumab has shown long-term survival benefit in other cancer types, including advanced melanoma, advanced renal cell carcinoma, and unresectable pleural mesothelioma.

The same session featured other studies demonstrating positive outcomes of immunotherapy in NSCLC. Serving as a discussant, Ferdinandos Skoulidis MD, PhD, commented, “I would argue that we are now at an inflection point where we can claim that we are altering the natural history of the disease for a subset of patients.” Dr. Skoulidis is an associate professor of thoracic oncology at the University of Texas MD Anderson Cancer Center.

Updated results

CheckMate 227 enrolled patients with metastatic or recurrent NSCLC, excluding those with EGFR/ALK alterations. Patients with PD-L1 expression greater than or equal to 1% (PD-L1 positive, n = 1,189) were randomized to NIVO-IPI, NIVO, or chemotherapy. Patients with PD-L1 expression less than 1% (n = 550, PD-L1 negative) were randomized to NIVO-IPI, NIVO plus chemotherapy, or chemotherapy alone. The 5-year landmark analysis, which was published by the National Center for Biotechnology Information, showed overall survival rate of 24% among PD-L1 greater than or equal to 1% patients (PD-L1 positive) and 19% in PD-L1 less than 1% (PD-L1 negative) patients who received IPI-NIVO therapy, compared with 14% and 7%, respectively, in the chemotherapy only groups.

At WCLC, Dr. Peters presented data extending to 6 years of follow-up, as well as exploratory analyses. At 6 years of follow-up, in PD-L1 positive patients, 22% of the NIVO-IPI group remained alive, versus 13% of the chemotherapy group (hazard ratio, 0.78; 95% confidence interval, 0.67-0.91), while there was no significant improvement in OS for nivolumab alone, compared with chemotherapy. In the PD-L1 negative group, 16% were alive at 6 years in the IPI-NIVO group (HR, 0.65; 95% CI, 0.52-0.81), as were 10% in NIVO plus chemotherapy (HR, 0.79; 95% CI, 0.64-0.98) group, versus 5% in the chemotherapy group. The benefit of NIVO-IPI was significant in both squamous and non-squamous tumors for both PDL1-positive and PD-L1 negative patients.

At 6 years follow-up, 27% of PD-L1 positive patients who responded to NIVO-IPI remained in response, versus 22% in the NIVO group and 4% in the chemotherapy only group. Among PD-L1 negative patients, 25% of combination therapy responders remained in response at 6 years, while there were 10% still in response among the NIVO group, and none in the chemotherapy only group.

Exploratory analyses

Dr. Peters presented a slide showing tumor burden reductions occurring in responders. “What has to be concluded from this very interesting graph is that there are more, deeper responses in the NIVO-IPI versus chemotherapy. Very importantly, too, this is strongly correlated with survival. In both treatment arms, a high magnitude of tumor burden reduction is correlated with an improved survival,” said Dr. Peters. Specifically, among PD-L1 positive patients with more than 80% tumor reduction, survival was 59% at 6 years (95% CI, 44-71%). The figure was 68% in the NIVO only arm (95% CI, 47-82%), and 42% in the chemotherapy only arm (95% CI, 15-66%).

Among PD-L1 negative patients, “there are more, deeper responses in NIVO-IPI versus chemotherapy. That is very clear. And probably differently from the positive PD-L1 arm, the tumor burden reduction is correlated with survival but really only strongly observed in the NIVO-IPI arm,” said Dr. Peters. The figure was 20% in the nivolumab arm (95% CI, 3-48%) and 0% in the chemotherapy only arm (95% CI, not available). “So really something is correlating the tumor burden reduction with the outcome and specifically correlating it in the negative PD-L1 with the treatment of NIVO-IPI,” said Dr. Peters.

The researchers also noted longer progression-free survival and overall response rate in the NIVO-IPI group than the chemotherapy group in both PD-L1 positive and PD-L1 negative patients.

With respect to health-related quality of life, the researchers found a correlation between higher scores at baseline on the EQ-5D-3L scale and overall survival in the chemotherapy group (HR, 0.61; 95% CI, 0.51-0.74) and a trend in the NIVO-IPI group (HR, 0.83; 95% CI, 0.69-1.01). “So this baseline history, the quality of life, is correlated with the outcome regardless of the treatment you deliver,” said Dr. Peters.

Personalizing immunotherapy in NSCLC

In his comments, Dr. Skoulidis highlighted the length of responses. “Most importantly, approximately 50% of these patients that are alive at six years are also disease free, suggesting that we are indeed making a dent on the natural history of the disease for these patients,” he said.

He also made a case for personalizing immunotherapy and suggested that CheckMate 227 could provide some guidance. “Ipilimumab/nivolumab – the CheckMate 227 regimen – appears to be particularly active in terms of inducing long-term, long-lasting responses and overall survival in patients harboring tumors that are negative for PD-L1,” he said.

Dr. Skoulidis also highlighted the 16% six-year overall survival among PD-L1 negative patients who received NIVO-IPI, calling it “impressive.” Of those who responded, 25% continued to respond at 6 years. “This is particularly notable in the subset of patients with squamous histology and lack of PD-L1 expression, where the six year overall survival rate with NIVO-IPI versus chemo was 18% versus 4%. So perhaps in patients with squamous histology and lack of PD-L1 expression, NIVO-IPI might represent a favorable regimen to improve long term outcomes,” said Dr. Skoulidis.

CheckMate 227 was funded by Bristol Myers Sqiubb. Dr. Peters has financial relationships with a wide range of pharmaceutical companies, including Bristol Myers Squibb. Dr. Skoulidis has financial relationships with Moderna, BioNTech, Amgen, Intellisphere, Navire, BeiGene, Medscape, Calithera Biosciences, Tango Therapeutics, Guardant Health, Novartis, AIMM Therapeutics, Mirati Therapeutics, Boehringer Ingelheim, Merck, and Pfizer.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.