Adding Opdivo to Frontline Chemo Boosts Survival in Advanced GI Cancers

Frontline Opdivo (nivolumab) plus chemotherapy improved survival outcomes compared to chemotherapy alone for patients with advanced or metastatic gastric cancer, gastroesophageal junction cancer or esophageal adenocarcinoma, according to research presented at the 2024 Gastrointestinal Cancers Symposium.

The median overall survival (OS), which is the time patients live before death of any cause, was 12.6 months in the combination arm compared to 10 months in the chemotherapy-alone arm. At three months, the OS rate was 83.2% versus 84.2%; at six months it was 75.8% versus 70.4%; at nine months it was 61.3% versus 56.1%, and at 12 months it was 53.3% versus 38.1% between the combination and monotherapy arms, respectively.

The median progression-free survival (PFS), which is the time patients live before their disease gets worse, was seven months in the Opdivo arm versus 5.7 months in the chemotherapy-alone arm. At six months, the PFS rate was 60.0% versus 48.2%, and at 12 months it was 20.1% versus 19.2% between the combination and monotherapy arms, respectively.

“This is one of the first real-world studies of (Opdivo) plus chemotherapy for the first-line treatment of advanced gastroesophageal adenocarcinoma since its approval by the FDA in April 2021,” Dr. Ian Chau, professor, and consultant medical oncologist from The Royal Marsden NHS Foundation Trust, said during the presentation at the conference.

This study enrolled 528 patients with 231 receiving Opdivo plus chemotherapy and 297 receiving chemotherapy alone. Patients received the combination or monotherapy alone between April 1, 2021, and Dec. 31, 2022.

Patients were excluded if they had received Herceptin (trastuzumab) before the start of the study treatment or an experimental drug during the study period.

Of the patients enrolled, 53.7% in the combination arm and 36.7% in the chemotherapy arm had a combined positive score (CPS) test. In patients tested for PD-L1 — the biomarker that Opdivo targets— CPS of five or more occurred in 54.8% of patients.

The median age at treatment initiation was 66 years old versus 67 years, 72.7% versus 66.7% of patients were male, and 58.9% versus 59.6% of patients were White in the Opdivo and monotherapy arms, respectively. Additionally, the most common disease between arms was gastric cancer (42.9% versus 47.1%), and most patients were diagnosed with metastatic disease (79.2% versus 69.7%) and had an ECOG performance status of 1 (34.2% versus 34.7%), indicating that they could perform most of their daily activities with no assistance.

During treatment, 37.7% of patients in the Opdivo group and 46.5% in the monotherapy group died.

The median OS for patients with a CPS of 1 or more was 15.4 months in the Opdivo arm versus 8.9 months in the chemotherapy alone arm. For those with a CPS of 5 or more, the median OS was 14.6 months in the combination arm and 8.9 months in the chemotherapy-alone arm.

Between the combination and monotherapy arms, the median PFS for patients with a CPS of less than 1 was 8.1 months, versus 5.6 months; a CPS of 1 or more was 7.5 months versus 6.3 months; a CPS of less than five was 8.1 months versus 6.1 months; and a CPS of 5 or more was 6.9 months versus 5.5 months.

Limitations to the study were also presented and included the data gathered from the Flatiron Health database as there is no complete inpatient data or medical histories outside of the oncology platform. Additionally, there is variability in monitoring and collecting data in a real-world trial versus a randomized and controlled one. The data were also collected from community practices and may not apply to academic or other settings.

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