Background: The phase 3 CheckMate 649 established superior overall survival of nivolumab in combination with chemotherapy (NIVO + chemo) compared with chemotherapy (chemo) alone as a first-line treatment for patients with Her2-negative advanced gastric cancer, gastroesophageal junction cancer, and esophageal adenocarcinoma (GC/GEJC/EAC). This post hoc trial analysis aimed to evaluate the benefit of NIVO + chemo using quality-adjusted time without symptoms or toxicity (Q-TWiST) to further account for quality of life (QoL) in different health states depending on disease progression and treatment toxicity.
Methods: Using data from CheckMate 649, we evaluated the quality-adjusted survival gain associated with NIVO + chemo compared with chemo alone among all randomized patients and repeated similar analyses among those with programmed cell death-ligand 1 (PD-L1) combined positive score (CPS) ≥ 5. Relative Q-TWiST gains of ≥ 10% were predefined as clinically important.
Results: In all randomized patients, those receiving NIVO + chemo had a mean Q-TWiST gain of 1.8 (95% CI 0.9, 2.7) months compared with those receiving chemo alone. The relative Q-TWiST gain was estimated to be 12.8%. Patients with PD-L1 CPS ≥ 5 had greater quality-adjusted survival gain from NIVO + chemo with an estimated Q-TWiST gain of 2.8 (95% CI 1.5, 4.1) months, representing a relative gain of 20.6%. Subgroup analyses and sensitivity analyses with various QoL utility values yielded consistent findings in favor of NIVO + chemo compared with chemo alone. Q-TWiST gain from NIVO + chemo increased with longer duration of follow-up.
Conclusions: NIVO + chemo was associated with a statistically significant and clinically important gain in quality-adjusted survival compared with chemo alone among previously untreated patients with advanced GC/GEJC/EAC.
Keywords: Gastric cancer; Nivolumab; Quality of life; Quality-adjusted survival; Quality-adjusted time without symptoms or toxicity.
© 2023. The Author(s).