A randomized phase 3 study included 210 patients with untreated stage III–IV non-small cell lung cancer.[2][3] Patients received immunotherapy (sintilimab or pembrolizumab) in combination with chemotherapy either before 15:00 (early group, 105 patients) or from 15:00 (late group, 105 patients) during the first four cycles.[2][3] The early group had a median progression-free survival of 11.7 months, while the late group had a median progression-free survival of 5.4 months.[2] Overall survival was approximately 70% longer in the earlier group than in the later group.[3] The treatment response rate reached 69.5% in the earlier group and 56.2% in the later group.[2] Toxicity was similar in both groups.[2] The study demonstrated a statistically significant improvement in progression-free survival and overall survival when immunochemotherapy was administered before 3:00 p.m.[3]