Table 2.

Summary of clinical trials about anti-PD-1 in ES-SCLC

Trial	Phase	No. of Patients	Treatment	FDA Approval	OS	PFS	ORR (%)		AEs (%)
ASTRUM-005	III	585	Serplulimab + chemotherapy vs. chemotherapy	No	15.38 vs. 11.0 months (HR, 0.62; 95% CI, 0.48-0.80; p<0.001)	n.r.	n.r.		n.r.
KEYNOTE-604	III	453	Pembrolizumab + chemotherapy vs. chemotherapy	No	10.8 vs. 9.7 months (HR, 0.80; 95% CI, 0.64-0.98; p=0.0164)	4.5 vs. 4.3 months (HR 0.75, 95% CI 0.61-0.91, p=0.0023)	70.6 vs. 61.8		Grade 3/4 AEs 76.7 vs. 74.9
CheckMate-451	III	834	Nivolumab vs. Nivolumab plus Ipilimumab vs. Placebo	No	10.4 months (9.5 to 12.1) vs. 9.2 months (8.2 to 10.2) vs. 9.6 months (8.2 to 11.0)	1.9 months (1.6 to 2.6) vs. 1.7 months (1.5 to 2.6) vs. 1.4 months (1.4 to 1.5)	11.5 vs. 9.1 vs. 4.2		Grade 3/4 AEs 11.5 vs. 52.2 vs. 8.4
CheckMate-331	III	569	Nivolumab vs. Topotecan or amrubicin	No	7.5 months vs. 8.4 months (HR, 0.86; 95% CI, 0.72-1.04)	1.4 months (95% CI: 1.4-1.5) vs. 3.8 months (95% CI: 3.0-4.2)	13.7 vs. 16.5		Grade 3/4 AEs 13.8 vs. 73.2
PASSION	II	47	camrelizumab plus apatinib	No	8.4 months *(9.6 months vs. 8.0 months)	3.6 months *(3.6 months vs. 2.7 months)	34 (95% CI: 20.9-49.3) *(37.5% versus 32.3%)		Grade 3 or higher AEs 72.9
KEYNOTE 158	II	107	Pembrolizumab	No	9.1 months (95% CI, 5.7-14.6)	2 months (95% CI: 1.9-2.1)	18.7 (95% CI: 11.8-27.4)		Treatment-related AEs 59
A phase II study	II	45	Pembrolizumab	No	9.6 months (95% CI, 7.0-12.0)	1.4 months (95% CI: 1.3-2.8)	11.1 (95% CI: 4.8-23.5)		All grades AEs. 10 or higher
CheckMate-032	I/II	243	Nivolumab vs. Nivolumab + Ipilimumab	No	5.7 months (3.8-7.6) vs. 4.7 months (3.1-8.3)	1.4 months (1.3-1.4) vs. 1.5 months (1.4-2.2)	11.6 vs. 21.9		Grade 3/4 AEs 12.9 vs. 37.5
KEYNOTE 028	IB	24	Pembrolizumab	No	9.7 months (95% CI, 4.1-n.r.)	1.9 months (95% CI: 1.7-5.9)	33.3		Grade 3 or higher AEs 8.3

OS: overall survival; PFS: progression-free survival; ORR: objective response rate; AEs: adverse events; n.r.: not reported. *Chemotherapy-sensitive and chemotherapy-resistant patients.