BACKGROUNDEndostar™ (rh-endostatin, YH-16) is a new recombinant human endostatin developed by Medgenn Bioengineering Co. Ltd., Yantai, Shandong, P.R.China. Pre-clinical study indicated that YH-16 could inhibit tumor endothelial cell proliferation, angiogenesis and tumor growth. Phase I and phase II studies revealed that YH-16 was effective as single agent with good tolerance in clinical use.The current study was to compare the response rate , median ti me to progression (TTP) ,clinical benefit andsafety in patients with advanced non-small cell lung cancer ( NSCLC) , who were treated with YH-16 plus vi-norelbine and cisplatin (NP) or placebo plus NP.METHODSFour hundred and ninety-three histologically or cy-tologically confirmed stage IIIB and IV NSCLC patients , withlife expectancy > 3 months and ECOG perform-ance status 0-2 , were enrolledin a randomized ,double-blind ,placebo-controlled , multicenter trial ,either trialgroup : NP plus YH-16 (vinorelbine 25 mg/m² on day 1 and day 5 ,cisplatin 30mg/m² on days 2 to 4 , YH-167.5mg/m² on days 1 to 14) or control group : NP plus placebo (vinorelbine 25 mg/m² on day 1 and day 5 ,cis-platin 30 mg/m² on days 2 to 4 ,0.9% sodium-chloride 3 .75 ml on days 1 to 14) every 3 weeks for 2-6 cycles .The trial endpoints included response rate ,clinical benefit rate ,time to progression,quality of life and safety .RESULTSOf 486 assessable patients , overall response rate was 35.4% in trial group and 19.5% in controlgroup (P=0 .0003) . The median TTP was 6 .3 months and 3 .6 months for trial group and control group respectively (P < 0 .001) . The clinical benefit rate was 73 .3 %in trial group and 64.0% in control group (P=0 .035) .In untreated patients of trial group and control group ,the response rate was 40 .0% and 23.9%(P=0 .003) ,the clinical benefit rate was 76 .5 % and 65 .0 % (P=0 .023) ,the median TTP was 6 .6 and 3 .7months (P=0 .0000) ,respectively .In pretreated patients of trial group and control group ,the response ratewas 23.9% and 8.5%(P=0 .034) ,the clinical benefit rate was 65.2% and 61.7%(P=0 .68) ,the median TTP was 5 .7 and 3 .2 months (P=0 .0002) ,respectively . The relief rate of clinical symptoms in trial groupwas higher than that of those in control group ,but no significance existed (P > 0 .05) . The score of quality oflife in trial group was significantly higher than that in control group (P=0 .0155) after treatment . There were no significant differences in incidence of hematologic and non-hematologic toxicity , moderate and severe sideeffects betweentrial group and control group .CONCLUSIONSThe addition of YH-16 to NP regimen results in significantly and clinically meaningful improvement in response rate , median time to tumor progression,and clinical benefit rate compared with NP alone in advanced NSCLC patients . YH-16 in combination with chemotherapy shows a synergic activity and a favorable toxic profile in advanced cancer patients .