In 2nd line, DCR was significantly better for gem over non gem (Odds Ratio (OR) OR 6.5, p=0.004), seemingly more for ARID1A-mt (OR of mt VS wild-type (wt) 28 VS 4.2)….This is the largest study of OCCC pts receiving gem based therapy. We show that gemcitabine improved DCR for all OCCC patients, and mPFS in ARID1A-mt especially when used earlier.