35MO Quality-adjusted survival in patients with advanced or recurrent endometrial carcinoma treated with atezolizumab in combination with carboplatin-paclitaxel versus carboplatin-paclitaxel in the AtTEnd/ENGOT-EN7 trial

In the phase III randomized international multicentric academic AtTEnd trial, the addition of atezolizumab (atezo) to standard carboplatin and paclitaxel chemotherapy (CP) demonstrated a statistically significant improvement in progression free survival versus CP alone for patients (pts) with advanced/recurrent endometrial carcinomas (EC) with a substantial benefit in pts with a mismatch repair deficient (dMMR) carcinoma. This is a post-hoc analysis of the quality-adjusted time without symptoms of disease progression or toxicity of treatment (Q-TWiST) in dMMR and all comer population. Pts were randomized (2:1 ratio) to receive either CP and atezo (N=360) or placebo (N=189), followed by atezo or placebo until disease progression. In safety population (356 pts in atezo arm and 185 pts in placebo arm), overall survival was partitioned into three health status: the time without symptoms of progression or toxicity (TWiST), the time before progression with Grade ≥ 3 adverse events (TOX), and the time from progression to death (REL). The restricted mean survival time (measured up to 36 months for the all-comers population and 23 months for the dMMR population) of each health status were adjusted using EQ-5D-5L questionnaire. Q-TWiST was calculated using the utility values for TOX and REL defined relative to TWiST. Overall, median follow-up duration was 28.3 months. In pts receiving atezo a significantly longer Q-TWiST was detected compared to pts receiving placebo (25.9 versus 24.0 months, p=0.0144). Q-TWiST was also significantly longer in atezo arm compared to placebo arm (20.3 versus 16.2 months, p<0.0001) for patients with a dMMR carcinoma (Table).Table: 35MOTOXTWiSTRELQ-TWiSTAll-comersATEZOLIZUMABEstimate (95%CI)3.0 (2.7 to 3.2)13.4 (12.3 to 14.6)9.8 (8.7 to 10.9)25.9 (24.6 to 27.2)PLACEBOEstimate (95%CI)2.1 (1.9 to 2.3)11.2 (9.8 to 12.7)11.5 (9.9 to 13.1)24.0 (22.2 to 25.8)DIFFERENCEEstimate (95%CI)0.9 (0.6 to 1.2)2.2 (0.4 to 4.1)-1.6 (-3.5 to 0.3)1.9 (0.4 to 3.5)p<0.0010.0180.0920.014Patients with dMMR carcinomaATEZOLIZUMABEstimate (95%CI)1.6 (1.4 to 1.7)14.4 (12.7 to 16.1)4.5 (3.1 to 6.0)20.3 (19.1 to 21.5)PLACEBOEstimate (95%CI)1.9 (1.6 to 2.2)7.7 (6.0 to 9.7)7.3 (5.3 to 9.2)16.2 (14.0 to 18.5)DIFFERENCEEstimate (95%CI)-0.3 (-0.7 to <-0.1)6.7 (4.1 to 9.1)-2.7 (-5.1 to -0.4)5.5 (3.3 to 7.6)p0.034<0.0010.022<0.001 Open table in a new tab In pts with advanced/recurrent EC, the addition of atezo to CP improved the quality-adjusted survival compared to CP alone.