Chemo plus atezolizumab improves survival while preserving life quality in advanced EC

Treatment with carboplatin-paclitaxel (CP) plus atezolizumab results in better quality-adjusted survival in patients with advanced or recurrent endometrial cancer (EC) as compared with CP alone, according to a post hoc analysis of the AtTEnd/ENGOT-EN7 trial. 

Moreover, “[q]uality of life was maintained over time in both arms, even if an initial reduction could not be excluded,” said co-author Dr Maria Pilar Barretina Ginesta from Institut Català d'Oncologia Girona, Girona, Spain. “Coupled with the significantly improved progression-free survival (PFS), these findings support the use of CP plus atezolizumab in advanced/recurrent EC.” [ESMO Gyn 2024, abstract 36M0] 

The phase III randomized international multicentre AtTEnd trial found a statistically significant improvement in PFS with CP plus atezolizumab versus CP alone for patients with advanced/recurrent EC, with a substantial benefit noted among those with a mismatch repair deficient (dMMR) carcinoma. 

In this post hoc analysis, the findings of which was presented at the recent ESMO Gynaecological Cancer Congress 2024, Ginesta and her team assessed the quality-adjusted time without symptoms of disease progression or toxicity of treatment (Q-TWIST) in dMMR and all-comer population. 

Specifically, patients were randomly assigned 2:1 to receive either CP plus atezolizumab (n=360) or placebo (n=189), followed by atezolizumab or placebo until disease progression. 

In the safety population consisting of 356 patients in the atezolizumab arm and 185 in the placebo arm, Ginesta and colleagues partitioned overall survival 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 EQ-5D-5L questionnaire was used to adjust the restricted mean survival time (measured up to 36 months for the all-comer population and 23 months for the dMMR population) of each health status. Finally, Q-TWIST was calculated using the utility values for TOX and REL defined relative to TWIST. 

The median follow-up time was 28.3 months. Patients in the atezolizumab arm demonstrated a significantly longer Q-TWIST than those in the placebo arm (25.9 vs 24.0 months; p=0.0144). Q-TWIST was also significantly longer with CP plus atezolizumab compared with CP alone (20.3 vs 16.2 months; p<0.0001) for patients with a dMMR carcinoma. [ESMO Gyn 2024, abstract 35M0] 

In further analysis, patient-reported outcomes revealed lower scores in most functional scales, except for emotional functioning, during cycle 6 of the treatment phase. All functional scales, however, improved during cycle 8 of the maintenance phase, with social functioning improving above baseline in the two arms and role functioning increasing above baseline in the atezolizumab arm only. 

Results of the symptom scales did not differ between treatment groups, except for back/pelvic pain score in which a significant decrease in severity from baseline was seen in those receiving atezolizumab (p=0.023). Also, mean scores on the EQ-5D-5L were similar in both arms. 

“Taken together, the prolongation of PFS and the significant gain in Q-TWIST demonstrate that atezolizumab added to chemotherapy is associated with a PFS improvement while preserving [the] patient’s health-related quality of life, particularly in dMMR population,” Ginesta said.