Subgroup analyses from READY: Real-world data from an Italian compassionate use program (CUP) of avelumab first-line maintenance (1LM) treatment for locally advanced or metastatic urothelial carcinoma (la/mUC).

Abstract

558 Background: A multicenter CUP provided early access to avelumab 1LM in Italian patients (pts) with Ia/mUC before reimbursement. Real-world pt characteristics and outcomes with avelumab 1LM from READY were reported previously. Here, we report updated data and subgroup analyses of effectiveness with avelumab 1LM. Methods: This prospective, noninterventional CUP included pts with la/mUC who were progression free after 1L platinum-based chemotherapy (PBC; 4-6 cycles, starting avelumab 1LM 4-10 wk after last PBC dose). Pts were enrolled from Jan 18, 2021 to Mar 7, 2022. Avelumab was provided per physician request and after approval by local ethics committees, per Italian compassionate-use regulations. Pts who had a relapse within 12 mo of prior adjuvant or neoadjuvant systemic therapy, including immune checkpoint inhibitors, were excluded. Results: 464 pts were included (78.45/21.55% male/female; median age, 70.0 y [interquartile range, 63.0-76.0]). At data cutoff (July 30, 2023), median follow-up from start of avelumab 1LM in 411 evaluable pts was 20.24 mo (95% CI, 19.78-20.93); median overall survival (OS) and progression-free survival (PFS) from start of avelumab were 26.22 mo (95% CI, 19.97-not estimable [NE]) and 7.63 mo (95% CI, 5.79-9.24), respectively. In pts aged <60 y (n=53), 60-70 y (n=150), and >70 y (n=208), median OS (95% CI) was not reached (NR; 12.86 mo-NE), NR (24.21 mo-NE), and 24.01 mo (16.94-NE), and median PFS was 5.20 mo (2.83-6.71), 7.70 mo (5.26-10.07), and 8.82 mo (6.05-12.93), respectively. In pts who received 1L cisplatin + gemcitabine (n=183) and 1L carboplatin + gemcitabine (n=219), median OS (95% CI) was NR (16.05 mo-NE) and 25.10 mo (19.97-NE), and median PFS was 6.61 mo (5.30-9.18) and 8.42 mo (6.05-12.73), respectively. The table shows OS and PFS in other subgroups defined by best response to 1L PBC and number of 1L PBC cycles received. Conclusions: Real-world outcomes with avelumab 1LM in this CUP in Italy show clinical benefit across various subgroups. These data are clinically relevant and are consistent with other real-world country-based studies and the phase 3 JAVELIN Bladder 100 trial. Findings further support the use of avelumab 1LM as standard of care in pts with la/mUC who are progression free after PBC. [Table: see text]