Long-term outcomes in patients with advanced urothelial carcinoma (UC) who received avelumab first-line (1L) maintenance with or without second-line (2L) treatment: Exploratory analyses from JAVELIN Bladder 100.

person Joaquim Bellmunt Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA info_outline Joaquim Bellmunt, Thomas Powles, Miguel Angel Climent Duran, Srikala S. Sridhar, Howard Gurney, Nuno Costa, Alessandra Di Pietro, Bo Huang, Shilpa Gupta, Petros Grivas

Authors person Joaquim Bellmunt Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA info_outline Joaquim Bellmunt, Thomas Powles, Miguel Angel Climent Duran, Srikala S. Sridhar, Howard Gurney, Nuno Costa, Alessandra Di Pietro, Bo Huang, Shilpa Gupta, Petros Grivas Organizations Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, Barts Cancer Institute, Experimental Cancer Medicine Centre, Queen Mary University of London, St. Bartholomew’s Hospital, London, United Kingdom, Medical Oncology Department, Instituto Valenciano de Oncología (IVO), Valencia, Spain, Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada, Macquarie University, Sydney, NSW, Australia, Pfizer, Porto Salvo, Portugal, Pfizer srl, Milan, Italy, Pfizer, Groton, CT, Cleveland Clinic, Cleveland, OH, University of Washington, Fred Hutchinson Cancer Research Center, Seattle Cancer Care Alliance, Seattle, WA Abstract Disclosures Research Funding Pharmaceutical/Biotech Company Pharmaceutical/Biotech Company Background: Avelumab 1L maintenance + best supportive care (BSC) significantly prolonged overall survival (OS) vs BSC alone in patients (pts) with advanced UC that had not progressed with 1L platinum-based chemotherapy (median OS, 23.8 vs 15.0 months; HR, 0.76 [95% CI, 0.631-0.915]; 2-sided p = 0.0036). Avelumab 1L maintenance is now considered standard of care per international guidelines. However, data on outcomes in pts who receive 2L treatment after avelumab 1L maintenance are limited. We report a descriptive analysis of outcomes in pts enrolled in the avelumab + BSC arm of the JAVELIN Bladder 100 trial based on receipt of 2L treatment. Methods: In the phase 3 JAVELIN Bladder 100 trial (NCT02603432), eligible pts had unresectable locally advanced or metastatic UC without progression with 4-6 cycles of 1L gemcitabine + cisplatin or carboplatin. Pts were randomized 1:1 to receive avelumab + BSC or BSC alone. Exploratory analyses of time from randomization to end of 2L treatment and OS were performed in the avelumab + BSC arm in subgroups defined by 2L treatment administered by investigators after discontinuation of study treatment. Results: In the avelumab + BSC arm (n = 350), median follow-up at data cutoff (June 4, 2021) was 38.0 months. 185 pts (52.9%) had discontinued avelumab 1L maintenance treatment for any reason and received 2L treatment, whereas 122 (34.9%) had discontinued avelumab and did not receive 2L treatment. Median OS (95% CI) in subgroups is shown in the Table. In 43 pts (12.3%) who were still receiving avelumab, median treatment duration was 154.6 weeks (range, 106.7-216.0). Among pts who received 2L treatment, median time from end of avelumab 1L maintenance to start of 2L treatment was 1.35 months (range, 0.3-30.9) and median time from randomization to end of 2L treatment was 11.7 months (95% CI, 9.7-13.8). 2L treatment comprised rechallenge with platinum-based chemotherapy in 75 pts (21.4%) or other 2L treatment in 110 pts (31.4%), including 2L anti–PD-(L)1 therapy in 11 pts (3.1%). Additional data based on different types of 2L treatment will be presented. Conclusions: In this exploratory analysis from the JAVELIN Bladder 100 trial with extended follow-up, approximately 60% of pts (185/307 pts) who had discontinued avelumab received 2L treatment. Long-term OS was observed in pts who received avelumab 1L maintenance with or without 2L treatment. Clinical trial information: NCT02603432. n Median OS (95% CI), mo Avelumab treatment ongoing 43 Not reached Any 2L treatment post avelumab discontinuation 185 19.9 (18.2-23.0) No 2L treatment post avelumab discontinuation 122 18.2 (10.0-34.4)