First-line maintenance therapy with avelumab plus best supportive care (BSC) significantly prolongs overall survival (OS) compared with BSC alone among patients with unresectable locally advanced or metastatic urothelial carcinoma who had disease that had not progressed while on first-line chemotherapy, according to study findings presented at the European Society for Medical Oncology (ESMO) Virtual Congress 2020 and published concurrently in the New England Journal of Medicine.

In the phase 3 JAVELIN Bladder 100 trial in which investigators randomly assigned 700 patients to receive avelumab, an immunotherapeutic drug, plus BSC or BSC alone, OS at 1 year was 71.3% in the avelumab group compared with 58.4% in the BSC-only arm, study investigator Petros Grivas, MD, PhD, of the University of Washington (UW) in Seattle, reported in a video presentation. Median OS was 21.4 months in the avelumab group compared with 14.3 months in the control group. Avelumab treatment was significantly associated with a 31% decreased risk of death (P =.001), according to Dr Grivas, associate professor of oncology at UW and director of UW Medicine’s Genitourinary Cancers Program.

In addition, avelumab significantly prolonged OS among PD-L1–positive patients. OS at 1 year was 79.1% in the avelumab group and 60.4% in the control group. Avelumab was significantly associated with a 44% decreased risk of death (P <.001).

The median progression-free survival (PFS) was 3.7 months in the avelumab group and 2.0 months in the control group in the study population as a whole and 5.7 months and 2.1 months, respectively, in the PD-L1-positive population.

Avelumab was significantly associated with a 38% and 44% decreased risk for disease progression or death in the study population as a whole and the PD-L1-positive population, respectively.

The investigators observed the OS and PFS survival benefit associated with avelumab regardless of which first-line chemotherapy regimen patients received (gemcitabine plus cisplatin or gemcitabine plus carboplatin). Avelumab was significantly associated with a 31% decreased risk of death and 37% decreased risk of disease progression or death among patients who received gemcitabine plus cisplatin and 34% and 41% decreased risk of death and disease progression or death, respectively, among those who received gemcitabine plus carboplatin, Dr Grivas reported.

Further, avelumab was significantly associated with improved OS and PFS regardless of patients’ best response to first-line chemotherapy (complete, partial, stable disease) as well age (65 years or older vs younger than 65 years), ECOG performance status, creatinine clearance, and PD-L1 status.

The incidence of adverse events (AEs) from any cause was 98.0% in the avelumab group and 77.7% in the control arm. The incidence of grade 3 or higher AEs was 47.4% and 25.2%, respectively.

Disclosure: This study was sponsored by Pfizer, and is part of an alliance between Pfizer and Merck KGaA, Darmstadt, Germany. Please see the original reference for a full list of authors’ disclosures.