ASCO GU 2022: Avelumab First-Line Maintenance + Best Supportive Care Versus BSC Alone in Asian Patients With Advanced Urothelial Carcinoma: JAVELIN Bladder 100 Subgroup Analysis

(UroToday.com) On the second day of the American Society for Clinical Oncology (ASCO) Genitourinary Cancer Symposium 2022 focused on urothelial carcinoma, in Poster Session B, Dr. Eto presented results of a subgroup analysis of Asian patients enrolled on JAVELIN Bladder 100, investigation avelumab maintenance in patients with advanced urothelial carcinoma (UC). In the primary report of this trial (NCT02603432), avelumab first-line maintenance therapy with best supportive care (BSC) showed significantly longer overall survival compared to BSC alone in patients with advanced UC that had not progressed with first-line platinum-based chemotherapy.

To briefly summarize, the JAVELIN Bladder 100 trial enrolled patients with unresectable locally advanced or metastatic UC without disease progression after 4-6 cycles of gemcitabine and cisplatin or carboplatin. These patients were then were randomized 1:1 to receive avelumab first-line maintenance + BSC or BSC alone, stratified by best response to first-line chemotherapy and visceral vs non visceral disease when initiating first-line chemotherapy. The primary endpoint was overall survival, assessed from randomization in all patients and patients with PD-L1+ tumors (Ventana SP263 assay).

Among the overall population of 700 patients, 147 Asian patients were enrolled on JAVELIN Bladder 100 at sites in Japan, South Korea, Taiwan, Hong Kong, and India of whom 73 and 74 were randomized to receive avelumab + BSC or BSC alone, respectively.

In keeping with the overall study analysis, avelumab prolonged overall survival and progression-free survival in both the intention to treat the population and the PD-L1+ subgroup of Asian patients enrolled on the trial. The median OS (95% CI) was 25.3 months (95% CI 18.6 months-not estimable [NE]) with avelumab + BSC, compared to 18.7 months (12.8 months-NE) with BSC alone (HR, 0.74 [95% CI, 0.434-1.260]) in all patients. A similar effect was seen in the PD-L1+ subgroup (HR, 0.66 [95% CI, 0.279-1.541]), in the PD-L1+ subgroup (n = 71).

The most common treatment-emergent adverse events (TEAEs) of any grade (any causality) in the avelumab + BSC arm were fever (23.6%), constipation, nasopharyngitis, and rash (19.4% each). In terms of grade ≥3 TEAEs, anemia (9.7%), amylase increased (5.6%), and urinary tract infection (4.2%) were the most common.

Thus, Dr. Eto concluded that this subgroup analysis of the JAVELIN Bladder 100 trial in Asian patients supports the use of avelumab maintenance therapy following first-line platinum-based chemotherapy in advanced UC.