(UroToday.com) At the 2022 American Society of Clinical Oncology Annual Meeting held in Chicago and virtually, the poster session focused on Kidney and Bladder cancers on Saturday afternoon included a presentation from Dr. Joaquim Bellmunt examining long-term outcomes from the JAVELIN Bladder 100 trial among patients receiving first-line avelumab maintenance therapy, with a specific focus on the use of subsequent second-line therapy.
The phase 3 JAVELIN Bladder 100 trial (NCT02603432) demonstrated that first-line avelumab maintenance + best supportive care (BSC) significantly prolonged overall survival (OS) compared to BSC alone in patients with advanced urothelial carcinoma (UC) that had not progressed during initial induction treatment with 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).
As a result, this approach has now become standard of care in international guidelines. However, outcomes among patients who receive subsequent second line therapy following avelumab maintenance are limited. Thus, the authors performed a descriptive analysis focused on patients in the intervention arm of the JAVELIN Bladder 100 trial.
While previously published, to briefly recap, JAVELIN Bladder 100 included patients with unresectable locally advanced or metastatic UC without progression after 4-6 cycles of first-line gemcitabine + cisplatin or carboplatin. Following their initial chemotherapy course, patients were randomized in a 1:1 fashion to receive avelumab + BSC (n = 350) or BSC alone (n = 350). Randomization was stratified two-fold: by best response to first-line chemotherapy (CR/PR vs SD) and by the presence of visceral (vs nonvisceral disease) at start of chemotherapy. In this abstract, the authors describe exploratory analyses examining the time from randomization to end of second-line treatment and overall survival among patients in the avelumab + BSC arm, with subgroups defined by non-protocol directed second-line treatment administered by investigators after discontinuation of study treatment.
With a data cutoff of June 4, 2021, the median follow-up was 38.0 months among the patients in the avelumab + BSC arm (n = 350). At this time, the majority (n=185; 52.9%) had discontinued avelumab first-line maintenance treatment for any reason and had received second-line treatment, whereas 122 (34.9%) had discontinued avelumab without receiving subsequent second-line treatment. The remaining 43 patients (12.3%) remained on avelumab maintenance therapy. In this subset, the median treatment duration was 154.6 weeks (range, 106.7-216.0).
Among those who received second-line treatment, median time from end of avelumab maintenance to start of second-line treatment was 1.35 months (range, 0.3-30.9) and median time from randomization to end of second-line treatment was 11.7 months (95% CI, 9.7-13.8). A variety of treatment approaches were used including rechallenge with platinum-based chemotherapy in 75 (21.4%) or other 2L treatment in 110 (31.4%), including second-line anti–PD-(L)1 therapy in 11 (3.1%).
Median overall survival was not reach among those receiving ongoing avelumab maintenance whereas it was 19.9 months (95% CI 18.2-23.0) among those who received second-line therapy following avelumab maintenance and 18.2 months (95% CI 10.0-34.4) among those who did not.
Thus, the authors concluded that this exploratory analysis of the JAVELIN Bladder 100 trial shows the second-line treatment is common following avelumab maintenance therapy. Long-term overall survival may be observed with or without second-line treatment.