Further JAVELIN Bladder 100 analyses add support for maintenance avelumab
medwireNews: A post-hoc analysis of the JAVELIN Bladder 100 trial in the advanced urothelial carcinoma (UC) setting suggests that maintenance avelumab is beneficial regardless of the duration of prior chemotherapy, while another analysis shows the benefit in the Japanese patient subgroup.
These findings were reported in posters at the 2021 Genitourinary Cancers Symposium, the first set by Yohann Loriot (Gustave Roussy, Villejuif, France) and colleagues, and the second by Norihiko Tsuchiya (Yamagata University Faculty of Medicine, Japan) and co-workers.
As previously reported by medwireNews, the primary analysis of the phase 3 study demonstrated a significant improvement in overall survival (OS) with the addition of maintenance avelumab to best supportive care (BSC) in patients with locally advanced or metastatic UC that had not progressed after first-line chemotherapy.
Loriot and colleagues explained, however, that the “optimal duration of [first-line] chemotherapy is unknown and some patients are unable to receive 6 cycles,” and so they conducted an analysis of avelumab efficacy by duration and number of cycles of chemotherapy.
Patients appeared to derive an OS benefit from the addition of maintenance avelumab to BSC irrespective of these factors.
For instance, the median OS duration among patients who received less than 15.0 weeks of chemotherapy was 18.9 months for the avelumab group and 13.0 months for the control arm, while the corresponding times were 24.0 and 17.9 months among participants who received chemotherapy for more than 20.1 weeks. The respective hazard ratios (HRs) were 0.65 and 0.63 in favor of the PD-L1 inhibitor, although neither of the comparisons was statistically significant.
Similarly, the median OS with versus without avelumab was 19.9 and 13.7 months, respectively, for participants who received four cycles (nonsignificant HR=0.69), and was 24.0 and 14.0 months for those who received six cycles (significant HR=0.66).
Ajjai Alva (University of Michigan Rogel Cancer Center), who discussed the study in a poster highlights session, said that although the aim should be to give the maximum number of chemotherapy cycles, provided the patient is able to tolerate it, these data provide reassurance that maintenance avelumab offers an OS benefit even after fewer chemotherapy cycles.
The second analysis focused on patients enrolled in sites in Japan, and found that the results were consistent with those of the overall study population, with “no safety concerns specific to Japanese patients.”
Among the 73 patients in the subgroup, median OS was 24.7 months for the 36 patients who received maintenance avelumab 10 mg/kg every 2 weeks alongside BSC and was 18.7 months for the 37 participants who received BSC alone. This gave an HR for death of 0.81 in favor of avelumab, albeit without reaching statistical significance.
The progression-free survival similarly favored the addition of avelumab to BSC, at a median of 5.6 months versus 1.9 months for BSC alone, and a nonsignificant HR for progression or death of 0.63.
Treatment-emergent adverse events (TEAEs) of at least grade 3 occurred in 50.0% of the avelumab group and 8.1% of the control group. A total of 11.1% of avelumab-treated patients discontinued due to TEAEs and one TEAE – a case of sepsis – was fatal.
Immune-related AEs of grade 3 were reported in 8.3% of patients in the avelumab arm and there were no such events of grade 4 or 5.
“Overall, these results support the consideration of avelumab [first-line] maintenance as a potential new standard of care in Japanese patients with advanced UC that has not progressed with [first-line] platinum-containing chemotherapy,” concluded Tsuchiya and team.
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This independent news story was supported by an educational grant from Pfizer and Merck Healthcare KGaA, Darmstadt, Germany