Atezolizumab proven safe, effective in understudied urinary tract carcinoma patients

A recent study has demonstrated the safety and efficacy of atezolizumab in under-represented individuals with metastatic urinary tract carcinoma, specifically those with older age, renal impairment, or upper tract urothelial carcinoma.

“The understudied populations included in the SAUL study had similar outcomes to those in more selected populations included in phase II/III trials of atezolizumab, except for those with Eastern Cooperative Oncology Group performance status (ECOG PS) 2,” the researchers said.

In this study, metastatic urinary tract carcinoma patients received atezolizumab 1,200 mg every 3 weeks until disease progression, unacceptable toxicity, loss of clinical benefit, or patient/physician decision. Safety was the primary endpoint and efficacy secondary.

The researchers prespecified analyses by programmed cell death ligand-1 (PD-L1) status, age, ECOG PS, and renal impairment. They also conducted post hoc analyses to explore outcomes by tumour location.

A total of 1,004 patients participated in this study. In subgroup analyses, the safety and efficacy of atezolizumab among patients with older age, renal impairment, or upper tract urothelial carcinoma were comparable to those without these characteristics.

Patients with ECOG PS 2 showed clinical features that correlated with aggressive disease. Their median overall survival was 2.3 months relative to 10.0 months in those with ECOG PS 0/1.

Furthermore, outcomes appeared to be better among patients with PD-L1 expression on ≥5-percent of tumour-infiltrating immune cells than those with <5-percent PD-L1 expression, but conclusions of the relative efficacy of atezolizumab could not be derived from this single-arm study.

“Age ≥80 years and/or creatinine clearance <30 ml/minute does not preclude administration of atezolizumab; however, treatment risk versus benefit must be carefully assessed in patients with ECOG PS 2,” the researchers said.