An Epidemiologic Study on PD-L1 Expression Combined With Clinical Observation in the Chinese MIUBC Patients.

The primary objective of this observational study is:

•To investigate the prevalence of high PD-L1 expression in Chinese MIUBC patients. High PD-L1 expression is defined as ≥25% tumor cell membrane positivity for PD-L1 at any intensity above background staining as noted on the corresponding negative control OR ≥25% tumor associated immune cell positivity for PD-L1 at any intensity above background staining as noted on the corresponding negative control.

Note: PD-L1 High (>=25% tumor cell membrane positivity for PD-L1 or 1) IF IC area >1%: >=25% tumor associated immune cell positivity for PD-L1; 2) If IC area=1%: 100% tumor associated immune cell positivity for PD-L1). PD-L1 Low if criteria not met for PD-L1 High.

The second objectives of this observational study are:

• To investigate the PD-L1 expression profile in TC or IC in Chinese MIUBC patients.
• To assess the concordance of PD-L1 testing results generated from the hospital labs with those from the central lab.
• To observe the initial treatment pattern for MIUBC patients in usual clinical practice in China.
• To observe 2-year OS of the Chinese MIUBC patients.

The exploratory objectives of this observational study are:

• To explore the relationship between the demographic characteristics and expression of PD-L1 and other exploratory biomarkers including immune cell (IC) subset CD8+ T cells and tumor mutation burden (TMB).
• To explore the relationship between OS and the demographic characteristics as well as the expression of biomarkers.
• To explore the relationship between PD-L1 and TMB, PD-L1 and CD8 positive T cell respectively.

Inclusion criteria

• Age ≥18 years at the time of screening.
• Be able and willing to sign the informed consent form (ICF).
• Patients with histologically or cytologically documented, muscle invasive urothelial carcinoma (ie, T2 toT4, any N, any M) of bladder (see National Comprehensive Cancer Network [NCCN] Bladder Cancer Guidelines), who had not been previously treated with any systemic chemotherapy, radiotherapy, investigational product, or biologic therapy for cancer treatment.
• For PD-L1 testing by IHC assay, all patients were able to provide a newly acquired tumor sample within 60 days before enrollment by cystectomy, transurethral resection or biopsy. Samples with limited tumor content and fine needle aspirate specimens were not acceptable. Specimens from metastatic bone lesions were typically unacceptable unless there was a significant soft tissue component. The tumor specimen submitted to establish PD-L1 status should be of sufficient quantity to allow for PD-L1 IHC analyses and was preferred in FFPE blocks.

Exclusion criteria

• Prior acquiring tumor tissue samples exposure to immune-mediated therapy (including Bacillus Calmette Guerin), including but not limited to, any anti-CTLA-4, anti-PD-1, anti-PD-L1, or anti PD L2 antibodies, therapeutic anticancer vaccines.
• Any concurrent chemotherapy, investigational product, or biologic therapy for cancer treatment. Note: Local treatment of isolated lesions, excluding target lesions, for palliative intent was acceptable (eg, local surgery or radiotherapy).