The first-line therapy of metastatic bladder cancer (urothelial carcinoma, UC) depends on whether a patient is cisplatin-fit or not. Cisplatin-fit patients should be treated with the standard chemotherapy protocol GC (gemcitabine/cisplatin) or alternatively MVAC (methotrexate/vinblastine/doxorubicin/cisplatin). The optimal first-line therapy for cisplatin-unfit patients remains unclear due to the lack of high level of evidence. One criterion for selecting therapy can be the PD-L1 (programmed cell death ligand 1) status of the tumor. The PD-L1-negative patients (PD-L1 <5% for atezolizumab and combined positivity score [CPS] <10 for pembrolizumab) seem to have a greater benefit from the combination chemotherapy GCa (carboplatin/gemcitabine). The PD-L1-positive patients (PD-L1 ≥5% or CPS ≥10) on the other hand may have a greater benefit from and a longer response to the two immune checkpoint inhibitors that are currently approved for this indication, namely atezolizumab and pembrolizumab. Two phase 3 trials that compare head-to-head immunotherapy alone or in combination with chemotherapy vs. chemotherapy alone may help to define the optimal first-line therapy for metastatic UC. Preliminary data from one of these studies indicate an advantage for the combination of immunotherapy with chemotherapy in all subgroups.
Keywords: Atezolizumab; Cisplatin; Pembrolizumab; Programmed cell death ligand 1; Programmed cell death 1.