ESMO Congress 2026

Zimberelimab (GLS-010) is a fully human IgG4 anti-PD-1 monoclonal antibody; preclinical studies showed a KD of 1.75×10-10 M for binding to PD-1, effective blockade of PD-L1/2 binding to PD-1, and significant antitumor activity in the MC38 model in human PD-1 knock-in mice ^[6]. Within the PD-1 class, ten anti-PD-1 antibodies including zimberelimab have been approved for multiple tumor types ^[1], and zimberelimab's global approval was granted in China ^[2]. Its published clinical evidence comes mainly from monotherapy phase II studies: in relapsed or refractory classical Hodgkin lymphoma, the IRC-assessed objective response rate among 85 patients was 90.6%, with a complete response rate of 32.9% and a 12-month progression-free survival rate of 78% ^[3]; a phase II study in previously treated recurrent or metastatic cervical cancer enrolled 105 patients ^[4]. The literature also notes that response rates with PD-1/PD-L1 monotherapy remain low, and combination therapy is the main path to superior efficacy and higher response rates ^[1].

At ESMO26, Randy Sweis, MD (UChicagoMed/UCCancerCenter), presented interim results from cohort 7 of the phase 1b TROPHY-U-01 trial: SG + EV + zimberelimab as first-line treatment for treatment-naive metastatic urothelial cancer. The key figure given in the on-site posts is an objective response rate of 81% (n=21); the poster described the efficacy as promising and said they look forward to results from larger phase II/III trials. Beyond ORR, duration of response, progression-free survival, and safety data were not disclosed in the posts.

Relative to existing knowledge, this readout extends zimberelimab's evidence base beyond the published monotherapy phase II data in classical Hodgkin lymphoma and cervical cancer ^[3][4] into a frontline solid-tumor combination setting, partnering with SG and EV, consistent with the literature's overall view that PD-1/PD-L1 monotherapy has limited response rates and that combinations deliver superior antitumor efficacy and higher response rates ^[1]. Note that the 81% comes from a treatment-naive population, whereas the published data are all in previously treated patients (cHL after two or more lines of therapy ^[3]; cervical cancer after first- or subsequent-line chemotherapy ^[4]); tumor type and line of therapy differ, so the numbers should not be compared directly.

The limitations are clear: this is an interim result from a single phase 1b cohort of only 21 patients, with ORR as the only efficacy figure given in the posts; safety and other efficacy endpoints were not disclosed, and historical data from treated populations do not provide a comparable baseline. As the poster noted, confirmatory results from larger phase II/III trials are still awaited.