Efficacy and safety evaluation of HLX10 (a recombinant humanized anti-PD-1 monoclonal antibody) combined with albumin-bound paclitaxel in patients with advanced cervical cancer who have progressive disease or intolerable toxicity after first-line standard chemotherapy: A single-arm, open-label, phase 2 study.

e17510 Background: Limited effective treatments are available for advanced cervical cancer patients who progress after first-line chemotherapy. Historic data indicate PD-1 antibodies have significant activity in advanced cervical cancer patients. This study was designed to determine the efficacy and safety of HLX10 (a recombinant humanized anti-PD-1 monoclonal antibody) plus albumin-bound paclitaxel in patients with advanced cervical cancer who have progressed on or are intolerant to first-line standard chemotherapy. Methods: This is an ongoing single-arm, open-label, multicenter, two-stage phase 2 study (NCT04150575). 143 eligible patients aged between 18 and 75, with histologically or cytologically diagnosed cervical cancer and positive PD-L1 expression (combined positive score [CPS] ≥1) were planned to be enrolled and given intravenous infusion of HLX10 (4.5 mg/kg) plus albumin-bound paclitaxel (260 mg/m2) every 3 weeks. Stage one (N = 20) was a safety run-in and preliminary efficacy exploration study with primary endpoints of adverse events, serious adverse events and objective response rate (ORR, assessed by IRRC per RECIST v1.1). In this stage, after all patients completed two tumor evaluations (every 6 weeks), a safety evaluation and a preliminary evaluation of anti-tumor efficacy were conducted to determine whether to proceed to the second stage (N = 123). Stage two is a single-arm, open-label, multicenter, phase 2 study with primary endpoint of ORR assessed by IRRC per RECIST v1.1. Results: Here we report the stage one results (safety and preliminary efficacy) of HLX10 in advanced cervical cancer patients. By cut-off date Oct 14, 2020, 21 eligible patients with median age of 50 (range: 31–65) and average CPS of 39.33 were enrolled; the median follow-up duration was 4.34 months. 71.4% patients had ECOG PS 1. The ORR assessed by IRRC and investigators were 52.4% (95% CI: 29.8%, 74.3%) and 42.9% (95% CI: 21.8%, 66.0%), respectively. The most common grade 3 or worse treatment-emergent adverse events (TEAEs) were decreased neutrophil counts (n = 7, 33.3%), decreased white blood cell count (n = 6, 28.6%) and anemia (n = 4, 19.0%). No TEAEs leading to drug discontinuation were observed. One death (multiple organ dysfunction syndrome) possibly related to treatment was reported. Conclusions: Stage one results demonstrated a manageable safety profile and encouraging efficacy (ORR 52.4%) of HLX10 plus albumin-bound paclitaxel in advanced cervical cancer patients who have progressive disease or intolerable toxicity to first-line standard chemotherapy, representing a novel potential treatment option that warranted further investigation. Clinical trial information: NCT04150575.