Part 1:~This is an open label study. Sample size recommendations for this phase II study are determined according to Simon's two-stage Optimal design.~In the first stage, 13 patients will be accrued. The patients will receive 3 mg/kg of HLX10 every two weeks infusion combined with 600 mg HLX07 weekly (stage 1L). These patients will be assessed for treatment response after 8 weeks of first infusion of study drugs. If there are 3 or fewer responsive patients in these 13 patients, additional 13 patients will be accrued. These additional 13 patients will receive 3 mg/kg of HLX10 every two weeks infusion combined with 800 mg HLX07 weekly (Stage 1H). If 3 or fewer responses after eight weeks treatment noted in these 13 patients in stage 1H, the trial will be stopped.~If 4 or more patients are responsive to therapy in stage 1, the trial will be continued to stage 2, 30 additional patients will be accrued to reach a total of 43 patients. These additional 30 patients will receive the same dose of regimen as the prior patients.~Part 2:~This is a randomized, double-blind, multi-center, phase II clinical study to evaluate the clinical efficacy and safety of HLX10 in combination with HLX07 and chemotherapy versus HLX10 in combination with placebo and chemotherapy in the first-line treatment of R/M HNSCC. Approximately 75 first-line R/M HNSCC subjects are planned to be recruited. The sample size calculation is not based on the statistical hypothesis.~Eligible subjects after screening will be randomly assigned to the treatment group (group A) or the control group (group B) in a ratio of 2:1, with PD-L1 CPS (≥ 20 and < 20) as the stratification factor at randomization (Figure 1):~Group A: approximately 50 subjects, HLX10 in combination with HLX07 and chemotherapy (cisplatin in combination with 5-FU).~Group B: approximately 25 subjects, HLX10 in combination with placebo and chemotherapy (cisplatin in combination with 5-FU).~Cisplatin may be replaced with carboplatin when the subject is judged intolerant to cisplatin by the INV.~The study will be unblinded overall for ORR analysis approximately 3 months after the first dose of the last subject.
Part1:~A mutilpe-center, open-label, Phase II clinical trial to evaluate the efficacy and the safety of HLX10 in combination with HLX07 in patients with advanced advanced head and neck tumors.~Part2:~A randomized, double-blind, multi-center, phase II clinical study to evaluate the clinical efficacy and safety of HLX10 in combination with HLX07 and chemotherapy versus HLX10 in combination with placebo and chemotherapy in the first-line treatment of R/M HNSCC.