The goal of this clinical trial is to evaluate the efficacy and safety of Iparomlimab and Tuvonralimab (anti PD-1/CTLA-4) combined with albumin-paclitaxel in the second-line treatment of patients with advanced gastric/gastroesophageal junction adenocarcinoma. The main questions it aims to answer are: 1. Can the combination of Iparomlimab/Tuvonralimab and albumin-paclitaxel for advanced gastric cancer/gastroesophageal junction cancer who has progressed or is intolerant to first-line SOC prolong the PFS and OS, improve ORR, DCR, and prolong DoR; 2. Whether Iparomlimab/Tuvonralimab ( anti PD-1/CTLA-4) combined with albumin-paclitaxel for second-line treatment remains effective for patients who have progressed from first-line PD-1±chemotherapy; 3. The safety and tolerability of Iparomlimab/Tuvonralimab in combination with albumin-paclitaxel for second-line treatment.Participants will:1. Use Iparomlimab/Tuvonralimab 5.0mg/kg, D1, Q3W; At least 30 minutes later, administer the chemotherapy albumin-paclitaxel: 260mg/m², D1, Q3W, and complete the infusion within 30 minutes. The combined regimen was administered every 3 weeks, with efficacy evaluated every 2 cycles (RECIST 1.1) until disease progression, intolerable toxicity or patient withdrawal.

Inclusion Criteria:

• Aged 18-75;
• ECOG PS 0-2;
• Histologically confirmed advanced of the gastric cancer/gastroesophageal junction adenocarcinoma;
• Failure of first-line treatment: Progression or intolerance after receiving platinum-based (oxaliplatin/cisplatin) + fluorouracil (5-FU/ capecitabine /S-1) regimens;
• The first-line use of PD-1 inhibitors is permitted;
• At least one measurable lesion (RECIST v1.1);
• Good organ function (ANC≥1.5×109/L, PLT≥100×109/L, with normal liver and kidney functions）.

Exclusion Criteria:

• Her2-positive gastric cancer/gastroesophageal junction adenocarcinoma;
• Active autoimmune disease;
• Previously received PD-1/CTLA-4 bispecific antibody or taxanes at first-line treatment.