tislelizumab + oxaliplatin + tegafur

The combination of tislelizumab, oxaliplatin, and tegafur (often referred to as SOX regimen when tegafur/S-1 is combined with oxaliplatin) represents a treatment approach being investigated primarily for gastric and gastroesophageal junction cancers. Tislelizumab is a humanized IgG4 monoclonal antibody that targets PD-1, designed to maximize inhibition of PD-1 binding to PD-L1 while minimizing binding to Fcγ receptors[6]. Oxaliplatin is a platinum-based chemotherapy agent, and tegafur (often administered as S-1, which contains tegafur, gimeracil, and oteracil) is a fluoropyrimidine antineoplastic agent. ## Clinical Development This combination is being studied in several clinical trials, particularly for gastric and gastroesophageal junction (G/GEJ) cancers. A phase 2 trial investigated tislelizumab combined with S-1 plus oxaliplatin (SOX) in patients with advanced locally advanced G/GEJ cancer[1][2]. The results showed promising efficacy: - 53.1% of patients achieved major pathological response (MPR) - 25.0% had a pathological complete response (pCR) - 1-year overall survival rate was 91.4% - 1-year recurrence-free survival rate was 90.0%[1] The treatment regimen typically consists of: - Tislelizumab: 200 mg intravenously once every 3 weeks - S-1 (tegafur): 40 mg/m² orally twice daily for 14 days followed by 7 days off - Oxaliplatin: 130 mg/m² intravenously on day 1 every 3 weeks[2] ## Safety Profile The combination appears to have a manageable safety profile. In the phase 2 trial, adverse events occurred in 65.6% of patients, with grade III-IV adverse events observed in 12.5% during the neoadjuvant period[1]. The study concluded that the neoadjuvant PD-1 inhibitor tislelizumab combined with SOX had promising application potential without increasing treatment-related adverse events[1][2]. ## Mechanism of Action The combination works through multiple mechanisms: 1. Tislelizumab blocks PD-1, restoring T-cell function and resulting in immune-mediated antitumor activity[6][8] 2. Oxaliplatin is a platinum compound that forms DNA adducts, inhibiting DNA replication and transcription 3. Tegafur/S-1 is a prodrug that converts to 5-fluorouracil in the body, inhibiting thymidylate synthase and disrupting DNA synthesis This multi-modal approach combines immunotherapy with traditional chemotherapy, potentially offering synergistic effects in treating cancer.

Brand names

TeysunoEloxatinTevimbra

Other names

tislelizumab + SOXtislelizumab + S-1 + oxaliplatin