Results from the STAMP Study: Adjuvant GemCis versus Capecitabine in Patients with Resected Lymph Node–Positive eCCA

Adjuvant capecitabine (CAP) is the current standard of care as adjuvant therapy for patients with resected cholangiocarcinoma (CCA); however, patient outcomes are still suboptimal. The multicenter, open-label, randomized, phase 2 STAMP study investigated the role of adjuvant gemcitabine/cisplatin (GemCis) versus standard CAP in patients with resected lymph node–positive extrahepatic cholangiocarcinoma (eCCA). Results of the STAMP trial were presented at the 2022 ASCO annual meeting.

Between July 2017 and November 2020, the study enrolled patients aged ≥19 years with ECOG performance status 0/1, adenocarcinoma of a perihilar or distal bile duct, ≥1 regional lymph node metastases (N1 or greater), and complete macroscopic (R0 or R1) resection within 12 weeks before being randomly assigned to a treatment group. Patients with distant metastasis, R2 disease, previous chemotherapy or radiotherapy, or a serum cancer antigen 19.9 level ≥100 U/mL were excluded.

Eligible patients were randomly assigned 1:1 to receive 8 cycles of GemCis (gemcitabine 1000 mg/m² intravenously [IV], cisplatin 25 mg/m² IV, on days 1 and 8, every 3 weeks) or CAP (1250 mg/m² orally twice daily on days 1-14, every 3 weeks). The primary end point was disease-free survival (DFS); secondary end points included overall survival (OS) and safety.

The intention-to-treat population enrolled a total of 101 patients (GemCis group, 50; CAP group, 51). Overall, the primary tumor sites included perihilar bile duct in 45 (44.6%) patients and distal bile duct in 56 (55.4%) patients; 32 (31.7%) patients had R1 resection. Patient characteristics were well-balanced between the 2 arms.

With a median follow-up of 33.4 months, the 2-year DFS rates were numerically higher in the GemCis group compared with the CAP group, 38.5% (90% confidence interval [CI], 29.5%-47.4%) versus 25.1% (90% CI, 17.4%-33.5%), but this difference was not statistically significant (P = .430). The median DFS was 14.3 months in the GemCis group and 11.1 months in the CAP group (hazard ratio [HR], 0.96; P = .430). The 2-year OS rate was 77.8% in the GemCis group and 71.0% in the CAP group (HR, 1.08; P = .404).

A higher proportion of patients in the GemCis group experienced grade 3/4 adverse events (AEs) compared with the CAP group (84% vs 16%). The most common grade 3/4 AE was neutropenia (72%) in the GemCis group and hand-foot skin reaction (8%) in the CAP group.

The results of the STAMP study indicated that GemCis did not improve DFS and OS outcomes compared with CAP in a prognostically homogeneous population of patients with resected lymph node–positive eCCA. Therefore, it was concluded that CAP should remain standard adjuvant therapy in this setting.

Source: Yoo C, Jeong H, Kim K, et al. Adjuvant gemcitabine plus cisplatin versus capecitabine in patients with resected lymph node–positive extrahepatic cholangiocarcinoma (STAMP): a multicenter, open-label, randomized, phase 2 study. American Society of Clinical Oncology Annual Meeting 2022. Abstract 4019.