104P - Final analysis of the prospective, randomized phase II STAMP trial: Adjuvant gemcitabine plus cisplatin (GemCis) versus capecitabine (CAP) in node-positive extrahepatic cholangiocarcinoma (CCA)

Background

The primary analysis of the STAMP trial demonstrated that adjuvant GemCis did not improve disease-free survival (DFS) compared to CAP in patients (pts) with resected, lymph node (LN)-positive extrahepatic CCA. As overall survival (OS) data were not matured at primary analysis, we report the updated analysis with an additional 19 months (mo) of follow-up.

Methods

Pts with adenocarcinoma of perihilar/distal bile duct with regional LN metastasis who underwent curative-intent surgery was randomized to receive GemCis (Gem 1000 mg/m2, Cis 25 mg/m2 on days 1, 8) or CAP (1250 mg/m2 twice daily on days 1–14) every 3 weeks for 8 cycles. Primary endpoint was DFS. Secondary endpoints were OS and safety. All P values were one-sided and considered significant if < 0.1.

Results

A total of 101 pts (50 in the GemCis and 51 in the CAP group) were included in the intention-to-treat population. The median follow-up duration was 52.8 mo (one-sided 90% CI, 50.1-58.2). In the GemCis and CAP groups, the median DFS was 14.6 mo (10.7-16.5) and 11.1 mo (8.4-12.7), respectively, and the 4-year DFS rates were 15.9% (9.4-24.0) and 19.4% (12.4-27.5) respectively (HR = 1.02 [0.76-1.37], P = 0.47). Median OS was 35.0 mo (29.5-42.7) and 32.3 mo (28.3-45.6), respectively, and the 4-year OS rates were 35.7% (26.5-45.1) and 38.4% (29.2-47.5), respectively (HR = 1.04 [0.75-1.44], P = 0.43). Subgroup analyses showed consistent results without significant interactions in the DFS and OS between groups, except that pts with R1 resection favored CAP in DFS and OS, and females favored GemCis in OS. Table: 104P

Conclusions

In this final analysis of the STAMP trial, adjuvant GemCis did not improve OS compared with CAP in LN-positive extrahepatic CCA. Biomarker analyses, including ctDNA-guided minimal residual disease (MRD), are currently underway.

Clinical trial identification

NCT03079427.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Chong Kun Dang Pharm, Ildong pharmaceuticals.

Disclosure

J.H. Jeong: Financial Interests, Personal, Other, honoraria: Boryung Pharmaceutical, Daewoong Phar- maceutical, Eisai, inno.N, Lilly, Novartis, Pfizer, Roche. H. Chon: Financial Interests, Personal, Advisory Role: Roche, BMS, Boryoung. C. Yoo: Financial Interests, Personal, Invited Speaker: Bayer, Celgene, Eisai, Ipsen, Servier, Roche, Novartis; Financial Interests, Personal, Advisory Board: AstraZeneca; Financial Interests, Personal, Research Grant: AstraZeneca, Bayer, Servier; Financial Interests, Institutional, Research Grant: Genentech. All other authors have declared no conflicts of interest.