5091 - Multicenter Phase I/II Feasibility Study of Adjuvant Treatment with S-1 in Patients after R0-Resection of Adenocarcinoma of the Stomach and Esophagogastric Junction (GMBH-STO-0114)

Background

S-1 has been shown to be an effective adjuvant treatment for East Asian patients who underwent gastrectomy with a D2 lymph-node dissection for stage II/III gastric cancer. We designed a phase I/II study to evaluate the efficacy, toxicity and feasibility of administering S-1 in the adjuvant setting after R0-Resection of adenocarcinoma of the stomach and esophagogastric junction in caucasian patients.

Methods

Eligible patients with histologically confirmed adenocarcinoma T2/T3/T4, any N category, M0 or any uT, N+, M0 of the stomach or esophago gastric junction had undergone R0-resection with or without neoadjuvant treatment and D2 lymph node dissection. They had performance status of ECOG 0-1 and adequate organ function. Treatment was orally administered S-1 (30mg/m² twice daily) for 14 days every three weeks for 18 cycles (54 weeks). A primary endpoint of the study is the determination of the recommended dose for S-1. Follow up will be continued until one year after last patient’s end of treatment.

Results

Between Oct 2015 and Feb 2018, 30 patients were enrolled in 12 German centres. Male/female ratio was 56.7%/43.3%, median age was 61.5 years. Of 30 patients included, 10 were diagnosed with gastric cancer, 20 with EGJ cancer (3 AEG I, 6 AEG II and 11 AEG III). Of 30 patients starting adjuvant therapy, 17 completed all 18 cycles, 2 patients had to terminate study treatment due to adverse events. Five patients terminated study treatment due to patients wish, 4 patients suffered a relapse or distant metastasis. Nine patients had to be reduced to dose level 25 mg/m², 1 patient had to be reduced to 20 mg/m². One patient was underdosed for the first 6 cycles and received full dosage from cycle 7. Of patients completing all 18 cycles, 5 had did so with reduced dosage of S-1. Documented grade ≥ 3 adverse events were neutropenia (n = 2), diarrhoea (n = 2), vomiting (n = 1), polyneuropathy (n = 1), palmar-plantar erythrodysaesthesia syndrome (n = 1) and rash (n = 1).

Conclusions

From this first analysis we can conclude that adjuvant treatment with S-1 for one year of patients suffering from gastric adenocarcinoma or EGJ cancer after R0-resection is a feasible and safe option for Caucasian patients.

Clinical trial identification

2014-004116-11.

Editorial acknowledgement

Legal entity responsible for the study

AIO-Studien-gGmbH, Berlin.

Funding

Funded by AIO-Studien-gGmbH, supported by Taiho Pharmaceutical Co., Ltd and Nordic Pharma Group.

Disclosure

All authors have declared no conflicts of interest.