A phase I/II study of S-1 plus cisplatin alternating with S-1 plus docetaxel in patients with advanced gastric cancer (AGC)

• Published in: Journal of clinical oncology Vol. 29; no. 4_suppl; p. 101
• Main Authors: Hosokawa, A., Ogawa, K., Kajiura, S., Tsukioka, Y., Kobayashi, T., Horikawa, N., Kobayashi, Y., Yoshioka, A., Sumi, S., Sugiyama, T.
• Format: Journal Article
• Language: English
• Published: 01.02.2011
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/jco.2011.29.4_suppl.101

Abstract only 101 Background: S-1 plus cisplatin has been regarded as standard first-line chemotherapy for patients with AGC in Japan, and S- 1 plus docetaxel showed promising results for AGC in clinical trials. To investigate the usefulness of S-1 plus cisplatin alternating with S-1 plus docetaxel as first-line treatment in patients with AGC, we conducted a phase I/II study to determine the maximum tolerated dose (MTD), the recommended dose (RD), preliminary efficacy and toxicity. Methods: Eligibility criteria included pathologically confirmed AGC; no prior chemotherapy; Age 20 to 74, ECOG performance status (PS) of 0 to 2; adequate organ function; and written informed consent. Cisplatin was administered on day1 and the dose was escalated by 10 mg/m 2 from starting dose of 40 mg/m 2 in phase I part. S-1 was given orally at 80 mg/m 2 on day1-14. Docetaxel was administered at 40 mg/m 2 on day 22 in combination with S-1 80 mg/m 2 on days 22-35. The treatment was repeated every 6 weeks. The RD was studied in every 3-6 patients cohort and determined according to the pre-defined DLTs. Primary endpoint of phase II was the response rate (RR). Results: Between Aug 2006 and Jul 2010, 33 pts were enrolled. Nine patients entered the phase I part and 24 enrolled in phase II part. In the phase I part, the MTD of cisplatin was presumed to be 50 mg/m 2 , because 50% of patients (3/6) developed DLTs. Therefore, the RD of cisplatin was estimated as 40 mg/m 2 , and the 27 patients received the treatment at RD level. Patients characteristics were as follows: median age=65 years (range 48-74), Male: female=21:6, PS 0:1:2=11:16:0, diffuse: intestinal=19:8, initially unresectable: recurrent=24:3. The RR was 59.2% (95% CI, 40.7-77.7). Median follow-up period was 14.6 months, median PFS was 7.9 months, and median survival time was 17.2 months, although survival data remain to be confirmed. Major grade 3/4 toxicities were neutropenia (63%), leucopenia (41%), and anemia (33%). These toxicities were tolerable and manageable. No treatment-related death was observed. The updated analysis will be presented at the meeting. Conclusions: This alternating treatment seems to be effective and well tolerated in the first-line treatments in patients with AGC. No significant financial relationships to disclose.