A Study of Trastuzumab Emtansine Versus Taxane in Participants With Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Advanced Gastric Cancer

Summary

This multicenter, randomized, adaptive Phase II/III study will evaluate the efficacy and safety of trastuzumab emtansine (T-DM1) compared to standard taxane (docetaxel or paclitaxel) treatment in participants with human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer. At the start of the trial (stage 1), participants will be randomized with a ratio 2:2:1 to one of three treatment arms: Arm A: trastuzumab emtansine 3.6 milligram per kilogram (mg/kg) per intravenous injection (IV) every 3 weeks; Arm B: trastuzumab emtansine 2.4 mg/kg IV every week; Arm C: standard taxane therapy (docetaxel 75 milligram per meter square \[mg/m\^2\] IV every 3 weeks or paclitaxel 80 mg/m\^2 kg IV every week per investigator choice). At the end of the first stage of the study, the dose and schedule of trastuzumab emtansine that will be used in the second stage of the study will be selected by an Independent Data Monitoring Committee (IDMC). The regimen selection analysis will be made after approximately 100 participants across all three study arms have been treated for at least 12 weeks. Once a trastuzumab emtansine regimen has been selected, Stage I participants who were assigned to the treatment arm which was selected for Stage II of the study and participants who were in the standard taxane group will continue to receive their assigned treatment regimen. Stage I participants who were assigned to the regimen that was not selected for further evaluation will continue to receive their assigned regimen and will continue to be followed for efficacy and safety. In Stage II of the study, additional participants will be recruited and randomized with a ratio 2:1 to either the selected regimen of trastuzumab emtansine or to the standard taxane therapy. Participants will receive study treatment until disease progression, unacceptable toxicity, initiation of another cancer therapy or withdrawal.

Timeline

Start

2012-09-03

Primary completion

2015-06-30

Completion

2016-04-30

Publications

• Shah MA, Kang YK, Thuss-Patience PC, Ohtsu A, Ajani JA, Van Cutsem E, Hoersch S, Harle-Yge ML, de Haas SL. Biomarker analysis of the GATSBY study of trastuzumab emtansine versus a taxane in previously treated HER2-positive advanced gastric/gastroesophageal junction cancer. Gastric Cancer. 2019 Jul;22(4):803-816. doi: 10.1007/s10120-018-00923-7. Epub 2019 Jan 31.
• Thuss-Patience PC, Shah MA, Ohtsu A, Van Cutsem E, Ajani JA, Castro H, Mansoor W, Chung HC, Bodoky G, Shitara K, Phillips GDL, van der Horst T, Harle-Yge ML, Althaus BL, Kang YK. Trastuzumab emtansine versus taxane use for previously treated HER2-positive locally advanced or metastatic gastric or gastro-oesophageal junction adenocarcinoma (GATSBY): an international randomised, open-label, adaptive, phase 2/3 study. Lancet Oncol. 2017 May;18(5):640-653. doi: 10.1016/S1470-2045(17)30111-0. Epub 2017 Mar 23.

Drugs

Indications