CabaGast: multicentre, Phase II study with cabazitaxel in previously treated patients with advanced or metastatic adenocarcinoma of the esophagogastric junction and stomach

INTRODUCTION: This is a single-arm study (NCT01956149) to determine the prolonged (≥ 4 months) disease control rate with cabazitaxel administered in second-(or later) setting for patients with advanced or metastatic adenocarcinoma of the esophagogastric junction (EGJ) and stomach.

METHODS: 65 patients with advanced EGJ and stomach cancer were treated with 20 mg/m2 cabazitaxel every 3 weeks for a maximum of six cycles. The main objective of the study is a prolonged disease control rate (pDCR: CR, PR or SD lasting at least 4 months). Secondary outcome measures were overall survival, progression-free survival, response rate by subgroup (with vs without previous treatment with a taxane) and toxicity. Patients were assessed for tumor response every 6 weeks during therapy and during the follow-up (up to 12 months).

RESULTS: 65 patients (median age: 63, range 31-86 years) were assigned to treatment. Median no. of prior therapies that had received prior taxane therapy was 2. 80%. Patients received a median of two cycles of cabazitaxel. Efficacy results are for the ITT population. The mDCR in n = 65 patients was 10.8% (95% CI 4.4-20.9%). There was a control of disease (CR + PR + SD) in n = 26 patients of n = 65, corresponding to a DCR of 40.0% (95% CI 28.0-52.9%). In patients without prior taxane use, it was 46.2% (95% CI 25.1-80.8%) and in patients with only one prior therapy, DCR was 50.0% (95% CI 31.3-68.7%). The median overall survival was 4.6 months (95% CI 3.16, 5.59) in the whole ITT population. In patients with only one prior therapy, median OS was 5.4 months (95% CI 2.60, 7.43) and in patients without taxane pretreatment, it was 6.4 months (95% CI 1.38, 14.17). The median progression-free survival time was 1.5 months (95% CI 1.32, 2.27) in the whole ITT population, 2.9 months (95% CI 0.72, 4.67) without prior taxane therapy and was 1.7 (95% CI 1.28, 3.35) months in patients with only one prior therapy median.

CONCLUSIONS: Cabazitaxel is active in heavily pretreated patients with metastatic and advanced esophagogastric junction and gastric adenocarcinoma. Efficacy results in a classic second-line population are comparable to other second-line studies, therefore, under the limitations of this trial, (single arm, Phase II design) cabazitaxel might be an option especially in patients without prior taxane therapy, in second line and even further line therapy of metastatic and advanced esophagogastric junction and gastric adenocarcinoma.