Randomized Phase II Study of Gemcitabine and Docetaxel Compared With Gemcitabine Alone in Patients With Metastatic Soft Tissue Sarcomas: Results of Sarcoma Alliance for Research Through Collaboration Study 002

TLDR

Gemcitabine alone and the gemcitabine–docetaxel combination have demonstrated activity in metastatic soft tissue sarcoma. The study aimed to determine whether adding docetaxel to gemcitabine improves clinical outcomes in metastatic soft tissue sarcoma patients. An open‑label phase II trial employed a Bayesian adaptive randomization design with tumor response (complete/partial response or stable disease ≥24 weeks) as the primary endpoint. Among 119 assessable patients, gemcitabine–docetaxel achieved higher response rates (16 % vs 8 %), superior median progression‑free survival (6.2 vs 3.0 months) and overall survival (17.9 vs 11.5 months) with posterior probabilities of superiority of 0.98 and 0.97, respectively, but also higher toxicity, and the adaptive randomization proved effective in reducing exposure to inferior therapy.

Abstract

Purpose Gemcitabine as a single agent and the combination of gemcitabine and docetaxel have activity in patients with metastatic soft tissue sarcoma. To determine if the addition of docetaxel to gemcitabine improved clinical outcome of patients with metastatic soft tissue sarcomas, we compared a fixed dose rate infusion of gemcitabine versus a lower dose of gemcitabine with docetaxel. Patients and Methods In this open-label phase II clinical trial, the primary end point was tumor response, defined as complete or partial response or stable disease lasting at least 24 weeks. A Bayesian adaptive randomization procedure was used to produce an imbalance in the randomization in favor of the superior treatment, accounting for treatment-subgroup interactions. Results One hundred nineteen of 122 randomly assigned patients had assessable outcomes. The adaptive randomization assigned 73 patients (60%) to gemcitabine-docetaxel and 49 patients (40%) to gemcitabine alone, indicating gemcitabine-docetaxel was superior. The objective Response Evaluation Criteria in Solid Tumors response rates were 16% (gemcitabine-docetaxel) and 8% (gemcitabine). Given the data, the posterior probabilities that gemcitabine-docetaxel was superior for progression-free and overall survival were 0.98 and 0.97, respectively. Median progression-free survival was 6.2 months for gemcitabine-docetaxel and 3.0 months for gemcitabine alone; median overall survival was 17.9 months for gemcitabine-docetaxel and 11.5 months for gemcitabine. The posterior probability that patients receiving gemcitabine-docetaxel had a shorter time to discontinuation for toxicity compared with gemcitabine alone was .999. Conclusion Gemcitabine-docetaxel yielded superior progression-free and overall survival to gemcitabine alone, but with increased toxicity. Adaptive randomization is an effective method to reduce the number of patients receiving inferior therapy.