When trabectedin was administered to soft tissue sarcoma (STS) patients receiving doxorubicin, neither progression-free nor overall survival significantly improved, investigators found.
In addition, patients who received both drugs were significantly more likely to experience adverse events.
“The combination of trabectedin plus doxorubicin did not show superiority over doxorubicin alone as first-line treatment of advanced STS patients, at least under this schedule. Moreover, the experimental arm was significantly more toxic than the control arm, especially regarding thrombocytopenia, vomiting, liver toxicity, and asthenia,” wrote Dr. Javier Martin-Broto of the Virgen del Rocio Hospital and Biomedicine Institute, Seville (Spain) and his associates (J Clin Oncol. 2016. doi: 10.1200/JCO.2015.65.3329).
Of 115 adult patients with advanced nonresectable or metastatic STS, 59 received doxorubicin only, 55 received both doxorubicin and trabectedin, and one patient was not treated. In the experimental group, doxorubicin was administered before trabectedin. Both the experimental and control groups underwent six cycles of their respective drug regime unless disease progression or unacceptable toxicity was observed.
A Cox proportional hazard regression model revealed that the progression-free survival was not significantly higher among patients receiving trabectedin and doxorubicin compared to patients only receiving doxorubicin (5.7 months vs. 5.5 months; hazard ratio, 1.16; 95% confidence interval, 0.79-1.71; P = .45). Overall survival was also not significantly different between the groups (13.3 months vs. 13.7 months; HR, 1.21; 95% CI, .77-1.92, P = .41).
However, compared with patients who only received doxorubicin, patients who received both trabectedin and doxorubicin experienced significantly more adverse events such as grade 3 or 4 thrombocytopenia (2% vs. 18%, P = .016), grade 3 or 4 liver toxicity (12% vs. 29%, P = .002), AST (0% vs. 8%, P = .007), ALT (0% vs. 19%, P less than .001), and grade 3 or 4 asthenia (4% vs. 25%, P = .002).
On Twitter @jess_craig94