Due to different modes of action the addition of trabectedin to pegylated liposomal doxorubicin (PLD), this regimen is assumed to benefit relapsed platinum-sensitive ovarian cancer patients. Phase III study results show a moderate improvement regarding the surrogate PFS of 1.7 months when trabectedin is added to PLD compared to the PLD arm alone. Hence, both, FDA and EMEA call for mature OS data to support the prolonged surrogate PFS. Further, due to lack of head-to-head trials with other available therapy options the relative efficacy of these regimens has to be determined.