Multicenter, randomised, open-label, non-comparative phase 2 trial on the efficacy and safety of the combination of bevacizumab and trabectedin with or without carboplatin in women with partially platinum-sensitive recurrent ovarian cancer

Background Trabectedin, in addition to its antiproliferative effect, can modify the tumour microenvironment and this could be synergistic with bevacizumab. The efficacy and safety of trabectedin and bevacizumab ± carboplatin have never been investigated. Methods In this phase 2 study, women progressing between 6 and 12 months since their last platinum-based therapy were randomised to Arm BT: bevacizumab, trabectedin every 21 days, or Arm BT+C: bevacizumab, trabectedin and carboplatin every 28 days, from cycles 1 to 6, then trabectedin and bevacizumab as in Arm BT. Primary endpoints were progression-free survival rate (PFS-6) and severe toxicity rate (ST-6) at 6 months, assuming a PFS-6 ≤35% for BT and ≤40% for BT+C as not of therapeutic interest and, for both arms, a ST-6 ≥ 30% as unacceptable. Results BT+C (21 patients) did not meet the safety criteria for the second stage (ST-6 45%; 95%CI: 23%–69%) but PFS-6 was 85% (95%CI: 62%–97%). BT (50 patients) had 75% PFS-6 (95%CI: 60%–87%) and 16% ST-6 (95%CI 7%–30%). Conclusions BT compared favourably with other platinum- and non-platinum-based regimens. The combination with carboplatin needs to be assessed further in a re-modulated safer schedule to confirm its apparent strong activity. Clinical Trial Registration NCT01735071 (Clinicaltrials.gov).