This is an open label, multi-center, Phase 1/2 clinical trial in subjects with recurrent adenocarcinoma of the ovary who have been previously treated with a minimum of two courses of platinum-based chemotherapy, and up to two additional cytotoxic regimens that may also have included platinum (no more than four total lines of prior therapy), with or without bevacizumab, whose cancer has recurred within six months of the most recent platinum-based chemotherapy. All eligible subjects will receive VAL 083 i.v. in a once weekly cycle until disease progression, development of other unacceptable toxicity, death, withdrawal of consent, loss to follow-up, or Sponsor ending the study, whichever occurs first.