Platinum resistant means that the cancer is not put into remission with the protocol using cis platinum. My wife had a full six treatments with taxol & cis platinum and did not go into remission . for that reason, her cancer is considered platinum resistant. I think they also consider it platinum refractory or resistant if it come back within 6 months of platinum therapy. Ovarian cancer that develops resistance is not good , and that is what my wife is battling with. If you read the intro page with the new developments in ovarian cancer on cancercompass you will see that there is a lot of research being done with this problem. Review the articles since Feb 1 to current and you will see several exciting new development for this problem. I just humbly pray to God that they will be the answer for my wife and so many other women that are suffering with this condition.