Weekly administration of temsirolimus for heavily pretreated patients with clear cell carcinoma of the ovary: a report of six cases

Clear cell carcinoma (CCC) of the ovary is well-known to be chemotherapy resistant compared with other histologic subtypes. An inhibitor against the mammalian target of rapamycin, temsirolimus (TEM) has been reported to be effective in renal CCC. Therefore, we investigated the effects of TEM in patients with CCC of the ovary. Six patients with CCC of the ovary who had been heavily pretreated by more than 4 regimens were given TEM: the cycle consisted of weekly TEM (10 mg/m²) for 3 weeks followed by 1 week off. The treatment was continued until development of either progressive disease, or unmanageable adverse effects. Response evaluation was based upon the Response Evaluation Criteria in Solid Tumors version 1.0. Adverse effects were analyzed according to Common Terminology Criteria for Adverse Events version 3.0. The median cycle of weekly TEM was 3 (range 2–14). Among five cases in which responses could be evaluated, partial response was observed in one case (20%) and stabilized disease was seen in another case (20%). There were no toxicities greater than grade 3, and no case developed severe toxicity requiring discontinuation of weekly TEM. The patient who showed a partial response obtained a progression-free period of 14 months. In conclusion, weekly TEM shows a potential therapeutic benefit for patients with CCC of the ovary. Further studies including a translational approach are needed to select candidates for whom TEM therapy would be beneficial.