Background: The purpose of the study was to assess the safety, tolerability, recommended phase II dose (RPTD), and preliminary antitumor activity of the combination of carboplatin–paclitaxel (Taxol)–temsirolimus.
Materials and methods: Patients with solid malignancies suitable for carboplatin–paclitaxel (CP) chemotherapy and two or less prior lines of chemotherapy received 15, 20, or 25 mg of temsirolimus per week with CP given every 21 days. Thirty-eight eligible patients were entered into six dose levels with the first two levels administering temsirolimus on days 8 and 15 and the subsequent four dose levels switching to days 1 and 8 temsirolimus administration.
Results: Days 8 and 15 administration of temsirolimus was not feasible due to myelosuppression on day 15. CP on day 1 with temsirolimus on days 1 and 8 was well tolerated. Dose-limiting toxicity (DLT) was grade 4 thrombocytopenia (n = 2) and grade 3 fatigue (n = 1). Relative dose intensities for carboplatin, paclitaxel, and temsirolimus at the RPTD were 92%, 82%, and 56%, respectively. Non-DLT treatment-related adverse events occurring in >20% of patients included fatigue, mucositis, alopecia, neuropathy, nausea, neutropenia, thrombocytopenia, and infection. Grade 3/4 non-hematological toxicity was rare. Partial responses (PRs) and disease stabilization were seen in 46% and 49% of patients, respectively. Nine of 11 (82%) endometrial cancer patients had objective PRs.
Conclusion: Carboplatin–paclitaxel–temsirolimus is well tolerated and the RPTD is carboplatin area under the curve 5 mg/ml/min, paclitaxel 175 mg/m2, both given on day 1 with temsirolimus 25 mg on days 1 and 8.