A phase II study of carboplatin plus paclitaxel in advanced thymoma or thymic carcinoma: E1C99

Abstract

8018 Background: Thymoma (THY) and thymic carcinoma (TC) are the most common tumors of the anterior mediastinum. Anthracycline-based combination chemotherapies have yielded response rates ranging from 50–90% in previously untreated patients (pts). The primary endpoint of this trial was to evaluate the objective response rate of paclitaxel plus carboplatin in previously untreated pts with advanced THYor TC. Secondary endpoints include the duration of response and toxicity for this regimen. Methods: Patients (pts) with histologically proven, unresectable THY or TC, PS <2, without prior systemic chemotherapy for thymic malignancies were eligible. Pts were treated with carboplatin (AUC = 5) plus paclitaxel (225 mg/m2) every 3 weeks for a maximum of six cycles of therapy. Results: From February, 2001 to December, 2007, 46 pts were enrolled (THY= 25; TC= 21). One pt was ineligible and never received therapy ( in THY). All treated pts were included in the toxicity analysis and all eligible were included in the survival analysis. Over 62 % of pts had Stage IV disease (most common metastasis sites were pleura and lung). Five pts had preexisting autoimmune disease including myasthenia gravis. Thirteen pts had ≥Grade 4 toxicity, most commonly, neutropenia. Using RECIST criteria, 3 CR and 5 PR (CR + PR= 33%, 90% CI 18–52%) were observed in 24 pts with THY; fifteen had stable disease. For the 21 pts with TC, no CR and 5 PRs (24%; 90% CI 10–44%) were observed; seven had stable disease. The progression-free survivals were 19.8 and 6.2 mos for THY and TC respectively. To date, only 3 (12%) pts with THY have died compared to 16 (76%) pts with TC. The median survival time is 15 mos for TC pts, but has not been reached for pts with THY. Conclusions: This represents one of the largest prospective trials in previously untreated, advanced thymic malignancies. Carboplatin plus paclitaxel has moderate clinical activity for patients with thymic malignancies that appears less than expected with cisplatin plus anthracycline-based therapy. Patients with thymic carcinoma have a poorer progression free survival and overall survival than patients with thymoma. No significant financial relationships to disclose.