Trastuzumab tolerability in the treatment of advanced (stage III-IV) or recurrent uterine serous carcinomas that overexpress HER2/neu.

Due to previously reported trastuzumab safety concerns and the scant data available in endometrial cancer patients, we sought to assess the safety, tolerability and toxicity profile of trastuzumab in patients with advanced/recurrent uterine serous carcinoma (USC) that overexpress HER2/neu in our multicenter randomized phase II trial. Patients were randomized 1:1 to receive carboplatin/paclitaxel (C/P) for 6 cycles ± trastuzumab (T) with the experimental arm continuing to receive single agent trastuzumab maintenance treatment until disease progression/toxicity. Progression-free-survival was the primary endpoint; overall-survival and toxicity were secondary endpoints. Adverse events (AEs) were compared between treatment arms. There were 28 patients in the C/P arm and 32 patients in the experimental (C/P + T) arm. Fifty-eight patients (97%) experienced 977 treatment-related AEs of which 875 (89.6%) were low-grade (grade 1–2) and 102 (10.4%) were high-grade (grade 3–5). The mean ± standard deviation of AEs per patient was 15.5 ± 16.3 in the C/P arm and 17.0 ± 16.0 in the C/P + T arm. Gastrointestinal AEs were the most common in both arms (n = 155, 15.7%) of which 94.2% were low-grade (n = 146). Importantly, no significant difference between treatment arms was detected in any system-organ class of AE including cardiac AE. Five (17%) of 29 patients who received prolonged trastuzumab maintenance therapy had no sign of cumulative toxicity after an average (range) of 5.1 (4.2–6.3) years. Trastuzumab appears to be safe and has a manageable toxicity profile both when used in combination with chemotherapy and when used for single agent maintenance in patients with HER2/neu positive USC. This safety profile is reassuring given the proven efficacy of trastuzumab in advanced/recurrent HER2/neu positive USC. • Our patients received an average of 21.2 and maximum of 94 cycles of Trastuzumab without significant toxicity. • The majority of adverse events were low-grade, most commonly fatigue, nausea, and constipation. • Patients who received trastuzumab maintenance had no sign of increased toxicity after an average of 5.1 years of treatment. • Elderly patients (≥70 years old) were more likely to experience a high-grade adverse event in both treatment arms. • Trastuzumab with chemotherapy appears to be safe and has a manageable toxicity profile in patients with HER2/Neu-positive USC. [ABSTRACT FROM AUTHOR]