Phase II study of a 3-weekly liposome-encapsulated doxorubicin/docetaxel/pegfligrastrim in combination with weekly trastuzumab as primary treatment in HER2 positive early stage breast cancer patients (II-IIIa). GEICAM 2003-03 study.

CTRC-AACR San Antonio Breast Cancer Symposium: 2008 Abstracts Abstract #5117 Objective: To assess the safety and efficacy of Myocet (M), Docetaxel (T), Trastuzumab (H) with prophylactic Pegfilgrastrim (N) as neoadjuvant chemotherapy in operable breast cancer patients (pts). The primary efficacy end point was pathologic complete response in the breast. Methods: Eligible pts had pathologically confirmed stage II or IIIA untreated breast cancer and HER2 overexpression determined by FISH in a central laboratory. M 50 mg/m2 and T 60 mg/m2 were given on day 1 and N on day 2 every 3 weeks for 6 cycles (Cy); H (4mg/Kgr loading dose, then 2 mg/Kgr/week) was given intravenously for 17 weeks, recommended dose in a phase I study (Proc ASCO 2007,25:596s Abstr.# 11.032). After all chemotherapy was completed, clinical responses were assessed. After surgery, pathological responses were evaluated using the Miller Payne scoring scale (MPSS). Results: 59 pts have been evaluated. Median age was 47.6 years (range 24-71) and median clinical tumour size 47.5 mm (range, 10-80). 19 pts (32.2%) presented with stage IIIA disease and 40 pts (67.8%) with stage II, 36 pts (61.0%) were premenopausal; 50 pts (84.8%) had histological grade 2-3 tumours; and 29 (49.2%) were ER-PgR-negative. All the pts received M and T 6 Cy with medium relative doses intense of 98.9% and 99.1% respectively. Objective clinical response rate was 84.7% (CI: 75.5-93.9) with 31 (52.5%) complete responses and 19 (32.2%) partial responses. 42 pts (71.2%) underwent conservative surgery, 17 pts (28.8%) achieved a pathological complete response in breast (Grade 5 in MPSS), of these, 16 pts (27.1%) achieved a pathological complete response in breast and axilar (Grade 5A+Grade 5D). Main grades (G) toxicities during MTHN treatment: leucopenia G3/4 was present in 18 pts (30.5%); neutropenia G3/4 in 17 pts (28.8%); febrile neutropenia G3 in 3 pts (5.1%); diarrhea G3 was present in 3 pts (5.1%); G2 rash in 2 pts (3.4%); G3 asthenia in 5 pts (8.5%) and stomatitis G3 in 1 pt (1.7%). 8 pts (13.6%) experienced asymptomatic and reversible cardiac left ventricular function G2. Conclusions: Concomitant administration of M plus THN is highly effective and active regimen with little toxicity in pts with HER2+ and early stage breast cancer. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5117.