[2065] Capecitabine (X) + trastuzumab (H) as first-line treatment in patients (pts) with HER2-positive metastatic breast cancer (MBC): phase II trial results.

Xu L, Song S, Zhu J, Luo R, Li L, Jiao S, Pan H, Tao M, Su Y, Liu D.. Cancer Hospital Affiliated to Fudan University, Shanghai, China; Beijing 307 Hospital of PLA, Beijing, China; Ruijin Hospital Affiliated to Shanghai No. 2 Medical University, Shanghai, China; First Military Medical University Nanfang Hospital, Guangzhou, China; Heilongjiang Provincial Cancer Hospital, Haerbin, China; Hospital 301 of PLA, Beijing, China; Shao Yifu Hospital Affiliated to Zhejiang University, Hangzhou, China; No. 1 Hospital Affiliated to Suzhou University, Suzhou, China; Jiangsu Provincial Peoples Hospital, Nanjing, China; General Hospital of Beijing Military Area, Beijing, China

Background: The oral fluoropyrimidine X (Xeloda) has consistently high activity and favorable safety in MBC. Adding X to docetaxel extends survival beyond docetaxel [OShaughnessy et al. 2002]. Adding H (Herceptin) to a taxane in HER2-positive MBC provides significant clinical benefit, including prolonged survival. H adds little to the toxicity of taxanes alone. Preliminary data [Bangemann et al. 2000] indicated that X+H is effective and well-tolerated in heavily pretreated pts with HER2-positive MBC (overall response rate [ORR] 47%). We evaluated the efficacy and safety of X+H in first-line MBC. Materials and Methods: 90/100 planned pts were enrolled between Mar03 and Feb05. All pts had measurable (WHO criteria), HER2-positive (IHC 3+ or IHC 2+/FISH positive), previously untreated MBC, with a KPS 60 and adequate organ function. Pts received X 1250mg/m² bid d1-14 q3w (max 6 cycles) and H, which was administered as a 4mg/kg loading dose followed by 2mg/kg i.v. weekly (until disease progression). Primary endpoint: progression-free survival (PFS). Results: 43 pts are evaluable and 47 are still being analyzed. Baseline characteristics of evaluable patients: median age 49 years (range 27-74), median KPS 90 (range 60-100). Primary tumor sites were lymph nodes 49%, lung 33%, liver 28%, breast 14%, thoracic wall 9%, chest 9%, other 12%. Prior treatment included surgery 77%, radiotherapy 21% and adjuvant chemotherapy 58% (including anthracyclines 35%, paclitaxel 7%, docetaxel 7%, other 21%). 6 pts received 3 cycles of X + H; the remaining 37 pts completed 6 cycles of treatment. 16 pts received H monotherapy after completing 6 cycles of X+H. 3 pts discontinued H due to disease progression. ORR was 63%, including 5 CRs and 22 PRs. At a median follow-up of 6 months, median PFS has not been reached. Most common grade 1/2 adverse events (AEs) were hand-foot syndrome (HFS) 14%, neutropenia 14%, SGOT abnormality 16%, and SGPT abnormality 14%. Grade 3 HFS occurred in 4 pts (9%) and grade 3 myelosuppression affected 1 pt (2%). AEs resolved in all pts. Discussion: X+H appears to be highly active and well-tolerated as first-line treatment for HER2-positive MBC. Updated data will be presented at the meeting.

Friday, December 15, 2006 7:00 AM

Poster Session II: Treatment: Antibody-based Regimens (7:00 AM-9:00 AM)