Randomized phase III study of trastuzumab, paclitaxel, and carboplatin compared with trastuzumab and paclitaxel in women with HER-2-overexpressing metastatic breast cancer.
OBJECTIVE
This randomized, multicenter, phase III trial evaluated the efficacy and safety of trastuzumab and paclitaxel with or without carboplatin as first-line therapy for women with HER-2-overexpressing metastatic breast cancer (MBC).


METHODS
HER-2 overexpression was defined as immunohistochemical staining scores of 2+ or 3+. Between November 1998 and May 2002, 196 women with HER-2-overexpressing MBC were randomly assigned to six cycles of either trastuzumab 4 mg/kg loading dose plus 2 mg/kg weekly thereafter with paclitaxel 175 mg/m2 every 3 weeks (TP), or trastuzumab 4 mg/kg loading dose plus 2 mg/kg weekly thereafter with paclitaxel 175 mg/m2 and carboplatin area under the time-concentration curve = 6 every 3 weeks (TPC) followed by weekly trastuzumab alone.


RESULTS
Baseline characteristics of the 196 patients were well balanced between study arms. Objective response rate (ORR) was 52% (95% CI, 42% to 62%) for TPC versus 36% (95% CI, 26% to 46%) for TP (P = .04). Median progression-free survival (PFS) was 10.7 months for TPC and 7.1 months for TP (hazard ratio [HR], 0.66; 95% CI, 0.59 to 0.73; P = .03). Improved clinical outcomes with TPC were most evident in HER-2 3+ patients, with an ORR of 57% (95% CI, 45% to 70%) v 36% (95% CI, 25% to 48%; P = .03) and median PFS of 13.8 v 7.6 months (P = .005) for TPC and TP, respectively (HR, 0.55; 95% CI, 0.46 to 0.64). Both regimens were well tolerated, and febrile neutropenia and neurotoxicity occurred infrequently; grade 4 neutropenia occurred more frequently with TPC (P < .01).


CONCLUSIONS
The addition of carboplatin to paclitaxel and trastuzumab improved ORR and PFS in women with HER-2-overexpressing MBC. This well-tolerated regimen represents a new therapeutic option.
Robert
Nicholas
N
US Oncology Research Inc, Houston, TX, USA. nicholas.robert@usoncology.com
Leyland-Jones
Brian
B
Asmar
Lina
L
Belt
Robert
R
Ilegbodu
Des
D
Loesch
David
D
Raju
Robert
R
Valentine
Elizabeth
E
Sayre
Robert
R
Cobleigh
Melody
M
Albain
Kathy
K
McCullough
Cecelia
C
Fuchs
Lea
L
Slamon
Dennis
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D016190:Carboplatin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D017239:Paclitaxel / Q000008:administration & dosage; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D016019:Survival Analysis; D000068878:Trastuzumab
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D016190:Carboplatin; D017239:Paclitaxel; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab