Two concurrent phase II trials of paclitaxel/carboplatin/trastuzumab (weekly or every-3-week schedule) as first-line therapy in women with HER2-overexpressing metastatic breast cancer: NCCTG study 983252.
OBJECTIVE
The efficacy and tolerability of 2 different schedules of paclitaxel/carboplatin/trastuzumab for HER2-overexpressing metastatic breast cancer (MBC) were evaluated in this parallel multicenter phase II trial.


METHODS
Patients received every-3-week therapy (n = 43) consisting of a 200 mg/m(2) dose of paclitaxel/carboplatin area under the curve (AUC) of 6 mg/mL per minute and trastuzumab (an initial 8 mg/kg dose and subsequent 6 mg/kg doses) administered every 21 days for 8 cycles or weekly therapy (n = 48) consisting of an 80-mg/m(2) dose of paclitaxel/carboplatin AUC of 2 mg/mL per minute for 3 of 4 weeks, with weekly trastuzumab (an initial 4-mg/kg dose and subsequent 2-mg/kg doses) administered every 4 weeks for 6 cycles. Trastuzumab was continued until disease progression or unacceptable toxicity. HER2 status was confirmed by a central laboratory review.


RESULTS
The overall response rate (ORR) with every-3-week therapy was 65% (90% confidence interval [CI], 51%-77%), with a median time to disease progression of 9.9 months and median overall survival (OS) time of 2.3 years. The ORR with weekly therapy was 81% (90% CI, 70%-90%), with a median time to disease progression of 13.8 months and a median OS time of 3.2 years. Hematologic and nonhematologic toxicities occurred significantly less frequently with weekly therapy versus every-3-week therapy: grade 3/4 neutropenia (52% vs. 88%); grade 3 thrombocytopenia (4% vs. 30%); and grade 3 neurosensory toxicity (2% vs. 19%), respectively.


CONCLUSIONS
Every-3-week and weekly regimens of paclitaxel/carboplatin/trastuzumab are highly active in women with HER2-overexpressing MBC. However, fewer patients developed severe neutropenia, leukopenia, or thrombocytopenia with the weekly schedule.
Perez
Edith A
EA
Mayo Clinic and Mayo Foundation, Jacksonville, FL 32224, USA. perez.edith@mayo.edu
Suman
Vera J
VJ
Rowland
Kendrith M
KM
Ingle
James N
JN
Salim
Muhammad
M
Loprinzi
Charles L
CL
Flynn
Patrick J
PJ
Mailliard
James A
JA
Kardinal
Carl G
CG
Krook
James E
JE
Thrower
Abby R
AR
Visscher
Daniel W
DW
Jenkins
Robert B
RB
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000009:adverse effects; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D016190:Carboplatin / Q000008:administration & dosage / Q000009:adverse effects; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008875:Middle Aged; D017239:Paclitaxel / Q000008:administration & dosage / Q000009:adverse effects; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D015996:Survival Rate; D000068878:Trastuzumab; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D016190:Carboplatin; D017239:Paclitaxel; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab