Phase II study of receptor-enhanced chemosensitivity using recombinant humanized anti-p185HER2/neu monoclonal antibody plus cisplatin in patients with HER2/neu-overexpressing metastatic breast cancer refractory to chemotherapy treatment.
OBJECTIVE
To determine the toxicity, pharmacokinetics, response rate, and response duration of intravenous (i.v.) administration of recombinant, humanized anti-p185HER2 monoclonal antibody (rhuMAb HER2) plus cisplatin (CDDP) in a phase II, open-label, multicenter clinical trial for patients with HER2/neu-overexpressing metastatic breast cancer.


METHODS
The study population consisted of extensively pretreated advanced breast cancer patients with HER2/neu overexpression and disease progression during standard chemotherapy. Patients received a loading dose of rhuMAb HER2 (250 mg i.v.) on day 0, followed by weekly doses of 100 mg i.v. for 9 weeks. Patients received CDDP (75 mg/m2) on days 1, 29, and 57.


RESULTS
Of 37 patients assessable for response, nine (24.3%) achieved a PR, nine (24.3%) had a minor response or stable disease, and disease progression occurred in 19 (51.3%). The median response duration was 5.3 months (range, 1.6-18). Grade III or IV toxicity was observed in 22 of 39 patients (56%). The toxicity profile reflected that expected from CDDP alone with the most common toxicities being cytopenias (n = 10), nausea/vomiting (n = 9), and asthenia (n = 5). Mean pharmacokinetic parameters of rhuMAb HER2 were unaltered by coadministration of CDDP.


CONCLUSIONS
The use of rhuMAb HER2 in combination with CDDP in patients with HER2/neu-overexpressing metastatic breast cancer results in objective clinical response rates higher than those reported previously for CDDP alone, or rhuMAb HER2 alone. In addition, the combination results in no apparent increase in toxicity. Finally, the pharmacology of rhuMAb HER2 was unaffected by coadministration with CDDP.
Pegram
M D
MD
Department of Medical Oncology, The University of California at Los Angeles, USA. mpegram@ucla.edu
Lipton
A
A
Hayes
D F
DF
Weber
B L
BL
Baselga
J M
JM
Tripathy
D
D
Baly
D
D
Baughman
S A
SA
Twaddell
T
T
Glaspy
J A
JA
Slamon
D J
DJ
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D002945:Cisplatin / Q000008:administration & dosage*; D018450:Disease Progression; D019008:Drug Resistance, Neoplasm; D005260:Female; D018734:Genes, erbB-2; D006801:Humans; D008875:Middle Aged; D000068878:Trastuzumab
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D000068878:Trastuzumab; D002945:Cisplatin