Phase II study of CT-2103 as first- or second-line chemotherapy in patients with metastatic breast cancer: unexpected incidence of hypersensitivity reactions.
This study evaluated the safety and efficacy of CT-2103, a novel conjugate of paclitaxel and poly-L-glutamate, in patients with HER2-negative, metastatic breast cancer who had received 0 or 1 prior lines of chemotherapy. Although CT-2103 had activity in this small study, neurotoxicity and hypersensitivity reactions were more frequent in this patient population than expected, and led to early termination of the trial.


OBJECTIVE
To evaluate the safety and efficacy of CT-2103, a novel conjugate of paclitaxel and poly-L-glutamate, in patients with metastatic breast cancer who had received 0 or 1 prior lines of chemotherapy.


METHODS
Eighteen women with HER2-negative breast cancer were enrolled. Patients received intravenous CT-2103 at a dose of 175 mg/m2 of conjugated paclitaxel over 10 min every 3 weeks, without routine premedication. Eighty-three percent of women had received prior chemotherapy as part of adjuvant (39%), metastatic (17%), or both adjuvant and metastatic (28%) treatment. Three patients (17%) had previously received a taxane in the adjuvant setting.


RESULTS
Objective responses were observed in 4 of 18 patients (overall response rate, 22%, 95% confidence interval, 6 to 48%). Grade 3 or 4 neuropathy was observed in four patients. Grade 3 or 4 hypersensitivity reactions (HSR) were observed in four patients; none occurred prior to cycle 4 of therapy. Because of the higher-than-expected rate of HSR, the study was terminated early.


CONCLUSIONS
Although CT-2103 had activity in this small study of women with HER2-negative metastatic breast cancer, neurotoxicity and hypersensitivity reactions were more frequent in this patient population than expected. Hypersensitivity reactions were most likely to occur in later cycles of treatment, suggesting a true drug allergy, distinct from the HSR typically seen with standard paclitaxel.
Lin
Nancy U
NU
Department of Medical Oncology, Dana-Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA.
Parker
Leroy M
LM
Come
Steven E
SE
Burstein
Harold J
HJ
Haldoupis
Margaret
M
Ryabin
Nicole
N
Gelman
Rebecca
R
Winer
Eric P
EP
Shulman
Lawrence N
LN
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D018450:Disease Progression; D004342:Drug Hypersensitivity / Q000209:etiology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D017239:Paclitaxel / Q000031:analogs & derivatives; D011099:Polyglutamic Acid / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use / Q000031:analogs & derivatives; D043823:Taxoids / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*
D000970:Antineoplastic Agents; D043823:Taxoids; D011099:Polyglutamic Acid; D017239:Paclitaxel; C509139:paclitaxel poliglumex