Phase II Trial of weekly nanoparticle albumin-bound paclitaxel with carboplatin and trastuzumab as first-line therapy for women with HER2-overexpressing metastatic breast cancer

Document Type

Article

Department

Haematology and Oncology, East Africa

Abstract

Purpose: This multicenter phase II trial evaluated the efficacy and safety of weekly nanoparticle albumin-bound paclitaxel with carboplatin and weekly trastuzumab as first-line therapy for women with HER2-overexpressing metastatic breast cancer (MBC).

Patients and Methods: We treated 32 patients who had measurable MBC that was HER2-positive defined by an immunohistochemical staining score of 3+ or gene amplification by fluorescence in situ hybridization, required for those with an IHC of 2+. Patients were treated with albumin-bound paclitaxel 100 mg/m2 and carboplatin at area under the curve (AUC) = 2 on days 1, 8, and 15 of a 28-day cycle. Trastuzumab was administered at 2 mg/kg weekly after a loading dose of 4 mg/kg. Because of hypersensitivity reactions occurring during carboplatin infusion numbers 6–8 in 4 of the first 13 patients with this premedication-free regimen, the protocol was amended for carboplatin and dosed at AUC = 6 day 1 each 28-day cycle, in lieu of introducing steroid prophylaxis. Patients were treated with 6 cycles and allowed to continue with all 3 drugs or trastuzumab alone if free of progression and unacceptable toxicity after 6 cycles.

Results: The overall response rate (ORR) was 62.5% (95% CI, 45.7%–79.3%) with 3 confirmed complete responders (CRs; 9%) and 17 confirmed partial responses (PRs; 53%). An additional 6 patients (19%) had stable disease (SD) for greater than 16 weeks for a clinical benefit rate (ORR + SD > 16 weeks) of 81%. As of April 16, 2009, 20 patients (63%) had progressed with a median progression-free survival (PFS) of 16.6 months (95% CI, 7.5-26.5 months). Antitumor activity was similar for patients treated with weekly carboplatin and every-4-week carboplatin (ORR, 65% vs. 67%, respectively). Hematologic toxicities were the only grade 4 toxicities noted and were infrequent with grade 4 neutropenia in 3 patients (9%) and 1 febrile neutropenia. Grade 2/3 peripheral neuropathy was uncommon (13%/3%).

Conclusion: Weekly albumin-bound paclitaxel with carboplatin and trastuzumab is highly active in HER2-overexpressing MBC. In the absence of corticosteroid premedication, which we avoided with albumin-bound paclitaxel, carboplatin seems best dosed every 4 weeks rather than weekly because of carboplatin-associated hypersensitivity reactions. The regimen was very well tolerated with few grade 3 and 4 nonhematologic toxicities experienced, and severe hematologic toxicity and peripheral neuropathy were infrequent.

Comments

This work was published before the author joined Aga Khan University.

Publication (Name of Journal)

Clinical Breast Cancer

DOI

https://doi.org/10.3816/CBC.2010.n.036

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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