A phase II open-label study of ganetespib, a novel heat shock protein 90 inhibitor for patients with metastatic breast cancer.

BACKGROUND: Ganetespib is a small molecule, nongeldanamycin HSP90 inhibitor with potent inhibitory effects on HSP90-dependent oncoproteins of relevance to breast cancer pathogenesis. We therefore tested ganetespib in an unselected cohort of patients with MBC. PATIENTS AND METHODS: Patients were treated with single agent ganetespib at 200 mg/m(2) once weekly for 3 weeks, on a 28-day cycle. Therapy was continued until disease progression. The primary end point was ORR using Reponse Evaluation Criteria in Solid Tumors version 1.1. RESULTS: Twenty-two patients were enrolled with a median age of 51(range, 38-70) years and a median Eastern Cooperative Oncology Group performance status of 0 (range, 0-1). Most patients had at least 2 previous lines of chemotherapy in the metastatic setting. Most common toxicities, largely grade 1/2, were diarrhea, fatigue, nausea, and hypersensitivity reaction. The ORR in this unselected population was 9%, with all responses coming from the subset of patients with HER2-positive MBC (2/13; 15%). One patient with TNBC had objective tumor regression in the lung metastases. The clinical benefit rate (complete response + partial response + stable disease > 6 months) was 9%, median progression-free survival was 7 weeks (95% confidence interval [CI], 7-19), and median overall survival was 46 weeks (95% CI, 27-not applicable). CONCLUSION: The study did not meet the prespecified criteria for ORR in the first stage of the Simon 2-stage model in this heavily pretreated unselected population of MBC. However, activity was observed in trastuzumab-refractory HER2-positive and TNBC. Ganetespib was well tolerated and responses in more targeted populations harboring specific HSP90-dependent oncoproteins justifies its further study, particularly as part of rational combinations.

The safety of dose-dense doxorubicin and cyclophosphamide followed by paclitaxel with trastuzumab in HER-2/neu overexpressed/amplified breast cancer.

PURPOSE: Dose-dense (dd) doxorubicin and cyclophosphamide (AC) followed by paclitaxel (P) is superior to every 3-weekly AC followed by P. Given the demonstrated cardiac safety for trastuzumab (T) with conventionally scheduled AC followed by P, we tested the safety of dd AC followed by P with T. The primary end point was cardiac safety, and the secondary end points were time to recurrence and overall survival. METHODS: Patients with HER-2/neu immunohistochemistry (IHC) 3+ or fluorescent in situ hybridization (FISH)-amplified breast cancer and baseline left ventricular ejection fraction (LVEF) of >or= 55% were enrolled, regardless of tumor size or nodal status. Treatment consisted of AC (60/600 mg/m(2)) x 4 followed by P (175 mg/m(2)) x 4 every 2-weekly with pegfilgrastim (6 mg on day 2) + T x1 year. LVEF by radionuclide scan was obtained at baseline, at months 2, 6, 9, and 18. RESULTS: From January 2005 to November 2005, 70 patients were enrolled. The median age was 49 years (range, 27 to 72 years); median LVEF at baseline was 68% (range, 55% to 81%). At month 2 in 70 of 70 patients, the median LVEF was 67% (range, 58% to 79%); at month 6 in 67 of 70 patients, it was 66% (range, 52% to 75%); at month 9 in 68 of 70 patients, it was 65% (range, 50% to 75%); and at month 18 in 48 of 70 patients, it was 66% (range, 57% to 75%). As of December 1, 2007, the median follow-up was 28 months (range, 25 to 35 months). One patient (1%) experienced congestive heart failure (CHF). There were no cardiac deaths. CONCLUSION: Dose-dense AC followed by P/T followed by T is feasible and is not likely to increase the incidence of cardiac events compared to established regimens.