Annals of Oncology Advance Access published online on May 13, 2008
Annals of Oncology, doi:10.1093/annonc/mdn280
Oblimersen combined with docetaxel, adriamycin and cyclophosphamide as neo-adjuvant systemic treatment in primary breast cancer: final results of a multicentric phase I study
1 Department of Gynecology and Obstetrics, University of Heidelberg, Heidelberg
2 German Breast Group, Neu Isenburg
3 Frauenklinik vom Roten Kreuz, München
4 Sanofi-Aventis GmbH, Berlin
5 Department of Pathology, University of Heidelberg, Heidelberg
6 University of Frankfurt, Department of Gynecology and Obstetrics, Frankfurt, Germany
* Correspondence to: Dr J. Rom, Department of Gynecology and Obstetrics, University of Heidelberg, Vossstrasse 9, D-69115 Heidelberg, Germany. Tel: +49-6221-56 37987; Fax: +49-6221-56-7066; E-mail: joachim.rom{at}med.uni-heidelberg.de
Background: Combining the Bcl-2 down-regulator oblimersen with cytotoxic treatment leads to synergistic antitumor effects in preclinical trials. This multicentric phase I study was carried out to evaluate maximum tolerated dose (MTD), safety and preliminary efficacy of oblimersen in combination with docetaxel, adriamycin and cyclophosphamide as neo-adjuvant systemic treatment (NST) in primary breast cancer (PBC).
Methods: Previously untreated patients with PBC T2–4a–c N0–3 M0 received one cycle of docetaxel 75 mg/m2, adriamycin 50 mg/m2 and cyclophosphamide 500 mg/m2 administered on day 5 combined with escalating doses of oblimersen as a 24-h continuous infusion on days 1–7 followed by five cycles of combination of docetaxel, adriamycin and cyclophosphamide (TAC) without oblimersen every 3 weeks. Prophylactic antibiotic therapy and granulocyte colony-stimulating factor administration were used in all six cycles. Blood serum samples were taken throughout the treatment period for pharmacokinetic analysis.
Results: Twenty-eight patients were enrolled (median age, 50 years; ductal-invasive histology, 68%; tumorsize 2–5 cm, 61%; grade 3, 43%; hormone receptor negative, 36%; Her2 positive 18%) and received oblimersen in a dose of 3 mg/kg/day (cohort I, nine patients), 5 mg/kg/day (cohort II, nine patients) and 7 mg/kg/day (cohort III, 10 patients) respectively. No dose-limiting toxicity occurred. Following oblimersen combined with TAC, the most severe toxicity was neutropenia [National Cancer Institute—Common Toxicity Criteria (NCI-CTC) grades 1–2/3/4] which developed in 0/0/56% of patients (cohort I), 11/0/56% of patients (cohort II) and 20/20/50% of patients (cohort III). No febrile neutropenia occurred. Most common adverse events (all NCI-CTC grade 
2) were fatigue, nausea, alopecia, headache and flue-like symptoms observed in 78% (cohort I), 89% (cohort II) and 90% (cohort III) of patients. With increasing dose of oblimersen, a higher incidence of grade IV leukopenia and neutropenia was noted. At the MTD of 7 mg/kg/day of oblimersen, serious adverse events occurred in 40% of the patients.
Conclusion: Oblimersen up to a dose of 7 mg/kg/day administered as a 24-h infusion on days 1–7 can be safely administered in combination with standard TAC on day 5 as NST in patients with PBC. The safety and preliminary efficacy warrants further evaluation of oblimersen in combination with every cycle of the TAC regimen in a randomized trial.
breast cancer, neo-adjuvant systemic treatment, oblimersen
Received for publication January 23, 2008. Revision received April 6, 2008. Accepted for publication April 7, 2008.