2019 ASCO Annual Meeting!
Session: Breast Cancer—Local/Regional/Adjuvant
Type: Oral Abstract Session
Time: Monday June 3, 9:45 AM to 12:45 PM
Location: Hall D2
Docetaxel, trastuzumab, pertuzumab versus trastuzumab emtansine as neoadjuvant treatment of HER2-positive breast cancer: Results from the Swedish PREDIX HER2 trial identifying a new potential de-escalation standard?
2019 ASCO Annual Meeting
J Clin Oncol 37, 2019 (suppl; abstr 501)
Author(s): Jonas C. S. Bergh, Anne Andersson, Judith Bjohle, Ana Bosch, Lena Carlsson, Ann Charlotte Dreifaldt, Zakaria Einbeigi, Hanna Fredholm, Erika Isaksson-Friman, Theodoros Foukakis, Ellinor Elinder, Mats Hellstrom, Hemming Johansson, Tobias Lekberg, Henrik Lindman, Claudia Maes, Yvonne Brandberg, Thomas Hatschek; Karolinska Institutet and University Hospital, Stockholm, Sweden; Umea University, Umea, Sweden; Karolinska University Hospital, Stockholm, Sweden; Lund University Cancer Center, Lund, Sweden; County Hospital, Sundsvall, Sweden; Orebro University Hospital, Orebro, Sweden; Sahlgrenska University Hospital, Gothenburg, Sweden; Capio St Göran, Stockholm, Sweden; Sodersjukhuset, Stockholm, Sweden; Karolinska University Hospital, Clinical Trial Unit Oncology, Stockholm, Sweden; Department of Oncology, Karolinska Institutet and University Hospital, Stockholm, Sweden; Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden; Uppsala University Hospital, Uppsala, Sweden; Karolinska Institutet, Department of Oncology-Pathology (OnkPat), Karolinska University Hospital, Stockholm, Sweden
Background: Neoadjuvant therapy produces high rates of pathological complete response (pCR) and is the standard of care in HER2 positive breast cancer; however, the optimal treatment regimen remains to be established. Methods: In this randomized phase II study patients ≥18 years with HER2 positive breast cancer > 20mm or verified lymph node metastases were randomized to 6 courses of docetaxel, trastuzumab and pertuzumab (DTP, group A) or trastuzumab emtansine (T-DM1, group B), q 21 days. The protocol allowed switch to the competing treatment upon lack of response or drug-related severe toxicity. Patients received postoperative epirubicin+cyclophosphamide, trastuzumab for a total of one year and endocrine therapy. Accrual was completed in October 2018 after randomization of 202 patients, data on pCR were available for 190 at the time for this abstract submission. Median age, 52 years (26-74), menopausal status, histological type and grade were well balanced between the treatment groups. 62.6% of the tumors were hormone receptor (HR) positive. Results: Primary endpoint was pathological objective response. 190 patients completed the protocol-specified preoperative treatment. pCR was achieved in 45.3% of patients, 46.4% in patients treated with DTP and 44.1% with T-DM1 (chi-sq., p = 0.75). In HR-positive tumors, pCR was obtained in 35.3% of patients, 35.9% in group A vs. 34.6% in group B (p = 0.87); in HR-negative tumors, the overall pCR rate was 62.0%, 66.7% in group A vs. 57.9% in group B (p = 0.45). Severe (grade 3/4) toxicity was reported at 68 occasions related to DTP, compared with 16 related to T-DM1, 26 vs. 3 caused by febrile neutropenia. Significantly better quality of life was reported by patients treated with T-DM1. Conclusions: Our data on TDM-1 demonstrates similar efficacy and less toxicity, in particular for patients with HER2 and HR positive cancers, being a potential new standard for neoadjuvant therapy. Clinical trial information: NCT02568839