Abstract S3-04: Primary analysis of PERTAIN: A randomized, two-arm, open-label, multicenter phase II trial assessing the efficacy and safety of pertuzumab given in combination with trastuzumab plus an aromatase inhibitor in first-line patients with HER2-positive and hormone receptor-positive metastatic or locally advanced breast cancer

Background:Preclinical and clinical evidence suggest that cross-talk between HER2 and estrogen receptor signaling pathways in breast cancer (BC) contributes to treatment resistance (Kaufman et al. J Clin Oncol 2009; Arpino et al. J Natl Cancer Inst 2007). First-line pertuzumab (P), in addition to trastuzumab (H) + docetaxel (T), significantly improved progression-free survival (PFS) and overall survival (OS) compared with H + T in patients (pts) with HER2-positive metastatic BC (MBC) (Swain et al. N Engl J Med 2015; Baselga et al. N Engl J Med 2012). PERTAIN (NCT01491737) is the first study to assess first-line P + H + an aromatase inhibitor (AI) ± induction taxane therapy in postmenopausal women with hormone receptor-positive, HER2-positive locally advanced (LA)/MBC.Methods:Pts with HER2-positive, hormone receptor-positive LA/MBC who had not received prior systemic therapy (except endocrine therapy) were randomized 1:1 to Arm A: P + H + AI or Arm B: H + AI. Study medication: P 840 mg loading dose followed by 420 mg every 3 weeks (q3w); H 8 mg/kg followed by 6 mg/kg q3w; anastrozole 1 mg daily (qd) or letrozole 2.5 mg qd. Induction T q3w or paclitaxel (PAC) weekly could be given for 18–24 weeks at the investigator's discretion before the start of endocrine therapy. Treatment was continued until disease progression or unacceptable toxicity. The primary endpoint was PFS, stratified by induction chemotherapy (yes/no) and time since adjuvant hormone therapy (
Source: Cancer Research - Category: Cancer & Oncology Authors: Tags: General Session Abstracts Source Type: research