Liposomal Cisplatin Response Prediction In Heavily Pretreated Breast Cancer Patients: A Multigene Biomarker In A Prospective Phase 2 Study.

e13077Background: In an ongoing, open-label Phase 2 study liposomal cisplatin (LiPlaCis) was evaluated in metastatic breast cancer (mBC) patients selected by a cisplatin-specific mRNA-based drug response predictor (DRP). The DRP was part of a Phase 2 trial screening program with u003e 1400 mBC patients using archival tumor tissue to classify the patients as DRP high (top 2/3) or low (bottom 1/3). Methods: Eligible were DRP high mBC patients after at least 2 prior treatment lines for advanced disease. 75 mg LiPlaCis was administered on days 1 and 8 every 3 weeks (wks) with efficacy evaluation every 6 wks. Efficacy was measured as progression-free survival (PFS) and objective response rate (ORR) against outcome of latest prior treatment. Top 1/3 in DRP level was compared with middle 1/3. Results: In all 12 patients have been included with a planned enrollment of 20 evaluable patients. Two patients did not receive a full cycle due to early death, deemed unrelated to LiPlaCis by a safety committee. ORR in the int...