2552 Background: Eribulin mesylate is a microtubule dynamics inhibitor approved by FDA for patients (pts) with metastatic breast cancer after treatment with at least two prior chemotherapeutic regimens. This Phase Ib, open-label dose-escalation study determined the maximum tolerated dose (MTD) of eribulin in combination with capecitabine. Methods: Pts with advanced solid malignancies refractory to standard therapies, adequate organ function and ECOG performance status ≤2 received eribulin mesylate (2–5-min IV) by Schedule 1 (1.2, 1.6 or 2.0 mg/m2 on Day 1) or Schedule 2 (0.7, 1.1 or 1.4 mg/m2 on Days 1 and 8), in combination with twice-daily oral capecitabine 1000 mg/m2 Days 1-14 every 21 days. The MTD was defined as the highest dose in each schedule where ≤1/6 pts experienced dose-limiting toxicity (DLT). Safety and pharmacokinetics (PK) were assessed. Results: Of the 34 pts recruited, 19 (53% male; median age 62 years; 42% ECOG 0, 58% ECOG 1) and 15 (33% male; median age 61 years; 33% ECOG 0, 60% ECOG 1, 7% ECOG 2) were enrolled in Schedules 1 and 2, respectively. Most common tumor types were large intestine (20.6%), lung/bronchus (17.7%) and breast (14.7%). DLTs are shown in the table; there were no unexpected toxicities with the combination. The MTD for eribulin mesylate was 1.6 and 1.4 mg/m2 for Schedules 1 and 2, respectively, in combination with capecitabine 1000 mg/m2 twice-daily. Eribulin PK were dose proportional and independent of schedule or capecitabine co-administration. Combination with eribulin had no effect on the disposition of capecitabine and its metabolites. Although sample size was small, preliminary signs of efficacy were observed. Conclusions: The combination of eribulin and capecitabine was well tolerated with no unexpected safety findings. Schedule 2 MTD (1.4 mg/m2 Days 1 and 8) delivered a higher dose intensity of eribulin than Schedule 1 and was selected for evaluation in an ongoing Phase II breast cancer study. [Table: see text]
A phase Ib, open-label, dose-escalation study of the safety and pharmacology of taselisib (GDC-0032) in combination with either docetaxel or paclitaxel in patients with HER2-negative, locally advanced, or metastatic breast cancer
