A Q7D phase I study of TPI 287, a novel taxane, in advanced malignancies: Imaging studies, pharmacokinetics (PK) and circulating tumor cell (CTC) quantitation

12008 Background: Taxanes have demonstrated activity across a broad range of cancers, but resistance remains an issue. TPI 287 is a third generation taxane designed to overcome issues of resistance secondary to mdr and mutant tubulin. The purpose of this Phase I study was to determine the maximum tolerated dose and pharmacokinetics of IV TPI 287. Methods: Phase I study: TPI 287 is administered IV on days 1, 8, 15 of a 28 day cycle (Q7D) with at least 3 patients treated per dose escalation, in a typical phase I design. Dosing began at 7 mg/m 2 and has advanced to the fifth cohort of patients, who are being treated at a dose of 85 mg/m 2 . Tumor response is assessed after every second cycle via imaging and tumor measurements. Samples are collected for PK analysis and circulating tumor cell (CTC) quantitation. Results: Sixteen pts have been enrolled (9 males, median years = 60.11; 7 females, median years = 50.71: median number of previous chemotherapies = 4). Diagnoses included colorectal (4), prostate (3), breast, kidney, cervical, brain, lung, osteosarcoma, basal cell, endometrial, ovarian cancers. Of 16 pts, 8 and 5 have completed 1, 2 cycles, respectively. Only one drug related grade 3 adverse event (hypersensitivity reaction) occurred, at 14 mg/m 2 . No other reported toxicities are related to TPI 287. PK and CTC studies are ongoing. Conclusions: These initial results show that TPI 287 is well tolerated at a dose up to 56 mg/m 2 administered Q7D, and dose escalation continues. [Table: see text]