A phase 1 open-label, sequential dose-escalation study investigating the safety, tolerability, and pharmacokinetics of intravenous TLC388 administered to patients with advanced solid tumors.

PURPOSE: The first-in-human phase 1 trial examined the dose-limiting toxicities (DLT), maximum tolerated dose (MTD), pharmacokinetic profile, and antitumor activity of TLC388, a novel camptothecin with a unique lactone ring modification, in patients with advanced solid tumors. EXPERIMENTAL DESIGN: TLC388 was administered intravenously to patients with metastatic chemotherapy refractory solid tumors on days 1, 8, and 15 of a 28-day cycle. Patients underwent tumor assessments every other cycle. Pharmacokinetic samples were drawn on days 1, 8, and 15 of cycles 1 and 2. RESULTS: Fifty-four patients were enrolled at doses ranging from 1.5 to 60.0 mg/m(2) over 12 cohorts. Treatment was generally well-tolerated and no cumulative toxicity observed. Two of six patients treated at 60.0 mg/m(2) developed DLTs of grade 3 neutropenia causing dose delay and grade 3 febrile neutropenia. The next lower dose, 50.0 mg/m(2), was declared as MTD. Treatment-related grade 3-4 hematologic toxicities included neutropenia (19 %), leukopenia (15 %), anemia (9 %), and thrombocytopenia (7 %). Grade 3-4 nonhematologic toxicities included diarrhea (2 %) and hyponatremia (4 %). Pharmacokinetics of both diastereomers (S,R and S,S) of TLC388, a mixture of two diastereomers, was dose independent; mean (SD) values for the volume of distribution at steady-state and clearance were 857 (1122) L/m(2) for S,R and 996 (1333) L/m(2) for S,S, and 2174 (2526) L/h-m(2) for S,R and 2670 (2988) L/h-m(2) for S,S, respectively. The half-life values averaged 0.67 (1.15) hours for S,R and 0.64 (1.11) hours for S,S. The best overall response was stable disease in 21 (39 %) patients. Prolonged (≥ 6 months) stable disease was noted in eight patients. CONCLUSIONS: TLC388 at 50 mg/m(2) on the current treatment schedule is generally safe and well tolerated.

Interactions of Pluronics with phospholipid monolayers at the air-water interface.

Pluronics are triblock copolymers which are extensively applied excipients shown to interact with cell membranes. The aim of our study was to apply monolayer techniques and epifluorescence microscopy to investigate the interaction behavior between selected Pluronics and phospholipid monolayers which serve as a model of cell membranes. The results showed that Pluronic L61 with hydrophobic proportions much larger than those of F68 demonstrated condensed film-like surface behavior while F68 exhibited more expanded behavior. The increments of surface pressure and the changes of image were more obvious in adding Pluronic L61 than F68 to the subphase of dipalmitoylphosphatidylcholine (DPPC) monolayers, which indicated that the interaction may be related to van der Waals forces and hydrophobic interaction. Pluronics selected with higher hydrophobicities demonstrated larger surface activities and penetration abilities while being added to the subphase of DPPC and dimyristoylphosphatidylcholine (DMPC) monolayers. Pluronic P85 and F68 were found to be squeezed to subphase at higher surface pressures, which may be attributed to their relatively higher hydrophilicities.