14078 Background: IT-101 is a de novo designed experimental therapeutic comprised of linear, cyclodextrin(CD)-containing polymer conjugates of camptothecin(CPT) that assemble into ca. 40 nm diameter nanoparticles via polymer-polymer interactions that involve inclusion complex formation between the CPT and the CD. Particle size, near neutral surface charge and CPT release rate were specifically designed into IT-101. Published pre-clinical animal studies show extended circulation times (t1/2 of ca. 20 h in rodents), tumor accumulation, slow release of the CPT and anti-tumor efficacy that directly correlate to the properties of the nanoparticle. Release of CPT can disassemble the nanoparticle into individual polymer chains that have size ca. 10 nm that are capable of renal clearance (t1/2 of several minutes in rodents). Methods: Patients with relapsed or refractory cancer were evaluated every two cycles of therapy (90 minute IV infusions of IT- 101 in D5W on days 1, 8 and 15 of a 28 day cycle). Three dose levels of 6, 12 and 18 mg CPT eq./m2 have been tested. Results: At the time of this interim analysis, eight patients have been enrolled and five evaluated. In general, IT-101 is well tolerated and pancytopenia is the DLT. The expected MTD is 12 mg/ m2.Three out of five patients demonstrated stable disease on CT scan evaluation. One pancreatic cancer patient remains stable for 6 months. PK data are available from the first 5 patients. Total and free CPT display biphasic elimination from plasma with mean terminal elimination half lives of 38±3.7 and 61±43 hours, respectively. The mean Vd and CLsys of total CPT are 6.1±1.4 L and 0.1±0.03 L/h and are unrelated to dose over the range tested, with a mean total-to-free AUC ratio of 10.7±3.7. Conclusions: These first in human PK data for IT-101 confirm that 40 nm particles with near neutral surface charge provide favorable PK properties. The stable disease rate, although not yet conclusive, is consistent with promising efficacy. The preliminary results of this phase I study warrant continued enrollment that is ongoing. No significant financial relationships to disclose.
Thrombosis: A Function of Surface Charge and/or Chemistry of Collagen