Intraoperative Imaging and Nanoparticle Delivery for Novel Glioma

Intraoperative Imaging and Nanoparticle Delivery for Novel Glioma Therapy Author : Updated : Joseph M. Piepmeier, M. D. and Toral R. Patel, M. D. June 20, 2010

Yale Brain Tumor Center Author : Updated :

From BTSG to EORTC “Chasing our tail” 1978 2005 A BC D Author : Updated : Courtesy of H. Richard Winn MD

Author : Updated :

Author : Updated :

5. Gliomas: Reasons for Failure • Pattern of Infiltration/Blood-Brain Barrier

6. Objective To directly address the infiltrative nature of malignant gliomas with regional delivery of therapeutic agents

7. Regional Drug Delivery: Wafers • Drug-loaded biodegradable polymer wafers (Gliadel®) – Modest improvements in survival – Sustained drug release over 3 weeks – Significant safety concerns – Passive diffusion: high local concentration, poor drug penetration

8. Regional Drug Delivery: CED • Convection-Enhanced Delivery (CED) – External pressure gradient – Continuous infusion via bulk flow – Increased depth of penetration – Transient • PRECISE Study – Phase III randomized trial of CED of IL 13 -PE 38 QQR vs. Gliadel wafers for recurrent glioblastoma – No significant survival difference – Major limitation: • Agent targeting to residual tumor R. R. Lonser et al. , Journal of Neurosurgery 97 (2002) 905 -913

9. Regional Drug Delivery We have developed novel methods for polymer technology AND convection-enhanced delivery to successfully address the limitations of regional drug delivery.

10. Regional Drug Delivery: Nanoparticles • Nanoparticles: – – – Small Biodegradable Efficient encapsulation Controlled-release Targeted Polymer-based – Major Limitation: • Thus far, the volume of distribution for polymer nanoparticles delivered via CED has been prohibitively small. • This is due, in part, to the inability to produce small, non-aggregated nanoparticles.

11. Nanoparticle Formulation • Goals: – Produce smaller (60 – 100 nm) polymer nanoparticles – Eliminate particle aggregation • Novel Modifications: – High-power sonication – High-speed, stepwise, partial centrifugation – Cryoprotection – Improved delivery apparatus

12. In Vivo Nanoparticle Delivery • Study Design: – Dye (fluorescent)-loaded PLGA nanoparticles infused stereotactically into the rat caudate • 20 u. L of nanoparticles [100 mg/m. L], infused at 2/3 u. L/min, depth = 5 mm – 4 groups (n=4/group): • Large, no cryoprotectant • Large, with cryoprotectant • Small, no cryoprotectant • Small, with cryoprotectant – Animals sacrificed 30 minutes postprocedure, brains flash frozen – Serial coronal sections taken and fluorescent signal analyzed (via previously established methods)

13. In Vivo Distribution Results Small nanoparticles, with cryoprotectant, have a 10 -fold higher volume of distribution than large nanoparticles

14. In Vivo Distribution Results Large – no cryoprot. Large – w/ cryoprot. Small – no cryoprot. Small – w/ cryoprot.

15. In Vivo Distribution Results Small, non-aggregated, polymer nanoparticles have a significantly higher volume of distribution than previously published polymer nanoparticle formulations

16. Alternative Imaging Strategies A B MR image of Gadolinium-loaded small nanoparticles PET image of radiotracer-labeled small nanoparticles

17. Identification of Novel Therapeutics Glioma Stem Cells Drug Discovery Step 1: High Throughput Screening 427 1940 Step 2: Sphere Formation Assay Drugs 32 427 Step 3: Verification of Lead Drugs (IC 50, Stem Cell Markers) Nucleic Acid Discovery Step 1: Assay Development Control si. RNA Nestin si. RNA Step 2: Validation Study/Kinome Screen Step 3: Whole-Genome Screen Reya, et al. Stem cells, cancer, and cancer stem cells. Nature 2001; 414: 105 -111

18. Conclusions/Future Implications • We have developed polymer nanoparticles that are ideally suited for intracranial delivery: – Tailored delivery to infiltrative, microscopic disease – Selective targeting to tumor cells – Sustained drug release – Treatment is independent of genomic variability – Reduced systemic toxicity – Can be imaged with MRI and PET techniques • This technology is readily applicable to many CNS diseases Time (weeks)

19. Acknowledgements Jiangbing Zhou Whitney Sheen Rachael Sirianni Erik Shapiro Anita Huttner Michael Wyler Joseph Piepmeier Mark Saltzman