It is increasingly evident that rationally designed combination therapies impacting multiple targets will most likely to improve outcomes in patients with glioblastoma (GBM). However, the selective delivery of multiple regimens to the right place, at the right time, and in the correct sequence with consideration of mechanistic interactions remains a major challenge. Light-activated approaches combined with nanotechnology provide a unique opportunity to deliver multiple agents targeted at several key molecular pathways. Photodynamic therapy (PDT) is a light-based cytotoxic modality that can synergize with chemo and biological agents. PDT is FDA-approved for several cancers and it is in phase III trial for GBM. The underlying hypothesis is that properly timed, nanotechnology-assisted combination therapies based on interactive mechanisms that target multiple non-overlapping tumor growth/survival pathways is key to improving treatment efficacy, and allows for non-overlapping toxicities and reduced dose. This proposal leverages image-guided approaches and polymer engineering to develop a photoimmunoconjugate-nanocarrier (PICNC) that integrates an FDA-approved PDT agent (verteporfin), a clinically promising chemodrug (SN-38), and a multi-receptor tyrosine kinase inhibitor (RTKi, cediranib). All the agents are compartmentalized for appropriate release kinetics to ensure the correct sequence of action that accounts for the mechanistic synergism of the combination treatment. During the K99 phase, SN-38-loaded nanocarriers will be decorated with cetuximab-verteporfin photoimmunoconjugates (PICs) for tumor targeting and image-guided combination therapy (PDT + SN-38). It is hypothesized that SN- 38 improves tumor tissue oxygenation to favor oxygen-dependent PDT, while PDT destroys efflux pumps to increase intracellular SN-38 levels, will improve the overall outcome. To prepare for R00 transition, Dr. Huang will leverage his chemical engineering background to develop a variety of modified polymer nanoparticles loaded with a third RTKi agent, engineered to modulate the RTKi release kinetics, which will be incorporated into the PICNC. The hypothesis is that the customized RTKi release kinetics will maximize the mitigation of the compensatory RTK survival pathways elicited by PDT and SN-38 to improve outcome. During the R00 phase, Dr. Huang will establish the molecular impact and the image-guided treatment planning of PICNCs, and then evaluate the therapeutic effects of PICNCs and customized PDT schedule. A strong mentoring committee has been assembled to guide Dr. Huang's research and facilitate his transition to independence. Dr. Tayyaba Hasan (primary mentor) will train Dr. Huang in photobiology, PIC-nanocarriers, and combination mechanism. Dr. David Boas (co-mentor) is an expert in optical and spectral imaging of tissue oxygen metabolism. Additional distinguished members are: Dr. Brian Pogue, a fluorescence imaging expert; Dr. Shiladitya Sengupta, an polymer nanoparticle expert; Drs. Robert Martuza, Xandra Breakefield, and Anat Stemmer-Rachamimov are experts in clinical management, animal models and molecular biology of GBM.
Despite the advances in therapeutic cocktails, without a breakthrough in drug delivery strategies and a solid mechanistic basis, the glioblastoma prognosis has remained unchanged for several decades. This proposal leverages quantitative imaging and polymer engineering to develop a photoresponsive nanoplatform that can delivery three regimens in a unique manner, where one treatment primes the target for the second modality, and the subsequent evasion pathways are mitigated by a third agent; all agents are rationally selected and released in an appropriate time and sequence to account for mechanistic interactions and to improve outcomes. The principle and the nanoplatform developed here will be adaptable to treating a broad range of diseases.
|Obaid, Girgis; Broekgaarden, Mans; Bulin, Anne-Laure et al. (2016) Photonanomedicine: a convergence of photodynamic therapy and nanotechnology. Nanoscale 8:12471-503|