All therapeutic agents injected intravenously for cancer therapy require doses well in excess of that needed if all the administered drug was placed inside the tumors; these elevated doses create high blood levels to maximize the blood-to-tissue concentration gradient that drives the drug passively across the vascular wall and into the tumors. Many times, despite near maximal tolerated doses, only a very small fraction of the therapeutic agents reach the interior tumors where the drug can be most effective. To overcome the restrictive barrier formed by the tumor vascular endothelium that prevents therapeutic agents from penetrating into solid tumors, we are exploring the clinical utility of the caveolae-pumping system to enable precision delivery of antibody-drug conjugates (ADC) and radioimmunotherapies directly into primary and metastatic tumors. Preliminary data supports the clinical translation of our approach, which will be further explored with rigorous preclinical development in testing in Projects 1 and 2. Part of that effort will be the humanization of the lead caveola- targeting antibody. Here in Project 3, clinical translation will be done stepwise by establishing a lack of significant toxicity of the humanized form of the targeting antibody (hAnnA1) conjugated to an imaging radionuclide and subsequently to a novel chemotherapy in the form of hAnnA1-ADC.
Specific Aims of this project are to conduct: 1) preclinical evaluations to enable IND filings, including toxicology and safety testing of the radiolabeled antibody and ADC in non-human primates; 2) pilot imaging clinical trial of 89Zr-labeled hAnnA1 in patients with metastatic solid tumors; and 3) Phase 1 dose escalation study of novel caveolae-targeting hAnnA1-ADC. The humanized antibody will be produced in Core B, that will also be responsible for the scale-up and cGMP production of the ADC that will be used in clinical trials. Core D will produce the radiolabeled antibody for the clinical imaging trial. Core E will provide support for the statistical analysis and translational/clinical protocols, including design, conduct collection and analysis of data, from the investigator-initiated trials.
PROJECT 3 NARRATIVE The overall goal of the proposed research seeks to overcome current limitations to effective delivery of antibody-drug conjugates and radioimmunotherapies into solid tumors. Project 3 includes the first clinical trial to evaluate a PET-based 89Zr-labeled antibody for tumor imaging that is actively pumped across the tumor endothelium to deliver the highest levels to solid tumors that have been achieved, based on preclinical studies. This Project also provides for a clinical trial to treat metastatic solid tumors, also for the first time, using a mechanism where the novel caveolae-targeted drug conjugates are actively pumped across the tumor endothelium to deliver the highest levels of therapeutic agent into the tumor. If successful, this novel approach could greatly improve patient survival and quality of life with more therapeutic impact and less toxicities. Because this approach could be used with a broad range of therapeutic agents, it would clearly constitute a paradigm shift in drug delivery and therapeutics in oncology.
