James Markert, MD - US grants

PROJECT SUMMARY We are requesting three years of support to conduct an open-label, dose-escalating, Phase I clinical trial in subjects with recurrent malignant glioma (MG) to determine the Recommended Phase 2 Dose (RP2D), safety and toxicities of a novel modification of a ??134.5 Herpes Simplex Virus (??134.5 HSV) that expresses human interleukin-12 (M032, NSC733972). This oncolytic HSV was developed under a Program Project Grant (CA071933) and has been extensively tested in vitro and preclinically in two animal species, including nonhuman primates. These studies have shown M032 to be as safe as other clinical oncolytic ??134.5 HSV (G207, 1716) used intracerebrally, to have no unexpected toxicities in immunocompromised mice or immunocompetent animals (mice, non-human primates), and to replicate 10-1000 fold better than G207 in a variety of preclinical models of MG. We have conducted three Phase I clinical trials with G207 in a similar patient population (17 of 35 subjects had objective responses) and will apply our unique knowledge and experience to evaluate this novel HSV. The NExT program produced cGMP clinical grade M032 (NSC733972) at >3 x 109 PFU/ml, generating >560 single-dose vials. The FDA has issued IND #14,946, a trial protocol and informed consent were IRB- approved and the first subject has been treated without DLTs (NCT02062827). In Aim 1, this first-in-human Phase I clinical trial will use a modified Continual Reassessment Method (CRM) to determine dose modifications to obtain both safety and toxicity data as well as secondary biologic correlative information critical to assessing the potential application of this virus to treat malignant brain tumors. Subjects with biopsy-proven recurrent MG will have M032 infused (400?l/hr x 6 hrs) in up to four sites in the enhancing tumor mass via stereotactically placed catheters and will be monitored adverse effects and survival. Dose escalation in each subsequent subject will occur after a 24 day interval and will be defined by the CRM. We will determine the RP2D, will identify any unanticipated toxicities and will determine, secondarily, progression-free and overall survivals. In Aim 2, we will simultaneously acquire biological specimens from each subject on a designated longitudinal timeline and process these for immediate analyses or for cryopreservation and batch analyses at a later time. We propose to: a) assess M032 shedding in blood, saliva, and conjunctival secretions by virus culture and PCR; b) document serological (antibody titers) and cellular immune responses (profiling, proliferation and function of immune subsets) to M032 infusion; c) define changes from an immune suppressing environment to an immune enhancing environment, including changes in circulating cytokines and peripheral blood mononuclear cells; and d) establish tumor genotype differences that might reveal molecular bases for tumor susceptibility or resistance. Previously archived tumor tissues (when available) and blood DNA will be analyzed to provide an in-depth molecular profile for each subject's tumor. Analyses will be focused to define a RP2D of M032 and will consider all clinical variables and correlative parameters to better inform future trial designs for the best outcomes.

? DESCRIPTION (provided by applicant): Despite significant advances in the treatment of patients harboring GBM, there have been modest increases in overall survivals, on the order of 1 month for every decade of research. While the EORTC-NCIC trial by Hegi et al (13) implicated the status of MGMT promoter methylation as a biomarker of GBM patient response to Temozolomide (TMZ), all GBM patients continue to be treated with TMZ, regardless of their MGMT status (13). The lack of enthusiasm to systematically use MGMT promoter methylation to guide treatment is due to: 1) lack of other therapeutic options; 2) 50% of patients with methylated MGMT promoter (a good prognostic factor) do not survive 2 years; and, 3) 15% of patients with unmethylated MGMT promoter (bad prognosis) survived 2 years. Moreover, MGMT methylation status is associated with improved outcome both in the TMZ-based chemoradiation and radiation-only arms. All of these observations suggest that MGMT promoter methylation status may be partly a prognostic marker associated with the nature of the tumor, rather than a truly therapy- specific predictive marker. Cytochrome c Oxidase (CcO) is a mitochondrial enzyme involved in cellular ATP generation. We previously demonstrated that CcO plays a central role in acquired resistance to TMZ. Importantly, in a retrospective trial, we showed that CcO activity was inversely correlated with clinical outcomes. The long term goal is to identify robust and clinically relevant molecular markers that can add value to classical clinicl prognostic factors in order to tailor medical treatment to individual tumor characteristics and to design better clinical trials for new drugs against gliomas. The objective of the proposed biomarker clinical trial is to determine whether CcO activity represents a novel and valuable prognostic biomarker for patients receiving standard of care therapy. Our hypothesis is that high tumor CcO activity is associated with poor outcomes independently of MGMT promoter methylation status. Additionally, we hypothesize that MGMT promoter methylation status is a true predictive biomarker of how patients will respond to standard of care TMZ-based chemoradiation in tumors with low CcO activity. This will be tested by pursuing two specific aims: 1) determine overall and progression-free survival times relative to CcO activity; 2) compare the prognostic value of CcO activity to other commonly used prognostic markers. The approaches are innovative because we will validate activity of a mitochondrial enzyme, CcO, as a strong prognostic biomarker for primary GBM. Moreover, clinical trial designs based on CcO activity and MGMT promoter methylation stratification have tremendous potential to optimize and individualize therapy by prospectively identifying those patients who will benefit most from TMZ standard therapy and those who will not. This proposed research is significant because it is expected to vertically advance and expand the application of new prognostic and predictive biomarkers for GBM patients in order to tailor medical treatment based on individual tumor characteristics and to design better clinical trials for new drugs leading to personalized therapy for GBM patients.

PROJECT SUMMARY: Gliomas are the most frequently occurring primary malignant brain tumors, with glioblastoma multiforme (GBM) being one of the most fatal and treatment-refractory of all cancers. New treatments are urgently needed. First-generation oncolytic Herpes Simplex Viruses (1st gen oHSVs) used in Phase I clinical trials were safe and produced a 50% response rate however, only a minority of patients had a durable anti-tumor response. Analysis of the 1st gen oHSV-treated glioma specimens shows that increased antiviral and immunostimulatory activity in the tumor directly correlates with longer survival in the Phase Ib study. The 1st Gen oHSVs were designed to restrict viral replication and therefore could not maintain infection or sustain an antiviral immune response. To improve oHSV antitumor activity, we have developed a next- generation oHSV, C134, with enhanced immunostimulatory activity. C134 is designed to activate antiviral cellular pathways important for amplifying the immune response and to improve viral replication in tumor cells. While it shares a similar safety profile as the 1st gen oHSVs, C134 has superior anti-tumor efficacy in pre- clinical models. Murine studies also show that C134 more effectively induces T cell and antigen presenting cell responses that are associated with improved patient survival in the Phase Ib studies. We will test our hypothesis that ?C134 is safe and induces immune activity that enhances the anti-tumor response in patients with recurrent malignant glioma? by the following aims: Aim 1: To conduct a Phase I clinical trial to determine a safe C134 (IND 17296) dose in patients with recurrent malignant glioma. Hypothesis: Intratumoral administration of C134 is safe in patients with recurrent malignant gliomas. We are ready to start our Phase I trial. Our clinical grade C134 has received regulatory approval from the NIH-Recombinant DNA Council (RAC) and FDA-Investigational New Drug (IND#17296). C134 will be intratumorally-administered to patients using a Continual Reassessment Method (CRM) design and will be monitored for C134 safety and tolerability. AIM 2 To monitor immune response changes associated with oHSV mediated anti-tumor responses among C134-treated patients. Hypothesis: C134-induced antiviral and Th1 immune activity contribute to anti- tumor efficacy and can be inferred from peripheral blood samples. Our past clinical trial results indicate that oHSV-induced immune activity is associated with improved survival. We will therefore monitor patient's peripheral blood (immunophenotyping and cytokine) after C134-treatment and define how immune response changes relate to anti-tumor response. Studies will also examine how sustained viral activity and T cell clonal changes contribute to the C134-anti-tumor response. Impact: Successful completion of these studies is the first step in establishing an effective therapy for an incurable tumor and would provide a way to monitor and potentially enhance the virotherapeutic response.