SBIR-STTR Award

This project brings together an experienced, integrated project team with complementary expertise to advance a new approach to treating melanomas that cannot cured by surgery and have spread in the body. The project attacks a new target, renalase, an endogenous protein that can function as a survival factor, which becomes overexpressed in melanoma, and plays a role in suppressing the body’s host defense to protect the tumor. Melanoma incidence is the highest of all cancers, and despite significant advances in systemic therapies that prolong survival, the death rate from melanoma has increased by 33.2% from 2003 to 2016. These statistics underscore the urgent need for new therapies. Several lines of data point to renalase as a target for melanoma. Renalase expression is higher in metastatic than in primary tumors in patients and these patients have worse outcomes. Preventing renalase production in cancer cells through siRNA in tissue culture or in mouse melanoma models dramatically decreases tumors. Normal mice lacking the renalase gene, have a normal life expectancy and are resistant to melanoma, further suggesting renalase is a feasible target. Renalase is overexpressed by tumor associated macrophages and facilitates tumor growth through a known cancer signaling pathway, STAT 3. Rabbit antibodies have been generated that can recognize renalase and these antibodies block or reduce melanoma in mouse models. Of high interest, in initial studies using melanoma cell lines resistant to current immunotherapies, our antibodies were effective both as single agents and were synergistic when used in combination with existing immunotherapies. This project is designed to translate these results toward a therapeutic product and specifically to humanize several candidate antibodies and evaluate, characterize and prioritize them preclinically. The project will deliver an innovative lead humanized renalase antibody and back up drugs poised for scale up, further development, including toxicological and pharmacologic evaluation, and ultimately, an IND submission to conduct clinical trials.

Public Health Relevance Statement:
Project Narrative This is a Phase 1 SBIR application to develop a new therapy for advanced melanoma, a disease for which cures are uncommon and, despite significant advances in systemic therapies, the death rate has continued to increase. We have discovered a new drug target, renalase, whose over expression in patients is associated with the worst outcomes. The therapy being developed, a humanized monoclonal antibody directed against renalase, is an innovative therapeutic with potential as a precision medicine to reduce melanoma tumor growth, and act synergistically with immune checkpoint inhibitors, including in patients resistant to current drugs.

Project Terms:
Affinity; Allografting; Anti-PD-1; anti-PD1 antibodies; Antibodies; Automobile Driving; Back; base; Blocking Antibodies; Blood Chemical Analysis; Blood Pressure; BRAF gene; cancer cell; cell killing; Cell Line; Cell Survival; Cells; Cessation of life; Chimera organism; Chinese Hamster Ovary Cell; Clinical; clinically relevant; Complementarity Determining Regions; Conduct Clinical Trials; Congenic Mice; Control Animal; Coupled; cross reactivity; CTLA4 gene; Cytotoxic T-Lymphocytes; cytotoxicity; Data; Death Rate; design; Development; Disease; Dose; Drug Targeting; Evaluation; experience; Exposure to; Flavoproteins; Genes; GNAQ gene; Growth; Host Defense; Human; humanized antibody; humanized monoclonal antibodies; IgG1; IgG4; Immune checkpoint inhibitor; Immunocompetent; Immunoglobulin Fragments; Immunoglobulin G; Immunotherapy; improved; In Vitro; in vitro activity; in vitro testing; in vivo; Incidence; inhibitor/antagonist; Injury; innovation; interest; Kinetics; knock-down; Knockout Mice; Lead; Life Expectancy; liver function; Longevity; macrophage; Malignant neoplasm of pancreas; Malignant Neoplasms; MAP Kinase Gene; Measures; MEKs; melanoma; Melanoma Cell; Metastatic Melanoma; Metastatic to; Modality; Modeling; Monoclonal Antibodies; mortality; mouse model; Mus; mutant; Mutation; Neoplasm Metastasis; neoplastic cell; new therapeutic target; novel strategies; novel therapeutics; Nude Mice; Operative Surgical Procedures; Organ; Oryctolagus cuniculus; Outcome; overexpression; Pathway interactions; Patients; Phage Display; Pharmaceutical Preparations; Pharmacology; Pharmacology and Toxicology; Phase; PI3K/AKT; plasmonics; Play; pre-clinical; precision medicine; prevent; Primary Neoplasm; Production; Proteins; Proteinuria; Proto-Oncogene Protein c-kit; Rattus; Reaction Time; Renal function; Resistance; response; Role; Safety; scale up; Serum; Signal Pathway; Signal Transduction; Small Business Innovation Research Grant; Small Interfering RNA; STAT3 gene; statistics; Surface; Systemic Therapy; T-cell inflamed; Testing; Therapeutic; Therapeutic antibodies; Therapeutic Effect; Therapeutic Index; tissue culture; Toxic effect; Translating; Trastuzumab; treatment strategy; tumor; Tumor Burden; tumor growth; Tumor-associated macrophages; Unresectable; Uveal Melanoma; Vertebral column; Weight

Most patients with advanced cancer either do not respond durably or do not respond to current interventions,including immune-oncology checkpoint inhibitors. For melanoma, a major focus for immunotherapies, five-yearsurvival improved dramatically, yet only ~ 40% of patients respond to PD-1 inhibitors, and many developresistance over time. The combination with another checkpoint inhibitor of CTLA-4 yields a higher responserate, but with a higher rate of toxicities, and > 40% of patients have resistant tumors. In most other tumortypes, responses are seen less frequently, and duration of response is shorter. There is, therefore, a greatneed for additional systemic interventions. In prior studies, including from a Phase 1 grant, the teamestablished the role of the secreted flavoprotein renalase (RNLS) as a new target in melanoma and proof ofconcept that inhibiting RNLS signaling blocks tumor growth. RNLS knock-out mice also rejected these murinemelanomas, providing a rationale for targeting RNLS in tumors. Moreover, RNLS levels inversely correlatewith patient outcomes, thus, increased RNLS expression in human tumors, melanoma cells and/or tumorassociated macrophages are associated with decreased survival including patients treated with anti-PD-1-based regimens. Anti-RNLS antibodies (anti-RNLS mAb) developed in the project and used as single agentsregressed murine melanoma tumors resistant to PD-1 inhibitors. In combination with anti-PD-1, anti-RNLSmAb showed synergy with no apparent toxicity. Tumor rejection was driven by both macrophages and T cells.In Phase I progress was made towards developing a humanized anti-RNLS monoclonal Ab (anti-RNLS mAb)as a 1st in class clinical candidate for tumors resistant to PD-1 inhibitors. Additional studies have yielded a leadanti-RNLS mAb (K16). K16 was effective in two murine melanoma models. Also, two new sensitive andselective ELISA assays were developed and used to: measure plasma RNLS levels and anti-RNLS mAblevels. These will be available for future use. In this grant, non GMP K16 will be scaled up and two murinemelanoma models will be used to confirm and extend studies of the mAb. Additionally, pharmacokinetic, anddose-ranging and acute toxicology studies on K16 will be performed and an estimate of a therapeutic Index(≥10x desired) will be calculated. The outcomes from this project, with continuing success, have considerablevalue, including: 1) elucidation and utility of a new and novel anticancer drug target - RNLS; 2) development ofa unique anticancer therapy-anti-RNLS mAb; 3) significantly extending and improving the anticancer activityand cost effectiveness of checkpoint inhibitors and in checkpoint inhibitor resistant cancer patients.

Public Health Relevance Statement:
Project Narrative Despite major advances in immunotherapy, most patients with advanced cancer are neither cured nor achieve optimum results by current interventions, including checkpoint inhibitors PD-1 with or without anti-CTLA-4. This Phase 2 grant is advancing the development of a humanized, recombinant monoclonal antibody to the protein renalase to treat melanoma that is resistant to PD-1 inhibition. Renalase is a new drug target with a compelling rationale for significantly improved therapy for PD-1 resistant melanoma, as well as other advanced tumors.

Project Terms:
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