SBIR-STTR Award

Diabetic retinopathy (DR) is a common complication of diabetes and a leading cause of vision loss in the United States. Unfortunately, there is no FDA-approved pharmacotherapy for DR. Current treatments in clinical practice and trails, such as laser photocoagulation, corticosteroids and anti-vascular endothelial growth factor (VEGF) agents, are effective in some, but not in all, DR patients. Therefore, there is an urgent medical need to develop alternate approaches for treating this sight-threatening disease. The Wnt pathway mediates multiple pathological processes, including angiogenesis, vascular permeability, inflammation and fibrosis, as it regulates many pathogenic factors, such as VEGF, tumor necrosis factor-alpha (TNF-¿), intercellular adhesion molecule-1 (ICAM-1), connective tissue growth factor (CTGF), fibronectin (FN), and Cox-2. Recent research suggests the Wnt pathway plays a pathogenic role in the development of DR. There are 19 Wnt ligands and 10 Fz receptors that involves in the activation of the Wnt pathway, while only two cell surface co-receptors, low-density lipoprotein receptor-related protein 5 and 6 (LRP5 & 6), are essential for the activation of Wnt pathway. Thus, LRP5/6 becomes an attractive target for developing effective treatments of DR. Through generating and screening a series of mouse anti-human LRP6 monoclonal antibodies (mAbs), 2F1mab has been identified as a specific anti-LRP6 mAb and a potent Wnt inhibitor. Preliminary data showed that 2F1mab specifically recognizes LRP6, blocks Wnt pathway, reduces Wnt-mediated multiple pathogenic factors including VEGF, TNF-¿, ICAM-1 and CTGF, and inhibits multiple pathological processes of DR such as retinal vascular leakage, inflammation and neovascularization. Based on these observations, we hypothesize that 2F1mab has great potential to become an effective drug for the treatment of DR since it can alleviates the major pathological processes of DR through controlling multiple pathogenic factors. The therapeutic potential of 2F1mab strongly warrants further development of an antibody-based therapy modality which is suitable to clinical use in DR patients. The goal of this project is to generate a humanized therapeutic antibody derived from its parent 2F1mab for the treatment of DR. We have produced a series of humanized antibodies. Among them, the clone CLT-020 binds to LRP6 with a high specificity and affinity. Its affinity is 35.1-fold greater than 2F1mab, suggesting that CLT-020 is more effective than 2F1mab. This SBIR Phase I project will serve as a proof-of-concept study to produce CLT-020 and determine its in vivo efficacy. The program includes two specific aims: Aim 1 will establish a stable cell line to produce large amounts of CLT-020. Aim 2 will evaluate the efficacies of CLT-020 on the Wnt pathway, retinal vascular leakage and inflammation in a diabetic animal model. The proposed studies will lay a solid groundwork for future Phase II preclinical studies of CLT-020 and this project may develop a more effective therapeutics to cure DR.

Public Health Relevance Statement:


Public Health Relevance:
Diabetic retinopathy is a common complication of diabetes and a leading cause of vision loss in the United States. There is no FDA-approved pharmacotherapy for diabetic retinopathy and current medications for diabetic retinopathy are unsatisfactory. Therefore, there is a vital medical need to develop alternate therapies for diabetic retinopathy. This project will develop a novel and more effective approach to improve the treatment of this sight-threatening disease.

Project Terms:
Adrenal Cortex Hormones; Affinity; angiogenesis; Animal Model; Antibodies; base; Binding (Molecular Function); Blindness; Blood Vessels; Cell Culture Techniques; Cell Line; Cell surface; Cell Surface Receptors; Chinese Hamster Ovary Cell; Clinical; clinical practice; Complementarity Determining Regions; Complications of Diabetes Mellitus; Concanavalin A; connective tissue growth factor; Data; Development; diabetic; Diabetic Angiopathies; diabetic rat; Diabetic Retinopathy; Disease; drug candidate; Drug Delivery Systems; Drug Formulations; Drug Kinetics; effective therapy; Evaluation; Evans blue stain; Extravasation; FDA approved; Fibronectins; Fibrosis; Fluorescein-5-isothiocyanate; Freedom; Future; G Cells; Genes; Goals; Human; humanized antibody; Immunoglobulin G; improved; in vivo; Inflammation; inhibitor/antagonist; Intercellular adhesion molecule 1; Intervention; intravitreal injection; laser photocoagulation; LDL-Receptor Related Protein 1; Leukocytes; Leukostasis; Ligand Binding Domain; Ligands; lipoprotein receptor related protein 5; lipoprotein receptor-related protein 6; macular edema; Measures; Mediating; Medical; Methods; Modality; Molecular Target; Monoclonal Antibodies; Mus; neovascularization; nonhuman primate; novel; Parents; Pathologic Processes; Pathway interactions; Patients; Phage Display; Pharmaceutical Preparations; Pharmacotherapy; Phase; Phosphorylation; Play; preclinical study; Production; programs; Proteins; public health relevance; receptor; Research; Retina; Retinal; Role; Route; safety study; screening; Series; Signal Transduction; Small Business Innovation Research Grant; Solid; Specificity; stable cell line; Staining method; Stains; Streptozocin; TCF Transcription Factor; Techniques; Therapeutic; Therapeutic antibodies; TNF gene; Tumor Necrosis Factor-alpha; United States; Vascular Endothelial Growth Factors; Vascular Permeabilities; Visio

Diabetic retinopathy (DR) is a common complication of diabetes and a leading cause of vision loss in the United States. Although the anti-vascular endothelial growth factor (VEGF) drugs have shown impressive efficacies on wet age-related macular degeneration (AMD), they are only effective in approximately 50% of patients with DR, likely due to the multi-factorial nature of DR. Therefore, inhibition of VEGF alone may not be sufficient and alternative therapies with non-VEGF targets are desired to improve the treatment of this sight- threatening eye disease. The Wnt pathway mediates multiple pathological processes, including angiogenesis, vascular permeability, inflammation and fibrosis, as it regulates multiple pathogenic factors, such as VEGF, tumor necrosis factor-alpha (TNF-a), intercellular adhesion molecule-1 (ICAM-1), connective tissue growth factor (CTGF), fibronectin (FN), and Cox-2. Recent research suggests that over-activation of the Wnt pathway in the retina plays a key pathogenic role in the development of DR. There are 19 Wnt ligands and 10 Fz receptors that involve in the activation of the Wnt pathway, while only two cell-surface co-receptors, low-density lipoprotein receptor-related protein 5 and 6 (LRP5 & 6), are essential for the activation of Wnt pathway. Previous evidence indicates that LRP6 plays a major role in Wnt signaling in the retina and retinal pigment epithelia, and thus, LRP6 6 represents a promising molecular target for developing effective treatments of DR. Through generating and screening a series of mouse anti-human LRP6 monoclonal antibodies (mAbs), we have identified 2F1mab as a specific blocker of LRP6. Our Phase I project showed that the anti-LRP6 antibody specifically recognizes LRP6, blocks Wnt pathway, reduces Wnt-mediated expression of pathogenic factors including VEGF, TNF-a, ICAM-1 and CTGF, and ameliorates multiple pathological processes of DR such as retinal vascular leakage, inflammation and neovascularization. Based on these observations, we hypothesize that anti-LRP6 antibody has great potential to become an effective drug for the treatment of DR. since it can alleviates the major pathological processes of DR through controlling multiple pathogenic factors. Due to target to a main pathway which mediates production of multiple pathogenic factors and major pathological processes of DR, anti-LRP6 antibody should be more effective for DR than the drugs with a single target. Recently, we have generated humanized anti-LRP6 antibody (CLT-020) derived from its parent 2F1mab. CLT-020 showed higher affinity to LRP6 and higher potency in blocking Wnt signaling than 2F1mab. Affinity of CLT-020 is 35.1-fold greater than that of the murine antibody, and antibody also significantly inhibited over- activation of the Wnt pathway and retinal vascular leakage. The goal of this project is to complete the efficacy, pharmacokinetic (PK), and toxicity studies of CLT-020 required for the FDA approval of an Investigational New Drug (IND) application. The Phase II project includes three specific aims: Aim 1 will compare efficacy of CLT- 020 and anti-VEGF antibody; Aim 2 will analyze PK and ocular distribution of CLT-020; Aim 3 will evaluate pre- GLP toxicology of CLT-020. The proposed studies will lay a solid groundwork for future Phase III preclinical studies and IND application of CLT-020 to develop a therapy to be used as an alternative or in combination with the anti-VEGF drugs. Upon the completion of the proposed studies, Charlesson's commercial partner, Velocity Pharmaceutical Development, will support and initiate Phase III preclinical studies including GMP material production and GLP toxicology study, IND application and clinical trials for this drug candidate.

Public Health Relevance Statement:


Public Health Relevance:
DR is a common complication of diabetes and a leading cause of vision loss in the United States. Anti- VEGF antibodies are only effective in approximately 50% of DR patients, due likely to the multi-factorial nature of DR. Therefore, inhibition of VEGF alone may not be sufficient and there is a vital medical need to develop alternate therapies with non-VEGF targets for DR. This project will develop a novel and more effective approach to improve the treatment of DR.

NIH Spending Category:
Biotechnology; Diabetes; Eye Disease and Disorders of Vision; Macular Degeneration; Neurodegenerative

Project Terms:
Affinity; Age related macular degeneration; Alternative Therapies; angiogenesis; Antibodies; Area Under Curve; Autopsy; base; Biological Assay; Blindness; Blood Vessels; Cell surface; Cell Surface Receptors; Clinical; Clinical Pathology; Clinical Trials; comparative efficacy; Complications of Diabetes Mellitus; connective tissue growth factor; Data; Development; diabetic; Diabetic Angiopathies; diabetic rat; Diabetic Retinopathy; Disease; drug candidate; Drug Kinetics; effective therapy; Evaluation; Extravasation; Eye diseases; FDA approved; Fibronectins; Fibrosis; Future; Goals; Half-Life; Head; Human; improved; Inflammation; inhibitor/antagonist; Intercellular adhesion molecule 1; Intervention; intravenous injection; intravitreal injection; Investigational New Drug Application; LDL-Receptor Related Protein 1; Letters; Ligands; lipoprotein receptor related protein 5; lipoprotein receptor-related protein 6; Lucentis; macular edema; matrigel; Maximum Tolerated Dose; Measures; Mediating; Medical; Miniature Swine; Modeling; Molecular Target; Monoclonal Antibodies; Mus; Nature; neovascularization; NOEL; novel; novel therapeutics; Occupational; Ophthalmology; Optical Coherence Tomography; Oryctolagus cuniculus; Parents; Pathologic Processes; Pathway interactions; Patients; Permeability; Pharmaceutical Preparations; Pharmacologic Substance; Phase; Play; pre-clinical; preclinical study; Production; programs; public health relevance; Rattus; receptor; Research; Retina; Retinal; Retinal Neovascularization; Role; Safety; screening; Series; Signal Transduction; Small Business Innovation Research Grant; Solid; Staging; Streptozocin; Structure of retinal pigment epithelium; Tissues; Toxic effect; Toxicokinetics; Toxicology; Tumor Necrosis Factor-alpha; United States; Vascular Endothelial Growth Factors; Vascular Permeabilities; Vision