This application contains, as a separate part of the disclosure, a Sequence Listing in computer-readable form which is incorporated by reference in its entirety and identified as follows: Filename: 51085A_Seglisting.txt; Size 23,955 bytes; Created: May 3, 2019.

FIELD OF THE INVENTION

The disclosure generally relates to anti-secretogranin III antibodies and uses thereof.

BACKGROUND

Diabetic retinopathy (DR) and age-related macular degeneration (AMD) are major causes of vision loss. DR affects about 93 million people world-wide, including about 28 million with vision-threatening diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR). DR in early stages is characterized by apoptosis of endothelial cells (ECs) and pericytes, vascular leakage and leukocyte adhesion, and may progress towards acellular capillaries, microaneurisms, retinal vein occlusion, DME and PDR. AMD has two clinical forms: dry (atrophic) and wet (neovascular or exudative). Neovascular AMD (nAMD) with choroidal neovascularization (CNV) afflicts 10-20% of individuals with the disease, but accounts for about 90% of all cases with severe vision loss from the disease.

Angiogenic factors play an important role in the pathogenesis of DME with retinal vascular leakage, PDR with retinal neovascularization, and nAMD. The approval of vascular endothelial growth factor (VEGF) inhibitors, including LUCENTIS (ranibizumab) and EYLEA (aflibercept), was a major breakthrough in DR and nAMD therapy (Schwartz et al.Expert Opin Emerg Drugs.2014; 19(3):397-405; Shao et al.Dev Ophthalmol.2016; 55:125-36). However, anti-VEGF therapies have limited efficacies and can improve vision only in less than 50% of DR and nAMD cases (Dedania and BakriClin Ophthalmol.2015; 9:533-42), suggesting that other angiogenic factors may be involved in the pathogenesis of these diseases. Due to limited options, patients with a poor response to one anti-VEGF drug are often switched to another VEGF inhibitor (Pinheiro-Costa et al.Ophthalmologica.2014; 232(3):149-55), despite their similar mechanisms of action. Additionally, most angiogenic factors regulate neovascularization in both normal and diseased vessels, so therapies against these targets may thus affect normal vessels and cells with detrimental effects. Consequently, all VEGF inhibitors are approved for AMD therapy only via intravitreal administration. Despite the low rate of side effects for a single intravitreal injection, repetitive intravitreal injections may cause adverse effects in the eye, such as endophthalmitis, retinal detachment, increased intraocular pressure and cataracts. The prevention of DME, PDR and nAMD in early stage or high-risk subjects requires repeated intravitreal injections of VEGF inhibitors. Therefore, anti-VEGF therapy is not approved for the prevention of DME, PDR or nAMD. To resolve the problems of existing treatments, new therapies for DR and AMD via topical eye drops or with long-lasting duration are needed to avoid or reduce the frequency of intravitreal injection.

Anti-VEGF therapy has also been evaluated for use in treating retinopathy of prematurity (ROP), which is the most common cause of blindness in children. ROP affects 14,000 to 16,000 pre-term infants each year in the U.S., with similar high rates in other countries. ROP is characterized by pathological retinal neovascularization (NV) and may progress toward partial or complete retinal detachment with severe visual impairment and even blindness. Infants with ROP are considered to be at higher risk for developing other ocular diseases in adulthood, such as retinal detachment, myopia, strabismus, amblyopia and glaucoma (Davidson and Quinn,Pediatrics.2011; 127(2):334-9). ROP is currently treated with laser therapy or cryotherapy (Hellstrom et al.,Lancet.2016; 40(3):189-202). Unfortunately, both treatments destroy the peripheral vision to save the central vision and do not address the underlying cause of ROP. Several clinical trials with VEGF inhibitors showed limited efficacy for ROP (Sankar et al.,Cochrane Database Syst. Rev.2016; 2:CD009734), and the safety of anti-VEGF therapy for ROP is a major concern. VEGF is crucial to vascular morphogenesis and retinal development at embryonic and neonatal stages. Mice with homozygous deletion of either VEGF receptor 1 or 2 die in the uterus (Fong et al.,Nature.1995; 376(6535):66-70; Shalaby et al.,Nature.1995; 376(6535):62-6). Similarly, mice with the deletion of a single VEGF allele are embryonically lethal (Ferrara et al.,Nature.1996; 380(6573); 439-42). Off-label use of VEGF inhibitors to treat ROP was also associated with significant adverse outcomes (Beharry et al,Semin Perinatol.2016; 40(3)189-202). These findings raise a significant safety concern regarding anti-VEGF therapy in preterm infants. Consequently, owing to the limited efficacy and safety, VEGF inhibitors are not approved for ROP therapy, more than a decade after their approval for nAMD, and there is currently no FDA-approved drug for ROP.

Developing new anti-angiogenic therapies with high efficacy, VEGF-independent mechanisms, and flexible administration routes are priorities for DR, nAMD, and ROP, and can be effective for treating other diseases, including cancer.

SUMMARY

The disclosure is directed to antibodies, and fragments and derivatives thereof, that specifically bind to secretogranin III (Scg3) and their use in treating diseases including diabetic retinopathy (DR), neovascular age-related macular degeneration (nAMD), retinopathy of prematurity (ROP), and cancer.

In one aspect, the disclosure provides an antibody or antigen-binding fragment thereof that cross-blocks a reference antibody from binding to Scg3, wherein the reference antibody is selected from the group consisting of an antibody comprising complementarity determining regions (CDRs) of SEQ ID NOs: 3-8; an antibody comprising CDRs of SEQ ID NOs: 11-16; an antibody comprising CDRs of SEQ ID NOs: 19-24; an antibody comprising CDRs of SEQ ID NOs: 27, 4, 28, 22, 29, and 24; an antibody comprising CDRs of SEQ ID NOs: 27, 4, 28, 32, 29, and 24; and an antibody comprising CDRs of SEQ ID NOs: 3, 4, 28, 22, 29, and 24. For example, the reference antibody is selected from the group consisting of an antibody comprising a heavy chain variable region comprising SEQ ID NO: 1 and a light chain variable region comprising SEQ ID NO: 2; an antibody comprising a heavy chain variable region comprising SEQ ID NO: 9 and a light chain variable region comprising SEQ ID NO: 10; an antibody comprising a heavy chain variable region comprising SEQ ID NO: 17 and a light chain variable region comprising SEQ ID NO: 18; an antibody comprising a heavy chain variable region comprising SEQ ID NO: 25 and a light chain variable region comprising SEQ ID NO: 26; an antibody comprising a heavy chain variable region comprising SEQ ID NO: 30 and a light chain variable region comprising SEQ ID NO: 31; an antibody comprising a heavy chain variable region comprising SEQ ID NO: 38 and a light chain variable region comprising SEQ ID NO: 33; and an antibody comprising a heavy chain variable region comprising SEQ ID NO: 34 and a light chain variable region comprising SEQ ID NO: 35.

In another aspect, the disclosure provides an antibody or antigen-binding fragment thereof that binds secretogranin III and comprises CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3, wherein (a) CDR-H1 comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 11, 19, and 27; (b) CDR-H2 comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 4, 12, and 20; (c) CDR-H3 comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 5, 13, 21, and 28; (d) CDR-L1 comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 6, 14, 22, and 32; (e) CDR-L2 comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 7, 15, 23, and 29; and (f) CDR-L3 comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 8, 16, and 24. For example, the antibody or antigen binding fragment thereof comprises (a) CDR-H1 comprising the amino acid sequence set forth in SEQ ID NO: 3; (b) CDR-H2 comprising the amino acid sequence set forth in SEQ ID NO: 4; (c) CDR-H3 comprising the amino acid sequence set forth in SEQ ID NO: 5; (d) CDR-L1 comprising the amino acid sequence set forth in SEQ ID NO: 6; (e) CDR-L2 comprising the amino acid sequence set forth in SEQ ID NO: 7; and (f) CDR-L3 comprising the amino acid sequence set forth in SEQ ID NO: 8. In another example, the antibody or antigen binding fragment thereof comprises (a) CDR-H1 comprising the amino acid sequence set forth in SEQ ID NO: 11; (b) CDR-H2 comprising the amino acid sequence set forth in SEQ ID NO: 12; (c) CDR-H3 comprising the amino acid sequence set forth in SEQ ID NO: 13; (d) CDR-L1 comprising the amino acid sequence set forth in SEQ ID NO: 14; (e) CDR-L2 comprising the amino acid sequence set forth in SEQ ID NO: 15; and (f) CDR-L3 comprising the amino acid sequence set forth in SEQ ID NO: 16. In still another example, the antibody or antigen binding fragment thereof comprises (a) CDR-H1 comprising the amino acid sequence set forth in SEQ ID NO: 19; (b) CDR-H2 comprising the amino acid sequence set forth in SEQ ID NO: 20; (c) CDR-H3 comprising the amino acid sequence set forth in SEQ ID NO: 21; (d) CDR-L1 comprising the amino acid sequence set forth in SEQ ID NO: 22; (e) CDR-L2 comprising the amino acid sequence set forth in SEQ ID NO: 23; and (f) CDR-L3 comprising the amino acid sequence set forth in SEQ ID NO: 24. In one example, the antibody or antigen binding fragment thereof comprises (a) CDR-H1 comprising the amino acid sequence set forth in SEQ ID NO: 27; (b) CDR-H2 comprising the amino acid sequence set forth in SEQ ID NO: 4; (c) CDR-H3 comprising the amino acid sequence set forth in SEQ ID NO: 28; (d) CDR-L1 comprising the amino acid sequence set forth in SEQ ID NO: 22; (e) CDR-L2 comprising the amino acid sequence set forth in SEQ ID NO: 29; and (f) CDR-L3 comprising the amino acid sequence set forth in SEQ ID NO: 24. In another example, the antibody or antigen binding fragment thereof comprises (a) CDR-H1 comprising the amino acid sequence set forth in SEQ ID NO: 27; (b) CDR-H2 comprising the amino acid sequence set forth in SEQ ID NO: 4; (c) CDR-H3 comprising the amino acid sequence set forth in SEQ ID NO: 28; (d) CDR-L1 comprising the amino acid sequence set forth in SEQ ID NO: 32; (e) CDR-L2 comprising the amino acid sequence set forth in SEQ ID NO: 29; and (f) CDR-L3 comprising the amino acid sequence set forth in SEQ ID NO: 24. In still another example, the antibody or antigen binding fragment thereof comprises (a) CDR-H1 comprising the amino acid sequence set forth in SEQ ID NO: 3; (b) CDR-H2 comprising the amino acid sequence set forth in SEQ ID NO: 4; (c) CDR-H3 comprising the amino acid sequence set forth in SEQ ID NO: 28; (d) CDR-L1 comprising the amino acid sequence set forth in SEQ ID NO: 22; (e) CDR-L2 comprising the amino acid sequence set forth in SEQ ID NO: 29; and (f) CDR-L3 comprising the amino acid sequence set forth in SEQ ID NO: 24.

In another aspect, the disclosure provides an antibody or antigen-binding fragment thereof that binds secretogranin III and comprises a heavy chain variable region comprising SEQ ID NO: 1, 9, 17, 25, 30, 38, or 34 and a light chain variable region comprising SEQ ID NO: 2, 10, 18, 26, 31, 33, or 35. For example, the antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO: 1 and a light chain variable region comprising SEQ ID NO: 2. In another example, the antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO: 9 and a light chain variable region comprising SEQ ID NO: 10. In still another example, the antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO: 17 and a light chain variable region comprising SEQ ID NO: 18. In one example, the antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO: 25 and a light chain variable region comprising SEQ ID NO: 26. In another example, the antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO: 30 and a light chain variable region comprising SEQ ID NO: 31. In still another example, the antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO: 38 and a light chain variable region comprising SEQ ID NO: 33. In another example, the antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO: 34 and a light chain variable region comprising SEQ ID NO: 35. In one aspect, the disclosure provides an antibody or antigen-binding fragment thereof that binds secretogranin III and comprises a heavy chain variable domain comprising an amino acid sequence at least 90% identical to SEQ ID NO: 1, 9, 17, 25, 30, 38, or 34, and comprising a light chain variable region comprising an amino acid sequence at least 90% identical to SEQ ID NO: 2, 10, 18, 26, 31, 33, or 35.

In another aspect, the disclosure provides a nucleic acid encoding an antibody or antigen-binding fragment described herein. In one aspect, the disclosure provides an expression vector comprising a nucleic acid encoding an antibody or antigen-binding fragment described herein and a host cell transformed with said expression vector.

In one aspect, the disclosure provides a pharmaceutical composition comprising an antibody or antigen-binding fragment described herein and a physiologically acceptable diluent, excipient or carrier. In another aspect, the disclosure provides a kit comprising an antibody or antigen-binding fragment thereof described herein or pharmaceutical composition comprising said antibody or antigen-binding fragment thereof.

The disclosure also provides medical uses for the antibodies and antigen-binding fragments described herein. In one aspect, a method of treating nAMD in a subject in need thereof comprising administering a therapeutically effective amount of an antibody, antigen-binding fragment thereof, or pharmaceutical composition described herein. For example, the antibody, antigen-binding fragment thereof, or pharmaceutical composition is administered in an amount effective to inhibit CNV and/or polypoidal choroidal vasculopathy (PCV), the latter of which is considered to be a variant of nAMD.

In one aspect, a method of treating diabetic retinopathy in a subject in need thereof is provided, wherein the method comprises administering a therapeutically effective amount of the antibody, antigen-binding fragment thereof or pharmaceutical composition described herein. In another aspect, a method of treating retinopathy of prematurity in a subject in need thereof is provided, wherein the method comprises administering a therapeutically effective amount of the antibody, antigen-binding fragment thereof or pharmaceutical composition described herein. For example, the antibody, antigen-binding fragment thereof, or pharmaceutical composition is administered in an amount effective to decrease retinal vascular leakage and/or retinal neovascularization and/or choroidal neovascularization.

In one aspect, a method of treating cancer in a subject in need thereof is provided, the method comprising administering a therapeutically effective amount of the antibody, antigen-binding fragment thereof or pharmaceutical composition described herein. For example, the antibody, antigen-binding fragment thereof, or pharmaceutical composition is administered in an amount effective to reduce tumor burden (e.g., decrease tumor size or reduce the number of cancer cells in the body).

In another aspect, a method of treating an angiogenesis-related disease in a subject in need thereof is provided, the method comprising administering a therapeutically effective amount of the antibody, antigen-binding fragment thereof or pharmaceutical composition described herein. For example, the angiogenesis-related disease is a disease selected from neovascular glaucoma, corneal neovascularization, pterygium, retinal vein occlusions, retinal and macular neovascularization from myopia, inflammatory condition, inherited retinal dystrophies, and sickle cell retinopathy, arthritis, synovitis, osteomyelitis, osteophyte formation, multiple sclerosis, vascular malformations, autoimmune diseases, atherosclerosis, transplant arteriopathy, obesity, psoriasis, warts, allergic dermatitis, scar keloids, pyogenic granulomas, blistering disease, Kaposi sarcoma (e.g., in AIDS patients), primary pulmonary hypertension, asthma, nasal polyps, inflammatory bowel disease, periodontal disease, liver cirrhosis, ascites, peritoneal adhesions, endometriosis, uterine bleeding, ovarian cysts, ovarian hyperstimulation, restenosis, and cystic fibrosis.

The foregoing summary is not intended to define every aspect of the invention, and other features and advantages of the present disclosure will become apparent from the following detailed description, including the drawings. The present disclosure is intended to be related as a unified document, and it should be understood that all combinations of features described herein are contemplated, even if the combination of features are not found together in the same sentence, paragraph, or section of this disclosure. In addition, the disclosure includes, as an additional aspect, all embodiments of the invention narrower in scope in any way than the variations specifically mentioned above. With respect to aspects of the disclosure described or claimed with “a” or “an,” it should be understood that these terms mean “one or more” unless context unambiguously requires a more restricted meaning. With respect to elements described as one or more within a set, it should be understood that all combinations within the set are contemplated. If aspects of the disclosure are described as “comprising” a feature, embodiments also are contemplated “consisting of” or “consisting essentially of” the feature. Where aspects of the disclosure are described as “methods of treatment,” it will be appreciated that uses of the disclosed antibody or antigen-binding fragment thereof for the referenced disease or disorders also is contemplated. For example, the disclosure contemplates use of the antibody or antigen-binding fragment thereof described herein for treating neovascular age-related macular degeneration in a subject in need thereof; treating diabetic retinopathy in a subject in need thereof; or treating retinopathy of prematurity in a subject in need; treating an angiogenesis-related disease in the eye, optionally selected from neovascular glaucoma, corneal neovascularization, pterygium, retinal vein occlusions, retinal and macular neovascularization from myopia, inflammatory condition, inherited retinal dystrophies, and sickle cell retinopathy, in a subject in need thereof. Additional features and variations of the disclosure will be apparent to those skilled in the art from the entirety of this application, and all such features are intended as aspects of the disclosure.

