Publication Reference Index

Invest Ophthalmol Vis Sci. 2011 May 16;52(6):3174-80. doi: 10.1167/iovs.09-5078.

ABSTRACT

PURPOSE: Keratoconjunctivitis sicca (KCS) is characterized by inflammation and decreased production of tears containing increased levels of cytokines. The release occurs in the setting of conjunctival and lacrimal gland inflammation, potentially mediated by the interaction between lymphocyte function-associated antigen (LFA)-1, a cell surface protein found on lymphocytes, and its cognate ligand intercellular adhesion molecule (ICAM)-1. SAR 1118 is a novel LFA-1 antagonist and may be an effective therapeutic agent for the treatment of KCS. The following studies were performed to assess the in vitro activity of SAR 1118 and to evaluate the clinical efficacy of topical SAR 1118 for the treatment of idiopathic canine KCS.

METHOD: Pharmacodynamics were assessed by measuring the ability of SAR 1118 to inhibit Jurkat T-cell binding with recombinant human ICAM-1 and to inhibit cytokine release from human peripheral blood mononuclear cells (PBMCs) stimulated by staphylococcal enterotoxin B. For the assessment of clinical efficacy, 10 dogs diagnosed with idiopathic KCS were treated with SAR 1118 1% topical ophthalmic solution three times daily for 12 weeks. Schirmer's tear test (STT) was used to measure tear production.

RESULTS: SAR 1118 demonstrated concentration-dependent inhibition of Jurkat T-cell attachment, inhibition of lymphocyte activation, and release of inflammatory cytokines, particularly the Th1, Th2, and Th17 T-cell cytokines IFN-γ, IL-2, and IL-17F, respectively. Mean STT values increased from 3.4 mm during week 1 to 5.8 mm at week 12 (P < 0.025). No SAR 1118-related adverse events were observed.

CONCLUSIONS: SAR 1118 appears to be an effective anti-inflammatory treatment for KCS. Additional studies are warranted to establish the efficacy of SAR 1118 for the treatment of KCS in humans.

PMID:21330663 | DOI:10.1167/iovs.09-5078

Doc Ophthalmol. 2012 Feb;124(1):59-72. doi: 10.1007/s10633-011-9306-x. Epub 2011 Dec 27.

ABSTRACT

We compared the suitability of pentobarbital sodium (PB) and propofol (PF) anesthetics for multifocal electroretinograms (mfERGs) in rhesus macaques. mfERGs were collected from 4 ocularly normal rhesus macaques. All animals were pre-anesthetized with intramuscular ketamine (10-15 mg/kg). Intravenous PB induction/maintenance levels were 15 mg/kg/2-10 mg/kg and for PF, 2-5 mg/kg/6-24 mg/kg/h. There were 3 testing sessions with PB anesthesia and 5-7 testing sessions with PF anesthesia. All PB sessions were carried out before PF. First-order (K1) and second-order (first slice) kernels (K2.1) response density amplitude (RDA), implicit time (IT), and root mean square signal-to-noise ratios (RMS SNR) of the low-frequency (LFC) and high-frequency (HFC) components were evaluated. The use of PF or PB anesthesia resulted in robust, replicable mfERGs in rhesus macaques; however, RMS SNR of K1 LFC in ring and quadrant analyses was significantly larger for PF than for PB. Additionally, K1 RDA under PF was significantly larger than under PB for N1, P1, and P2 components (ring and quadrant) and for N2 (quadrant). PF IT was significantly prolonged (<1 ms) relative to PB IT for N1, P1 (ring), and N1 (quadrant), while PB IT was significantly prolonged (0.8-4.2 ms) relative to PF IT for N2 and P2 (ring and quadrant). K1 HFC and K2.1 LFC did not differ significantly between PB and PF in the ring or quadrant analyses. The response differences found with PB and PF anesthesia likely arise from variable relative effects of the anesthetics on retinal γ-aminobutyric acid (GABA(A)) receptors, and in part, on glycine and on glutamate receptors. Given the advantages of a stable anesthetic plane with continuous intravenous infusion and a smoother, more rapid recovery, PF is an appealing alternative for mfERG testing in rhesus macaques.

PMID:22200766 | PMC:PMC3295608 | DOI:10.1007/s10633-011-9306-x

Arch Ophthalmol. 2012 Jan;130(1):65-75. doi: 10.1001/archophthalmol.2011.295. Epub 2011 Sep 12.

ABSTRACT

OBJECTIVE: To characterize functional and anatomic sequelae of a bleb induced by subretinal injection.

METHODS: Subretinal injections (100 μL) of balanced salt solution were placed in the superotemporal macula of 1 eye in 3 cynomolgus macaques. Fellow eyes received intravitreal injections (100 μL) of balanced salt solution. Fundus photography, ocular coherence tomography, and multifocal electroretinography were performed before and immediately after injection and again at intervals up to 3 months postinjection. Histopathologic analyses included transmission electron microscopy and immunohistochemistry for glial fibrillary acidic protein, rhodopsin, M/L-cone opsin, and S-cone opsin.

RESULTS: Retinas were reattached by 2 days postinjection (seen by ocular coherence tomography). Multifocal electroretinography waveforms were suppressed post-subretinal injection within the subretinal injection bleb and, surprisingly, also in regions far peripheral to this area. Multifocal electroretinography amplitudes were nearly completely recovered by 90 days. The spectral-domain ocular coherence tomography inner segment-outer segment line had decreased reflectivity at 92 days. Glial fibrillary acidic protein and S-cone opsin staining were unaffected. Rhodopsin and M/L-cone opsins were partially displaced into the inner segments. Transmission electron microscopy revealed disorganization of the outer segment rod (but not cone) discs. At all postinjection intervals, eyes with intravitreal injection were similar to baseline.

CONCLUSIONS: Subretinal injection is a promising route for drug delivery to the eye. Three months post-subretinal injection, retinal function was nearly recovered, although reorganization of the outer segment rod disc remained disrupted. Understanding the functional and anatomic effects of subretinal injection is important for interpretation of the effects of compounds delivered to the subretinal space.

CLINICAL RELEVANCE: Subretinal injection is a new potential route for drug delivery to the eye. Separating drug effects from the procedural effects is critical.

PMID:21911651 | PMC:PMC3254795 | DOI:10.1001/archophthalmol.2011.295

Vet Ophthalmol. 2012 Mar;15 Suppl 1:71-8. doi: 10.1111/j.1463-5224.2011.00970.x. Epub 2011 Nov 30.

ABSTRACT

INTRODUCTION: Episcleral venous pressure (EVP) has an important role in intraocular pressure (IOP) homeostasis and accounts for more than 70% of the IOP in the normal dog. A frequently used species in glaucoma research is the normotensive dog especially when evaluating the efficacy of prostaglandin analogues and prostamides; however, aqueous humor dynamic studies in normal dogs are lacking, and the effect of 0.005% latanoprost on canine EVP is not known. We sought to determine the effects to the EVP of topically applied 0.005% latanoprost in the normotensive beagle dog.

METHODS: Female beagle dogs (n = 14) were used and each had a normal ophthalmic examination on study entry. EVP was determined using a standard episcleral venomanometer. Animals were dosed in one eye with 0.005% latanoprost, and the effects on EVP were compared with the averaged baseline EVP's determined in the predosing phase and the fellow nondosed eye. The Mixed Model Repeated Measures method was used to analyze the EVP data.

RESULTS: During the dosing phase of the study with topical 0.005% latanoprost, the mean EVPs of dosed eyes were significantly higher than that of nondosed eyes (P < 0.0001).

CONCLUSIONS: The increase in EVP in the dog with exposure to topical 0.005% latanoprost has not been observed in other species that have been studied, such as in the mouse and in humans, where the drug had no significant effect on the EVP. This response may be unique to dogs and suggests that dogs may not fully mimic human aqueous humor dynamics with topical 0.005% latanoprost. Although frequently performed in human studies, EVP should not be regarded to be a constant value in aqueous humor dynamic studies in the normal beagle dog.

PMID:22129101 | DOI:10.1111/j.1463-5224.2011.00970.x

Arch Ophthalmol. 2011 Aug;129(8):1042-52. doi: 10.1001/archophthalmol.2011.210.

ABSTRACT

OBJECTIVE: To evaluate the efficacy of systemic and intravitreous administration of VEGF Trap (aflibercept) in a nonhuman primate model of choroidal neovascularization (CNV).

METHODS: VEGF Trap treatment on laser-induced CNV was evaluated in 48 adult cynomolgus monkeys. In the prevention arms of the study, VEGF Trap was administered by intravenous injection (3 or 10 mg/kg weekly) or intravitreous injection (50, 250, or 500 μg/eye every 2 weeks) beginning before laser injury. In the treatment arm, a single intravitreous injection (500 μg) was given 2 weeks following laser injury. Laser-induced lesions were scored from grade 1 (no hyperfluorescence) to grade 4 (clinically relevant leakage). Representative lesions were evaluated histologically.

RESULTS: Grade 4 leakage developed at 32.4% and 45.4% of the laser sites in animals receiving intravitreous or intravenous administration of placebo at 2 weeks following laser injury, respectively. In contrast, the development of grade 4 lesions was completely or nearly completely prevented in all groups receiving intravenous or intravitreous injections of VEGF Trap. A single intravitreous injection of VEGF Trap (500 μg) administered following the development of CNV reduced the frequency of grade 4 lesions from 44.4% to 0% within 14 days of treatment. Intravitreous VEGF Trap was well tolerated with either no or only mild ocular inflammation. Histological evaluation showed decreased scores for morphologic features of tissue proliferation in the VEGF Trap prevention groups.

CONCLUSIONS: VEGF Trap prevented the development of clinically relevant CNV leakage when administered at the lowest doses tested. Moreover, a single intravitreous injection induced inhibition of active CNV leakage.

CLINICAL RELEVANCE: The animal model used in this study has an established track record as a predictor of pharmacologic efficacy of antineovascular drugs in humans having the neovascular, or wet, form of age-related macular degeneration.

PMID:21825187 | DOI:10.1001/archophthalmol.2011.210

Invest Ophthalmol Vis Sci. 2012 Apr 30;53(4):2368-76. doi: 10.1167/iovs.11-8475.

ABSTRACT

Purpose. The scanning laser polarimetry with variable corneal compensation (GDx VCC) methodology was established and verified in monkeys with experimental glaucoma (ExpG). Terminal GDx parameters were correlated with axon counts and electrophysiologic measures. The effects of memantine on these parameters were investigated. Methods. ExpG was induced in monkeys and intraocular pressure monitored weekly. Some monkeys received memantine in their diet before and after ExpG induction (1-10 months). GDx VCC scans, stereophotographs, and multifocal visual evoked potential (mfVEP) data were collected at baseline and every 6 to 8 weeks until euthanasia. Optic nerves were prepared for axon counting and other morphologic analysis. Results. There was no difference in IOP elevation exposure between memantine-treated and no-memantine-treated monkeys. The percentage of the optic nerve area composed of connective tissue septa was significantly greater in ExpG eyes than in Fellow eyes. There was a strong positive correlation between axon counts and terminal GDx parameter measures. Animals not receiving memantine exhibited significantly lower mfVEP amplitudes in ExpG eyes compared with the ipsilateral baseline or the final value in the Fellow eye. ExpG eyes from memantine-treated animals had higher overall mean amplitudes that were not significantly different relative to the ipsilateral baseline and final amplitudes in the Fellow eye. Conclusions. The authors' studies confirm that GDx VCC can be utilized in monkey ExpG studies to detect early retinal structural changes and that these changes are highly correlated with optic nerve axon counts. These structural changes may or may not lead to central functional changes as shown by the mfVEP in response to investigational therapies.

PMID:22427549 | PMC:PMC3833458 | DOI:10.1167/iovs.11-8475

Ophthalmic Surg Lasers Imaging Retina. 2014 Sep-Oct;45(5):394-7. doi: 10.3928/23258160-20140909-03.

ABSTRACT

BACKGROUND AND OBJECTIVE: This study examines the clinical response of patients transitioned to aflibercept, the newest anti-VEGF medication, due to persistent evidence of exudation on optical coherence tomography (OCT) despite regular treatment with bevacizumab and/or ranibizumab.

PATIENTS AND METHODS: Aflibercept was administered to 111 patients considered for study inclusion. Eyes were included if they were transitioned to aflibercept for treatment of persistent exudation on OCT despite regular treatment with at least three injections of ranibizumab or bevacizumab. Retrospective data were collected from medical records.

RESULTS: Complete resolution of exudation was seen in 34% of eyes at final follow-up. Clear improvement in exudation amount or severity without complete resolution was seen in 25%. No improvement was seen in 34%, and 6% demonstrated worsening of exudation. Snellen visual acuity at the time of transition versus final follow-up after aflibercept injection did not appreciably change (logMAR 0.494 to 0.505, Snellen equivalent 20/62 to 20/64; P = .84). The mean center point neurosensory retina thickness decreased from 228.6 to 176.9 µm (P = .001).

CONCLUSION: Aflibercept may decrease the amount of exudation in a significant number of patients. However, this reduction did not result in an improvement in Snellen visual acuity.

PMID:25230402 | DOI:10.3928/23258160-20140909-03

Invest Ophthalmol Vis Sci. 2014 Nov 4;55(12):7786-98. doi: 10.1167/iovs.14-14527.

ABSTRACT

PURPOSE: To test a hypothesis of regional variation in the effect of experimental glaucoma on choroidal blood flow (ChBF) and retinal function.

METHODS: Five rhesus macaques underwent laser trabecular destruction (LTD) to induce elevated intraocular pressure (IOP). Intraocular pressures were elevated for 56 to 57 weeks. Multifocal electroretinographic (mfERG) and multifocal visual evoked cortical potential (mfVEP) testing were performed at regular intervals before and during the period of IOP elevation. At euthanasia, the IOP was manometrically controlled at 35 (experimentally glaucomatous eye) and 15 (fellow control eye) mm Hg. Fluorescent microspheres were injected into the left ventricle. Regional ChBF was determined.

RESULTS: All of the experimentally glaucomatous eyes exhibited supranormal first-order kernel (K1) root mean square (RMS) early portions of the mfERG waveforms and decreased amplitudes of the late waveforms. The supranormality was somewhat greater in the central macula. Second-order kernel, first slice (K2.1) RMS mfVEP response was inversely correlated (R(2) = 0.97) with axonal loss. Total ChBF was reduced in the experimentally glaucomatous eyes. The mean blood flow was 893 ± 123 and 481 ± 37 μL/min in the control and glaucomatous eyes, respectively. The ChBF showed regional variability with the greatest proportional decrement most often found in the central macula.

CONCLUSIONS: This is the first demonstration of globally reduced ChBF in chronic experimental glaucoma in the nonhuman primate. Both the alteration of mfERG waveform components associated with outer retinal function and the reduction in ChBF were greatest in the macula, suggesting that there may be a spatial colocalization between ChBF and some outer retinal effects in glaucoma.

PMID:25370515 | PMC:PMC4254281 | DOI:10.1167/iovs.14-14527

J Ocul Pharmacol Ther. 2014 Jun;30(5):429-39. doi: 10.1089/jop.2013.0222. Epub 2014 Apr 10.

ABSTRACT

PURPOSE: Taprenepag isopropyl is an EP2 receptor agonist that is in development for the treatment of glaucoma. Iritis, photophobia, and increased corneal thickness observed in a Phase 2 clinical trial with taprenepag isopropyl were not previously observed in topical ocular toxicity studies in rabbits and dogs. In vivo studies using cynomolgus monkeys and in vitro models were used to elucidate the mechanisms underlying these ocular events.

METHODS: Monkeys were dosed daily for 28 days in 1 eye with taprenepag and in the other with vehicle control. Complete ophthalmic examinations were performed at baseline and weekly thereafter. Serial sections of eyes were examined histopathologically at the end of the study. Recovery after the discontinuation of taprenepag was assessed for 28 days in the monkeys in the high-dose group. In vitro studies evaluated cell viability, paracellular permeability, and cytokine induction with human corneal epithelial or endothelial cell cultures.

RESULTS: Monkeys demonstrated a dose-related incidence of iritis and increased corneal thickness that resolved within 28 days of discontinuing taprenepag. There was no evidence in vivo of taprenepag toxicity to the corneal endothelium or epithelium. Cell viability of stratified epithelial cells was primarily affected by excipients and was similar to Xalatan(®). The viability of HCEC-12 cells was not affected by taprenepag at concentrations up to 100 μM.

CONCLUSIONS: The lack of in vivo or in vitro endothelial cytotoxicity and the reversibility of the increase in corneal thickness and iritis in the monkey provide confidence to permit further clinical development of taprenepag.

PMID:24720348 | DOI:10.1089/jop.2013.0222

Regul Toxicol Pharmacol. 2014 Jul;69(2):187-200. doi: 10.1016/j.yrtph.2014.03.005. Epub 2014 Mar 26.

ABSTRACT

The development path described for JNJ-26489112 provides perspectives on interpretation of retinal effects observed in nonclinical studies and their implications for clinical development. JNJ-26489112 is a CNS-active investigational drug that has potential as a novel treatment for treatment-resistant and bipolar depression, epilepsy, and neuropathic/inflammatory pain. In a 6-month toxicity study in albino rats, retinal atrophy was observed at supratherapeutic exposures to JNJ-26489112. The histopathological changes and topography of the lesions were characteristic of light-induced damage specific to albino rats. The species/strain specificity is supported by an absence of any ocular effects in dogs and in pigmented and albino rats, housed under standard and reduced lighting, respectively. To further evaluate its potential to cause ocular effects, in vivo functional and structural ocular analyses were included in a 9-month monkey toxicity study. Reductions in rod- and cone-mediated electroretinograms were observed at supratherapeutic exposures but without any histopathologic changes. These data suggested that the effects of JNJ-26489112 in monkeys were neuromodulatory and not neurotoxic. Taken together, data related to the light-induced atrophy in albino rats and reversible neuromodulatory effects in monkeys, supported the safe evaluation of JNJ-26489112 in a clinical proof-of-concept study that included comprehensive functional and structural ocular monitoring.

PMID:24680767 | DOI:10.1016/j.yrtph.2014.03.005

J Ocul Pharmacol Ther. 2015 Dec;31(10):589-604. doi: 10.1089/jop.2015.0064. Epub 2015 Nov 5.

ABSTRACT

This article reviews ocular adverse events (AEs) reported in association with administration of antibody-drug conjugates (ADCs) in human clinical trials. References reporting ocular toxicity or AEs associated with ADCs were collected using online publication searches. Articles, abstracts, or citations were included if they cited ocular toxicities or vision-impairing AEs with a confirmed or suspected association with ADC administration. Twenty-two references were found citing ocular or vision-impairing AEs in association with ADC administration. All references reported use of ADCs in human clinical trials for treatment of various malignancies. The molecular target and cytotoxic agent varied depending on the ADC used. Ocular AEs affected a diversity of ocular tissues. The most commonly reported AEs involved the ocular surface and included blurred vision, dry eye, and corneal abnormalities (including microcystic corneal disease). Most ocular AEs were not severe (≤ grade 2) or dose limiting. Clinical outcomes were not consistently reported, but when specified, most AEs improved or resolved with cessation of treatment or with ameliorative therapy. A diverse range of ocular AEs are reported in association with administration of ADCs for the treatment of cancer. The toxicologic mechanism(s) and pathogenesis of such events are not well understood, but most are mild in severity and reversible. Drug development and medical professionals should be aware of the clinical features of these events to facilitate early recognition and intervention in the assessment of preclinical development programs and in human clinical trials.

PMID:26539624 | PMC:PMC4677113 | DOI:10.1089/jop.2015.0064

Hum Gene Ther Clin Dev. 2015 Sep;26(3):165-76. doi: 10.1089/humc.2015.076.

ABSTRACT

Applied Genetic Technologies Corporation is developing rAAV2tYF-CB-hRS1, a recombinant adeno-associated virus (rAAV) vector for treatment of X-linked retinoschisis (XLRS), an inherited retinal disease characterized by splitting (schisis) of retinal layers causing poor vision. We report here results of a study evaluating the safety and biodistribution of rAAV2tYF-CB-hRS1 in normal cynomolgus macaques. Three groups of male animals (n = 6 per group) received an intravitreal injection in one eye of either vehicle, or rAAV2tYF-CB-hRS1 at one of two dose levels (4 × 10(10) or 4 × 10(11) vg/eye). Half the animals were sacrificed after 14 days and the others after 91 or 115 days. The intravitreal injection procedure was well tolerated in all groups. Serial ophthalmic examinations demonstrated a dose-related anterior and posterior segment inflammatory response that improved over time. There were no test article-related effects on intraocular pressure, electroretinography, visual evoked potential, hematology, coagulation, clinical chemistry, or gross necropsy observations. Histopathological examination demonstrated minimal or moderate mononuclear infiltrates in 6 of 12 vector-injected eyes. Immunohistochemical staining showed RS1 labeling of the ganglion cell layer at the foveal slope in vector-injected eyes at both dose levels. Serum anti-AAV antibodies were detected in 4 of 6 vector-injected animals at the day 15 sacrifice and all vector-injected animals at later time points. No animals developed antibodies to RS1. Biodistribution studies demonstrated high levels of vector DNA in the injected eye but minimal or no vector DNA in any other tissue. These results support the use of rAAV2tYF-CB-hRS1 in clinical studies in patients with XLRS.

PMID:26390090 | PMC:PMC4788136 | DOI:10.1089/humc.2015.076

J Control Release. 2016 Dec 28;244(Pt A):1-13. doi: 10.1016/j.jconrel.2016.10.026. Epub 2016 Nov 1.

ABSTRACT

A potent anti-vascular endothelial growth factor (VEGF) biologic and a compatible delivery system were co-evaluated for protection against wet age-related macular degeneration (AMD) over a 6month period following a single intravitreal (IVT) injection. The anti-VEGF molecule is dimeric, containing two different anti-VEGF domain antibodies (dAb) attached to a human IgG1 Fc region: a dual dAb. The delivery system is based on microparticles of PolyActive™ hydrogel co-polymer. The molecule was evaluated both in vitro for potency against VEGF and in ocular VEGF-driven efficacy models in vivo. The dual dAb is highly potent, showing a lower IC₅₀ than aflibercept in VEGF receptor binding assays (RBAs) and retaining activity upon release from microparticles over 12months in vitro. Microparticles released functional dual dAb in rabbit and primate eyes over 6months at sufficient levels to protect Cynomolgus against laser-induced grade IV choroidal neovascularisation (CNV). This demonstrates proof of concept for delivery of an anti-VEGF molecule within a sustained-release system, showing protection in a pre-clinical primate model of wet AMD over 6months. Polymer breakdown and movement of microparticles in the eye may limit development of particle-based approaches for sustained release after IVT injection.

PMID:27810558 | PMC:PMC5494198 | DOI:10.1016/j.jconrel.2016.10.026

Toxicol Appl Pharmacol. 2016 Oct 15;309:55-62. doi: 10.1016/j.taap.2016.08.025. Epub 2016 Aug 28.

ABSTRACT

AUY922, a heat shock protein 90 inhibitor is associated with ocular adverse events (AEs). To provide a better understanding of ocular AEs in patients, 4 investigative studies were performed in a step-wise approach to assess retinal structure and function in pigmented (Brown Norway) and albino (Wistar) rats. In rats administered 30mg/kg of AUY922, the AUC0-24h and Cmax are comparable to that in patients at 70mg/m(2). AUY922 at ≥30mg/kg was poorly tolerated by rats with morbidity or mortality generally after the third weekly treatment. Electroretinography (ERG) changes were observed at doses ≥30mg/kg. The ERG changes were dose dependent, consistent with an effect on the photoreceptors, and fully reversible. The ERG effects could not be minimized by decreasing the Cmax while maintaining AUC. Histopathological changes were seen mainly when rats were administered AUY922 at 100mg/kg. The 2-hour infusion of AUY922 at 100mg/kg caused disorganization of the outer segment photoreceptor morphology in male Brown Norway rats; the severity of the disorganization increased with the number of administrations, but was reversible during a 4-week posttreatment period. There was no major difference in ocular response between Brown Norway and Wistar rats. No changes in serum iron levels, and no changes in rhodopsin, PDE6α, β-transducin concentrations, or retinal pigment epithelium-specific protein RPE65 expression were observed after single and multiple infusions of AUY922 at 100mg/kg compared to vehicle-treated controls. AUY922 retinal toxicity in rats recapitulates and further characterizes that reported in patients and is shown to be reversible, while a precise molecular mechanism for the effect was not determined.

PMID:27576608 | DOI:10.1016/j.taap.2016.08.025

Hum Gene Ther Clin Dev. 2016 Mar;27(1):37-48. doi: 10.1089/humc.2015.164.

ABSTRACT

Applied Genetic Technologies Corporation (AGTC) is developing rAAV2tYF-PR1.7-hCNGB3, a recombinant adeno-associated viral (rAAV) vector expressing the human CNGB3 gene, for treatment of achromatopsia, an inherited retinal disorder characterized by markedly reduced visual acuity, extreme light sensitivity, and absence of color discrimination. We report here results of a study evaluating the safety and biodistribution of rAAV2tYF-PR1.7-hCNGB3 in cynomolgus macaques. Three groups of animals (n = 2 males and 2 females per group) received a subretinal injection in one eye of 300 μl containing either vehicle or rAAV2tYF-PR1.7-hCNGB3 at one of two concentrations (4 × 10(11) or 4 × 10(12) vector genomes/ml) and were evaluated over a 3-month period before being euthanized. Administration of rAAV2tYF-PR1.7-hCNGB3 was associated with a dose-related anterior and posterior segment inflammatory response that was greater than that observed in eyes injected with the vehicle control. Most manifestations of inflammation improved over time except that vitreous cells persisted in vector-treated eyes until the end of the study. One animal in the lower vector dose group was euthanized on study day 5, based on a clinical diagnosis of endophthalmitis. There were no test article-related effects on intraocular pressure, visual evoked potential responses, hematology or clinical chemistry parameters, or gross necropsy observations. Histopathological examination demonstrated minimal mononuclear infiltrates in all vector-injected eyes. Serum anti-AAV antibodies developed in all vector-injected animals. No animals developed antibodies to CNGB3. Biodistribution studies demonstrated high levels of vector DNA in the injected eye but minimal or no vector DNA in any other tissue. These results support the use of rAAV2tYF-PR1.7-hCNGB3 in clinical studies in patients with achromatopsia caused by CNGB3 mutations.

PMID:27003753 | PMC:PMC4851175 | DOI:10.1089/humc.2015.164

Hum Gene Ther Clin Dev. 2016 Mar;27(1):27-36. doi: 10.1089/humc.2015.163.

ABSTRACT

Applied Genetic Technologies Corporation (AGTC) is developing rAAV2tYF-PR1.7-hCNGB3, a recombinant adeno-associated virus (rAAV) vector expressing the human CNGB3 gene, for treatment of achromatopsia, an inherited retinal disorder characterized by markedly reduced visual acuity, extreme light sensitivity, and absence of color discrimination. We report here results of a study evaluating safety and biodistribution of rAAV2tYF-PR1.7-hCNGB3 in CNGB3-deficient mice. Three groups of animals (n = 35 males and 35 females per group) received a subretinal injection in one eye of 1 μl containing either vehicle or rAAV2tYF-PR1.7-hCNGB3 at one of two dose concentrations (1 × 10(12) or 4.2 × 10(12) vg/ml) and were euthanized 4 or 13 weeks later. There were no test-article-related changes in clinical observations, body weights, food consumption, ocular examinations, clinical pathology parameters, organ weights, or macroscopic observations at necropsy. Cone-mediated electroretinography (ERG) responses were detected after vector administration in the treated eyes in 90% of animals in the higher dose group and 31% of animals in the lower dose group. Rod-mediated ERG responses were reduced in the treated eye for all groups, with the greatest reduction in males given the higher dose of vector, but returned to normal by the end of the study. Microscopic pathology results demonstrated minimal mononuclear cell infiltrates in the retina and vitreous of some animals at the interim euthanasia and in the vitreous of some animals at the terminal euthanasia. Serum anti-AAV antibodies developed in most vector-injected animals. No animals developed antibodies to hCNGB3. Biodistribution studies demonstrated high levels of vector DNA in vector-injected eyes but little or no vector DNA in nonocular tissue. These results support the use of rAAV2tYF-PR1.7-hCNGB3 in clinical studies in patients with achromatopsia caused by CNGB3 mutations.

PMID:27003752 | PMC:PMC4851180 | DOI:10.1089/humc.2015.163