Gene Transfer for Neovascular Age- Related Macular Degeneration Peter A. Campochiaro The Wilmer Eye Institute The Johns Hopkins University School of Medicine Baltimore, MD

Financial Disclosure Research Support GenzymeGenzyme Oxford BioMedicaOxford BioMedica AskBioAskBio

Topics Neovascular AMD Background Current Treatment Why Consider Gene Transfer? Endpoints for Clinical Trials Targeted Delivery Repeat Administration

Age-Related Macular Degeneration (AMD) EarlyIntermediateAdvanced Multiple small or a few intermediate drusen Extensive intermediate drusen Choroidal Neovascularization Geographic Atrophy Subretinal Fibrosis

Advanced AMD Major Public Health Problem No. of individuals (millions) Number of Individuals With Neovascular AMD or Geographic Atrophy (millions)

Ranibizumab for NVAMD Mean Change in Visual Acuity Over Time 17.7 letter benefit * 17.0 letter benefit * * P < vs. sham

Subjects Gaining ≥15 Letters from Baseline Marina Trial 1-year outcomes2-year outcomes % of patients Ranibizumab 0.3 mg (n = 238) Ranibizumab 0.5 mg (n = 238) Sham (n = 240)

Why Consider Gene Transfer? Monthly intraocular injections provide best results Burden on patients and physicians Societal burden- expense Not feasible throughout most of the world Treatment as needed Increased risk of visual loss Gradual Catastrophic

AAV2.CBA-sFLT01 sFLT01 – contains domain 2 of Flt-1 coupled by 9Gly linker to human IgG1 Fc - high affinity VEGF binding protein CBA promoter Packaged in rAAV2

Retinostat Endostatin and Angiostatin CMV promoter Packaged in Equine Infectious Anemia Viral (EIAV) Vector

11 Study Populations Subjects with AMD, aged 50 years or more with active CNV that shows evidence of active leaking on fluorescein angiography BCVA less than or equal to 20/200 in the study eye BCVA in the fellow eye of 20/200 or better Subjects unlikely to benefit from standard of care – subfoveal fibrosis

12 Endpoints Primary Endpoint The incidence of adverse events Changes in best corrected visual acuity (BCVA) Evidence of ocular inflammation Intraocular pressure Secondary Endpoints The change from baseline in the amount of subretinal and intraretinal fluid measured by optical coherence tomography (OCT) Change in size of active choroidal neovascularisation measured on fluorescein angiography The change from baseline in BCVA at all time points Transgene product levels in aqueous fluid

sFlt01 Trial Two phases Dose escalation MTD evaluation Dose escalation (Patients with limited visual potential due to macular scarring) Four doses to be tested 2x10 8, 2x10 9, 6x10 9, 2x10 10 vp Minimum three patients per cohort Patients enrolled to show safety and biological activity MTD evaluation (Patients without scarring) Two doses to be tested (MTD and one dose below) Five patients per cohort Patients enrolled to show safety, biological activity, possible efficacy

14 Retinostat Trial Cohort Dose level # of PatientsVolume µl µl µl 4 MTD µl

Key information to be gained MTD Can vector cause reduction in amount of fluid within and under retina- measured by OCT? Level and duration of transgene product expression- measured in aqueous humor. Intravitreous vs subretinal injections

Advantages of Gene Transfer in NVAMD 1) 1) OCT provides a good quantitative outcome measure that allows us to assess biological activity even with poor visual potential 2) 2) We know what a good outcome should look like 3) 3) Secreted transgenes allow us to measure expression level over time- we should learn what levels are needed and if they are maintained long term.

Phase III Study Design and Endpoints VIEW q q q8 8.1 Rq4 Week

Phase III Study Design Visits q4wks- BCVA, eye exam, SD-OCT Primary Endpoint 52 weeks Group 1 Injection of vector dose 1 at baseline f/u visits- injection of RBZ if intraretinal or subretinal fluid Group 2 Injection of vector dose 2 at baseline f/u visits- injection of RBZ if intraretinal or subretinal fluid Group 3 Injection of RBZ at baseline f/u visits- injection of RBZ if intraretinal or subretinal fluid Group 4 Injection of RBZ at baseline f/u visits- injection of RBZ q visit

Phase III Endpoints Mean change in BCVA from baseline Number of injections of RBZ Need non-inferiority regarding BCVA Need superiority regarding # of injections of RBZ Secondary endpoints Intraretinal and subretinal fluid by OCT Size of active NV lesion by FA

Targeted Delivery Secreted transgene products so not necessary to deliver to diseased cell type However must target cells that are capable of robust and prolonged expression Vector, promoter, and route of injection are important

AAV2 Subretinal injection Transduction of retinal pigmented epithelium (RPE) and photoreceptors RPE-specific promoters can be used to exclude photoreceptors and other cells Very consistent among species including primates Intravitreous injection Ganglion cells, but differences among species

Lentiviral vectors Subretinal injection Transduction of retinal pigmented epithelium (RPE) and photoreceptors RPE-specific promoters can be used to exclude photoreceptors and other cells Very consistent among species including primates

Repeat Administration Long term expression after intraocular injection of AAV or lentiviral vectors in animals Determination of duration of expression in man is major objective of early phase trials

Fluocinolone Acetonide levels in the aqueous after single injection of sustained delivery pellet

Repeat Administration Treatment of fellow eye with gene transfer Since other treatments exist, not an urgent need Subretinal injection route has theoretical advantages

Gene Delivery for NVAMD Conclusions Early phase trials will provide valuable information relevant to all ocular gene therapy Level and duration of expression with various vectors and routes of administration Quantitative endpoints (OCT) allow assessment of biological activity even in small trials and even when visual potential is limited Incorporating reduced injection burden into primary endpoint for phase III trials would be a major benefit