Steve Pakola
Analyst · Gena Wang from Barclays. Your line is now open
Thanks, Ken. I'll begin with an update on RGX-314, which is being developed in collaboration with AbbVie to treat multiple ocular indications, including wet AMD and diabetic retinopathy. RGX-314 uses the NAV AAV8 vector to deliver a gene encoding a therapeutic antibody fragment to inhibit vascular endothelial growth factor or VEGF. Wet AMD is the leading cause of vision loss in people over 60, affecting more than two million patients in the U.S., Europe and Japan. The current standard-of-care for wet AMD is anti-VEGF treatments, which require patients to receive injections into the eye every four to 12 weeks for the duration of the disease. Real-world evidence shows that patients with wet AMD are severely undertreated due to the unsustainable treatment burden of these frequent injections required with currently approved anti-VEGF therapies. As a result, the majority of wet AMD patients experience significant vision loss over time. RGX-314 is being developed as a onetime treatment for wet AMD that has the potential to reduce the frequency of anti-VEGF treatments and preserve vision for wet AMD patients. In our Phase 1/2 clinical trial of RGX-314 for the treatment of wet AMD, using the subretinal delivery approach and its long-term follow-up study, we have observed a durable treatment effect over three years, including mean improvement in vision and stable retinal thickness and reduction in anti-VEGF treatment burden. We believe RGX-314 represents a significant potential advancement for the treatment of wet AMD. We continue to enroll patients in the ATMOSPHERE trial, the first of two pivotal trials to evaluate the efficacy and safety of RGX-314 in patients with wet AMD using the subretinal delivery approach. We also recently announced in January the initiation of the ASCENT trial, our second of two pivotal trials evaluating the efficacy and safety of subretinal delivery of RGX-314 in patients with wet AMD. Importantly, the ASCENT trial is the first trial to be initiated under our Eye Care Collaboration agreement with AbbVie. These two trials are expected to support BLA submission for RGX-314 in 2024. We are also developing RGX-314 using an in-office suprachoroidal delivery approach. In November 2021, we presented interim six-month data from Cohort 2 of the Phase 2 AVA trial at the American Academy of Ophthalmology meeting. The data presented continues to demonstrate evidence of the emerging clinical profile of RGX-314, with patients in Cohort 2 showing stable visual acuity and retinal fitness as well as a 72% reduction in anti-VEGF treatment burden compared to the mean annualized injection rate during the 12 months prior to receiving RGX-314. Looking at the safety profile across all Cohorts. As of November 4, 2021, RGX-314 was reported to be well tolerated in 50 patients from Cohorts 1 to 3 with no drug-related serious adverse events. Mild intraocular inflammation was observed on slit-lamp examination at similar incidents across both levels. Dose levels in Cohorts 1 and 2 with 4 out of 15 patients in Cohort 1 and 3 out of 15 patients in Cohort 2 and resolved quickly with topical corticosteroids. We are also pleased to announce the completion of enrollment in Cohort 4 and the expected completion of Cohort 5 in the first half of 2022. Cohorts 4 and 5 are evaluating RGX-314 at a third dose level of 1E12 genome copies per eye, and we look forward to sharing additional data from these cohorts. Moving to RGX-314 for the treatment of diabetic retinopathy or DR. DR is a complication of diabetes and is the leading cause of blindness in adults between the age of 24 to 75 worldwide. An estimated 27 million patients are affected by this debilitating disease worldwide, making it a large opportunity for REGENXBIO. Unlike with AMD, DR does not present itself to caregivers with a set of acute morbidities early on. Instead, it is a progressive disease, and while a large proportion of DR patients develop vision-threatening complications, including diabetic macular edema or DME, and neovascularization that can lead to blindness, many with this condition do not receive anti-VEGF treatment, a proven therapy to reduce the risk of developing these vision-threatening complications. And that's because of the unsustainable treatment burden required with today's available treatments. A product profile like RGX-314 that has the potential to be a onetime in-office treatment could potentially overcome this hurdle and provide an important therapy for patients with diabetic retinopathy. We recently presented six-month data from our Phase 2 ALTITUDE trial at the Angiogenesis conference in February that demonstrated a clinically meaningful, that is in at least two-step improvement from baseline on the Diabetic Retinopathy Severity Scale or DRSS, after a single RGX-314 administration in 47% of the 15 patients treated in Cohort 1 compared to 0% of patients in the observational control. Importantly, this was an increase from the 33% observed at three months. We are encouraged by what we are seeing at this stage. The data demonstrate comparability as well using the same endpoint to the outcome seen in the other trials that were the basis of approval for the current approved anti-VEGF treatments for DR. Furthermore, as of January 2022, RGX-314 was reported to be well tolerated in the 15 patients dosed with RGX-314 in Cohort 1 with no drug-related SAEs and no intraocular inflammation observed. Shifting to our rare disease portfolio. Our team has made significant progress advancing RGX-202, our potential onetime gene therapy for the treatment of Duchenne. We are developing RGX-202 to be a highly differentiated product and have designed it to deliver a transgene for a novel microdystrophin that includes the functional elements of the C-terminal or CT domain found in naturally occurring dystrophin. In preclinical studies, the presence of the CT domain has been shown to recruit several key proteins to the muscle cell membrane, leading to improved muscle resistance to contraction induced muscle damage in dystrophic mice models. Additional design features, including codon optimization and reduced CPG content have the potential to improve gene expression, increased translational efficiency and reduced immunogenicity. RGX-202 is designed to support the delivery and targeted expression of genes throughout the skeletal and heart muscle using our NAV AAV8 vector and a well-characterized muscle-specific promoter, SPc5-12. This product has now received both orphan and rare pediatric disease designation, which mark important milestones and acknowledgment of the need for new treatment options for patients with Duchenne. In January, we announced our IND was cleared by the FDA, and we are now on track to initiate our Phase 1/2 AFFINITY Duchenne trial in the first half of the year. We provided other key updates to our rare genetic disease portfolio at this year's Annual WORLDSymposium, highlighting Phase 1/2 data for both RGX-121 and RGX-111, our onetime gene therapies for the treatment of MPS II or Hunter syndrome, and severe MPS I or Hurler syndrome. For RGX-121, we presented updated data from all three cohorts. Importantly, we observed dose-dependent reductions in CSF biomarkers with Cohort 3 patients approaching normal levels of the D2S6 biomarker along with demonstration of meaningful improvements in neurodevelopmental function and caregiver reported outcomes observed up to two years after RGX-121 administration. For RGX-111, data at the WORLD was our first reveal. And while the patient numbers are small, we did observe emerging evidence of CSF biomarker activity along with neurodevelopmental assessments indicating an encouraging potential CNS profile. We plan to enroll additional patients in Cohort 2. And in both updates as of December 20, 2021, RGX-121 and RGX-111 were well tolerated with no drug-related SAEs. Overall, we have already made significant progress in 2022, and we look forward to providing further updates throughout the year. Now I'll turn the call back over to Ken.