Kenneth Mills
Analyst · Morgan Stanley
Thank you, Patrick, and good afternoon, everyone. Thank you for joining us today. On this call, we will provide you with an update on the company and our ongoing development programs, review accomplishments, progress made over the last 3 months, share financial results for the third quarter and look ahead to milestones for the remainder of the year. After that, we will open up the call for any questions.
I'm going to start by reviewing our key areas of focus. We are developing our proprietary NAV Technology Platform with the vision of realizing potential of gene therapy to improve the lives of patients suffering from severe diseases. In order to accomplish this vision, we are focusing our development efforts on building our internal pipeline of lead product candidates while also licensing our NAV vectors to third-party companies in the gene therapy space who share our vision. As of September 30, 2016, our NAV Technology Platform was being applied in the development of 29 product candidates, including 5 internally developed product candidates and 24 candidates being developed by our NAV Technology licensees.
We believe that our NAV Technology Platform, which is supported by the breadth and depth of our intellectual property portfolio, coupled with our focused internal and external development strategy, establish us as the leader in the AAV gene therapy space. As a reminder, our NAV Technology Platform is a proprietary AAV gene delivery platform that consists of more than 100 novel AAV vectors, including AAV7, AAV8, AAV9 and AAVrh10. These AAV vectors have demonstrated clinical efficacy in severe genetic, central nervous system and hematological disorders and share the following important and differentiating attributes when compared to earlier-generation AAV vectors: higher and longer-term gene expression, broad and novel tissue selectivity, lower immune response and improved manufacturability. Our therapeutic focus at REGENXBIO is on metabolic, retinal and neurodegenerative diseases, areas where we believe our vectors are uniquely suited to impact specific mechanisms of diseases for patient populations that are facing significant unmet medical needs. I'm going to share with you an overview and update on our 4 internal programs: homozygous familial hypercholesterolemia, wet age-related macular degeneration, Mucopolysaccharidosis Type I and Mucopolysaccharidosis Type II.
First, I'll start with our metabolic disease franchise. RGX-501 is our lead candidate -- lead development candidate for the treatment of homozygous familial hypercholesterolemia or HoFH. HoFH is caused by a defect in the low-density lipoprotein receptor or LDLR gene. Patients with this defect in the LDLR gene have little to no LDL receptor function, which leads to the buildup of LDL cholesterol or LDLC, the bad cholesterol in the bloodstream. This in turn causes coronary artery disease at a young age that is severe and ultimately fatal.
RGX-501 uses our AAV8 vector to deliver the LDL receptor gene to liver cells. We view AAV8 as the optimal choice for delivery to the liver, given the significant preclinical data to date that demonstrates higher efficient and -- highly efficient and durable expression mediated by AAV8. To remind you, this is the same vector used in the first demonstration of efficacy in a gene therapy study in hemophilia B.
While other therapies for HoFH are available to patients, existing treatments fail to address the underlying cause of disease. Further, widespread use is limited due to poor tolerability or inability to meaningfully lower LDLC levels to safe ranges. We believe that RGX-501 has the potential to directly address the underlying cause of the disease and, therefore, provide significant therapeutic benefit.
As many of you know, REGENXBIO, in collaboration with our partners at the University of Pennsylvania, initiated our first clinical trial, a Phase I/II study of RGX-501 earlier this year. The RGX-501 trial is an open-label, single-site study evaluating the safety and efficacy of RGX-501 in up to 12 patients. The primary endpoint is to assess the safety of a single intravenous administration of RGX-501. The secondary endpoint is to determine the change from baseline of LDLC at 12 weeks.
This is a dose escalation study with patients receiving either a single dose of 2.5 x 10 to the 12 or 7.5 x 10 to the 12 genome copies per kilogram. Penn continues to actively recruit and screen patients to enroll in the trial, both from our -- its own patient population and in other centers that treat HoFH patients. This process continues to progress. In this quarter, eligible patients were identified and screened and the scheduling process for dosing is underway. We remain on track to enroll the first patient into the study by the end of this year.
Before I move on to the next program, let me just mention that the FDA has granted orphan drug designation to RGX-501 for the treatment of HoFH. This designation allows for additional marketing exclusivity, financial benefits.
Next, I'm going to turn my attention to our second program, RGX-314 from our retinal disease franchise. We're developing RGX-314 for the treatment of wet age-related macular degeneration, also known as wet AMD. Patients suffering from wet AMD experience formation of excess blood vessels in the retina, resulting in fluid leakage that eventually leads to vision loss.
In the U.S. alone, an estimated 600,000 patients suffer from vision loss due to wet AMD. Current standard of care available to physicians involves the use of one of several VEGF inhibitors, which help impede excess blood vessel formation. These therapies, however, are less than ideal as they require frequent, as often as monthly, physician-administered injections into the patient's eye.
RGX-501 could truly prove transformational as it is being developed as a potential onetime administration for wet AMD. Utilizing our AAV8 vector, RGX-314 encodes a gene for a protein that binds to VEGF, inhibiting VEGF activity and affecting some -- the same mechanism as a well-accepted standard of care used to treat wet AMD.
Preclinical studies have shown that AAV8 is very high-performing vector targeting cells in the back of the eye, as demonstrated in animal models durability and expression levels that are substantially better than what has been seen with previous-generation vectors. Our modeling work continues as we compare results seen with the standard of care versus RGX-314 in the expression of VEGF in the retina versus other parts of the eye. Our preclinical studies are ongoing, and we look forward to sharing the results in an appropriate scientific meeting in the future. We anticipate that these results will support preclinical data we've shared, showing high levels of expression of RGX-314 in the back of the eye and suggesting a high potential for RGX-314 to inhibit VEGF.
We're currently completing our IND-enabling studies for RGX-314, including the evaluation of safety and toxicology. We've made additional progress with our RGX-314 program in this quarter with the initiation of manufacturing of material for the anticipated Phase I clinical trial. And we continue to expect to file an IND with the FDA for RGX-314 in the first quarter of 2017.
Finally, let's move on to our 2 lead central nervous system programs in our neurodegenerative disease franchise. We are developing RGX-111 and RGX-121 for the treatment of Mucopolysaccharidosis Type I and Type II or MPS I and MPS II, respectively. Both MPS I and MPS II are genetic diseases caused by deficiency of enzymes required to break down -- required for the breakdown of waste products inside cells. Ultimately, most MPS I and MPS II patients exhibit severe cognitive decline.
For both of these programs, we utilize the AAV9 vector to deliver genes directly to the CNS or central nervous system. We believe the AAV9 vector is an excellent candidate for targeting the CNS as it has demonstrated some unique and applicable properties, notably a strong affinity for cells in the CNS and an ability to cross the blood-brain barrier. Existing treatments for MPS I and MPS II include enzyme replacement therapies. But because these treatment options do not cross the blood-brain barrier, they only address the non-CNS symptoms of these diseases.
Both RGX-111 and RGX-121 are designed to address this significant unmet need by preventing or stabilizing neurodegenerative and neurocognitive decline, which is not accompanied by -- which is not addressed by the current standard of care. We believe global delivery through CNS is necessary to broadly reach cells with defective genes. Therefore, to optimize the therapeutic potential, we plan to administer RGX-111 and RGX-121 directly into the fluid in the CNS to achieve global delivery.
Recently published preclinical study results for both programs support our long-term clinical development plans and our mission to utilize NAV gene therapies to improve the lives of patients suffering from severe neurodegenerative diseases. In a preclinical study of RGX-111 for the treatment of MPS I published in Molecular Genetics and Metabolism, RGX-111 used the AAV9 vector to deliver human alpha-iduronidase (sic) [ alpha-l-iduronidase ] or IDUA gene to the CNS. Results demonstrated dose-dependent expression of IDUA and correction of disease pathology in the brain with reduction in spinal cord compression after a single administration of AAV9 vectors expressing IDUA. These data are expected to help establish the minimum effective dose for REGENXBIO's planned first-in-human study.
In another preclinical study published in Human Gene Therapy, RGX-121 used the NAV AAV9 vector to deliver the human iduronate-2-sulfatase or IDS gene to the CNS to treat MPS II in a mouse model. These results also demonstrated dose-dependent expression of gene in correction of disease pathology in the brain after a single administration.
Levels of IDS in the brain tissue, cerebral spinal fluid and serum all approached or exceeded normal levels. And the treated mice also demonstrated improvement in long-term memory and in novel object recognition tests as well as evidence of correction of the disease in the liver and heart.
From a regulatory perspective, the FDA has granted orphan drug and rare pediatric disease designations to both RGX-111 for MPS I and RGX-121 for the treatment of MPS II. The rare pediatric disease designations create potential to receive a priority review voucher from the FDA upon approval, which can be redeemed to obtain priority review for any subsequent marketing application and may be sold or transferred.
Now I want to touch on our manufacturing capabilities because product manufacturing remains a key focus area for us as a company, and we continue to invest in people, technology and capabilities across our programs. We've built a seasoned team with deep experience in biologics manufacturing from industry. We're expanding our in-house capabilities and anticipate completion of our advanced manufacturing analytics lab by the end of this year.
Our manufacturing team is also working with leading biologics manufacturers to produce current batches and scale up our manufacturing processes for use in future clinical studies. By the end of 2016, we expect to have initiated or completed manufacturing of the material for the initial studies for all 4 of our lead programs.
In addition to our internal development efforts, we are also advancing NAV Technology Platform through the efforts of our NAV Technology licensees. The majority of our partnerships are structured as licenses to a single NAV vector for the indication the licensee is pursuing, for example, AAV8 for the treatment of hemophilia A with Shire or AAV9 for the treatment of spinal muscular atrophy with AveXis. This partnering strategy allows us to focus on our core therapeutic areas internally while retaining the flexibility to sublicense treatments for other areas of unmet medical need.
As licensee programs move into the clinic and demonstrate safety and efficacy, they validate the strength of the NAV Technology Platform for developing gene therapy treatments. This approach also provides us with additional milestones upon which the success of our technology platform can be measured and brings additional knowledge and advances to these important gene therapy programs.
As of September 30, 2016, our technology has been licensed to 9 NAV Technology licensees. Four of our licensees programs are currently clinical stage. We're encouraged by the achievement of clinical proof-of-concept as reported by our NAV Technology licensees, including the AAV8 vector for the treatment of hemophilia and more recently, the AAV9 vector for the treatment of spinal muscular atrophy or SMA.
Our licensee, AveXis, recently announced that based on its receipt of minutes following a Type B meeting with the FDA that AveXis planned pivotal study for AVX-101 (sic) [ AVXS-101 ] in spinal muscular atrophy type I will reflect a single-arm design. Additionally, AveXis announced that the FDA strongly recommended that AveXis request an end-of-Phase I meeting at the completion of its Phase I study of AVXS-101, which is expected to occur in the first half of 2017. That would include a discussion of whether the data from the Phase I study might provide the substantial evidence necessary to support a marketing application.
We're encouraged by the potential for early approval of gene therapy based on our NAV Technology Platform. We continue to see strong interest in our vectors across a wide range of therapeutic applications.
Overall, I'm really pleased to report that to date, 2016 has been a highly productive year for REGENXBIO. Operationally, we've continued to build our infrastructure across all areas of the company to support our mission and vision. This quarter, we also made important additions to our leadership team and Board of Directors. Of recent note, we appointed Daniel Abdun-Nabi and Daniel Tassé to the REGENXBIO Board of Directors, and we named Patrick Christmas as our Senior Vice President and General Counsel.
With that, I'll turn it over to Vit for a review of the financials.