Stephen Yoo
Analyst · Morgan Stanley. Your line is now open
Thanks Ken. I would like to begin today with our RGX-314 program for the treatment of wet AMD, with a focus on the data we released this morning. As a quick reminder, wet AMD is a disease affecting more than 2 million patients in the US, Europe and Japan and usually requires continual anti-VEGF therapy to prevent vision loss. Continual therapy is a burden to the patients and families affected. Many patients struggle to comply with the recommended therapeutic regimen for current anti-VEGF therapies and lack of compliance can lead to reduced therapeutic affect and ultimately vision loss. RGX-314 utilizes the NAV AAV8 vector which includes a gene that encodes for a therapeutic anti-VEGF protein which is designed to be continually made by retinal cells [Astra] injection. The expressed anti-VEGF antibody fab is designed to neutralize VEGF activity in a continuous fashion after a single administration. Continuous inhibition of VEGF activity will be something new to the treatment of wet AMD. The NAV AVV8 vector has been selected for this product candidate because it has demonstrated affective transaction of retinal cells in multiple pre-clinical animal models and the ability to produce high levels of therapeutic protein. On the next slide, we see a depiction of the current RGX-314 clinical trial. This is a phase 1 multi-center, open-label, multiple cohorts, dose escalation study in adults with wet AMD in United States. The study to date has included 18 previously treated wet AMD subjects who have had at least four anti-VEGF injections in the previous eight months. We observed the majority of enrolled subjects in the study have demonstrated a high need for regular and frequent anti-VEGF therapy. Most of the subjects are treated with many years of previous therapy with over 35 injections on average prior to entry. In addition, the subject’s responsiveness to anti-VEGF therapy was confirmed through a measurement of response by OCT after administration of an anti-VEGF injection. The study was designed to evaluated three doses of RGX-314, 3 x 10^9, 1 x 10^10 and 6 x 10^10 genome copies per eye. To-date subjects have followed for an average of 11 months for cohort 1, nine months for cohort 2 and six months for cohort 3. Turning to slide 9, I would like to highlight the primary objective of the study is to evaluated the safety and tolerability of RGX-314 at six months after a single dose administered by sub-retinal delivery. Secondary endpoints are also being evaluated to assess the potential meaningful signals in clinical outcome measures, including ocular examine and imaging such as BCVA and SD-OCT. In addition to the need for additional anti-VEGF therapy which could be given at the investigators discretion for new or persistent fluid or loss of vision. The data released today covers the first three cohorts as of July 27, 2018. From a total 18 previously treated wet AMD subjects who’ve enrolled in the study. I’ll start here on slide 10 by discussing the safety data. We reported today that RGF-314 has been well tolerated with no drug related adverse events to date. Most adverse events in the trial have been mild and there have been no observed immune reactions, drug related ocular inflammation or post-surgical inflammation beyond what is expected from a routine vitrectomy. Five SAEs were reported in total to date. We are encouraged by the safety profile of RGX-314 to date. I would now like to turn your attention to some of the secondary objectives of the study to assess for positive signals in clinical outcome measures in this first in human phase 1 clinical trial. We announced today initial around several efficacy parameters in the study including RGX-314 protein expression, supplemental anti-VEGF injections, retinal thickness as measured by SD-OCT and visual acuity as measured by BCVA. We are pleased to observe dose dependent protein expression levels, dose dependent reduction in anti-VEGF injections, maintenance of retinal thickness and maintain to improved visions across all dose cohorts. I will walk through this data on the following slides. Let’s begin with a summary of the protein levels by cohort shown here on slide 11. RGX-314 levels have been detected in all subjects treated to date; aqueous samples taken from the front of the eye were measured for protein levels by ELISA at approximately four weeks after administration of RGX-314. We’re encouraged of this evidence of dose dependent protein expression across all dose and cohorts. Moving to slide 12, we present the data regarding the number of anti-VEGF injections required post administration of RGX-314. We observe at six months after RGX-314 administration, the number of rescue injections has decreased across all dose and cohorts. You can see here in the slide, the average number of injection at six months post-dosing in the three cohorts. In the six months post-dosing cohort 1 required at average of 4.7 injections, cohort 2 required at average of 3.8 injections and cohort 3 required an average of 1.3 injections. Since this trial was a phase 1 first in human open-label study with no control arm, we wanted to understand how the frequency of anti-VEGF injections has changed for these subjects by comparing the number of anti-VEGF injections each subject received post-314 administration to each subject’s history prior to enrolling in the study. We did this by comparing the number of anti-VEGF injections each subject had received during the six months prior to their most recent anti-VEGF injection preceding their enrollment in the study to a number of injections received in the six months following RGF-314 administration. In cohort 3, the mean number of anti-VEGF injections received following RGX-314 administration was reduced by 53% when compared to this prior history. Additionally, I’d like to mention that 50% of subjects treated in cohort 3 have been free of anti-VEGF injection since the administration of RGX-314. On the next slide, we present central retinal thickness values as measured by Heidelberg SD-OCT. Maintenance of CRT from baseline to six months has been observed in all three dosing cohorts. The data from large phase 3 wet-AMD studies in naïve subjects show that subjects typically experience the greatest reduction in CRT in response to anti-VEGF therapy in the first few months of treatment. The subjects who entered this study with many years of previous therapy, we would expect their goal to be maintenance of CRT with regular injections. The CRT data indicate that these subjects who’ve demonstrated a high need for anti-VEGF therapy are receiving enough anti-VEGF therapy to maintain their central retinal thickness while in the study. In cohort 3, we are encourage our subjects are able to produce another anti-VEGF protein to maintain their central retinal thickness while reducing a number of anti-VEGF injections. Similar to changes in CRT in phase 3 studies of naïve wet AMD subjects, the greatest gain in visual acuity in response of anti-VEGF therapy is in the first few months. On slide 14, we can look at the mean BCVA from baseline to month six. We observe maintenance of vision in cohort 1 to improved vision in cohort 2 and 3. Subjects in the third cohort experienced a mean gain of 8 ETDRS letters, with cohort also receiving fewer anti-VEGF injections on average. Although the number of subjects treated is small, it is encouraging that subjects with previous therapy in cohort 3 have experienced further improvement in BCVA at six months post dosing. Furthermore, we note that all subjects in cohort 3 have maintained or gained vision at six months. On the next slide, we’ve graphed overtime for all three cohorts to illustrate the trends and vision in OCT. The vision is graphed in orange with the values on the left Y axis; the OCT values are represented in the blue bars with the values on the right Y axis. This overlay illustrates the maintenance of CRT as measured by Heidelberg SD-OCT with maintenance of vision in cohort 1 and improvement in vision in cohort 2 and 3. We’re encouraged that there is maintenance of CRT with improvement in vision with a reduction of anti-VEGF injections in cohort 3. On slide 16, I’d specially like to highlight that 50% of subjects in cohort 3 were free of anti-VEGF injections through six months. As a reminder, subjects in the study had previously required significant anti-VEGF therapy. And these subjects have received no anti-VEGF injections following RGX-314 administration. There is evidence of clinically meaningful maintenance of mean CRT with a reduction of 21 micros and mean improvement of 8 EDTRS letters in BCVA at month six versus baseline. These subjects also generally had a higher aqueous protein expression levels as measured at 12 weeks post RGX-314 administration So in summary, on the next slide of the [data] for six months, it shows there is a dose dependent protein expression levels, dose dependent reduction in anti-VEGF injections received following 314 administration and maintenance of CRT by SD-OCT across all cohorts. Additionally and through month six, BCVA assessments have shown maintained to improved mean changes in visual acuity. In particular, cohort 3 shows a combination of a reduction in anti-VEGF injections while maintaining central retinal thickness and improvement in BCVA with 50% of the cohort subjects receiving no anti-VEGF injections through six months. We are encouraged by the evidence of biologic activity based on the observation that subjects with the highest levels of measure protein expression are also the subjects who are showing the best clinical response. The study results we released today along with additional study results over the next couple of months are expected to be presented at the American Association of Ophthalmology Conference in 2018 at the annual meeting in Chicago, Illinois. Now I will turn to Ken to discuss next steps for RGX-314.