REGENXBIO Inc.

look in addition to regulatory and product development plans. These forward-looking statements are subject to risks and uncertainties that may cause actual results to differ from those forecasted and can be identified by words such as expect, plan, will, may, anticipate, believe, should, intend, and other words of similar meaning. Any such forward-looking statements are not guarantees of future performance and involve certain risks and uncertainties. These risks are described in the risk factors and the management discussion and analysis sections of Regenexx BIOS annual report on Form 10-K for the full year ended December 31, 2020, and comparable risk factors sections of Regenexx BIOS quarterly reports on Form 10-Q, which are on file with the Securities and Exchange Commission and available on the SEC's website. Any information we provide on this conference call is provided only as of the date of this call, August 9th, and we undertake no obligation to update any forward-looking statements we may make on this call on account of new information, future events, or otherwise. Please be advised that today's call is being recorded and webcast. In addition, any unaudited or pro forma financial information that may be provided is preliminary and does not purport to project financial positions or operating results of the company. Actual results may differ materially. I would now like to turn the call over to Ken Mills.

Thank you, Patrick. Good afternoon, everyone. Thanks for joining us. I hope you're all having a safe and nice summer. On today's call, we'll begin with a recap of recent business highlights. Steve will provide an update on our clinical programs, and Vit will provide an overview of financial results for the second quarter of 2021. At the end of the call, we'll open the line for questions. I'm pleased to report that 2021 has been productive for Regenexx Bio. We've made important progress across our clinical development programs and anticipate a busy second half of 2021. Our dedicated team remains focused on bringing the therapeutic potential of our pipeline programs to patients in need, and we look forward to continuing our leadership in AAV-based gene therapy development and manufacturing. Our focus this year continues to be on execution across our pipeline programs. Our clinical programs evaluating RGX314 for the treatment of wet AMD and diabetic retinopathy have expanded and continue to be on track. The first trial in our pivotal program evaluating subretinal delivery of RGX314 in patients with wet AMD, Atmosphere, continues to enroll patients, and our second pivotal trial is expected to initiate in the fourth quarter of 2021. In addition, we continue to advance our two phase two trials evaluating the superchoroidal delivery of RGX314 using the SCS microinjector. The first interim data from cohort one of AVA, our phase two trial in wet AMD, will be presented at the Retina Society 54th Annual Scientific Meeting that begins in September in Chicago, Illinois. We're on track to report initial data in diabetic retinopathy later this year in the fourth quarter. For RGS121, our one-time gene therapy for the treatment of MPS2 or Hunter syndrome, we were pleased to share additional positive interim data from our clinical program at ASGCT in May. We continue to drive this program forward, enrolling additional patients at a higher dose and enrolling pediatric patients over the age of five years old. Finally, our work on RGX202 also continues. We now expect to file an IND for the treatment of Duchenne muscular dystrophy by the end of this year. I will now turn the call over to Steve for an even more detailed clinical and regulatory update.

Thanks, Ken. As Ken mentioned, our pivotal program evaluating the subretinal delivery of RGX314 for the treatment of wet AMD continues to be on track. We are enrolling patients in the Atmosphere, the first of two planned PIDRAL trials expected to support a VLA in 2024. As a reminder, Atmosphere is expected to enroll approximately 300 patients and evaluates RJX314 compared to repeated Ranavizumab intraocular injections, a standard treatment option for patients with wet AMD. We also expect to initiate the second of two randomized well-controlled clinical trials as part of our pivotal program in the fourth quarter of 2021, and we look forward to sharing additional details. Beyond our pivotal program for RGX314, we've made progress in our two Phase II trials evaluating RGX314 when delivered to the suprachoroidal space. We have completed dosing of patients in the third cohort of our Phase II trial for the treatment of wet AMD, known as AV8. This is the cohort of patients that received the same dose of RGX314 as patients in the second cohort, that is 5E11 genome copies per eye. But the patients in the third cohort are neutralizing antibody or NAB positive at entry. This may provide us additional information about the effects of RGX314 in NAB positive patients. potentially broadening the patient population that could be treated with this in-office delivery approach. I am also pleased to announce that we plan to present initial data from cohort one at the lower dose of 2.5 E11 GZ per eye at the Retina Society 54th Annual Scientific Meeting, which runs from September 29th to October 2nd. Additionally, we plan to report initial data from cohort two in the fourth cohort sorry, the fourth quarter of 2021. For altitude, our phase two trial to evaluate RGX314, suprachoroidal delivery in patients with diabetic retinopathy, we have completed enrollment of cohort one, and we expect to report initial data in the fourth quarter of 2021. We have also begun enrolling patients in cohort two at a higher dose, and are pleased to announce that we will be expanding into a third cohort of patients in this trial. As with AV8, cohort three of altitude will evaluate efficacy, safety, and tolerability in up to 20 patients who are NAV positive. And the same dose evaluated in cohort two will be evaluated in cohort three. As in previous cohorts, patients will not receive prophylactic immune suppressive corticosteroid therapy before or after administration of RGX314. In addition, we are making great strides in our rare disease portfolio and are well positioned to provide key clinical updates in the second half of 2021 and beyond. From our ongoing Phase 1-2 trial of RGX121 in MPS II patients up to five years old, we were pleased to share additional positive interim data from cohorts one and two at ASGCT in mid-May. As reported, RGX121 continued to be well-tolerated with no drug-related serious adverse events. Biomarkers and measures of neurodevelopmental function indicated CNS activity following RGX121 administration, with continued evidence of systemic enzyme expression and biomarker activity observed. We also began dosing patients in cohort three at an increased dose level of 2E11 GC per gram brain mass in the second quarter of 2021. We continue to enroll patients in this cohort. Our phase one two trial of RGX121 for the treatment of MPS2 in pediatric patients over the age of five years old also continues to enroll patients. and we look forward to keeping you updated across both of our RGX121 Phase 1-2 trials. Enrollment is ongoing in Cohort 2 of our Phase 1-2 trial of RGX111 for the treatment of MPS1 at a dose of 5E10 GC per gram brain mass as we are focused on realizing the therapeutic potential of RGX111 for MPS1 patients in need. Our team is preparing to submit the IND for RGX202, a potential one-time gene therapy for the treatment of Duchenne. We plan to submit this IND package by the end of 2021. Lastly, we remain on track to provide program updates for RGX181 for the treatment of CLN2 disease and RGX381 for the treatment of ocular manifestations of CLN2 disease by the end of 2021. Our team has made significant progress in the first half of this year, and we look forward to driving this momentum throughout the second half of 2021. With that, I turn the call back over to Ken.