Taysha Gene Therapies, Inc.

financial results and corporate update conference call. At this time, all participants are in listen-only mode. Following management's prepared remarks, we'll hold a brief question-answer session. As a reminder, this call is being recorded today, May 11th, 2021. I'll now turn the call over to Dr. Kimberly Lee, Senior Vice President of Corporate Communications and Investor Relations. Please go ahead.

Good morning and welcome to Tayshia's first quarter 2021 financial results and corporate update conference call. Joining me on today's call are Ari Session II, Tayshia's president, CEO, and founder, Dr. Suresh Prasad, chief medical officer and head of R&D, and Cameron Alam, chief financial officer. After our formal remarks, we will conduct a question and answer session and instructions will follow at that time. Earlier today, Tayshia issued a press release announcing financial results for the first quarter ended March 31, 2021. A copy of this press release is available on the company's website and through our SEC filing. Please note that on today's call, we will be making forward-looking statements, including statements relating to the safety and efficacy and the therapeutic and commercial potential of our investigational drug candidates. These statements may include the expected timing and results of clinical trials for our drug candidates and the regulatory status and market opportunities for those programs, as well as patient manufacturing plans. This call may also contain forward-looking statements relating to patients' growth and future operating results, discovering development of drug candidates, strategic alliances and intellectual property, as well as matters that are not historical facts or information. Various risks may cause patients' actual results to differ materially from those stated or implied in such forward-looking statements. These risks include insurgencies related to the timing and results of clinical trials and preclinical studies of our drug candidates, our dependence upon strategic alliances and other third-party relationships, our ability to obtain patent protections for our discoveries, limitations imposed by patents owned or controlled by third parties, and the requirements of substantial funding to conduct our research and development activities. For a list and description of the risks and uncertainties that we face, please see the reports we filed with the Securities and Exchange Commission. This conference call contains time-sensitive information that is as accurate only as of date of this live broadcast, May 11th, 2021. Tisha undertakes no obligations to revise or update any forward-looking statements to reflect events or circumstances after the date of this conference call, except as may be required by applicable securities law. With that, I'd now like to turn the call over to our President, CEO, and Founder, R.A. Session II.

Thank you, Kim. Good morning and welcome, everyone, to our first quarter Corporate Update and Financial Results Conference Call. As always, we hope you and your families continue to remain safe and healthy. Keisha has made great progress in the first quarter and continues to execute on its corporate initiatives. I will elaborate on some of the key achievements made thus far this year and highlight the expected milestones for the remainder of 2021. Following this, I will turn the call over to Suyash and Cameron for updates on our pipeline development and financial results, respectively. TASHA has transformed into a pivotal stage gene therapy company with the recent acquisition of exclusive worldwide rights to a groundbreaking clinical program, TASHA 120, an AAV9 interfecally dosed gene therapy invented by our chief scientific advisor, Dr. Stephen Gray of UT Southwestern. The NIH is conducting an ongoing clinical trial of TASHA 120 for the treatment of giant axonal neuropathy, organa. Notably, The GAN program is the first interfecally dosed AAV gene therapy study in history and, as such, has had significant impact on the field. As the program has laid the foundation for our extensive pipeline, we believe this acquisition represents a clear strategic and value-accretive opportunity that will provide read-through across our entire portfolio and inform the development of our gene therapy product candidates. We are thrilled to carry on the work done by Dr. Gray's lab and the NIH. As Suyesh will discuss in more detail, TASHA 120 has a comprehensive preclinical and clinical package that we believe may support an expedited approval pathway. The clinical data for TASHA 120 in patients with GAN are statistically significant, clinically relevant, dose-dependent, and durable, with a clear halt in disease progression at therapeutic doses. We are very encouraged that this represents significant value as the first potentially disease-modifying treatment for an estimated 2,400 patients living with GAN in the U.S. and in Europe alone. As such, we intend to engage with major regulatory agencies as soon as possible and, in parallel, will be accelerating the build-out of our commercial infrastructure to support patient identification, payer engagement, and product distribution. We believe that TASIA 120, if approved, represents a near-term commercial opportunity for TASIA of more than $2 billion. Beyond further advancing our new clinical stage programs, we continue to achieve significant progress with our preclinical programs that we expect will provide the next wave of novel gene therapy. We are extremely excited to announce the recent publication of new preclinical data for TASIA 102 in Rett Syndrome, in a highly regarded scientific journal, Brain. For the first time, we have quantitative evidence of MI Rare's ability to demonstrate genotype-dependent regulation of MEKP2 gene expression across different brain regions in both wild-type and knockout mouse models of Rett syndrome. Various challenges such as phenotypic variability, mosaicism, and targeting a dose-sensitive gene like MEKP2 make development of a gene therapy difficult. MI Rare offers a solution by allowing for the regulation of MEXP2 gene expression on a cell-by-cell basis without causing overexpression-related toxicity. Importantly, treatment with TASHA-102 in 4- to 5-week-old knockout mice with Rett syndrome resulted in a statistically significant survival extension by 56%. which is a very impressive result as these mice had meaningful accumulated disease. In our view, the benefits in these adolescent knockout mice should be a more translatable model of the disorder in humans. We believe these data validate our novel approach to treating REC, help de-risk the clinical program, and support the advancement of TASHA-102 into Phase I-II clinical trials by end of the year. We remain on track to file an IND or CTA in the second half of this year. You will hear from Suya shortly, as he will review the robust data in greater detail. Our Chief Scientific Advisor, Dr. Steven Gray, initiated his work on MI Rare and TASHA-102 in 2007. We are very pleased that his team's efforts are being realized and recognized. Amongst other compelling preclinical data packages, we are particularly excited about HACIA-113, which has demonstrated successful AAV-mediated gene knockdown, resulting in reduced tau expression in mouse models of human tauopathy. These data may have significant implications for certain neurodegenerative diseases, including Alzheimer's disease. We are also pleased with preclinical results for TASHA 105 and SLC13A5 deficiency that demonstrate a reduction in plasma citrate levels, normalized EEG activity, and reduced number of seizures and seizure susceptibility in SLC13A5 knockout mice. In SLC6A1 haploid insufficiency, TASHA 103 improved nesting and EEG activity in the SLC6A1 knockout mouse model and reduced spike train activity in both the SLC6A1 knockout and heterozygous mouse models. In lefora disease, TASHA111 leforin and TASHA111 malin have achieved effective knockdowns of GYS1 expression in its soluble glycogen and decreased lefora body formation in the appropriate lefora disease mouse model. In APBD, TASHA 112 has generated significant reduction in GYS1 protein, abnormal glycogen accumulation, and polyglucosome body formation in the APBD knockout mouse model. In Angelman disease, TASHA 106 increased UBE3A expression through shRNA-mediated knockdown of UBE3A-ATF, an in vitro cell line. We believe that this promising result demonstrated by our preclinical candidates validates our scientific approach and underscore our ability to drive a sustainable development engine for innovative gene therapy with the potential to impact meaningful patient populations. We are working diligently to advance our other preclinical programs in IMD-CTA-enabling studies and to date have already advanced six programs into IND-CTA-enabling studies with an IND or CTA plan for at least one of these programs by the end of 2021. We look forward to providing further updates on our key programs at our R&D event, which will take place over two days on June 28th and 29th. To support our programs, we have developed several key partnerships, Notably, we have established collaborations with Yale University, Cleveland Clinic, and the UT Southwestern Gene Therapy Program to support the creation of a novel next-generation mini-gene platform that is designed to overcome key challenges in gene therapy. These mini-gene payloads for AAV gene therapy will be targeted for the treatment of genetic epilepsy, neurodevelopmental disorders, and other CNS diseases. We are excited to leverage each partner's unique capabilities to expand the boundary of AAV vector engineering and potentially open the door to treating genetic CNS diseases that have been traditionally precluded from treatment with gene therapies. Foundational to our success is our team, which remains focused on advancing the development of our portfolio of innovative gene therapy candidates. We intend to continue this momentum by further growing our experience team Since becoming a public company, we have expanded our team more than 10 times and have now surpassed 120 employees. We expect to grow the team to approximately 150 employees by year-end. As noted, we are complementing the efforts of our internal team with our collaborators at UT Southwestern. With the collective expertise and dedication of these teams, our seasoned board of directors, an independent, internationally renowned scientific advisory board, We believe we are uniquely positioned to expedite the development of our gene therapy candidates and our technology platform. I will now turn the call over to Suyesh to provide a more detailed update on our R&D initiative. Suyesh, please go ahead.