Taysha Gene Therapies, Inc.

Hello and welcome to the Tayshia Gene Therapies Second Quarter 2026 Financial Results Conference Call. At this time, all participants are in a listen-only mode. After the speaker presentation, there will be a question and answer session. To ask a question during the session, you will need to press star 11 on your telephone. You will then hear an automated message advising your hand has been raised. To withdraw your question, please press star 11 again. Please be advised that today's conference is being recorded. It is now my pleasure to introduce Vice President of Corporate Communications and Investor Relations, Hayleigh Collins.

Thank you. Good afternoon and welcome to Tayshia's 2026 Financial Results and Corporate Update conference call. Earlier today, Tayshia issued a press release announcing financial results for the quarter ended June 30th, 2026. A copy of this press release is available on the company's website and through our FDC file. Joining me on today's call are Sean Nolan, Tayshia's Chief Executive Officer, Sukumar Nagendran, President and Head of R&D, and Kamran Alam, Chief Financial Officer. We will hold a question and answer session following our prepared remarks. On today's call, we will be making forward-looking statements, including statements concerning the potential of Tayshia-102, including the reproducibility and durability of any favorable results initially seen in patients' dose-to-date and clinical trials including with respect to functional milestones to positively impact quality of life and alter the course of disease in the patients we seek to treat. Our research, development, and regulatory plans for our product candidates, including the timing of initiating additional trials, reporting data from our clinical trials, and making regulatory submissions, timing or outcomes of communications with the FDA on the regulatory pathway for TASHA 102, The Potential for Product Candidate to Receive Regulatory Approval from the FDA or Equivalent Foreign Regulatory Agency Our Ability to Realize the Benefits of Breakthrough Therapy Designations for Tayshia 102 Our Ability to Drive Long-Term Value for Stockholders and the Market Opportunity for our Programs This call may also contain forward-looking statements relating to Tayshia's growth, forecasted cash runway, and future operating results. Discovery and Development of Product 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. For a list and description of the risks and uncertainties that we face, please see the reports we've filed with the SEC, including our annual reports, on Form 10-K for the full year ended December 31st, 2025 that we filed on March 19th, 2026. This conference call contains time-sensitive information that's accurate only as of the date of this live broadcast, August 11th, 2026. Taysha undertakes no obligation to revise or update any forward-looking statements to reflect events or circumstances after the date of this conference call, except this may be required by applicable security laws. With that, I would now like to turn the call over to our CEO, Sean Thorne.

Thank you, Hayleigh, and welcome everyone to our second quarter 2026 Financial Results and Corporate Update conference call. On today's call, I will begin with an update on our recent clinical, manufacturing, and commercial readiness activities. Dr. Sukumar Nagendran, President and Head of R&D, will then discuss data presented at the recent IRSF Rett Syndrome Scientific Meeting which strengthens the clinical and scientific foundation of the Tayshia 102 program. Kamran Alam, our Chief Financial Officer, will follow up with a financial update and I will then provide closing remarks before opening the call up for questions. The second quarter of 2026 was a highly productive period for Tayshia. We continued to execute against our clinical development strategy while advancing key manufacturing and commercial readiness initiatives as we move toward a potential DLA submission for Tayshia-102. We achieved several important milestones, including the completion of dosing in both the REVEAL Pivotal and ASPIRE trials, as well as the presentation of compelling longer-term Part A data from the REVEAL Phase 1-2 trials. Beyond the clinical development, we expanded Our partnership with Catalan to include future commercial manufacturing support for Tayshia 102, completed payer research to inform further market access planning initiatives, continue to build our leadership team, and strengthen our balance sheet through a successful follow-on financing that is expected to support our planned activities into the second half of 2028 and through potential BLA approval. Collectively, we believe these accomplishments place us in a position of strength as we approach the planned six-month interim analysis from the REVEAL Pivotal trial, continue our engagement with the FDA, and advance commercial readiness activities. I will begin with a clinical update. We continue to execute with discipline across our REVEAL Pivotal and ASPIRE trials and are pleased with the significant progress made to date. We announced the successful completion of dosing in the over-enrolled Reveal Pivotal Trial with a total of 17 patients dosed with TASHA-102. Importantly, similar to our Reveal Part A trials, we enrolled a well-balanced distribution of ages across pediatric, adolescent, and adult patients. That's reflective of the broader Rett Syndrome population. We believe this allows us to generate a comprehensive data set that may support a broad label for TASHA-102. Once all 17 patients in the pivotal trial complete six months of follow-up, we will conduct a six-month interim analysis, which may serve as the basis for our planned BLA submission and potentially accelerate our submission timeline by at least two full quarters relative to filing on the 12-month data. Given our longer-term party data substantially exceeded Aspire is primarily a safety focus and to support a broad label for patients aged two years and older with Rett syndrome as part of our planned BLA package. In addition to generating supportive safety data, Aspire is designed to provide insight into the impact of early intervention, including the potential to reverse disease manifestations and restore function while also preventing further disease progression in younger patients. With dosing now complete in both trials, we are laser focused on preparing for the pivotal trial interim analysis and subsequent discussions with the FDA to inform next steps toward a BLA submission. We expect to provide an update on both fronts in the first half of 2027. We continue to believe the increasingly robust body of evidence generated across the program strengthens the rationale for this potentially expedited submission plan. Turning to safety. Both high and low dose Tayshia 102 continue to be generally well tolerated. There have been no severe treatment related serious adverse events or dose limiting toxicities observed Since the clinical trial began over three years ago, across the 33 patients treated in the Reveal Phase 1, 2, Pivotal, and Aspire trials as of the August 2026 data cutoff, supporting a favorable and consistent safety profile. In early July 2026, over the holiday weekend, one patient in the Reveal Pivotal trial experienced a single, moderate, rate 2, treatment-related adverse event of peripheral sensory neuropathy and expected AAV-associated risk approximately six weeks after treatment. Consistent with the Treating Institute's policy, the patient was admitted overnight for management and observation, thus resulting in a technical classification of the Grade II event as serious adverse event. The patient was discharged the following day and, importantly, Rapidly demonstrating substantial recovery. Clinical trial dosing is now complete, and we have surpassed three years since the first patient received TASHA-102. To date, 33 patients spanning a broad range of ages, genotypes, and disease severities have been treated, with no severe treatment-related serious adverse events or dose-limiting toxicities reported. The safety profile of Tayshia 102 has remained encouraging with a consistent benefit to risk profile throughout the program. I would like to recognize the expertise and vigilance of our participating principal investigators, the rigorous training and oversight provided by our clinical development and clinical operation teams, as well as our CRO partner. And importantly, the commitment of the patients and caregivers whose participation in the trials and dedication to help ensure the best possible outcomes for the Rett Syndrome community. Based on the totality of the data generated to date, including the favorable safety profile and compelling efficacy data from the longer-term follow-up from the Review Part A, we continue to believe Tayshia 102 has the potential to be a differentiated and transformative therapy for a broad population of patients with Rett Syndrome who continue to face high-end medical needs. The strengthened body of evidence supporting Tayshia 102 was highlighted at this year's IRSF Rett Syndrome Scientific Meeting, where we presented data that collectively reinforced the clinical and scientific foundation of our development program and registrational strategy. Sukumar will discuss the data in greater detail shortly, but before I turn the call over, I wanted to touch on our ongoing commercial readiness efforts. We have continued to make meaningful progress in preparation for a potential launch. This past quarter, we completed payer market research, which demonstrated strong support for Tayshia-102's value proposition and reimbursement potential. Specifically, the research demonstrated that Tayshia-102 was viewed as a high-value therapy due to its transformative disease-modifying potential in a population with significant unmet need. coupled with the convenience of a one-time intrathingal administration that is less invasive than other direct-to-CNS approaches and can be administered in a broadly accessible outpatient setting. Importantly, payer willingness to provide coverage was primarily driven by the potential for Tayshia 102 to deliver durable, clinically meaningful benefits. Payers consistently emphasized the importance of demonstrating durable functional gains and improvements that translate into real-world benefit for patients and caregivers, areas where we believe the growing body of clinical evidence supporting Tayshia-102 is particularly compelling and differentiated. Finally, the research demonstrated that strong efficacy, safety, and durability are expected to be the primary drivers of coverage and support reimbursement, with durable functional improvements serving as the most important determinant These findings reinforce our confidence in the Tayshia 102's commercial potential and reimbursement outlook. We are leveraging these insights to further refine our market access strategy and support a successful potential commercial launch. In tandem with our market access strategy, we have also expanded our long-standing partnership with CADWIN, the leading global contract development and manufacturing organization. Catalan will serve as our primary commercial manufacturing partner following potential FDA approval of Tayshia-102. This expanded agreement secures a long-term commercial manufacturing capacity and establishes a scalable supply framework intended to support Tayshia-102's potential launch and future demand. Under the agreement, manufacturing will be conducted at Catalan's FDA-licensed gene therapy campus in Harmans, Maryland, which is an established Catalan will leverage its experience across more than 90 gene therapy programs, including multiple commercial products. With BLA enabling process performance qualification activities underway, we believe we have established a strong manufacturing foundation necessary to support the anticipated significant demand for Tayshia-102 following its potential launch and commercialization. We continue to strengthen our organization through the key leadership hires that position us for the next phase of growth. This includes the recent appointment of Mike Johannesson as Chief Legal Officer. Mike brings more than three decades of experience across corporate law, governance, compliance, and strategic transactions, including extensive leadership experience in the gene therapy space. His tenure at Advanced Medicine Partners, Jaguar Gene Therapy, and Avexis will be instrumental as we execute on our strategic priorities and continue to evolve the organization. I would now like to turn the call over to Sukumar to dive deeper into our recent data presentations at the IRSF scientific meeting.