Taysha Gene Therapies, Inc. Common Stock 2026 Q2 Earnings Call

Thank you. Good afternoon, and welcome to Taysha's second quarter 2026 financial results and corporate update conference call. Earlier today, Taysha issued a press release announcing financial results for the quarter ended June 30, 2026. A copy of this press release is available on the company's website and through our SEC filings. Joining me on today's call are Sean Nolan, Taysha'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 TSHA-102, including the reproducibility and durability of any favorable results initially seen in patients dosed to date in 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 TSHA-102, the potential for product candidate to receive regulatory approval from the FDA or equivalent foreign regulatory agencies. Our ability to realize the benefits of breakthrough therapy designations for TSHA-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 Taysha'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 Taysha's 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 filed with the SEC, including our annual report on Form 10-K for the full year ended December 31, 2025, that we filed on March 19, 2026. This conference call contains time-sensitive information that is accurate only as of the date of this live broadcast, August 11, 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 as may be required by applicable securities laws. With that, I would now like to turn the call over to our CEO, Sean Nolan.

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. Suku 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 TSHA-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 Taysha. We continued to execute against our clinical development strategy while advancing key manufacturing and commercial readiness initiatives as we move toward a potential BLA submission for TSHA-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 I/II trials. Beyond the clinical development, we expanded our partnership with Catalent to include future commercial manufacturing support for TSHA-102, completed payer research to inform further market access planning initiatives, continued to build our leadership team, and strengthened 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. In June, we announced the successful completion of dosing in the over-enrolled REVEAL pivotal trial with a total of 17 patients dosed with TSHA-102. Importantly, similar to our REVEAL Part A trials, we enrolled a well-balanced distribution of ages across pediatric, adolescent, and adult patients that is 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 TSHA-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 Part A data substantially exceeded the FDA-aligned 33% minimum efficacy threshold established for the pivotal trial, we believe this further strengthens the potential for regulation based on the most current trial analysis. I also want to share that as of July, we have completed dosing in our ASPIRE trial, where we treated four patients aged two to less than four years old with TSHA-102. ASPIRE is primarily a safety-focused 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 TSHA-102 continue to be generally well-tolerated.

There have been no severe treatment-related SAEs or DLTs observed since the clinical trial began over three years ago across the 33 patients treated in the REVEAL phase I/II 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 grade 2 treatment-related adverse event of peripheral sensory neuropathy, an 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 2 event as SAE. 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 TSHA-102.

To date, 33 patients spanning a broad range of ages, genotypes, and disease severities have been treated, with no severe treatment-related SAEs or DLTs reported. The safety profile of TSHA-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 REVEAL Part A, we continue to believe TSHA-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 unmet medical need. The strengthened body of evidence supporting TSHA-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. Suku 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 TSHA-102's value proposition and reimbursement potential. Specifically, the research demonstrated that TSHA-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 intrathecal 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 TSHA-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 TSHA-102 is particularly compelling and differentiating.

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 of value. These findings reinforce our confidence in TSHA-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 longstanding partnership with Catalent, the leading global contract development and manufacturing organization. Catalent will serve as our primary commercial manufacturing partner following potential FDA approval of TSHA-102. This expanded agreement secures a long-term commercial manufacturing capacity and establishes a scalable supply framework intended to support TSHA-102's potential launch and future demand.