Tenaya Therapeutics Q3 2024 Financial Results and Business Update

Data Safety and Monitoring Board Endorsed Dose Escalation and Broadening of Inclusion Criteria in the MyPEAKTM-1 Phase 1b/2 Trial of TN-201 Gene Therapy

Initial TN-201 Data from Cohort 1 of MyPEAK-1 to be Reported in December 2024

SOUTH SAN FRANCISCO, Calif., Nov. 06, 2024 - Tenaya Therapeutics, Inc., a clinical-stage biotechnology company with a mission to discover, develop and deliver potentially curative therapies addressing the underlying causes of heart disease, today announced its financial results for the third quarter ending September 30, 2024, and provided a corporate update.

"We are thrilled to announce substantial progress in our leading TN-201 gene therapy program during this quarter, highlighted by an initial positive safety update and DSMB's clearance for dose escalation to Cohort 2 in the MyPEAK-1 study. We anticipate sharing early clinical data from the first three patients from Cohort 1 of this trial in December," stated Faraz Ali, Chief Executive Officer of Tenaya. "Additionally, we introduced updates to the MyPEAK-1 study's eligibility criteria, which are expected to foster greater enrollment and modifications to the timing and frequency of cardiac biopsies, likely to offer deeper insights into TN-201 expression moving forward. These developments set a positive momentum for the year-end data release and future updates anticipated in 2025."

**Business and Program Updates**

**TN-201 – Gene Therapy for MYBPC3-Associated Hypertrophic Cardiomyopathy (HCM)**

Tenaya completed the initial dosing of the first three patients at the 3E13 vg/kg dose level (Cohort 1) in the MyPEAK-1 clinical trial. No unexpected events or toxicities associated with the study drug were observed. The safety data from Cohort 1 were reviewed by an independent Data Safety and Monitoring Board (DSMB), which recommended proceeding with dose escalation to 6E13 vg/kg (Cohort 2), following the protocol. MyPEAK-1 is a Phase 1b/2 multi-center, open-label, dose-escalation trial designed to evaluate the safety, tolerability, and clinical efficacy of a one-time intravenous infusion of TN-201 in treating patients with HCM caused by MYBPC3 gene mutations. The study is conducted across ten clinical sites in the U.S.

Tenaya has implemented changes to the MyPEAK-1 protocol to support future development. These changes include introducing a baseline biopsy, expanding trial participant eligibility to include patients with obstructive HCM and those without implantable cardioverter defibrillators (ICDs), and increasing the potential number of patients in the dose expansion phase of the clinical trial. Tenaya plans to share interim results from MyPEAK-1, encompassing safety and tolerability assessments, cardiac biopsy analyses, and changes from baseline in cardiac biomarkers from the first cohort of patients in December 2024.

At the virtual HCM Society’s Scientific Sessions in September, Tenaya presented data from a study conducted in partnership with the Sarcomeric Human Cardiomyopathy Registry (SHaRe), highlighting the higher disease burden faced by MYBPC3-associated pediatric HCM patients, with 50% experiencing significant morbidity by age 40. In July, TN-201 was granted rare pediatric disease designation by the U.S. Food and Drug Administration for treating MYBPC3-associated HCM in individuals under the age of 18. Tenaya has enrolled over 200 retrospective and prospective patients across 29 sites in the MyClimb Natural History Study, aimed at better characterizing MYBPC3-associated pediatric HCM patients.

**TN-401 – Gene Therapy for PKP2-Associated Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)**

Tenaya has initiated six clinical sites in the RIDGETM-1 clinical trial and has been actively screening potential patients. RIDGE-1 is a global, multicenter, open-label, dose-escalation trial designed to evaluate the safety, tolerability, and clinical efficacy of a one-time intravenous infusion of TN-401 for treating ARVC caused by PKP2 gene mutations. Additionally, Tenaya has activated over 20 sites in six countries for the RIDGE seroprevalence and natural history study.

In October 2024, the U.S. Patent and Trademark Office issued U.S. Patent Number 12,104,165 (the ’165 patent), covering a method of treating ARVC with an AAV9 virion encoding the PKP2 protein. This patent provides method of treatment protection for Tenaya’s PKP2 gene therapy program for ARVC and is set to expire no earlier than 2040.

**Corporate Update**

In August 2024, Tenaya entered into a $45 million credit facility with Silicon Valley Bank (SVB). Tenaya has not drawn on the credit facility and is under no obligation to do so.

**Third Quarter 2024 Financial Highlights**

**Cash Position and Guidance:** As of September 30, 2024, Tenaya had $79.5 million in cash, cash equivalents, and investments in marketable securities. The company estimates these funds will support operations into the second half of 2025.

**Research & Development (R&D) Expenses:** R&D expenses for the quarter ended September 30, 2024, were $20.4 million, compared to $23.1 million for the same period in 2023. Non-cash stock-based compensation included in R&D expenses was $2.0 million for the quarter ended September 30, 2024, compared to $1.9 million for the same period in 2023.

**General & Administrative (G&A) Expenses:** G&A expenses were $6.4 million for the quarter ended September 30, 2024, compared to $7.8 million for the same period in 2023. Non-cash stock-based compensation included in G&A expenses was $1.9 million for the quarter ended September 30, 2024, compared to $2.2 million for the same period in 2023.

**Net Loss:** Net loss for the quarter ended September 30, 2024, was $25.6 million, or $0.30 per share, compared to a net loss of $29.1 million, or $0.39 per share, for the same period in 2023.

**About Tenaya Therapeutics**

Tenaya Therapeutics is a clinical-stage biotechnology company focused on discovering, developing, and delivering therapies that address the fundamental causes of heart disease. Tenaya utilizes integrated internal capabilities, including modality agnostic target validation, capsid engineering, and manufacturing, to develop a portfolio of genetic medicines for both rare genetic disorders and more common heart conditions. Tenaya’s pipeline includes TN-201 for MYBPC3-associated hypertrophic cardiomyopathy (HCM), TN-401 for PKP2-associated arrhythmogenic right ventricular cardiomyopathy (ARVC), TN-301 for heart failure with preserved ejection fraction (HFpEF), and several early-stage programs in preclinical development.