TNYA

Positive Interim Data Shared in 2Q 2026 from the MyPEAK™-1 and RIDGE™-1 Clinical Trials Each Demonstrated Meaningful Improvements in Key Disease Characteristics Additional Data Releases Plus Updates on Regulatory Discussions on Pivotal Trial Plans for TN-201 and TN-401 Anticipated in 4Q 2026 TN-301 Advancing toward Phase 2 Trial Start in 2H 2027 $10 million Upfront Payment Received from Alnylam Collaboration Extends Cash Runway Through Q3 2027 SOUTH SAN FRANCISCO, Calif., Aug. 05, 2026 (GLOBE NEWSWIRE) -- Tenaya Therapeutics, Inc. (NASDAQ: TNYA), a clinical-stage biotechnology company with a mission to discover, develop and deliver potentially curative therapies that address the underlying causes of heart disease, today announced financial results for the second quarter ended June 30, 2026, and provided a corporate update. “The second quarter marked an important period of execution for Tenaya as we shared new safety and clinical benefit data for TN-201 and TN-401,” said Faraz Ali, Chief Executive Officer of Tenaya. “We remain excited by the encouraging results emerging from our TN-201 MyPEAK-1 clinical trial in patients with MYBPC3-associated disease and the most recent RIDGE-1 data add to our confidence in TN-401’s potential as a highly promising candidate to address the underlying cause of PKP2-associated ARVC. We are engaging with regulators to discuss the efficient late-stage development and approval pathways for each candidate.” Mr. Ali continued, “We also believe that advancing TN-301 toward Phase 2 represents an opportunity to create significant value while further diversifying our pipeline. We remain focused on disciplined execution, efficient use of capital, and advancing programs with the greatest potential to deliver meaningful impact for patients and stockholders.” Business and Program Updates TN-201 – Gene Therapy for MYBPC3-Associated Hypertrophic Cardiomyopathy (HCM) In June 2026, Tenaya shared promising new safety and efficacy data from the ongoing MyPEAK-1 Phase 1b/2 clinical trial of TN-201 in adults with MYBPC3-associated HCM. The data shared reflected 78-104 weeks of follow-up for three patients who received TN-201 at the 3E13 vg/kg dose (Cohort 1), and 26-52 weeks of follow-up for four patients at the 6E13 vg/kg dose (Cohort 2). Key findings include: Tenaya has completed enrollment needed in the MyPEAK-1 clinical trial to characterize dose response and inform dose selection for late-stage clinical trials. In June 2026, Tenaya announced that TN-201 received PRIority MEdicine (PRIME) designation by the European Medicines Agency (EMA) and was accepted into the Food and Drug Administration’s Rare Disease Evidence Principles (RDEP) process for severe pediatric patients. Tenaya is pursuing alignment with regulatory authorities on late-stage pivotal trial plans for TN-201. The company plans to provide an update on the status of these discussions in the fourth quarter of 2026. TN-401 – Gene Therapy for PKP2-Associated Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) At the ASGCT Annual Meeting, Tenaya presented positive interim data from the ongoing RIDGE-1 Phase 1b/2 clinical trial of TN-401 gene therapy. The data set included three patients dosed at 3E13 vg/kg (Cohort 1) with follow-up ranging from Week 32-52 and three patients dosed at 6E13 vg/kg (Cohort 2) with 20-32 weeks of follow-up. Key findings include: Tenaya has completed enrollment needed in the RIDGE-1 clinical trial to characterize dose response and inform dose selection for late-stage clinical trials, In May 2026, Tenaya announced receipt of PRIME designation by the EMA. Tenaya is currently engaging with regulators on late-stage pivotal trial planning for TN-401 and plans to provide an update on the status of its discussions in the fourth quarter of 2026. TN-301 – Small Molecule HDAC6 Inhibitor for the Potential Treatment of Heart Failure with Preserved Ejection Fraction (HFpEF) and Related Cardiac, Metabolic, or Muscular Diseases Tenaya is currently conducting enabling toxicology work to support the advancement of TN-301 toward clinical trials in patients. The company intends to share additional details regarding its TN-301 development plans in the fourth quarter of 2026, and to initiate at least one company-sponsored proof-of-activity Phase 2 clinical trial in the second half of 2027. HFpEF and Duchenne muscular dystrophy are among the most promising potential indications identified to date. Corporate Updates In June 2026, Tenaya announced the appointment of Eric Hyllengren as Chief Financial Officer of Tenaya, effective July 13, 2026. In June 2026, Tenaya entered into a Lease Termination Agreement for its Genetic Medicines Manufacturing Center (GMMC) which was decommissioned in 2025. Exiting this lease is part of the company’s ongoing efforts to reduce costs. Tenaya has sufficient inventory of TN-201 and TN-401 to support its ongoing clinical trials and plans to work with a global contract development manufacturing organization for cGMP material to support future needs. In April 2026, under the terms of the Alnylam collaboration agreement, Tenaya received an upfront payment of $10.0M and is eligible for future development, regulatory and sales-based milestones totaling up to $1.1 billion, in addition to reimbursement of associated research costs. Second Quarter 2026 Financial Highlights Cash: As of June 30, 2026, cash and cash equivalents were $78.1 million, including the $10.0 million upfront payment received from the collaborative agreement with Alnylam. Tenaya expects existing cash and cash equivalents will be sufficient to fund planned operations through Q3 of 2027. Research & Development (R&D) Expenses: R&D expenses were $16.6 million for the second quarter of 2026, compared to $17.4 million for the same period in 2025. Non-cash stock-based compensation included in R&D expense was $0.9 million for the second quarter of 2026 compared to $1.9 million for the same period in 2025. General & Administrative (G&A) Expenses: G&A expenses were $5.4 million for the second quarter of 2026 compared to $6.7 million for the same period in 2025. Non-cash stock-based compensation included in G&A expense was $0.8 million for the second quarter of 2026 and $1.8 million for the same period in 2025. Net Loss: Net loss was $43.4 million, or $0.20 loss per share, for the second quarter ended June 30, 2026, compared to a net loss of $23.3 million, or $0.14 per share, for the same period in 2025. The increase in net loss was primarily due to a $21.8 million non-cash impairment charge related to the early termination of the Company's Union City GMMC facility lease. About Tenaya TherapeuticsTenaya Therapeutics is a clinical-stage biotechnology company committed to a bold mission: to discover, develop and deliver potentially curative therapies that address the underlying drivers of heart disease. Tenaya’s pipeline includes clinical-stage candidates TN-201, a gene therapy for MYBPC3-associated hypertrophic cardiomyopathy (HCM); TN-401, a gene therapy for PKP2-associated arrhythmogenic right ventricular cardiomyopathy (ARVC); and TN-301, a highly specific small molecule HDAC6 inhibitor with broad potential clinical utility in cardiac, metabolic and muscular conditions, including heart failure with preserved ejection fraction (HFpEF) and Duchenne muscular dystrophy (DMD). Tenaya has employed a suite of integrated internal capabilities including modality agnostic target discovery and validation, to generate a portfolio of novel medicines based on genetic insights, aimed at the treatment of both rare genetic disorders and more prevalent heart conditions.   For more information, visit www.tenayatherapeutics.com. Forward Looking Statements This press release contains forward-looking statements as that term is defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Statements in this press release that are not purely historical are forward-looking statements. Words such as “anticipated,” “potential,” “believe,” “focused,” “promising,” “plans,” “expects,” “intends,” “will,” and similar expressions are intended to identify forward-looking statements. Such forward-looking statements include, among other things, planned timing for sharing data from RIDGE-1 and MyPEAK-1 and the expected content of such data releases; the therapeutic potential for TN-201 as a treatment for MYBPC3-associated HCM and TN-401 as a treatment for PKP2-associated ARVC; the potential for TN-301 to create significant value for Tenaya; Tenaya’s focus on disciplined execution, efficient use of capital and advancing programs with the greatest potential; planned timing for sharing updates on regulatory interactions for the TN-201 and TN-401 programs; planned timing for sharing additional details regarding TN-301 development plans; the sufficiency of Tenaya’s cash resources to fund the company through Q3 of 2027; and statements made by Tenaya’s chief executive officer. The forward-looking statements contained herein are based upon Tenaya’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. These forward-looking statements are neither promises nor guarantees and are subject to a variety of risks and uncertainties, including but not limited to: availability of data at the referenced times; the timing and progress of Tenaya’s clinical trials; unexpected concerns that may arise as a result of the occurrence of adverse safety events by patients who received Tenaya products; the potential failure of Tenaya’s product candidates to demonstrate safety and/or efficacy in clinical testing; the potential for any clinical trial results to differ from preclinical, interim, preliminary, topline or expected results; the potential for the FDA to conclude at any time that Tenaya’s clinical programs may not have an appropriate risk/benefit profile; Tenaya’s ability to enroll and maintain patients in clinical trials; risks associated with the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics and operating as an early stage company; Tenaya’s ability to develop, initiate or complete preclinical studies and clinical trials, and obtain approvals, for any of its product candidates; Tenaya’s continuing compliance with applicable legal and regulatory requirements; regulatory developments in the United States and foreign countries; Tenaya’s ability to raise any additional funding it will need to continue to pursue its business and product development plans; Tenaya’s reliance on third parties; Tenaya’s manufacturing, commercialization and marketing capabilities and strategy; the loss of key scientific or management personnel; competition in the industry in which Tenaya operates; Tenaya’s ability to comply with specified operating covenants and restrictions in its loan agreement; Tenaya’s ability to obtain and maintain intellectual property protection for its product candidates and platform technology; general economic and market conditions; and other risks. Information regarding the foregoing and additional risks may be found in the section entitled “Risk Factors” in documents that Tenaya files from time to time with the Securities and Exchange Commission. These forward-looking statements are made as of the date of this press release, and Tenaya assumes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. Tenaya ContactsMichelle CorralVP, Corporate Communications and Investor [email protected] InvestorsAnne-Marie FieldsPrecision AQ [email protected] MediaWendy RyanTen Bridge [email protected]

One-Year Cohort 1 Data and Initial Cohort 2 Data from RIDGE™-1 Phase 1b/2 Trial of TN-401 for PKP2-Associated ARVC to be Presented at ASGCT 2026 New Data from Both Cohorts of the MyPEAK™-1 Phase 1b/2 Trial of TN-201 for Adults with MYBPC3-Associated HCM Expected in the Second Quarter 2026 Preclinical Data at MDA 2026 Highlighted TN-301’s Activity in Duchenne Muscular Dystrophy Disease Models; Distinct Mechanism of HDAC6 Inhibition Supportive of TN-301’s Potential in Multiple Indications Entered Research Collaboration with Alnylam to Identify and Validate Genetic Targets for Cardiovascular Conditions SOUTH SAN FRANCISCO, Calif., May 06, 2026 (GLOBE NEWSWIRE) -- Tenaya Therapeutics, Inc. (NASDAQ: TNYA), a clinical-stage biotechnology company with a mission to discover, develop and deliver potentially curative therapies that address the underlying causes of heart disease, today announced financial results for the first quarter ended March 31, 2026, and provided a corporate update. “We are entering a catalyst-rich period for Tenaya, with multiple clinical milestones expected across our lead gene therapy programs throughout 2026. Building on the encouraging initial readouts we reported in 2025, we believe the additional data expected this year from both TN-201 and TN-401 may support alignment on registrational pathways for these novel gene therapies,” said Faraz Ali, Chief Executive Officer of Tenaya. Mr. Ali continued, “While our focus remains on the advancement of TN-201 and TN-401 for patients suffering from these genetic cardiomyopathies, we also announced meaningful steps in the direction of our next horizon of opportunities to address unmet patient needs and to create value for stockholders. We presented new preclinical data for TN-301, our clinical-stage small molecule candidate, in Duchenne muscular dystrophy adding to the body of compelling preclinical evidence for the broad clinical utility of this molecule in multiple prevalent and rare cardiac and cardiac-adjacent indications. Advancing TN-301 toward a trial in patients reflects our commitment to building a diversified portfolio grounded in mechanistic insight and translational rigor. The recently announced collaboration with Alnylam also reinforces the strength of Tenaya's innovation engine and expands the reach and impact of our modality-agnostic research capabilities.” Business and Program Updates TN-201 – Gene Therapy for MYBPC3-Associated Hypertrophic Cardiomyopathy (HCM) On May 9, 2026, at the upcoming European Society of Cardiology (ESC) Heart Failure Conference, in Barcelona, Spain, Milind Desai, M.D., Director of the Hypertrophic Cardiomyopathy Center, Vice Chair of the Heart, Vascular & Thoracic Institute at Cleveland Clinic, and principal investigator for the MyPEAK-1 clinical trial, will present insights that emerged early in the trial that enabled reductions in the cumulative dose and duration of immune suppressive medications, even when TN-201 is administered at the higher dose. Per the MyPEAK-1 protocol, sirolimus and prednisone are administered prophylactically in patients receiving TN-201 gene therapy, accompanied by post dose tapering in conjunction with monitoring of liver enzyme levels – an early indicator of potential complement system activation. Investigators found that minor adjustments, including administering sirolimus earlier, reducing the starting dose of prednisone and monitoring patients weekly, led to faster tapering and an overall decrease in the burden of immunosuppression. The ESC-HF presentation offers more detail on the immunosuppressive regimen results previously reported in November 2025 and includes safety data for the first seven patients enrolled in MyPEAK-1. The optimized regimen and monitoring protocols that were successfully deployed in MyPEAK-1 are also being utilized in the RIDGE-1 clinical trial of TN-401. Tenaya expects to report interim MyPEAK-1 data for Cohort 2 (6E13 vg/kg) and updates from Cohort 1 (3E13 vg/kg) in the second quarter of 2026. In January, Tenaya resumed enrollment and screening in MyPEAK-1 following implementation of modest protocol amendments in alignment with U.S. Food and Drug Administration (FDA) input. At the American Society of Gene and Cell Therapies (ASGCT) Annual Meeting, taking place May 11-15, 2026, in Boston, MA, Tenaya will present results from a survey exploring parental perceptions of gene therapy treatment for children with cardiomyopathies. This work was conducted by Tenaya in partnership with DDC Clinic and Children’s Cardiomyopathy Foundation. The poster presentation is scheduled for May 12, 2026. TN-401 – Gene Therapy for PKP2-Associated Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) Data from the ongoing RIDGE-1 Phase 1b/2 clinical trial of TN-401 in adults with ARVC due to variants in the PKP2 gene have been accepted as a late-breaking presentation at the upcoming ASGCT Annual Meeting. The presentation, scheduled for Friday, May 15, is expected to include one-year data for Cohort 1 (3E13 vg/kg) and initial Cohort 2 (6E13 vg/kg). Tenaya management plans to conduct a webcast conference call on Friday, May 15, 2026, at 10:30 a.m. EDT / 7:30 am PDT following the Late Breaker Session. The webcast conference call, including an accompanying slide presentation, will be accessible from the Investor section of the Tenaya website at www.tenayatherapeutics.com. In January, the RIDGE-1 data and safety monitoring board (DSMB) reviewed all available data for the six patients that have received TN-401 gene therapy. The DSMB determined that TN-401 had an acceptable safety profile and endorsed continued enrollment of patients in RIDGE-1 expansion cohorts at either dose. TN-301 – Small Molecule HDAC6 Inhibitor for the Potential Treatment of Heart Failure with Preserved Ejection Fraction (HFpEF) and Related Cardiac, Metabolic, or Muscular Diseases In March 2026, Tenaya presented encouraging preclinical data comparing TN-301, the company’s highly selective HDAC6 inhibitor, with givinostat, an approved pan-HDAC inhibitor, in well-established preclinical models of Duchenne muscular dystrophy (DMD) at the Muscular Dystrophy Association’s 2026 Clinical and Scientific Congress. Results of the study showed that: TN-301 treatment at doses as low as 3 mg/kg improved grip strength to wild-type levels within five weeks, whereas mdx mice treated with givinostat (10 mg/kg, approximating clinical exposures) failed to reach wild-type performance. TN-301-mediated functional improvements were accompanied by reductions in circulating creatine kinase and favorable changes in gene expression, indicating reduced muscle cell injury. In cardiomyocytes derived from human DMD-induced pluripotent stem cells, TN-301 corrected calcium handling abnormalities and mitochondrial dysfunction, while givinostat exacerbated these established drivers of DMD cardiomyopathy. TN-301 was granted both Rare Pediatric Disease Designation and Orphan Drug Designation for the treatment of DMD from U.S. Food and Drug Administration. In 2026, Tenaya plans to advance TN-301 toward clinical trials in patients in order to generate proof-of-activity data, with HFpEF and DMD being among the most promising potential indications identified to date. Research In March 2026, Tenaya entered into a multi-target research collaboration with Alnylam Pharmaceuticals to identify and validate novel genetic targets aimed at treating cardiovascular disease. Under the terms of the collaboration agreement, in April 2026, Tenaya received an upfront payment of $10.0M and may be eligible for future development, regulatory and sales-based milestones totaling up to $1.1 billion, in addition to reimbursement of associated research costs. Updated results of preclinical studies characterizing TN-501, a gene editing therapeutic candidate intended for the treatment of PLN-R14del-associated dilated cardiomyopathy (DCM) will be presented at ASGCT on Thursday, May 14, 2026. TN-501 is designed to specifically inactivate the pathogenic phospholamban (PLN) R14del allele while preserving healthy function. First Quarter 2026 Financial Highlights Cash: As of March 31, 2026, cash and cash equivalents were $80.9 million. Tenaya expects that such resources, along with the $10.0 million upfront payment from the Alnylam collaboration, will be sufficient to fund planned operations into the second half of 2027. Research & Development (R&D) Expenses: R&D expenses were $14.8 million for the first quarter of 2026, compared to $21.1 million for the same period in 2025. Non-cash stock-based compensation included in R&D expense was $1.2 million for the first quarter of 2026 compared to $2.0 million for the same period in 2025. General & Administrative (G&A) Expenses: G&A expenses were $5.4 million for the first quarter of 2026 compared to $6.5 million for the same period in 2025. Non-cash stock-based compensation included in G&A expense was $1.0 million for the first quarter of 2026 and $1.7 million for the same period in 2025. Net Loss: Net loss was $19.3 million, or $0.09 loss per share, for the first quarter ended March 31, 2026, compared to a net loss of $26.9 million, or $0.24 per share, for the same period in 2025. About Tenaya Therapeutics Tenaya Therapeutics is a clinical-stage biotechnology company committed to a bold mission: to discover, develop and deliver potentially curative therapies that address the underlying drivers of heart disease. Tenaya’s pipeline includes clinical-stage candidates TN-201, a gene therapy for MYBPC3-associated hypertrophic cardiomyopathy (HCM); TN-401, a gene therapy for PKP2-associated arrhythmogenic right ventricular cardiomyopathy (ARVC); and TN-301, a highly specific small molecule HDAC6 inhibitor with broad potential clinical utility in cardiac, metabolic and muscular conditions, including heart failure with preserved ejection fraction (HFpEF) and Duchenne muscular dystrophy (DMD). Tenaya has employed a suite of integrated internal capabilities including modality agnostic target discovery and validation, to generate a portfolio of novel medicines based on genetic insights, aimed at the treatment of both rare genetic disorders and more prevalent heart conditions. For more information, visit www.tenayatherapeutics.com. Forward Looking Statements This press release contains forward-looking statements as that term is defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Statements in this press release that are not purely historical are forward-looking statements. Words such as “expected,” “believe,” “may,” “focused,” “commitment,” “will,” “plans,” and similar expressions are intended to identify forward-looking statements. Such forward-looking statements include, among other things, planned timing for sharing data from RIDGE-1 and MyPEAK-1 and the expected content of such data releases; the potential for additional data from Tenaya’s TN-201 and TN-401 programs to support regulatory alignment on registrational pathways; Tenaya’s focus on the advancement of TN-201 and TN-401; Tenaya’s commitment to the building a diversified portfolio and advance TN-301 toward clinical trials; the potential for Tenaya to receive development, regulatory and sales-based milestone payments, as well as research reimbursement under the collaboration with Alnylam; planned presentation for TN-501; the sufficiency of Tenaya’s cash resources to fund the company into the second half of 2027; and statements made by Tenaya’s chief executive officer. The forward-looking statements contained herein are based upon Tenaya’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. These forward-looking statements are neither promises nor guarantees and are subject to a variety of risks and uncertainties, including but not limited to: availability of data at the referenced times; the timing and progress of Tenaya’s clinical trials; unexpected concerns that may arise as a result of the occurrence of adverse safety events in Tenaya’s clinical trials; the potential failure of Tenaya’s product candidates to demonstrate safety and/or efficacy in clinical testing; the potential for any clinical trial results to differ from preclinical, interim, preliminary, topline or expected results; the potential for the FDA to conclude at any time that Tenaya’s clinical programs may not have an appropriate risk/benefit profile; Tenaya’s ability to enroll and maintain patients in clinical trials; risks associated with the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics and operating as an early stage company; Tenaya’s ability to develop, initiate or complete preclinical studies and clinical trials, and obtain approvals, for any of its product candidates; Tenaya’s ability to achieve the expected benefits from the collaboration with Alnylam; the occurrence of any event, change or other circumstance that could give rise to the termination of the collaboration with Alnylam; Tenaya’s continuing compliance with applicable legal and regulatory requirements; regulatory developments in the United States and foreign countries; Tenaya’s ability to raise any additional funding it will need to continue to pursue its business and product development plans; Tenaya’s reliance on third parties; Tenaya’s manufacturing, commercialization and marketing capabilities and strategy; the loss of key scientific or management personnel; competition in the industry in which Tenaya operates; Tenaya’s ability to comply with specified operating covenants and restrictions in its loan agreement; Tenaya’s ability to obtain and maintain intellectual property protection for its product candidates and platform technology; general economic and market conditions; and other risks. Information regarding the foregoing and additional risks may be found in the section entitled “Risk Factors” in documents that Tenaya files from time to time with the Securities and Exchange Commission. These forward-looking statements are made as of the date of this press release, and Tenaya assumes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. Tenaya Contacts Michelle Corral VP, Corporate Communications and Investor Relations [email protected] Investors Anne-Marie Fields Precision AQ [email protected] Media Wendy Ryan Ten Bridge Communications [email protected]

Reported Promising Data for TN-201 and TN-401 Gene Therapies in Fourth Quarter of 2025; Additional Data Readouts and Pursuit of Regulatory Alignment for Each Program Planned in 2026 New Research Supports TN-301’s Potential in Multiple Indications; Presented Preclinical Data for TN-301 in Duchenne Muscular Dystrophy Model Entered into Multi-Target Research Collaboration with Alnylam Pharmaceuticals December Financing with Net Proceeds of $55.8M and Anticipated Upfront Payment Extend Cash Runway into Second Half of 2027 SOUTH SAN FRANCISCO, Calif., March 11, 2026 (GLOBE NEWSWIRE) -- Tenaya Therapeutics, Inc. (NASDAQ: TNYA), a clinical-stage biotechnology company with a mission to discover, develop and deliver potentially curative therapies that address the underlying causes of heart disease, today announced financial results for the fourth quarter and full year ended December 31, 2025, and provided a corporate update. “As we enter 2026, we are energized by the momentum and clinical advances achieved over the past year,” said Faraz Ali, Chief Executive Officer of Tenaya. “The encouraging data presented in 2025 from both of our lead gene therapy programs underscore the transformative potential of our science. In the first half of 2026, we expect to share additional updates, including longer-term follow-up data from the MyPEAK™-1 clinical trial of TN-201 for MYBPC3-associated HCM, as well as one-year Cohort 1 data and early Cohort 2 data from the RIDGE™-1 clinical trial of TN-401 for PKP2-associated ARVC. Over the course of the year, we also plan to pursue regulatory agency alignment on pivotal trial plans for both programs, a critical step toward accelerating the delivery of safe and effective gene therapies to patients with serious cardiac conditions.” Mr. Ali continued, “We are also excited to take modest but important steps to move TN-301 -- our clinical-stage, highly selective, small molecule HDAC6 inhibitor -- forward towards patients. New preclinical data in relevant DMD models that we presented at the recent MDA meeting adds to a growing body of external evidence supporting the potentially broad clinical utility of TN-301 in a range of cardiac and cardiac-adjacent indications with high unmet patient need and large market potential. The recently announced Alnylam collaboration further validates our platform capabilities that originally led to the discovery of TN-301. Together, these developments reflect the potential for Tenaya to add exciting new value drivers that are orthogonal to our portfolio of genetic medicines.” Business and Program Updates TN-201 – Gene Therapy for MYBPC3-Associated Hypertrophic Cardiomyopathy (HCM) In November 2025, Tenaya presented promising data from the MyPEAK-1 Phase 1b/2 clinical trial for the potential treatment of HCM due to MYBPC3 mutations. The interim data reported included safety, biopsy and leading indicators of efficacy results for the three patients who each received a 3E13 vg/kg dose (Cohort 1) with follow-up ranging from Week 52-78, as well as initial safety data and biopsy and efficacy results for three patients who received a 6E13 vg/kg dose (Cohort 2) as of the July 2025 data cut off. Key findings included: TN-201 was generally well tolerated at both dose levels. No dose-limiting toxicities were observed, and all patients had successfully tapered off immunosuppressive medicine. MyBP-C protein levels increased over time across patients in both Cohorts, with a substantial increase in protein levels observed commensurate with the higher dose in the first patient evaluable from Cohort 2. Multiple parameters associated with risk of complications and/or survival improved among a majority of patients with greater than 26 weeks of follow-up, including circulating biomarkers of heart muscle injury and measures of hypertrophy. All patients with efficacy assessments improved to New York Heart Association Class I, indicating no limitations to daily living due to symptoms. These data were presented at the 2025 American Heart Association Annual Scientific Sessions and simultaneously published in Cardiovascular Research. In January, following implementation of modest protocol amendments in alignment with the U.S. Food and Drug Administration (FDA) input, Tenaya resumed enrollment in MyPEAK-1 to generate additional safety and efficacy data. Tenaya outlined anticipated milestones associated with the TN-201 program for 2026, which include: Enrolling additional patients in the 6E13 vg/kg expansion cohort of MyPEAK-1 over the course of the year Reporting interim MyPEAK-1 data for Cohort 2 and updates from Cohort 1 in the first half of 2026 Presenting one-year Cohort 2 data and two-year Cohort 1 data in the second half of 2026 Providing an update on its progress in pursuing regulatory alignment for TN-201 pivotal plans in the second half of the year. TN-401 – Gene Therapy for PKP2-Associated Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) In December 2025, Tenaya reported positive initial data in the ongoing RIDGE-1 Phase 1b/2 clinical trial of TN-401 gene therapy for the potential treatment of ARVC caused by mutations in the plakophilin-2 (PKP2) gene. The data reported included safety, biopsy and arrhythmia results from the first three patients to receive TN-401 at a dose of 3E13 vg/kg (Cohort 1) as of the October 2025 data cut off, with follow-up ranging from 20-40 weeks post-dose. Key findings included: TN-401 was generally well tolerated at the 3E13 vg/kg dose, and no dose-limiting toxicities were observed. Adverse events (AEs) were generally mild, asymptomatic and manageable and deemed unrelated to TN-401 treatment. Enrollment and dosing of Cohort 2 was completed with no new serious AEs reported. Biopsies taken at eight weeks post-treatment demonstrated robust transduction and RNA expression in all patients. PKP2 protein levels increased by an average of 10 percent compared to baseline in the first two patients dosed. Clinically meaningful improvements in measures of electrical instability (premature ventricular contractions and non-sustained ventricular tachycardias) were observed in the first two patients with greater than six months follow-up after TN-401 dosing. In January, the RIDGE-1 data and safety monitoring board (DSMB) reviewed all available data for the six patients to have received either a 3E13 vg/kg (Cohort 1) or 6E13 vg/kg (Cohort 2) dose of TN-401. The DSMB determined that TN-401 had an acceptable safety profile and endorsed continued enrollment of patients in RIDGE-1 expansion cohorts at either dose. In 2026, Tenaya expects to achieve the following milestones associated with the TN-401 program’s advancement: Enrolling patients in 6E13 vg/kg expansion cohort of RIDGE-1 throughout the year Presenting one-year data for Cohort 1 and initial Cohort 2 data in the first half of 2026 Reporting interim Cohort 2 data in the second half of 2026 Pursuing regulatory alignment on TN-401 pivotal plans and sharing an update by year-end, as available. TN-301 – Small Molecule HDAC6 Inhibitor for the Potential Treatment of Heart Failure with Preserved Ejection Fraction (HFpEF) and Related Cardiac, Metabolic, or Muscular Diseases Tenaya presented encouraging preclinical data comparing TN-301, the company’s highly selective HDAC6 inhibitor, with givinostat, an approved pan-HDAC inhibitor, in a well-established mdx mouse model of Duchenne muscular dystrophy (DMD) at the Muscular Dystrophy Association’s 2026 Clinical and Scientific Congress. Results of the study showed that in mdx mice: TN-301 treatment at doses as low as 3 mg/kg improved grip strength to wild-type levels within five weeks, whereas mdx mice treated with givinostat (10 mg/kg, approximating clinical exposures) failed to reach wild-type performance. TN-301-mediated functional improvements were accompanied by reductions in circulating creatine kinase and favorable changes in gene expression, indicating reduced muscle cell injury. In cardiomyocytes derived from human DMD-induced pluripotent stem cells, TN-301 corrected calcium handling abnormalities and mitochondrial dysfunction, while givinostat exacerbated these established drivers of DMD cardiomyopathy. In 2026, Tenaya plans to advance TN-301 toward clinical trials in patients in order to generate proof-of-activity data, with HFpEF and DMD being among the most promising potential indications identified to date. Business Updates Tenaya entered into a multi-target research collaboration with Alnylam Pharmaceuticals to identify and validate novel genetic targets aimed at treating cardiovascular disease. Under the terms of the agreement, Tenaya will receive an upfront payment of up to $10.0 million and may be eligible for development, regulatory and sales-based milestones totaling up to $1.1 billion, in addition to reimbursement of associated research costs. Alnylam will be responsible for all development, manufacturing, regulatory and commercialization activities of therapeutics associated with the identified gene targets. In December 2025, Tenaya closed an underwritten public offering of 50,000,000 total units at a public offering price of $1.20 per unit, consisting of one share of Tenaya common stock and one warrant to purchase one share of Tenaya common stock at an exercise price of $1.50 per share, resulting in net proceeds of $55.8 million. Fourth Quarter and Full Year 2025 Financial Highlights Cash Position and Guidance: As of December 31, 2025, cash, cash equivalents and investments in marketable securities were $100.5 million, as compared to $61.4 million as of December 31, 2024. With the additional net proceeds of $55.8 million from the December 2025 public offering after deducting underwriting discounts and commissions and offering expenses. Tenaya expects that such resources, along with the expected upfront payment from the Alnylam collaboration, will be sufficient to fund planned operations into the second half of 2027. Research & Development (R&D) Expenses: R&D expenses were $14.8 million for the fourth quarter and $68.6 million for the full year ended December 31, 2025, a decrease compared to R&D expenses of $18.7 million and $86.7 million for the same period in 2024. Non-cash stock-based compensation included in R&D expense was $1.4 million for the fourth quarter and $6.8 million for the full year ended December 31, 2025, compared to $1.9 million and $8.2 million for the same period in 2024. General & Administrative (G&A) Expenses: G&A expenses were $6.0 million for the fourth quarter and $24.7 million for the full year ended December 31, 2025, compared to $6.0 million and $29.2 million for the same period in 2024. Non-cash stock-based compensation included in G&A expense was $1.3 million for the fourth quarter and $6.2 million for the full year ended December 31, 2025, compared to $1.8 million and $8.3 million for the same period in 2024. Net Loss: Net loss was $20.2 million, or $0.12 loss per share, for the fourth quarter ended December 31, 2025, compared to a net loss of $23.8 million, or $0.28 per share, for the same period in 2024. For the full year 2025, net loss decreased to $90.6 million, or $0.59 per share, compared to a net loss of $111.1 million, or $1.31 per share, in 2024. About Tenaya Therapeutics Tenaya Therapeutics is a clinical-stage biotechnology company committed to a bold mission: to discover, develop and deliver potentially curative therapies that address the underlying drivers of heart disease. Tenaya’s pipeline includes clinical-stage candidates TN-201, a gene therapy for MYBPC3-associated hypertrophic cardiomyopathy (HCM) and TN-401, a gene therapy for PKP2-associated arrhythmogenic right ventricular cardiomyopathy (ARVC). Tenaya has employed a suite of integrated internal capabilities, including modality agnostic target validation, capsid engineering and manufacturing, to generate a portfolio of novel medicines based on genetic insights, including TN-301, a clinical-stage small molecule HDAC6 inhibitor for the potential treatment of heart failure and related cardio/muscular disease, and multiple early-stage programs in preclinical development aimed at the treatment of both rare genetic disorders and more prevalent heart conditions. For more information, visit www.tenayatherapeutics.com. Forward Looking Statements This press release contains forward-looking statements as that term is defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Statements in this press release that are not purely historical are forward-looking statements. Words such as “planned,” “potential,” “anticipated,” “expect,” “plan,” “anticipated,” “eligible,” and similar expressions are intended to identify forward-looking statements. Such forward-looking statements include, among other things, planned timing for sharing data from MyPEAK-1 and RIDGE-1 and the expected content of such data releases; the clinical, therapeutic and commercial potential of TN-201,TN-401 and TN-301; anticipated 2026 milestones for Tenaya’s TN-201 and TN-401 programs, including enrollment, data announcements and regulatory alignment; the potential for new value divers to arise from Tenaya’s plans for TN-301 and collaboration activities; clinical development plans for TN-301; the potential for Tenaya to receive upfront, development, regulatory and sales-based milestone payments, as well as research reimbursement under the collaboration with Alnylam; the sufficiency of Tenaya’s cash resources to fund the company into the second half of 2027; and statements made by Tenaya’s chief executive officer. The forward-looking statements contained herein are based upon Tenaya’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. These forward-looking statements are neither promises nor guarantees and are subject to a variety of risks and uncertainties, including but not limited to: availability of data at the referenced times; the timing and progress of Tenaya’s clinical trials; unexpected concerns that may arise as a result of the occurrence of adverse safety events in Tenaya’s clinical trials; the potential failure of Tenaya’s product candidates to demonstrate safety and/or efficacy in clinical testing; the potential for any clinical trial results to differ from preclinical, interim, preliminary, topline or expected results; risks associated with the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics and operating as an early stage company; Tenaya’s ability to develop, initiate or complete preclinical studies and clinical trials, and obtain approvals, for any of its product candidates; Tenaya’s ability to achieve the expected benefits from the collaboration with Alnylam; the occurrence of any event, change or other circumstance that could give rise to the termination of the collaboration with Alnylam; Tenaya’s continuing compliance with applicable legal and regulatory requirements; regulatory developments in the United States and foreign countries; Tenaya’s ability to raise any additional funding it will need to continue to pursue its business and product development plans; Tenaya’s reliance on third parties; Tenaya’s manufacturing, commercialization and marketing capabilities and strategy; the loss of key scientific or management personnel; competition in the industry in which Tenaya operates; Tenaya’s ability to comply with specified operating covenants and restrictions in its loan agreement; Tenaya’s ability to obtain and maintain intellectual property protection for its product candidates and platform technology; general economic and market conditions; and other risks. Information regarding the foregoing and additional risks may be found in the section entitled “Risk Factors” in documents that Tenaya files from time to time with the Securities and Exchange Commission. These forward-looking statements are made as of the date of this press release, and Tenaya assumes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. Tenaya Contacts Michelle Corral VP, Corporate Communications and Investor Relations [email protected] Investors Anne-Marie Fields Precision AQ [email protected] Media Wendy Ryan Ten Bridge Communications [email protected]

Presentation of MyPEAK-1 Data and the American Heart Association Scientific Sessions Showed Consistent, Deeper, and Durable Improvement in Measures of Hypertrophy for Cohort 1 Patients Initial TN-201 Cohort 2 Data Demonstrated Early Dose Responsive Increases in TN-201 Transduction and MyBP-C Protein Expression Completed Dosing in Cohort 2 of RIDGE™-1 Trial of TN-401 for PKP2-associated ARVC; Cohort 1 Data On Track for Fourth Quarter Company Presentation Tenaya Management to Review New MyPEAK-1 Data on Webcast Call for Analysts and Investors Today at 8:00 a.m. EST SOUTH SAN FRANCISCO, Calif., Nov. 10, 2025 (GLOBE NEWSWIRE) -- Tenaya Therapeutics, Inc. (NASDAQ: TNYA), a clinical-stage biotechnology company with a mission to discover, develop and deliver potentially curative therapies that address the underlying causes of heart disease, today announced financial results for the third quarter ended September 30, 2025, and provided a corporate update. “Throughout the third quarter, we made important steps advancing our two lead gene therapy programs to provide transformative treatments to patients with serious genetic cardiomyopathies,” said Faraz Ali, Chief Executive Officer of Tenaya. “TN-201 and TN-401 each received positive recommendations from their respective Data Safety Monitoring Boards to advance into the dose expansion cohorts reflecting confidence in each product’s emerging safety profile. We were particularly pleased with the positive safety and promising clinical data presented on TN-201 as a potential treatment for MYBPC3-associated HCM at the recent AHA Scientific Sessions. We also look forward to sharing meaningful safety and interim biopsy and efficacy data from the RIDGE-1 trial of TN-401 for patients with PKP2-associated ARVC in the coming weeks.” Business and Program Updates TN-201 – Gene Therapy for MYBPC3-Associated Hypertrophic Cardiomyopathy (HCM) New data from the Phase 1b/2a MyPEAK-1 clinical trial of TN-201 were presented by Milind Desai, M.D., M.B.A., director of the Hypertrophic Cardiomyopathy Center at Cleveland Clinic and vice chair, Heart Vascular Thoracic Institute, Cleveland Clinic as a late-breaking oral presentation at the American Heart Association (AHA) Scientific Sessions on Saturday, November 8, 2025. The AHA presentation included updated data from Cohort 1 patients at ≥52-weeks of follow-up, as well as safety and available biopsy results for Cohort 2 patients. TN-201 achieved robust transduction and durable expression with dose-dependent increase in MyBP-C protein. Among Cohort 1 patients for whom there was greater than one year of follow up, decreases in circulating biomarkers and reductions in measures of left ventricular hypertrophy deepened over time. The data showed that single administration of TN-201 gene therapy was generally well-tolerated at both the 3E13 vg/kg and 6E13 vg/kg dose levels and immunogenicity was well managed through monitoring and individualized tapering of immunosuppressives. MyPEAK-1 is a multi-center, open-label, dose-escalation trial designed to assess safety, tolerability and clinical efficacy of a one-time intravenous infusion of TN-201 in treating patients with HCM caused by mutations in the MYBPC3 gene. A total of seven patients have been dosed with TN-201 to date. The independent Data Safety Monitoring Board (DSMB) for the MyPEAK-1 trial reviewed all available safety data over the summer and determined that TN-201 had an acceptable safety profile to enroll dose expansion cohorts at either the 3E13 vg/kg or 6E13 vg/kg dose level. There have been no new meaningful safety events associated with TN-201 since the DSMB review. Following a proactive outreach to the U.S. Food and Drug Administration (FDA) related to future plans for the TN-201 program, Tenaya is preparing a protocol amendment to the MyPEAK-1 clinical trial. The changes reflected in the amendment primarily focus on standardizing activities related to patient monitoring and management of the immunosuppressive regimen across trial sites. During this time, MyPEAK-1 is on clinical hold. Tenaya is working swiftly and collaboratively with the FDA to resolve the clinical hold and intends to resume dosing once the protocol changes have been implemented at trial sites The company does not expect the hold to impact data milestones or development timelines. In September 2025, results from a seroprevalence study of 100 adults with symptomatic MYBPC3-associated HCM were published in Frontiers in Medicine. Pre-existing immunity to AAV9 was absent or low in most MYBPC3-associated HCM patients, finding that nearly 95% would be below Nab titers of 1:80, the maximum allowable AAV9 titer threshold in the MyPEAK-1 gene therapy trial. (Nab) thresholds for AAV gene therapy trials. The study also indicated that either NAb or total antibody (TAb) assays may be suitable for patient eligibility screening. In August 2025, Tenaya presented interim data from the ongoing MyClimbTM natural history study of pediatric patients with MYBPC3-associated hypertrophic cardiomyopathy (HCM) at the European Society of Cardiology Congress. These data offer actionable information for predicting those patients who may be at higher risk of death or severe complications. The study enrolled more than 200 MYBPC3-associated HCM individuals diagnosed before the age of 18 across 29 clinical sites worldwide. MyClimb is believed to be the largest natural history study evaluating this patient population. Among the findings: 93% of participants had the nonobstructive HCM phenotype, for which there are currently no approved treatment options. MyClimb data demonstrates that children with MYBPC3-associated cardiomyopathy are at risk for severe morbidity and life-altering outcomes, even in childhood, including arrhythmia-related complications, heart failure-related hospitalizations, heart transplant, and death. Disease severity and age of diagnosis correlate to genetic inheritance patterns (homozygous, compound heterozygous and heterozygous). Initial modeling suggest Left Ventricular Mass Index (LVMI) was a significant predictor of risk in compound heterozygous and heterozygous groups and may serve as an appropriate surrogate marker of treatment efficacy in potential future studies. TN-401 – Gene Therapy for PKP2-Associated Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) Tenaya has completed enrollment and dosing of three patients at the 6E13 vg/kg dose (Cohort 2) in the Phase 1b RIDGE-1 clinical trial of TN-401. RIDGE-1 is a multi-center, open-label, dose-escalation trial designed to assess safety, tolerability and clinical efficacy of a one-time intravenous infusion of TN-401 in treating patients with PKP2-associated ARVC. Tenaya expects to share initial safety and biopsy data from the first three patients enrolled and dosed in RIDGE-1 at the 3E13 vg/kg dose (Cohort 1) in a company presentation before year-end 2025. In October 2025, Tenaya presented a poster detailing the RIDGE-1 clinical trial design, including methodologies for measuring biopsy samples for TN-401 DNA and mRNA and PKP2 protein level changes at the European Society of Gene and Cell Therapy 2025 (ESGCT 2025) Annual Congress. In July 2025, the RIDGE-1 DSMB reviewed all available data from Cohort 1 and issued a positive recommendation regarding enrollment of Cohort 2 and enrollment of additional patients in an expansion arm at the 3E13 vg/kg dose. Research and Business Updates In a late-breaking presentation at the AHA Scientific Sessions, Tenaya presented new preclinical data on significant and durable improvement of cardiac function in a pig model of ischemic heart failure, achieved with a proprietary in vivo reprogramming cocktail that induces cardiac regeneration when delivered precisely with a clinically relevant catheter. In October 2025, Tenaya published a paper in the Journal of the American College of Cardiology (JACC), which highlighted the potential benefit of decreased MTSS1 expression in dilated cardiomyopathy, a severe form of heart failure. The paper details Tenaya's novel target identification and validation platform which utilizes human iPSC-derived cardiomyopathy models, specialized high-throughput screening combined with artificial intelligence (AI) and engineered heart tissue to characterize the role of MTSS1 in modulating contractile function. In August 2025, Tenaya hosted an educational webinar with Michael Previs, Ph.D. Associate Professor of Cellular, Molecular, and Biomedical Sciences at the University of Vermont focused on methods for measuring protein expression in cardiac gene therapies. The session highlighted the value of measuring protein level changes as an early indicator of gene therapy’s potential, Tenaya’s use of liquid chromatography – mass spectrometry normalized to myosin to more accurately quantify protein levels and the challenges inherent in exact measurements given sample to sample variability. An archived replay of the webinar is available under “News & Events” within the Investors section on the Tenaya website. Third Quarter 2025 Financial Highlights Cash Position and Guidance: As of September 30, 2025, cash, cash equivalents and investments in marketable securities were $56.3 million. The company expects that as cost savings continue to be realized from prior spending reductions, its current funds should be sufficient to support planned company operations into the second half of 2026. Tenaya has not drawn on the credit facility established with Silicon Valley Bank and is not obligated to do so. Research & Development (R&D) Expenses: R&D expenses were $15.4 million for the third quarter of 2025 compared to $20.4 million for the same period in 2024. Non-cash stock-based compensation included in R&D expense was $1.5 million for the third quarter of 2025 and $2.0 million for the same period in 2024. General & Administrative (G&A) Expenses: G&A expenses were $5.6 million for the third quarter of 2025 and $6.4 million for the same period in 2024. Non-cash stock-based compensation included in G&A expense was $1.4 million for the third quarter of 2025 and $1.9 million for the same period in 2024. Net Loss: Net loss was $20.3 million, or $0.12 loss per share for the third quarter ended September 30, 2025, compared to a net loss of $25.6 million, or $0.30 per share, in the same period of 2024. Conference Call and Webcast Tenaya management will host a conference call today, Monday, November 10, 2025, at 8:00 a.m. ET/5:00 a.m. PT to discuss the TN-201 data presented and published on Saturday, November 8, 2025 at the AHA Scientific Sessions and the status of the MyPEAK-1 clinical trial. The webcast conference call, including an accompanying slide presentation, can be accessed from the investor section on the “Events and Presentations” page of the Tenaya website at www.tenayatherapeutics.com. About Tenaya Therapeutics Tenaya Therapeutics is a clinical-stage biotechnology company committed to a bold mission: to discover, develop and deliver potentially curative therapies that address the underlying drivers of heart disease. Tenaya’s pipeline includes clinical-stage candidates TN-201, a gene therapy for MYBPC3-associated hypertrophic cardiomyopathy (HCM) and TN-401, a gene therapy for PKP2-associated arrhythmogenic right ventricular cardiomyopathy (ARVC). Tenaya has employed a suite of integrated internal capabilities, including modality agnostic target validation, capsid engineering and manufacturing, to generate a portfolio of novel medicines based on genetic insights, including TN-301, a clinical-stage small molecule HDAC6 inhibitor for the potential treatment of heart failure and related cardio/muscular disease, and multiple early-stage programs in preclinical development aimed at the treatment of both rare genetic disorders and more prevalent heart conditions. For more information, visit www.tenayatherapeutics.com. Forward Looking Statements This press release contains forward-looking statements as that term is defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Statements in this press release that are not purely historical are forward-looking statements. Words such as “look forward,” “potentially,” “anticipates,” “may,” “plans,” “will,” “expects,” and similar expressions are intended to identify forward-looking statements. Such forward-looking statements include, among other things, planned timing for sharing data from MyPEAK-1 and RIDGE-1 and the expected content of such data releases; the clinical, therapeutic and commercial potential of TN-201 and TN-401; enrollment plans for MyPEAK-1 and RIDGE-1; planned timing for sharing data from My Climb; Tenaya’s plans to host a Key Opinion Leader event; the sufficiency of Tenaya’s cash resources to fund the company into the second half of 2026; and statements made by Tenaya’s chief executive officer. The forward-looking statements contained herein are based upon Tenaya’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. These forward-looking statements are neither promises nor guarantees and are subject to a variety of risks and uncertainties, including but not limited to: availability of data at the referenced times; the timing and progress of Tenaya’s clinical trials; unexpected concerns that may arise as a result of the occurrence of adverse safety events in Tenaya’s clinical trials; the potential failure of Tenaya’s product candidates to demonstrate safety and/or efficacy in clinical testing; the potential for any clinical trial results to differ from preclinical, interim, preliminary, topline or expected results; risks associated with the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics and operating as an early stage company; Tenaya’s ability to develop, initiate or complete preclinical studies and clinical trials, and obtain approvals, for any of its product candidates; Tenaya’s continuing compliance with applicable legal and regulatory requirements; risks related to the impact of the restructuring plan on Tenaya’s business; Tenaya’s ability to raise any additional funding it will need to continue to pursue its business and product development plans; Tenaya’s reliance on third parties; Tenaya’s manufacturing, commercialization and marketing capabilities and strategy; the loss of key scientific or management personnel; competition in the industry in which Tenaya operates; Tenaya’s ability to comply with specified operating covenants and restrictions in its loan agreement; Tenaya’s ability to obtain and maintain intellectual property protection for its product candidates; general economic and market conditions; and other risks. Information regarding the foregoing and additional risks may be found in the section entitled “Risk Factors” in documents that Tenaya files from time to time with the Securities and Exchange Commission. These forward-looking statements are made as of the date of this press release, and Tenaya assumes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law Tenaya Contacts Michelle Corral VP, Corporate Communications and Investor Relations [email protected] Investors Anne-Marie Fields Precision AQ [email protected] Media Wendy Ryan Ten Bridge Communications [email protected]

Enrollment Complete in Cohorts 1 and 2 of MyPEAK™-1 Phase 1b/2 Trial of TN-201 for MYBPC3-associated HCM; Positive DSMB Safety Review Enables Enrollment of Expansion Cohorts Cohort 1 of RIDGE™-1 Phase 1b Trial of TN-401 Enrolled and First PKP2-associated ARVC Patient Dosed in Cohort 2 Following DSMB Recommendation to Dose Escalate and Expand Data Readouts from Both TN-201 and TN-401 Clinical Programs Planned for the Fourth Quarter of 2025 Cash Runway into Second Half of 2026 SOUTH SAN FRANCISCO, Calif., Aug. 06, 2025 (GLOBE NEWSWIRE) -- Tenaya Therapeutics, Inc. (NASDAQ: TNYA), a clinical-stage biotechnology company with a mission to discover, develop and deliver potentially curative therapies that address the underlying causes of heart disease, today announced financial results for the second quarter ended June 30, 2025, and provided a corporate update. “During the first half of 2025, we achieved target enrollment in our ongoing gene therapy clinical trials of TN-201 for MYBPC3-associated HCM and of TN-401 for PKP2-associated ARVC. The subsequent positive recommendations for dose escalation and/or expansion from each trial’s independent Data Safety Monitoring Board following a review of all available safety data for TN-201 and TN-401 are critical milestones in our mission to address two of the most common and deadly genetic cardiomyopathies,” said Faraz Ali, Chief Executive Officer of Tenaya. “We look forward to sharing meaningful new data readouts for both TN-201 and TN-401 in the fourth quarter of 2025 that will bring us closer to delivering potentially transformative therapies to patients.” Business and Program Updates TN-201 – Gene Therapy for MYBPC3-Associated Hypertrophic Cardiomyopathy (HCM) In May, Tenaya completed enrollment and dosing of three patients at the 6E13 vg/kg dose level (Cohort 2) in the MyPEAK™-1 Phase 1b/2 clinical trial of TN-201 for MYBPC3-associated HCM. Following a review of all available safety data, the independent Data Safety Monitoring Board (DSMB) for the MyPEAK-1 trial determined that TN-201 had an acceptable safety profile to enroll dose expansion cohorts at either the 3E13 vg/kg or 6E13 vg/kg dose level. Tenaya currently anticipates enrolling patients in the 6E13 vg/kg dose expansion cohort. MyPEAK-1 is a multi-center, open-label, dose-escalation trial designed to assess safety, tolerability and clinical efficacy of a one-time intravenous infusion of TN-201 in treating patients with HCM caused by mutations in the MYBPC3 gene. Earlier this year, interim data from the first three patients who received TN-201 at the 3E13 vg/kg dose level (Cohort 1) were shared in a Late-Breaker presentation at the 2025 American College of Cardiology Scientific Sessions. TN-201 showed robust transduction and RNA expression with RNA and protein levels increasing over time. All three patients who had objectively severe disease at baseline were able to achieve New York Heart Association Class I, and two of the three patients experienced improvement in one or more measures of hypertrophy. Tenaya anticipates releasing initial Cohort 2 data and an update on Cohort 1 in the fourth quarter of 2025. An abstract regarding Tenaya’s pediatric non-interventional natural history study, known as MyClimb, has been accepted for presentation at the upcoming European Society of Cardiology (ESC) Annual Meeting being held August 29-September 1 in Madrid Spain. MyClimb has enrolled more than 200 patients at 29 sites worldwide to characterize the disease burden for patients diagnosed with MYBPC3-associated HCM before age 18 for whom there are currently no approved therapeutic agents. TN-401 – Gene Therapy for PKP2-Associated Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) Enrollment of the first cohort of three patients receiving TN-401 at a dose level of 3E13 vg/kg in the RIDGE-1 Phase 1b clinical trial was completed in April 2025. RIDGE-1 is a global multicenter, open-label, dose-escalation trial designed to assess safety, tolerability and clinical efficacy of a one-time intravenous infusion of TN-401 for the treatment of ARVC caused by mutations to the PKP2 gene. Tenaya anticipates providing initial Cohort 1 data focused on safety and biopsy results for the first three patients on study in the fourth quarter of 2025. In July 2025, the RIDGE-1 DSMB reviewed all available data from Cohort 1 and issued a positive recommendation regarding both enrollment of a higher dose cohort at 6E13 vg/kg and enrollment of additional patients at the 3E13 vg/kg dose. Tenaya is enrolling Cohort 2 and the first patient has been dosed at the 6E13 vg/kg dose level. Tenaya may enroll additional patients at the 3E13 vg/kg dose. In April 2025, Tenaya presented interim data from the non-interventional natural history and seroprevalence study known as RIDGE at the Heart Rhythm Society’s Annual Heart Rhythm Meeting. With 191 participants enrolled, RIDGE is the largest non-interventional natural history and seroprevalence study of adults with PKP2-associated ARVC to date and was designed to collect and assess participants’ clinical characteristics and medical history, as well as to test for preexisting neutralizing antibodies to adeno-associated virus-9 (AAV9). Data from RIDGE indicated that patients experience a high burden of arrhythmia: 83% continue to experience more than 500 premature ventricular contractions (PVCs) per day and 49% had a history of ventricular tachycardias despite standard of care treatments. Study participants show evidence of progressive structural changes that occur because of PKP2 mutations, in which the instability and disintegration of cellular structures in the desmosome results in fibrofatty scar tissue. PKP2-associated ARVC patients have low levels of preexisting immunity to AAV9 antibodies and the majority of RIDGE participants appear eligible for Tenaya’s RIDGE-1 Phase 1b clinical trial of TN-401 gene therapy. Research and Manufacturing In May 2025, Tenaya’s Research and Manufacturing teams presented several posters at the American Society for Gene Therapy 28th Annual Meeting, which detailed the outcome of efforts to advance Tenaya’s core capabilities in novel capsid engineering, identification, design and optimization of cardiomyocyte-targeting genetic medicines, and manufacturing of AAV gene therapies. Business Updates Tenaya plans to host a Virtual Key Opinion Leader event, “Measuring Protein Expression in Cardiac Gene Therapy,” on August 19, 2025, at 11:30am ET. The event will feature a discussion with Michael Previs, Ph.D., Associate Professor of Molecular Physiology and Biophysics at the University of Vermont and an expert in the development of mass spectrometry-based proteomic techniques. Analysts and investors are invited to join the live event by registering here. A replay will be available on the investor section of the Tenaya website under “Events”. Second Quarter 2025 Financial Highlights Cash Position and Guidance: As of June 30, 2025, cash, cash equivalents and investments in marketable securities were $71.7 million. The company expects that its current funds are sufficient to support planned company operations into the second half of 2026. Tenaya has not drawn on the credit facility established with Silicon Valley Bank and is not obligated to do so. Research & Development (R&D) Expenses: R&D expenses were $17.4 million for the second quarter of 2025 compared to $22.6 million for the same period in 2024. Non-cash stock-based compensation included in R&D expense was $1.9 million for the second quarter of 2025 and $2.2 million for the same period in 2024. General & Administrative (G&A) Expenses: G&A expenses were $6.7 million for the second quarter of 2025 and $8.2 million for the same period in 2024. Non-cash stock-based compensation included in G&A expense was $1.8 million for the second quarter of 2025 and $2.4 million for the same period in 2024. Net Loss: Net loss was $23.3 million, or $0.14 loss per share for the second quarter ended June 30, 2025, compared to a net loss of $29.4 million, or $0.34 per share, in the same period of 2024. About Tenaya Therapeutics Tenaya Therapeutics is a clinical-stage biotechnology company committed to a bold mission: to discover, develop and deliver potentially curative therapies that address the underlying drivers of heart disease. Tenaya’s pipeline includes clinical-stage candidates TN-201, a gene therapy for MYBPC3-associated hypertrophic cardiomyopathy (HCM) and TN-401, a gene therapy for PKP2-associated arrhythmogenic right ventricular cardiomyopathy (ARVC). Tenaya has employed a suite of integrated internal capabilities, including modality agnostic target validation, capsid engineering and manufacturing, to generate a portfolio of novel medicines based on genetic insights, including TN-301, a clinical-stage small molecule HDAC6 inhibitor for the potential treatment of heart failure and related cardio/muscular disease, and multiple early-stage programs in preclinical development aimed at the treatment of both rare genetic disorders and more prevalent heart conditions. For more information, visit www.tenayatherapeutics.com. Forward Looking Statements This press release contains forward-looking statements as that term is defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Statements in this press release that are not purely historical are forward-looking statements. Words such as “look forward,” “potentially,” “anticipates,” “may,” “plans,” “will,” “expects,” and similar expressions are intended to identify forward-looking statements. Such forward-looking statements include, among other things, planned timing for sharing data from MyPEAK-1 and RIDGE-1 and the expected content of such data releases; the clinical, therapeutic and commercial potential of TN-201 and TN-401; enrollment plans for MyPEAK-1 and RIDGE-1; planned timing for sharing data from MyClimb; Tenaya’s plans to host a Key Opinion Leader event; the sufficiency of Tenaya’s cash resources to fund the company into the second half of 2026; and statements made by Tenaya’s chief executive officer. The forward-looking statements contained herein are based upon Tenaya’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. These forward-looking statements are neither promises nor guarantees and are subject to a variety of risks and uncertainties, including but not limited to: availability of data at the referenced times; the timing and progress of Tenaya’s clinical trials; unexpected concerns that may arise as a result of the occurrence of adverse safety events in Tenaya’s clinical trials; the potential failure of Tenaya’s product candidates to demonstrate safety and/or efficacy in clinical testing; the potential for any clinical trial results to differ from preclinical, interim, preliminary, topline or expected results; risks associated with the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics and operating as an early stage company; Tenaya’s ability to develop, initiate or complete preclinical studies and clinical trials, and obtain approvals, for any of its product candidates; Tenaya’s continuing compliance with applicable legal and regulatory requirements; risks related to the impact of the restructuring plan on Tenaya’s business; Tenaya’s ability to raise any additional funding it will need to continue to pursue its business and product development plans; Tenaya’s reliance on third parties; Tenaya’s manufacturing, commercialization and marketing capabilities and strategy; the loss of key scientific or management personnel; competition in the industry in which Tenaya operates; Tenaya’s ability to comply with specified operating covenants and restrictions in its loan agreement; Tenaya’s ability to obtain and maintain intellectual property protection for its product candidates; general economic and market conditions; and other risks. Information regarding the foregoing and additional risks may be found in the section entitled “Risk Factors” in documents that Tenaya files from time to time with the Securities and Exchange Commission. These forward-looking statements are made as of the date of this press release, and Tenaya assumes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law Tenaya Contacts Michelle Corral VP, Corporate Communications and Investor Relations [email protected] Investors Anne-Marie Fields Precision AQ [email protected] Media Wendy Ryan Ten Bridge Communications [email protected]

Interim Data from Low Dose Cohort in MyPEAKTM-1 Clinical Trial of TN-201 Showed Encouraging Safety Profile, Transduction and Expression, Plus Improvements in Hypertrophy and NYHA Classification RIDGE Natural History and Seroprevalence Study Highlights Significant Disease Burden and Unmet Need Among Adults with PKP2-associated ARVC Data Readouts for TN-201 and TN-401 Clinical Programs On Track for the Second Half of 2025 Cash Runway Extended into Second Half of 2026 SOUTH SAN FRANCISCO, Calif., May 07, 2025 (GLOBE NEWSWIRE) -- Tenaya Therapeutics, Inc. (NASDAQ: TNYA), a clinical-stage biotechnology company with a mission to discover, develop and deliver potentially curative therapies that address the underlying causes of heart disease, today announced financial results for the first quarter ended March 31, 2025, and provided a corporate update. “2025 is off to a strong start for Tenaya as we delivered positive data from our MyPEAK-1 clinical trial evaluating TN-201 for the potential treatment of MYBPC3-associated HCM, shared new findings from the RIDGE natural history study of adults with PKP2-associated ARVC, and extended our cash runway into the second half of 2026,” said Faraz Ali, Chief Executive Officer of Tenaya. “We are pleased to report that patient enrollment is on track for both the MyPEAK-1 study for TN-201 and the RIDGE-1 study for TN-401 as we drive both programs toward meaningful clinical readouts in the second half of this year. We have also taken important steps to focus our financial resources on clinical execution to help ensure we can take TN-201 and TN-401 through to important clinical milestones in 2026.” Program and Business Updates TN-201 – Gene Therapy for MYBPC3-Associated Hypertrophic Cardiomyopathy (HCM) In March 2025, Tenaya shared new interim data from the first cohort enrolled in the MyPEAK-1 Phase 1b/2 clinical trial of TN-201 in a Late-Breaker presentation at the 2025 American College of Cardiology Scientific Sessions. New data from the first three patients showed that TN-201 was well tolerated at a dose of 3E13 vg/kg. Biopsy results from all three patients demonstrated robust DNA transduction and RNA expression similar to or greater than ranges observed in other AAV cardiac gene therapy trials. TN-201 RNA and myosin binding protein C (MyBP-C) protein levels increased over time in Patients 1 and 2 for whom serial biopsies were available at the time of the data readout. All three patients had objectively severe disease at baseline and achieved New York Heart Association (NYHA) Class I post-treatment, and two of the three patients experienced improvement in one or more measures of hypertrophy. Cardiac troponin, a biomarker of myocardial injury, was elevated in Cohort 1 patients at baseline and decreased by more than 60% in two patients, whose levels are now normal or near normal. MyPEAK-1 is a Phase 1b/2 multi-center, open-label, dose-escalation trial designed to assess safety, tolerability and clinical efficacy of a one-time intravenous infusion of TN-201 in treating patients with HCM caused by mutations in the MYBPC3 gene. In March 2025, Tenaya published the results of its preclinical studies of TN-201 in Nature Communications. The article, titled, “AAV9-Mediated MYBPC3 Gene Therapy with Optimized Expression Cassette Enhances Cardiac Function and Survival in MYBPC3 Cardiomyopathy Models,” describes results from both in vitro and in vivo preclinical studies. TN-201 led to sustained increases in MYBPC3 RNA and MyBP-C protein expression along with improved cardiac function in a severe knockout mouse model. Enrollment in Cohort 2 was initiated in December 2024 at the 6E13 vg/kg dose. Tenaya is on track to complete enrollment of Cohort 2 in the first half of 2025 and anticipates releasing initial Cohort 2 data along with further follow-up data from Cohort 1 in the second half of 2025. Tenaya plans to share data from its pediatric non-interventional natural history study, known as MyClimb, in the second half of 2025. MyClimb has enrolled more than 200 patients at 29 sites worldwide in an effort to characterize the disease burden for MYBPC3 patients diagnosed before age 18 for whom there are currently no approved therapeutic agents. TN-401 – Gene Therapy for PKP2-Associated Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) Enrollment of the first cohort of patients receiving TN-401 at a dose of 3E13 vg/kg in the RIDGE-1 Phase 1b clinical trial is on track for completion in the first half of 2025 and Tenaya expects to share initial Cohort 1 data in the second half of 2025. In April 2025, Tenaya shared interim data from the non-interventional natural history and seroprevalence study known as RIDGE at the Heart Rhythm Society’s annual meeting. As of the February data cut off, 144 participants were enrolled from sites in the U.S., UK and Europe. Despite standard-of-care treatment, data revealed a high burden of arrhythmias and progressive structural disease, with more than 80% of participants experiencing ≥500 premature ventricular contractions (PVCs) per day, a threshold linked with increased risk of malignant ventricular arrhythmias. Data from RIDGE indicated a large unmet need for treatments, such as TN-401 gene therapy, with the potential to reduce arrhythmic events and slow progression of disease by increasing PKP2 protein levels to address the underlying cause of disease. Greater than 90% of PKP2-associated ARVC adults had low levels of preexisting immunity to AAV9 antibodies, well within the eligibility criteria for TN-401 gene therapy. The RIDGE study is the largest natural history study conducted to date in this population and has enrolled more than 175 adult participants with PKP2-associated ARVC at more than 20 clinical sites in the U.S., UK, and EU. In February 2025, Tenaya was awarded an $8.0 million clinical grant from the California Institute for Regenerative Medicine (CIRM), which is expected to help fund clinical trial costs for the ongoing Phase 1b RIDGE-1 clinical trial of TN-401. Business Updates In March 2025, Tenaya completed an underwritten public offering with net proceeds of approximately $48.8 million after discounts, commissions, and other offering expenses. The offering consisted of 75 million units priced at $0.70 per unit, consisting of one share of Tenaya common stock, one warrant to purchase one share of Tenaya common stock at an exercise price of $0.80 per share and one warrant to purchase one half of a share of Tenaya common stock at an exercise price of $0.70 per share. The warrants are immediately exercisable and expire five years from the date of issuance and June 30, 2026, respectively. In alignment with Tenaya’s current focus to drive the TN-201 and TN-401 clinical programs through several meaningful data readouts, Tenaya implemented a restructuring plan including cost containment measures and a workforce reduction that are expected to significantly reduce Tenaya’s cash expenses, resulting in an expected extension of Tenaya’s cash runway into the second half of 2026. Tenaya estimates that it will incur approximately $1.6 million to $2.7 million of aggregate charges, primarily related to employee cash severance and continuing health benefits. Tenaya expects to recognize substantially all of the charges by the end of the third quarter of 2025. First Quarter 2025 Financial Highlights Cash Position and Guidance: As of March 31, 2025, cash, cash equivalents and investments in marketable securities were $88.2 million. With the additional estimated net proceeds of approximately $48.8 million from the March 2025 public offering, Tenaya expects that its current funds are sufficient to support planned company operations into the second half of 2026. Tenaya continues to maintain its $45.0 million credit facility with Silicon Valley Bank but has not drawn down on it to date and is not obligated to do so. Research & Development (R&D) Expenses: R&D expenses were $21.1 million for the first quarter of 2025 compared to $25.1 million for the same period in 2024. Non-cash stock-based compensation included in R&D expense was $2.0 million for the first quarter of 2025 and 2024. General & Administrative (G&A) Expenses: G&A expenses were $6.5 million for the first quarter of 2025 compared to $8.7 million for the for the same period in 2024. Non-cash stock-based compensation included in G&A expense was $1.7 million for the first quarter of 2025 and $2.2 million for the same period in 2024. Net Loss: Net loss was $26.9 million, or $0.24 loss per share for the first quarter ended March 31, 2025, compared to a net loss of $32.2 million, or $0.40 per share, in the same period of 2024. About Tenaya Therapeutics Tenaya Therapeutics is a clinical-stage biotechnology company committed to a bold mission: to discover, develop and deliver potentially curative therapies that address the underlying drivers of heart disease. Tenaya employs a suite of integrated internal capabilities, including modality agnostic target validation, capsid engineering and manufacturing, to generate a portfolio of genetic medicines aimed at the treatment of both rare genetic disorders and more prevalent heart conditions. Tenaya’s pipeline includes TN-201, a gene therapy for MYBPC3-associated hypertrophic cardiomyopathy (HCM), TN-401, a gene therapy for PKP2-associated arrhythmogenic right ventricular cardiomyopathy (ARVC), TN-301, a small molecule HDAC6 inhibitor intended for heart failure with preserved ejection fraction (HFpEF), and multiple early-stage programs in preclinical development. For more information, visit www.tenayatherapeutics.com. Forward Looking Statements This press release contains forward-looking statements as that term is defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Statements in this press release that are not purely historical are forward-looking statements. Words such as “on track,” “toward,” “ensure,” “anticipates,” “plans,” “potential,” “expected,” “estimates,” and similar expressions are intended to identify forward-looking statements. Such forward-looking statements include, among other things, status of enrollment for MyPEAK-1 and RIDGE-1; planned timing for sharing data from MyPEAK-1 and RIDGE-1 and the expected content of such data releases; Tenaya’s plans and expectations regarding its clinical development efforts and activities, including site activation, enrollment and dosing of patients and generating data for MyPEAK-1 and RIDGE-1; planned timing for sharing data from MyClimb, Tenaya’s non-interventional natural history study; the clinical, therapeutic and commercial potential of TN-201 and TN-401; the potential to use grant funding from CIRM to support RIDGE-1; the sufficiency of Tenaya’s cash resources to fund the company into the second half of 2026; expected charges relating to the restructuring plan and anticipated timing thereof; and statements made by Tenaya’s chief executive officer. The forward-looking statements contained herein are based upon Tenaya’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. These forward-looking statements are neither promises nor guarantees and are subject to a variety of risks and uncertainties, including but not limited to: availability of data at the referenced times; the timing and progress of Tenaya’s clinical trials; unexpected concerns that may arise as a result of the occurrence of adverse safety events in Tenaya’s clinical trials; the potential failure of Tenaya’s product candidates to demonstrate safety and/or efficacy in clinical testing; the potential for any clinical trial results to differ from preclinical, interim, preliminary, topline or expected results; risks associated with the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics and operating as an early stage company; Tenaya’s ability to develop, initiate or complete preclinical studies and clinical trials, and obtain approvals, for any of its product candidates; Tenaya’s continuing compliance with applicable legal and regulatory requirements; risks related to the impact of the restructuring plan on Tenaya’s business; the level of saving resulting from and charges related to the restructuring plan; Tenaya’s ability to raise any additional funding it will need to continue to pursue its business and product development plans; Tenaya’s reliance on third parties; Tenaya’s manufacturing, commercialization and marketing capabilities and strategy; the loss of key scientific or management personnel; competition in the industry in which Tenaya operates; Tenaya’s ability to comply with specified operating covenants and restrictions in its loan agreement; Tenaya’s ability to obtain and maintain intellectual property protection for its product candidates; general economic and market conditions; and other risks. Information regarding the foregoing and additional risks may be found in the section entitled “Risk Factors” in documents that Tenaya files from time to time with the Securities and Exchange Commission. These forward-looking statements are made as of the date of this press release, and Tenaya assumes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. Tenaya Contacts Michelle Corral VP, Corporate Communications and Investor Relations [email protected] Investors Anne-Marie Fields Precision AQ [email protected] Media Wendy Ryan Ten Bridge Communications [email protected]