Tenaya Therapeutics, Inc.
For the period ended Jun 30, 2026. Filed Aug 5, 2026.
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A company's report for each of its first three quarters. The financial statements are not audited. It shows how the business has moved since the last annual report, and what management says changed.
Jun 30, 2026 · Filed Aug 5, 2026
TNYA$0.36+14.0%Stored close · as of Nov 6, 2026
What changed in Management’s Discussion and Analysis?
Read the current filingPrevious report: 10-Q
Period ended 2026-03-31; filed 2026-05-06.
0001193125-26-209084
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of OperationsCurrent report: 10-Q
Period ended 2026-06-30; filed 2026-08-05.
0001193125-26-335140
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of OperationsThe baseline is this issuer’s latest earlier reporting period of the same form that was filed before the current report. A previous 10-Q is a different quarter, not a year-over-year comparison. Amendments are excluded.
Compared 100 previous paragraphs and 127 current paragraphs.
61 unchanged; 30 reworded; 30 added; 9 removed; 0 previous and 6 current paragraphs rearranged.
Tables are not compared: 3 previous and 5 current tables excluded. Dates, whitespace, punctuation and numbering changes are ignored; changes to financial figures remain significant.
A changed paragraph is not evidence that risk increased or decreased. An unchanged paragraph does not establish that risk stayed the same.
Added paragraphs (30)
Current report
We were founded with a long-term goal of building a fully integrated biopharmaceutical company focused on discovering, developing and ultimately commercializing first-/best-in-class precision medicines for heart disease. Early on in our company history, we invested in differentiated capabilities to enable modality-agnostic target identification and validation, anchored in human genetics and the use of human disease models. These highly productive platform drug discovery capabilities directly contributed to the development of our three clinical-stage programs, as well as to several earlier-stage pipeline programs.
Current report
In June 2026, we presented new interim safety and efficacy data from MyPEAK-1 as of a May 2026 data cut off. Data shared included 78-104 weeks of follow-up for the three Cohort 1 patients and 26-52 weeks of follow-up for four patients dosed with TN-201 at 6E13 vg/kg. Among the latest findings reported, six patients evaluable for efficacy endpoints demonstrated improvements in multiple clinical parameters of disease including echocardiographic (ECG) measures of hypertrophy, and one or more measures of symptom burden. Cardiac troponin, a known risk factor for cardiac-related morbidities or mortality, improved or remained stable in five of six patients and NT-pro BNP, a measure of heart muscle strain, improved in three patients. ECG measures of left ventricular structure showed decreases in multiple measures of left ventricular hypertrophy, a defining characteristic of HCM. All six evaluable patients achieved reductions in left ventricular mass index (LVMI) and five of six demonstrated reductions in one or more measures of wall thickness. Decreases in LVMI were durable through two years for the first two Cohort 1 patients and decreases among Cohort 2 patients were observed at an earlier timepoint post-dose compared to Cohort 1 patients.
Current report
Among all six patients, treatment with TN-201 resulted in a lessening of symptom burden as assessed by either New York Heart Association (NYHA) classification, a physician assessment of the impact of heart failure symptoms on activities of daily living, and/or the Kansas City Cardiomyopathy Questionnaire (KCCQ), a validated tool for measuring health status, symptom burden and quality of life among HCM patients. All patients were symptomatic at baseline (NYHA class II-III) and five of six improved by at least one class following treatment with TN-201. All five were assessed as Class I and no longer have heart failure symptoms that interfere with activities of daily living, while the sixth patient remained stable. Four of six patients demonstrated meaningful benefit in symptoms and quality of life, with KCCQ Clinical Summary Scores (KCCQ-CSS) improving by between 12 to 56 points from baseline, while the three evaluable Cohort 2 patients who received TN-201 at a dose of 6E13 vg/kg had improved KCCQ-CSS with a mean increase of 36 points. An improvement of 5 points or greater is considered clinically meaningful.
Current report
Functional capacity was also assessed by six-minute walk test (6MWT) and cardiopulmonary exercise testing (CPET) and improved by at least one of the two measures in three patients, with Cohort 2 patients showing greater benefit. Two patients from Cohort 2 and one Cohort 1 patient achieved meaningful improvements in 6MWT with changes from baseline ranging from 50- to 255-meters. An increase of 30 meters is considered clinically meaningful. Patient 4 from Cohort 2 also demonstrated clinically meaningful improvement in peak oxygen consumption (pVO2). CPET were not available as of the data cut off for the remaining Cohort 2 patients. Two patients from Cohort 1 experienced a decline in 6MWT, and no Cohort 1 patients saw improvements in CPET. Cohort 1 performance may be confounded by preexisting functional limitations and/or relatively longer duration and higher dose of immunosuppression.
Current report
TN-201 continued to be generally well tolerated across both MyPEAK-1 dose cohorts for the seven patients for whom safety data was reported. No dose-limiting toxicities were observed and all patients have tapered off immunosuppressive medicines. Adjustments to monitoring and immunosuppression during Cohort 1 resulted in faster tapers and lower cumulative corticosteroid doses in Cohort 2, despite the higher TN-201 dose. Results from serial cardiac biopsies taken at baseline or Week 8 and again post-dose or Week 52 showed that TN-201 DNA transduction and mRNA expression were robust, and MyBP-C levels increased by an average of 4% over time. Protein level changes were measured using liquid chromatography mass spectrometry (LCMS) normalized to myosin heavy chain (MYHC). As of the most recent assessment, MyBP-C levels were shown to increase in four of six patients, while variation in expression between individual biopsies is believed to have contributed to smaller differences in the remaining two patients. While additional follow-up is needed, the totality of results suggest that the higher dose of 6E13 vg/kg may result in equivalent or greater clinical benefit at an earlier timepoint post-dose.
Current report
In May 2026, we presented interim data from the first six patients dosed in RIDGE-1 at the American Society of Gene and Cell Therapies 2026 Annual Meeting. Data reported included electrophysiology, biopsy and safety results 20-52 weeks post-dose following a single infusion of TN-401. As of the April 2026 data cut off, all patients have completed all assessments and remain on study.
Current report
Treatment with TN-401 resulted in dramatic improvements in electrical stability, as measured by premature ventricular contractions (PVCs) and non-sustained ventricular tachycardias (NSVTs). PVCs and NSVTs are each important prognosticators of more serious, potentially life-ending ventricular arrythmias and their frequency is utilized as an important component in calculating patient risk and the need for an implantable cardiac defibrillator (ICD). All six patients had PVC counts of greater than 500 per day at baseline and demonstrated meaningful reductions in arrhythmia burden with a mean reduction in average daily PVC count of 60% for Cohort 1 and 67% for Cohort 2. Two patients with a high rate of NSVTs at baseline experienced substantial decreases, apparent as early as Week 20. Patient 2 had an NSVT burden of 78 counts per 24-hours, which dropped to zero and remained stable at Week 52. At baseline, Patient 5 had an NSVT count of 43 per 24 hours, which dropped to 4 per 24 hours at Week 20. Four patients had low NSVT burden at baseline and remained low. Other measures of clinical response including ECG changes (QRS duration and T wave inversions), heart structure and function and NYHA class were in the normal range at baseline and/or remained stable during the post-dose follow-up period.
Current report
Post-dose biopsies provided evidence of robust transduction and TN-401-specific expression for the first five patients for whom data was available at the time of data cut off. Biopsy samples were collected from the right ventricular septum at Week 8 for the first four patients and at Week 22 for Patient 5, with results from a second post-dose biopsy at Week 52 available for Cohort 1 patients. Robust evidence of dose-dependent TN-401 DNA transduction and mRNA expression were apparent, while changes in PKP2 protein levels in heart muscle cells from baseline to the most recent timepoints ranged from -4% to +15% as measured by LCMS normalized to MYHC. Measurements of PKP2 protein levels were impacted by the varied composition of cardiac tissue in an ARVC heart.
Current report
TN-401 was well tolerated across both RIDGE-1 dose cohorts and no dose-limiting toxicities had occurred as of the April 2026 data cut off. The prophylactic immune suppression regimen of sirolimus and prednisone successfully managed immune responses and all patients discontinued immunosuppressive medicines. Adverse events associated with TN-401 treatment were asymptomatic and self-resolved or responded to treatment. There was no clinical thrombotic microangiopathy, no ventricular arrhythmias related to TN-401 and no other cardiotoxicities associated with TN-401.
Current report
We expect to present interim Cohort 2 results in the fourth quarter of the year. We are also engaging with regulators on late-stage pivotal trial planning for TN-401 and plan to provide an update on the status of our discussions in the fourth quarter of 2026.
Current report
Sufficient clinical drug supply for both TN-201 and TN-401 to support our ongoing clinical trials was produced in our Genetic Medicines Manufacturing Center (GMMC). In June 2026, we terminated the lease for the GMMC Facility, which we decommissioned in 2025 to reduce costs. Notwithstanding the closure of the GMMC Facility, we have retained our internal process and assay development know-how and plan to transfer our AAV manufacturing process to a contract development manufacturing organization with global capabilities in anticipation of future late-stage development and/or commercial launch of TN-201 and/or TN-401.
Current report
Research and development expenses were $16.6 million and $17.4 million for the three months ended June 30, 2026 and 2025, respectively. The decrease of $0.8 million, or 4%, was primarily due to:
Current report
Impairment Loss
Current report
During the three months ended June 30, 2026, we recognized an impairment loss of $21.8 million, primarily related to leasehold improvements and manufacturing equipment at our Union City manufacturing facility, following the decision to exit the facility. No impairment loss was recognized in the prior-year period.
Current report
Loss On Lease Termination, Net
Current report
During the three months ended June 30, 2026, we recognized a net loss on lease termination of $1.4 million in connection with the termination of the lease for our Union City manufacturing facility. The loss primarily reflected the forfeiture of the facility’s security deposit and a brokerage commission incurred in connection with the lease termination, partially offset by gains associated with the remeasurement of the operating lease right-of-use asset and lease liability and the derecognition of the related asset retirement obligation liability. No comparable loss was recognized in the prior-year periods.
Current report
Comparison of the Six Months Ended June 30, 2026 and 2025:
Current report
NM - Not Meaningful
Current report
Research and Development Expenses
Current report
Research and development expenses were $31.4 million and $38.4 million for the six months ended June 30, 2026 and 2025, respectively. The decrease of $7.0 million, or 18%, was primarily due to:
Current report
General and Administrative
Current report
General and administrative expenses were $10.9 million and $13.2 million for the six months ended June 30, 2026 and 2025, respectively. The decrease of $2.3 million, or 18%, was primarily due to a $1.6 million decrease in stock-based compensation expense, as well as lower professional fees and depreciation expense.
Current report
Impairment Loss
Current report
During the six months ended June 30, 2026, we recognized an impairment loss of $21.8 million, primarily related to leasehold improvements and manufacturing equipment at our Union City manufacturing facility, following the decision to exit the facility. No impairment loss was recognized in the prior-year period.
Current report
Loss On Lease Termination, Net
Current report
During the six months ended June 30, 2026, we recognized a net loss on lease termination of $1.4 million in connection with the termination of the lease for our Union City manufacturing facility. The loss primarily reflected the forfeiture of the facility’s security deposit and a brokerage commission incurred in connection with the lease termination, partially offset by gains associated with the remeasurement of the operating lease right-of-use asset and lease liability and the derecognition of the related asset retirement obligation liability. No comparable loss was recognized in the prior-year periods.
Current report
Interest Income
Current report
Net Loss
Current report
Net loss for the six months ended June 30, 2026, was $62.7 million, compared to a net loss of $50.1 million for the six months ended June 30, 2025.
Current report
establish relationships with contract development manufacturing organizations (CDMOs) to support commercial-scale manufacturing;
Removed paragraphs (9)
Previous report
Early on in our company history, we invested in differentiated capabilities to enable modality-agnostic target identification and validation, anchored in human genetics and the use of human disease models. To support our initial focus on gene therapy candidates, we also internalized expertise in capsid engineering, novel promoter constructs and manufacturing anchored on the use of adeno-associated viruses (AAVs) as the method of delivery to the heart. That proprietary expertise has directly informed the discovery, design, optimization and production of our pipeline.
Previous report
In November 2025, we presented interim data from MyPEAK-1 at the American Heart Association’s Scientific Sessions 2025, with simultaneous publication in Cardiovascular Research. Interim data presented included safety, biopsy and efficacy results for the three patients enrolled in Cohort 1 with follow-up ranging from Week 52-78, and safety and available assessments for the patients in Cohort 2 who had post-dose assessments ranging from Week 12-26 as of the July 2025 data cut-off. Patient 5 was lost to further follow-up after week 12. TN-201 was generally well tolerated across both dose cohorts and no dose-limiting toxicities were observed. Reversible, asymptomatic liver enzyme elevations (Grade 1-3) were the most common treatment-related adverse events (AEs) reported. There were two treatment-related AEs classified as serious either due to inpatient administration of steroids or extended monitoring; a Grade 2 transaminase elevation that responded to steroids and a Grade 1 elevation of complement factors that resolved without additional intervention. Adjustments to monitoring and immunosuppression during Cohort 1 resulted in faster tapers and lower cumulative corticosteroid doses in Cohort 2, despite the higher TN-201 dose.
Previous report
DNA and RNA analyses of cardiac biopsy samples from all three patients in Cohort 1 showed evidence of sustained presence of TN-201 DNA in the heart and increasing mRNA expression over time. The first patient in Cohort 2 with serial biopsy data (Patient 6) had a greater than 2-fold increase in cardiac transduction and RNA expression at Week 12 relative to the average for these measures observed across Cohort 1 patients. MyBP-C protein levels across Cohort 1 increased over time by an average of 4% from the first biopsy taken to Week 52. The first evaluable patient in Cohort 2 (Patient 6) demonstrated a clear dose response, and early MyBP-C expression increased by 14% after only 12 weeks post-dose.
Previous report
All patients with greater than 26 weeks of follow-up demonstrated improvement in at least one parameter of disease, across biomarkers, hypertrophy and heart failure symptoms. Cardiac troponin I, a predictive risk factor of adverse cardiac outcomes such as ventricular arrhythmias, sudden cardiac death, and progression to end-stage heart failure, declined by as much as 74% from baseline, to normal or near-normal levels in all Cohort 1 patients. NT-proBNP, a biomarker of cardiac muscle strain, improved or remained stable in two of three Cohort 1 patients. All three patients in Cohort 1 showed evidence of significant improvement in one or more measures of hypertrophy at Week 52, with notable reductions in left ventricular posterior wall thickness (LVPWT) of between 21% and 39%. Greater LVPWT is an independent risk factor for reduced long-term survival after septal myectomy. Two out of three Cohort 1 patients saw reductions from baseline in left ventricular mass index (LVMI) of between 12% and 22% at Week 52. In the first Cohort 2 patient for whom Week 26 data were available (Patient 4), cardiac troponin I remained within the normal range and NT-proBNP remained stable. LVPWT and LVMI also remained stable at Week 26. New York Heart Association (NYHA) classification, a measure of the impact of heart failure symptoms on activities of daily living, improved in all patients by at least one class by Week 26, and all Cohort 1 patients were NYHA Class I (asymptomatic) as of the data cutoff date. Longer-term follow-up for all patients is required to further inform our understanding of TN-201’s potential as a treatment for MYBPC3-associated HCM.
Previous report
In December 2025, we presented interim data from RIDGE-1, including safety, biopsy and arrhythmia results as of the October 2025 data cut-off for three patients enrolled in Cohort 1, with follow-up ranging from Week 20 to Week 40. TN-401 was generally well tolerated and no dose-limiting toxicities were observed. AEs were generally mild, asymptomatic and manageable and a majority of the AEs were deemed unrelated to TN-401. Among the AEs related to TN-401, there was a Grade 1 incidence of elevated troponin levels categorized as a serious AE due to inpatient monitoring. There were no incidents of thrombotic microangiopathy or cardiotoxicities observed and no arrhythmias associated with TN-401 occurred. Additionally, no Cohort 1 patients had experienced an implantable cardioverter defibrillator (ICD) shock post-treatment and all had tapered off prophylactic immunosuppressive medicines.
Previous report
Serial biopsies taken at baseline and Week 8 post dose for Patients 1 and 2 provided consistent evidence of TN-401 transduction and expression. At Week 8, TN-401 robust mRNA expression was observed across all three patients. Post-treatment protein levels of PKP2 increased significantly in Patients 1 and 2 by a mean of 10% from baseline to Week 8 as measured by liquid chromatography–mass spectrometry normalized to myosin heavy chain, a motor protein in the sarcomere found exclusively in cardiomyocytes. Change in PKP2 protein levels for Patient 3 appeared slightly lower than baseline despite having the highest levels of TN-401 mRNA expression across Cohort 1. This confounding result for PKP2 protein level falls within the standard deviation of these methods and may be due to the inherent variability in sampling biopsies. A second post-dose biopsy will be collected and analyzed from Week 52 per protocol for all patients.
Previous report
All three patients in Cohort 1 had severe electrical instability with a history of ventricular arrhythmias and had undergone a catheter ablation procedure, an elective procedure to reduce ventricular tachycardia recurrence. At baseline, each Cohort 1 patient met the enrollment criteria of greater than 500 premature ventricular contractions per 24 hours as measured over a seven-day monitoring period prior to dosing. Two of three patients experienced significant and clinically meaningful improvements in electrical instability, as measured by seven-day ambulatory monitoring of premature ventricular contractions (PVCs) following dosing. Patient 1 experienced a decrease in PVCs by 46% as of their most recent (Week 40) visit, while Patient 2 experienced a decrease in PVCs of 89% as of their most recent (Week 32) visit. Non-sustained ventricular tachycardia (NSVT) burden was eliminated or stable six months after treatment with TN-401. Patient 1 had a low NSVT count at baseline, which remained low at their most recent visit (Week 40). Patient 2 also had a substantial NSVT burden of 78 counts per 24-hour period at baseline that dropped to zero and remained stable by Week 32. Meaningful changes in PVCs or NSVTs were not expected nor observed for Patient 3 as of the data cut off, which was less than six months following treatment with TN-401. Other potential measures of clinical response including QRS duration, T wave inversions, heart function and NYHA class were in the normal range or remained stable for all three Cohort 1 patients during the post-dose follow-up period. We expect to present one-year Cohort 1 data and initial Cohort 2 data in the first half of 2026, with interim Cohort 2 results anticipated in the second half of the year. We are also pursuing alignment with regulatory authorities on pivotal trial plans for TN-401 and plan to provide an update on progress by year end.
Previous report
Research and development expenses were $14.8 million and $21.1 million for the three months ended March 31, 2026 and 2025, respectively. The year-over-year decrease of $6.2 million, or 30%, was primarily due to:
Previous report
establish commercial-scale manufacturing capabilities;
Reworded paragraphs (30)
Previous wording
We are a clinical-stage biotechnology company focused on discovering, developing and delivering potentially curative therapies that address the underlying drivers of heart disease. Heart disease remains a leading cause of death in the world. We believe the emerging insights into the genetic causes of cardiovascular conditions and increased recognition for precision medicine approaches has created an opportunity to change the treatment paradigm for heart disease, and in doing so improve and extend the lives of patients.
Current wording
We are a clinical-stage biotechnology company focused on discovering, developing and delivering potentially curative therapies that address the underlying drivers of heart disease. Heart disease remains the leading cause of death in the world. We believe the emerging insights into the genetic causes of cardiovascular conditions and increased recognition for precision medicine approaches has created an opportunity to change the treatment paradigm for heart disease, and in doing so improve and extend the lives of patients.
Previous wording
We are primarily focused on advancing our clinical-stage gene therapy candidates, TN-201 for MYBPC3-associated hypertrophic cardiomyopathy (HCM), and TN-401 for PKP2-associated arrhythmogenic right ventricular cardiomyopathy (ARVC). Each candidate is currently in Phase 1b/2 trials to establish the safety profile of two different doses in adults with disease due to pathogenic/likely pathogenic mutations. We anticipate that data generated to date and over the course of 2026 will support our pursuit of regulatory alignment on late-stage development for these gene therapy product candidates. A third internally discovered clinical-stage candidate, TN-301, is a highly specific small molecule inhibitor of histone deacetylase 6 (HDAC6) with potentially broad utility in heart failure with preserved ejection fraction (HFpEF) and other cardiac, metabolic, muscular and pulmonary diseases, including but not limited to Duchenne muscular dystrophy (DMD), genetic dilated cardiomyopathy (DCM) and pulmonary arterial hypertension (PAH).
Current wording
Today, we are focused on advancing our clinical-stage gene therapy candidates, TN-201 for MYBPC3-associated hypertrophic cardiomyopathy (HCM), and TN-401 for PKP2-associated arrhythmogenic right ventricular cardiomyopathy (ARVC). Each candidate is currently in Phase 1b/2 trials to establish the safety profile of two different doses in adults with disease due to pathogenic/likely pathogenic mutations. We have presented promising interim results for both product candidates and are engaging with regulators to discuss pivotal trial plans. We plan to share additional follow-up data in the fourth quarter of 2026 and to provide an update on our interactions with regulators. We are also advancing a third internally discovered clinical-stage candidate, TN-301, a highly specific small molecule inhibitor of histone deacetylase 6 (HDAC6) with potentially broad utility in heart failure with preserved ejection fraction (HFpEF) and other cardiac, metabolic, muscular and pulmonary diseases, including but not limited to Duchenne muscular dystrophy (DMD), genetic dilated cardiomyopathy (DCM) and pulmonary arterial hypertension (PAH).
Previous wording
MyPEAKTM-1 is our Phase 1b/2 multi-center, open-label clinical trial, designed to assess the safety, tolerability and efficacy of a one-time intravenous infusion of TN-201. Enrollment and dosing in both the 3E13 vg/kg dose (Cohort 1) and 6E13 vg/kg dose (Cohort 2) cohorts are complete. A per protocol review by the independent data safety monitoring board (DSMB) of all available data from the first six patients dosed determined that TN-201 had an acceptable safety profile to proceed with dosing expansion cohorts at either dose level. We are enrolling additional patients in MyPEAK-1 to further characterize dose response and inform dose selection for late-stage clinical trials.
Current wording
MyPEAKTM-1 is our Phase 1b/2 multi-center, open-label clinical trial, designed to assess the safety, tolerability and efficacy of a one-time intravenous infusion of TN-201. We have completed enrollment in MyPEAK-1 necessary to characterize dose response and inform dose selection for late-stage clinical trials, including three patients at the 3E13 vg/kg dose (Cohort 1), three at the 6E13 vg/kg dose (Cohort 2) and additional patients in the 6E13 vg/kg dose expansion cohort. Other than Patient 5, all patients have completed every scheduled visit and remain in the trial.
Previous wording
We expect to present longer-term Cohort 1 and interim Cohort 2 data in the second quarter of 2026. In the second half of 2026, one-year Cohort 2 data and two-year Cohort 1 data from MyPEAK-1 are anticipated. We are also pursuing alignment with regulatory authorities on pivotal trial plans for TN-201 and plan to provide an update on progress by year end.
Current wording
We expect to present one-year Cohort 2 data and two-year Cohort 1 data from MyPEAK-1 in the fourth quarter of 2026. We are also engaging with regulatory authorities to obtain feedback on pivotal trial plans for TN-201 and plan to provide an update on progress in the fourth quarter of 2026.
Previous wording
The FDA has granted TN-201 Fast Track, Orphan Drug and Rare Pediatric Drug Designations. TN-201 has also received orphan medicinal product designation from the European Commission (EC).
Current wording
The FDA has granted TN-201 Fast Track, Orphan Drug and Rare Pediatric Drug Designations. TN-201 has also been accepted into the agency’s Rare Disease Evidence Principles (RDEP) process for biallelic children with MYBPC3-associated HCM. TN-201 received orphan medicinal product designation from the European Commission (EC) and was granted PRIority MEdicine (PRIME) designation by the European Medicines Agency (EMA).
Previous wording
TN-401 is our AAV9-based gene therapy for the treatment of ARVC due to disease-causing variants in the PKP2 gene. ARVC, also known as arrhythmogenic cardiomyopathy or ACM, is a chronic, progressive disease characterized by frequent, severe, and potentially life-threatening ventricular arrhythmias. The disease is associated with adverse heart remodeling, fibrosis, cardiac dysfunction, significant impairment to patients’ overall quality of life, as well as an elevated risk of sudden cardiac death. PKP2 mutations are the most common genetic cause of ARVC and result in insufficient expression of a protein needed for proper functioning of the desmosomal complex that maintains physical connections and electrical signaling between heart muscle cells. TN-401 utilizes a recombinant AAV9 capsid and is designed to deliver a working PKP2 gene to specific cells of the heart in order to produce plakophilin protein and thereby potentially slow or even reverse the course of PKP2-associated ARVC following a single infusion.
Current wording
TN-401 is our AAV9-based gene therapy for the treatment of ARVC due to disease-causing variants in the PKP2 gene. ARVC, also known as arrhythmogenic cardiomyopathy or ACM, is a chronic, progressive disease characterized by frequent, severe, and potentially life-threatening ventricular arrhythmias. The disease is associated with adverse heart remodeling, fibrosis, cardiac dysfunction, significant impairment to patients’ overall quality of life, as well as an elevated risk of sudden cardiac death. PKP2 mutations are the most common genetic cause of ARVC and result in insufficient expression of a protein needed for proper functioning of the desmosomal complex that maintains physical connections and electrical signaling between heart muscle cells. TN-401 utilizes a recombinant AAV9 capsid and is designed to deliver a working PKP2 gene to heart muscle cells in order to produce plakophilin protein and potentially slow or even reverse the course of PKP2-associated ARVC following a single infusion.
Previous wording
RIDGETM-1 is our Phase 1b/2 multi-center, open-label clinical trial, designed to assess the safety, tolerability and efficacy of a one-time intravenous infusion of TN-401. Enrollment and dosing in both the 3E13 vg/kg dose (Cohort 1) and 6E13 vg/kg dose (Cohort 2) cohorts are complete. In January 2026, the DSMB for RIDGE-1 reviewed all available data from Cohort 1 and Cohort 2, determined that TN-401 had an acceptable safety profile and endorsed proceeding into expansion cohorts at either dose level, per protocol. We are enrolling additional patients in RIDGE-1 to inform dose selection for late-stage clinical trials.
Current wording
RIDGETM-1 is our Phase 1b/2 multi-center, open-label clinical trial, designed to assess the safety, tolerability and efficacy of a one-time intravenous infusion of TN-401. We have completed enrollment in RIDGE-1 necessary to characterize dose response and inform dose selection for late-stage clinical trials, including three patients at the 3E13 vg/kg dose (Cohort 1), three at the 6E13 vg/kg dose (Cohort 2) and additional patients in the 6E13 vg/kg dose expansion cohort.
Previous wording
In February 2025, we were awarded a Clinical Grant (Clin2) of $8.0 million from CIRM, a state of California Agency that funds regenerative medicine, stem cell, and gene therapy research. Proceeds from the grant will help fund clinical trial costs for our ongoing Phase 1b/2 RIDGE-1 clinical trial of TN-401 gene therapy. RIDGE-1 is being conducted at multiple clinical trial sites with ARVC expertise at leading cardiology centers in the U.S. and United Kingdom.
Current wording
In February 2025, we were awarded a Clinical Grant (Clin2) of $8.0 million from California Institute for Regenerative Medicine (CIRM), a state of California Agency that funds regenerative medicine, stem cell, and gene therapy research. Proceeds from the grant help fund clinical trial costs for our ongoing Phase 1b/2 RIDGE-1 clinical trial of TN-401 gene therapy. RIDGE-1 is being conducted at multiple clinical trial sites with ARVC expertise at leading cardiology centers in the U.S. and United Kingdom.
Previous wording
To support our development efforts for TN-401, we have initiated RIDGE, a global noninterventional study to collect treatment history and seroprevalence to AAV9 antibodies data among ARVC patients who carry pathogenic or likely pathogenic PKP2 gene mutations. Interim data from RIDGE, believed to be the largest natural history study of adults with PKP2-associated ARVC, was presented at Heart Rhythm Society’s annual meeting in April 2025. Adults with PKP2-associated ARVC experience a high burden of arrhythmias despite treatments with anti-arrhythmic medications, beta blockers and the anti-arrhythmic flecainide, as well as surgical interventions such as ablation and ICD placement. Further, current treatments appeared to do little to halt or prevent progressive structural changes to the heart that occur as a result of PKP2 mutations. A large majority of adults with PKP2-associated ARVC would be eligible to participate in RIDGE-1 based on low levels of pre-existing antibodies to AAV9.
Current wording
To support our development efforts for TN-401, we have initiated RIDGE, a global noninterventional natural history and seroprevalence study of nearly 200 patients with ARVC due to PKP2 gene mutations. RIDGE is believed to be the largest natural history study of adults with PKP2-associated ARVC. Interim data from RIDGE was presented at Heart Rhythm Society’s annual meeting in April 2025 and showed that patients with PKP2-associated ARVC experience a high burden of arrhythmias despite treatments with approved anti-arrhythmic medications including flecainide, beta blockers and surgical interventions such as ablation and ICD placement. Further, current treatments appeared to do little to halt or prevent progressive structural changes to the heart that occur as a result of PKP2 mutations. A large majority of adults with PKP2-associated ARVC would be eligible to participate in RIDGE-1 based on low levels of pre-existing antibodies to AAV9.
Previous wording
TN-401 has received Orphan Drug and Fast Track designation from the FDA and orphan medicinal product designation from the EC.
Current wording
TN-401 has received Orphan Drug and Fast Track designation from the FDA. TN-401 has also received orphan medicinal product designation from the EC and was granted PRIME designation by the EMA.
Previous wording
We shared positive data from our Phase 1 clinical trial of TN-301 in healthy participants at the 2023 Heart Failure Society of America Annual Scientific Meeting. TN-301 was generally well tolerated across the broad range of doses studied. Pharmacokinetic results showed overall dose proportionality with a half-life supportive of once-daily dosing. Increasing doses and exposures with TN-301 correlated with increased pharmacodynamic effects. There were no changes in histone acetylation with TN-301 underscoring the selectivity of TN-301 for HDAC6 and potentially reducing the risk of off target effects. Extensivein vitro andin vivo studies have also shown that TN-301 addresses diverse pathological processes with direct and systemic benefits in models of HFpEF. In comparative studies, selective HDAC6 inhibition as a single agent has been shown to have similar efficacy to empagliflozin, an SGLT2 inhibitor which is approved for the treatment of HFpEF and co-administration of our HDAC6 inhibition with a SGLT2 inhibitor in a HFpEF mouse model demonstrated additive benefit. Taken together, these data support continued development of TN-301 as a potential treatment for patients with HFpEF and other severe diseases including those outside of cardiology in which inflammation, fibrosis and metabolic dysregulation may be implicated.
Current wording
Extensivein vitro andin vivo studies in HFpEF disease models have also shown that TN-301 addresses diverse pathological processes with direct and systemic benefits in models of HFpEF. In comparative studies, selective HDAC6 inhibition as a single agent has been shown to have similar efficacy to empagliflozin, an SGLT2 inhibitor which is approved for the treatment of HFpEF and co-administration of our HDAC6 inhibition with a SGLT2 inhibitor demonstrated additive benefit. Taken together, these data support continued development of TN-301 as a potential treatment for patients with HFpEF and other severe diseases including those outside of cardiology in which inflammation, fibrosis and metabolic dysregulation may be implicated.
Previous wording
In engineered heart tissues derived from human DMD-induced iPSCs, TN-301 corrected calcium handling abnormalities, a key driver of DMD cardiomyopathy, including beat-to-beat fluctuations in calcium amplitude. In contrast, givinostat exacerbated calcium handling irregularities. In an experiment of DMD patient-derived iPSC cardiomyocytes designed to measure oxygen consumption and mitochondrial stress, both known contributors to DMD cardiomyopathy, TN-301 corrected basal and maximal respiration whereas givinostat worsened both measures. Taken together, these data support advancement of TN-301 as a potential DMD therapy with benefits for both skeletal and cardiac muscle and reduced liabilities compared to pan-HDAC inhibitors.
Current wording
In engineered heart tissues derived from human DMD-induced iPSCs, TN-301 corrected calcium handling abnormalities, a key driver of DMD cardiomyopathy, including beat-to-beat fluctuations in calcium amplitude. In contrast, givinostat exacerbated calcium handling irregularities. In an experiment of DMD patient-derived iPSC cardiomyocytes designed to measure oxygen consumption and mitochondrial stress, both known contributors to DMD cardiomyopathy, TN-301 corrected basal and maximal respiration whereas givinostat worsened both measures. Taken together, these data support the potential advancement of TN-301 in DMD therapy, suggesting that HDAC6 inhibition may have benefits for both skeletal and cardiac muscle and reduced liabilities compared to pan-HDAC inhibitors.
Previous wording
We plan 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. Consistent with our strategy, we believe that TN-301’s late-stage development and commercialization in large indications would best be led by a strategic pharmaceutical partner with global resources to explore the full potential of the molecule.
Current wording
We plan 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. We also intend to share additional details regarding 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. Consistent with our strategy, we believe that TN-301’s late-stage development and commercialization in large indications would best be led by a strategic pharmaceutical partner with global resources to explore the full potential of the molecule.
Previous wording
The FDA has granted both Orphan Drug and Rare Pediatric Drug Designations to TN-301 as a treatment for DMD.
Current wording
The FDA granted both Orphan Drug and Rare Pediatric Drug Designations to TN-301 as a treatment for DMD.
Previous wording
In addition to our clinical-stage candidates, we have multiple early-stage programs using various therapeutic approaches, including gene addition, gene editing, gene silencing, and cellular regeneration to address other forms of rare and/or prevalent forms of heart disease. We do not have any products approve for sale and have not generated any product revenue to date.
Current wording
In addition to our clinical-stage candidates, we have multiple early-stage programs using various therapeutic approaches, including gene addition, gene editing, gene silencing, and cellular regeneration to address other forms of rare and/or prevalent forms of heart disease. We do not have any products approved for sale and have not generated any product revenue to date.
Previous wording
Collaboration revenue for the three months ended March 31, 2026 was $0.2 million, compared to none in the prior year period. The increase was primarily driven by the amortization of upfront fees associated with collaboration arrangements entered into during the first quarter of 2026.
Current wording
Collaboration revenue for the three months ended June 30, 2026 was $1.1 million, compared to none in the prior year period. The increase consisted of $0.7 million from the recognition of revenue associated with upfront fees and $0.4 million from reimbursements for research and development activities under collaboration arrangements entered into during the first quarter of 2026.
Previous wording
Research and development activities account for a significant portion of our operating expenses. Research and development expenses relate primarily to discovery and development of our research programs, product candidates and proprietary platform technology, and are recognized as incurred. Internal research and development costs include, among others, employee-related costs (including salaries, benefits and stock-based compensation for employees engaged in research and development functions), laboratory supplies, other non-capital equipment utilized for in-house research, and allocated overhead costs. External research and development expenses include, among others, fees paid to contract research organizations to execute preclinical studies and clinical trials on our behalf, and consulting fees. We do not allocate our costs by research program, product candidate or proprietary platform technology, as a significant amount of research and development expenses represent internal costs, which are deployed across our programs, product candidates, proprietary platform technology, and other activities.
Current wording
Research and development activities account for a significant portion of our operating expenses. Research and development expenses relate primarily to discovery and development of our research programs, product candidates and proprietary platform technology, and are recognized as incurred. Internal research and development costs include, among others, employee-related costs (including salaries, benefits and stock-based compensation for employees engaged in research and development functions), laboratory supplies, other non-capital equipment utilized for in-house research, and allocated overhead costs. External research and development expenses include, among others, fees paid to contract research organizations to execute preclinical studies and clinical trials on our behalf, and consulting fees. In connection with the closure of the GMMC Facility, our external research and development expenses may include fees paid to third-party contract development manufacturing organizations for future process development and manufacturing activities. We do not allocate our costs by research program, product candidate or proprietary platform technology, as a significant amount of research and development expenses represent internal costs, which are deployed across our programs, product candidates, proprietary platform technology, and other activities.
Previous wording
General and administrative expenses were $5.4 million and $6.5 million for the three months ended March 31, 2026 and 2025, respectively. The year-over-year decrease of $1.0 million, or 16%, was primarily due to decreases in employee-related costs driven by the 2025 Workforce Reduction and lower professional fees.
Current wording
General and administrative expenses were $5.4 million and $6.7 million for the three months ended June 30, 2026 and 2025, respectively. The decrease of $1.3 million, or 19%, was primarily due to a $0.9 million decrease in stock-based compensation expense and lower professional fees.
Previous wording
Interest income primarily consists of interest earned on our cash and cash equivalents balances. In prior period, interest income also included amounts earned on marketable securities. Interest income was $0.8 million and $0.6 million for the three months ended March 31, 2026 and 2025, respectively. The year-over-year increase of $0.2 million was primarily due to average higher cash and cash equivalents balances.
Current wording
Interest income primarily consists of interest earned on our cash and cash equivalents balances. In the prior-year period, interest income also included amounts earned on marketable securities. Interest income was $0.7 million and $0.8 million for the three months ended June 30, 2026 and 2025, respectively. The decrease of $0.1 million was primarily due to the absence of discount accretion on marketable securities in the current-year period.
Previous wording
Net loss for the three months ended March 31, 2026, was $19.3 million, compared to a net loss of $26.9 million for the three months ended March 31, 2025.
Current wording
Net loss for the three months ended June 30, 2026, was $43.4 million, compared to a net loss of $23.3 million for the three months ended June 30, 2025.
Previous wording
a $3.0 million decrease in research expenses, reflecting lower employee-related costs driven by the workforce reduction implemented in March 2025 (the 2025 Workforce Reduction) and reduced lab supply and service costs; and
Current wording
a $3.3 million decrease in research expenses, reflecting lower employee-related costs driven by the workforce reduction implemented in March 2025 (the 2025 Workforce Reduction) and reduced lab supply and service costs; and
Previous wording
a decrease of $2.0 million in manufacturing costs reflecting lower employee-related costs driven by the 2025 Workforce Reduction and lower facility maintenance fees and depreciation expense.
Current wording
a decrease of $2.2 million in manufacturing costs reflecting lower employee-related costs driven by the 2025 Workforce Reduction and lower facility maintenance fees and depreciation expense.
Previous wording
Since our inception, we have generated limited collaboration revenue and no product revenue, and we have incurred significant net losses and negative cash flows from operations. From our inception through March 31, 2026, we have funded our operations primarily from the sale and issuance of our equity securities. As of March 31, 2026, we had cash and cash equivalents of $80.9 million and an accumulated deficit of $624.3 million.
Current wording
Since our inception, we have generated limited collaboration revenue and no product revenue, and we have incurred significant net losses and negative cash flows from operations. From our inception through June 30, 2026, we have funded our operations primarily from the sale and issuance of our equity securities. As of June 30, 2026, we had cash and cash equivalents of $78.1 million and an accumulated deficit of $667.7 million.
Previous wording
On August 6, 2024, we entered into a Loan Agreement with Silicon Valley Bank (SVB). As of December 31, 2025, all of the term loan commitments expired under the Loan Agreement and no term loans were outstanding. The Loan Agreement provides that an additional loan of $20.0 million may be available at SVB’s discretion, subject to specified conditions.
Current wording
On August 6, 2024, we entered into a Loan Agreement with Silicon Valley Bank (SVB), which was subsequently amended on July 14, 2026. As of December 31, 2025, all of the term loan commitments expired under the Loan Agreement and no term loans were outstanding. The Loan Agreement provides that an additional loan of $20.0 million may be available at SVB’s discretion, subject to specified conditions.
Previous wording
Net cash used in operating activities for the three months ended March 31, 2025 was $23.1 million, which consisted primarily of a net loss of $26.9 million and a net change in operating assets and liabilities of $3.4 million, partially offset by $6.9 million in non-cash charges. The change in net operating assets and liabilities was primarily due to a decrease in accounts payable and accrued expenses and other current liabilities of $2.3 million and a decrease in operating lease liabilities of $0.7 million, an increase in prepaid expenses and other current assets of $0.5 million. Cash flows from operations are generally impacted by the timing of payments to vendors and vendor payment terms. The non-cash charges primarily consisted of stock-based compensation of $3.7 million and depreciation and amortization of $2.7 million.
Current wording
Net cash used in operating activities for the six months ended June 30, 2026 was $22.8 million, which consisted primarily of a net loss of $62.7 million, partially offset by $31.7 million in non-cash charges and a net change in operating assets and liabilities of $8.2 million. The change in net operating assets and liabilities was primarily due to an increase of contract liabilities of $9.7 million, partially offset by a decrease of in accounts payable and accrued expenses and other current liabilities of $1.5 million. Cash flows from operations are generally impacted by the timing of payments to vendors and vendor payment terms. The non-cash charges primarily consisted of loss on impairment of $21.8 million, stock-based compensation of $3.9 million and depreciation and amortization of $3.5 million.
Previous wording
Net cash used in operating activities for the three months ended March 31, 2026 was $19.2 million, which consisted primarily of a net loss of $19.3 million and a net change in operating assets and liabilities of $4.6 million, partially offset by $4.6 million in non-cash charges. The change in net operating assets and liabilities was primarily due to a decrease in accounts payable and accrued expenses and other current liabilities of $4.1 million. Cash flows from operations are generally impacted by the timing of payments to vendors and vendor payment terms. The non-cash charges primarily consisted of stock-based compensation of $2.2 million and depreciation and amortization of $1.8 million.
Current wording
Net cash used in operating activities for the six months ended June 30, 2025 was $38.7 million, which consisted primarily of a net loss of $50.1 million and a net change in operating assets and liabilities of $2.4 million, partially offset by $13.3 million in non-cash charges. The change in net operating assets and liabilities was primarily due to a decrease in accounts payable and accrued expenses and other current liabilities of $3.0 million. Cash flows from operations are generally impacted by the timing of payments to vendors and vendor payment terms. The non-cash charges primarily consisted of stock-based compensation of $7.4 million and depreciation and amortization of $4.7 million.
Previous wording
Net cash used in investing activities for the three months ended March 31, 2026 was immaterial and consisted of purchases of property and equipment.
Current wording
Net cash used in investing activities for the six months ended June 30, 2026 was $0.2 million, which consisted of purchases of property and equipment.
Previous wording
Net cash provided by investing activities for the three months ended March 31, 2025 was $22.2 million, which consisted primarily of proceeds from maturities of marketable securities of $11.7 million and sales of marketable securities of $11.0 million.
Current wording
Net cash provided by investing activities for the six months ended June 30, 2025 was $47.3 million, which consisted primarily of proceeds from maturities of marketable securities of $36.9 million and sales of marketable securities of $11.0 million.
Previous wording
Net cash used in financing activities for the three months ended March 31, 2026 was approximately $0.4 million, which consisted of payments of accrued offering costs.
Current wording
Net cash provided in financing activities for the six months ended June 30, 2026 was approximately $0.5 million, which consisted primarily of proceeds from exercise of warrants, partially offset by payments of accrued offering costs.
Previous wording
Net cash provided by financing activities for the three months ended March 31, 2025 was $50.3 million, which primarily consisted of net proceeds from our March 2025 follow-on offering of $49.3 million.
Current wording
Net cash provided by financing activities for the six months ended June 30, 2025 was $49.8 million, which primarily consisted of net proceeds of $48.8 million from our March 2025 follow-on offering.
Rearranged current paragraphs (6)
Current report — wording carried from elsewhere
We shared positive data from our Phase 1 clinical trial of TN-301 in healthy participants at the 2023 Heart Failure Society of America Annual Scientific Meeting. TN-301 was generally well tolerated across the broad range of doses studied. Pharmacokinetic results showed overall dose proportionality with a half-life supportive of once-daily dosing. Increasing doses and exposures with TN-301 correlated with increased pharmacodynamic effects. There were no changes in histone acetylation with TN-301 underscoring the selectivity of TN-301 for HDAC6 and potentially reducing the risk of off target effects.
Current report — wording carried from elsewhere
a $0.4 million decrease in research expenses, reflecting lower employee-related and lab service costs; and
Current report — wording carried from elsewhere
a $0.2 million decrease in manufacturing costs reflecting lower facility maintenance fees and depreciation expense.
Current report — wording carried from elsewhere
The following table summarizes our results of operations for the periods presented:
Current report — wording carried from elsewhere
The following table summarizes our research and development expenses for the periods presented:
Current report — wording carried from elsewhere
Interest income primarily consists of interest earned on our cash and cash equivalents balances. In the prior-year period, interest income also included amounts earned on marketable securities. Interest income was $1.5 million and $1.4 million for the six months ended June 30, 2026 and 2025, respectively, and remained relatively consistent between periods.