Secretome Therapeutics to Present Phase 1 Clinical Data for STM-01 in Heart Failure With Preserved Ejection Fraction
Secretome Therapeutics, a clinical-stage biotechnology company developing innovative therapies derived from neonatal cardiac progenitor cells (nCPCs), has announced that clinical data from its Phase 1 study evaluating STM-01 in patients with heart failure with preserved ejection fraction (HFpEF) will be presented at the Heart Failure Society of America (HFSA) Annual Scientific Meeting on October 11, 2026. The presentation will provide initial clinical findings on the safety, tolerability, and exploratory clinical outcomes associated with the investigational biologic therapy in patients with this complex cardiovascular condition.
STM-01 is being developed as a potential new therapeutic approach for HFpEF, a form of heart failure characterized by the heart’s inability to fill properly despite maintaining a relatively preserved ejection fraction. The condition can lead to symptoms such as breathlessness, fatigue, exercise intolerance, and reduced physical functioning. HFpEF is associated with several underlying biological processes, including inflammation, microvascular dysfunction, fibrosis, and changes in cardiac structure and function. These overlapping mechanisms can make the disease difficult to treat and highlight the need for therapeutic strategies that address more than one aspect of its pathophysiology.
According to Secretome Therapeutics, STM-01 is an investigational biologic derived from neonatal cardiac progenitor cells and is designed to provide anti-inflammatory, angiogenic, anti-fibrotic, and tissue-repair effects. These properties may have the potential to address biological processes implicated in HFpEF progression. The company’s Phase 1 study represents an early step in evaluating the therapy in patients, with the primary focus on establishing its initial safety and tolerability profile.
The study enrolled 10 patients with HFpEF across two dose cohorts and evaluated STM-01 at doses of 100 million and 200 million cells. Participants received treatment on Day 0 and Day 28, with follow-up assessments continuing through Day 56. In addition to safety monitoring, the study included evaluations of cardiac function, exercise capacity, patient-reported health status, and cardiovascular biomarkers.
The initial findings indicated that STM-01 was well tolerated at both evaluated dose levels. No treatment-related treatment-emergent adverse events (TEAEs) or treatment-related serious adverse events were reported. Exploratory assessments also showed generally favorable trends in patient-reported health status and exercise capacity, although results varied among participants and across the different clinical measures.
The data will be presented under the title “Phase 1, Safety and Tolerability of STM-01 in Heart Failure with Preserved Ejection Fraction (HFpEF).” Ambarish Pandey, MD, Professor of Internal Medicine and Frederick G. L. Huetwell Research Professor of Cardiovascular Medicine, and Director of the Center for Cardiometabolic Research at the University of Michigan, will present the findings.
STM-01 Targets Multiple Biological Processes Associated With HFpEF
HFpEF is a complex cardiovascular disorder that represents a substantial challenge for clinicians and researchers. Unlike heart failure with reduced ejection fraction, in which the heart’s pumping function is diminished, HFpEF is characterized by impaired ventricular filling despite a relatively preserved ability to eject blood with each heartbeat.
The condition is heterogeneous, meaning that its underlying causes, associated conditions, symptoms, and progression can differ considerably among patients. Factors such as obesity, diabetes, hypertension, kidney dysfunction, systemic inflammation, and cardiovascular aging can contribute to the development and progression of HFpEF.
Inflammation, impaired microvascular function, and fibrosis are among the biological processes being investigated for their roles in the disease. Inflammation can influence cardiac tissue function, while microvascular dysfunction may impair the delivery of oxygen and nutrients to heart tissue. Fibrosis, which involves the accumulation of excess connective tissue, can contribute to cardiac stiffness and impaired ventricular relaxation.
These processes may interact with one another and with other systemic conditions, making HFpEF difficult to address through a single therapeutic mechanism. Although available treatments can help reduce clinical risks and improve outcomes for certain patient populations, additional approaches are being investigated to address the disease’s underlying biological complexity.
STM-01 is being developed with the objective of influencing several of these processes. Secretome Therapeutics describes the investigational therapy as having anti-inflammatory, angiogenic, anti-fibrotic, and tissue-repair properties.
Anti-inflammatory activity could potentially help modulate inflammatory pathways implicated in cardiovascular dysfunction. Angiogenic properties relate to the formation and development of blood vessels and may be relevant to research into microvascular abnormalities. Anti-fibrotic effects could potentially address biological mechanisms associated with excessive tissue fibrosis, while tissue-repair properties may support investigations into the maintenance or restoration of cardiac tissue function.
The combined rationale behind these properties is to investigate whether a biologic therapy can influence multiple disease-related pathways in patients with HFpEF.
However, these mechanisms represent the therapeutic rationale for STM-01 rather than established clinical benefits. The Phase 1 study was designed primarily to assess safety and tolerability, and its exploratory findings do not establish that STM-01 improves heart function, prevents disease progression, or reduces heart failure-related hospitalizations. Additional clinical research will be required to determine whether the proposed biological effects translate into meaningful patient benefits.
Phase 1 Study Evaluated Two Dose Levels
The Phase 1 trial was an open-label, dose-escalation study involving 10 patients diagnosed with HFpEF. Participants were enrolled into two cohorts to evaluate STM-01 at different dose levels.
Five participants received 100 million cells, while the remaining five received 200 million cells. Treatment was administered on Day 0 and Day 28, and participants were followed through Day 56.
The dose-escalation design allowed investigators to examine the initial safety and tolerability of STM-01 at the two evaluated dose levels. Because the study was open-label, participants and investigators were aware of the treatment being administered. The trial also did not include a control group, which limits the ability to distinguish potential treatment effects from other influences, including natural variation in symptoms, changes in background treatment, and expectations associated with study participation.
In addition to monitoring adverse events, investigators conducted several clinical assessments to characterize the participants’ health status and cardiovascular function.
These included echocardiography, the six-minute walk test (6MWT), the Kansas City Cardiomyopathy Questionnaire (KCCQ), and biomarker measurements.
Echocardiography was used to assess cardiac structure and function, while the six-minute walk test provided a measure of functional exercise capacity. The KCCQ evaluated participants’ reported symptoms, physical limitations, and overall health status related to heart failure. Biomarkers provided additional information about cardiovascular status and potential changes during the observation period.
Together, these measures offered an initial assessment of STM-01 across several clinically relevant dimensions. The study’s small sample size, however, means that the findings should be interpreted as preliminary and used primarily to inform further development.
Safety and Tolerability Findings Support Continued Evaluation
The principal finding from the Phase 1 study was that STM-01 was well tolerated across both dose cohorts during the evaluated treatment and follow-up period.
Secretome Therapeutics reported no treatment-related TEAEs and no treatment-related serious TEAEs. No deaths were observed, and there were no treatment-emergent adverse events leading to discontinuation, withdrawal, or treatment interruption.
Overall, nine TEAEs were reported among five participants. None of these events was considered related to STM-01.
Treatment-emergent adverse events are medical events that arise or are reported after treatment begins, regardless of whether they are ultimately attributed to the investigational therapy. Investigators assess these events to determine their severity, clinical significance, and possible relationship to the treatment.
The absence of treatment-related adverse events in this small study is an encouraging initial observation. It suggests that no adverse events were identified as attributable to STM-01 during the reported evaluation period.
Nevertheless, the findings do not establish the long-term safety of the therapy. A study involving only 10 participants and follow-up through Day 56 has limited ability to identify uncommon adverse events, delayed effects, or risks that might emerge with broader or longer-term exposure.
Further studies involving larger patient populations and longer follow-up will be needed to characterize the safety profile more comprehensively. Future development will also need to assess whether the therapy remains well tolerated across different patient characteristics and clinical settings.
For a candidate being investigated in a population with complex cardiovascular disease and potentially multiple coexisting conditions, continued safety assessment will be an important component of clinical development.
Exploratory Findings Show Improvements in Patient-Reported Health Status
In addition to the safety results, the Phase 1 study produced exploratory findings suggesting generally favorable trends in patient-reported health status and exercise capacity.
Over the 56-day follow-up period, KCCQ scores and six-minute walk distance increased. These changes may provide preliminary information about how participants experienced their symptoms and physical functioning during the study.
The KCCQ is a disease-specific questionnaire used to evaluate the impact of heart failure on symptoms, physical limitations, social functioning, and quality of life. Changes in the score can help researchers assess whether patients report meaningful differences in their health status over time.
According to Secretome Therapeutics, seven of the 10 participants experienced an improvement of more than five points in their KCCQ score. An increase of this magnitude is generally considered clinically meaningful in heart failure assessments, indicating a potentially noticeable improvement in the patient’s reported health status.
The finding is relevant because HFpEF can substantially affect everyday activities. Patients may experience difficulty walking, climbing stairs, performing household tasks, or engaging in physical activity because of breathlessness and fatigue.
Patient-reported outcomes can therefore complement conventional cardiovascular measurements by providing insight into how a disease and its treatment affect daily life.
The increase in six-minute walk distance also suggested a favorable trend in exercise capacity among participants. The six-minute walk test measures the distance a person can walk over six minutes and is commonly used to assess functional capacity in people with cardiovascular and respiratory conditions.
An improvement in walking distance may indicate better functional performance, although results can be influenced by several factors, including baseline fitness, symptoms, motivation, and other medical conditions.
Importantly, the reported changes varied across participants and endpoints. Because the study was small, open-label, and lacked a control group, the observed improvements cannot be attributed conclusively to STM-01. The findings are exploratory and require confirmation in appropriately designed clinical trials.
Cardiac Function Measures Remained Broadly Stable
The study also evaluated cardiac function using echocardiographic measurements, including E/e′ and stroke volume.
E/e′ is an echocardiographic measure used to help assess left ventricular filling pressure and diastolic function. It compares the early transmitral blood-flow velocity with the early diastolic velocity of the mitral annulus. In the appropriate clinical context, this ratio can provide information about pressure conditions associated with ventricular filling.
Stroke volume refers to the amount of blood pumped by the heart’s left ventricle with each contraction. It is an important measure of cardiac performance and contributes to overall cardiac output.
Over the 56-day follow-up period, E/e′ and stroke volume remained broadly stable, according to the reported exploratory findings.
These results provide information about the observed course of the measured cardiac parameters during the study. However, stability in these measures does not independently demonstrate improved cardiac function or establish a treatment effect.
HFpEF involves several interconnected abnormalities, and no single echocardiographic measurement fully captures the disease’s complexity. Interpretation of these results will require additional clinical evidence, including larger studies designed to evaluate changes in cardiac function and their relationship to symptoms and clinical outcomes.
The combination of echocardiography, functional testing, patient-reported outcomes, and biomarker assessments provides a broader initial picture of the therapy’s performance than any single measure alone.
NT-proBNP Results Were Variable
The Phase 1 study also evaluated N-terminal pro-B-type natriuretic peptide (NT-proBNP), a biomarker commonly used in the assessment of heart failure.
NT-proBNP is released in response to stress on the heart and can provide information relevant to the diagnosis, prognosis, and monitoring of heart failure. Its levels may be influenced by several factors, including age, kidney function, body composition, and the severity of cardiovascular disease.
According to Secretome Therapeutics, NT-proBNP responses in the study were heterogeneous, and no statistically significant change was observed.
The variability in these responses highlights the challenges of interpreting biomarker changes in a small and clinically diverse HFpEF population. A lack of statistically significant change does not establish that the therapy has no biological effect, but it also does not provide evidence of a measurable treatment-related improvement in this endpoint.
Larger controlled studies will be necessary to determine whether STM-01 produces consistent changes in NT-proBNP or other biomarkers and whether any such changes correspond to improvements in patient symptoms, exercise capacity, cardiac function, or clinical outcomes.
The company’s findings should therefore be considered an early characterization of the therapy rather than evidence of established efficacy.
Clinical Data to Be Presented at the HFSA Annual Scientific Meeting
The Phase 1 results will be presented at the Heart Failure Society of America Annual Scientific Meeting, which brings together cardiovascular researchers, clinicians, and other healthcare professionals to discuss developments in heart failure science and treatment.
The presentation will be delivered by Ambarish Pandey, MD, a Professor of Internal Medicine and Frederick G. L. Huetwell Research Professor of Cardiovascular Medicine, as well as Director of the Center for Cardiometabolic Research at the University of Michigan. The presentation identifies him as formerly affiliated with UT Southwestern Medical Center.
The presentation details are as follows:
- Title: Phase 1, Safety and Tolerability of STM-01 in Heart Failure with Preserved Ejection Fraction (HFpEF)
- Presenter: Ambarish Pandey, MD, University of Michigan
- Meeting: Heart Failure Society of America Annual Scientific Meeting
- Date: October 11, 2026
- Time: 8:21–8:31 a.m. Mountain Standard Time (MST)
- Session: Oral Abstract Presentation Sessions — Oral Abstract Session 5A
- Poster number: 058
The presentation will provide an opportunity to communicate the initial clinical experience with STM-01, including its safety and tolerability profile and the exploratory changes observed in patient-reported health status, exercise capacity, cardiac function measurements, and biomarkers.
Background Heart Failure Therapies and the Potential Role of STM-01
The Phase 1 study evaluated STM-01 in patients receiving background heart failure treatments, with the company noting that a majority of participants were taking glucagon-like peptide-1 receptor agonists (GLP-1s) and sodium-glucose cotransporter-2 inhibitors (SGLT2 inhibitors).
These medication classes are relevant to contemporary cardiovascular care, particularly among patients with overlapping metabolic and cardiovascular conditions. SGLT2 inhibitors have an established role in the treatment of heart failure, including in relevant HFpEF populations. GLP-1-based therapies are also increasingly relevant in patients with obesity and associated cardiometabolic conditions.
The presence of these treatments in the study population is important context when interpreting the early results. The findings represent the initial experience with STM-01 in patients receiving their existing care rather than an assessment of the therapy in isolation.
Dr. Pandey emphasized this point when discussing the rationale for the program, noting that the disease’s complexity and the contribution of inflammation, microvascular dysfunction, and fibrosis support the investigation of additional therapeutic approaches.
He stated that the Phase 1 findings provide important initial clinical experience with STM-01 and support continued evaluation of its potential as a novel therapeutic approach for patients with HFpEF.
The study does not establish how STM-01 may compare with existing treatments or whether it offers additional clinical benefits when used alongside them. Those questions will require further investigation in controlled clinical trials.
Outlook for STM-01 Development
Secretome Therapeutics’ Phase 1 study provides an initial assessment of STM-01 in HFpEF, with the reported findings supporting continued clinical investigation of the investigational biologic.
The therapy was well tolerated across the two evaluated dose levels, with no treatment-related adverse events, treatment-related serious adverse events, deaths, or adverse events leading to discontinuation, withdrawal, or treatment interruption reported during the study. Nine TEAEs occurred among five participants, and none was considered related to STM-01.
Exploratory assessments also showed that seven of the 10 participants experienced a greater than five-point improvement in KCCQ score, while six-minute walk distance increased over the 56-day follow-up period. E/e′ and stroke volume remained broadly stable, and NT-proBNP responses varied without a statistically significant change.
These findings provide preliminary information about the therapy’s safety and its potential effects on measures relevant to HFpEF. However, the limited sample size, open-label design, short follow-up period, and absence of a control group mean that the results cannot establish efficacy.
Further clinical research will be needed to determine whether STM-01 can deliver consistent and clinically meaningful benefits, identify the most appropriate dose and treatment schedule, and establish its longer-term safety.
For Secretome Therapeutics, the presentation at the HFSA Annual Scientific Meeting marks an important step in advancing the STM-01 program and sharing its first clinical findings with the cardiovascular research community. As development progresses, larger and controlled studies will be essential to clarify whether the therapy’s proposed anti-inflammatory, angiogenic, anti-fibrotic, and tissue-repair properties can translate into meaningful improvements for patients living with heart failure with preserved ejection fraction.
About STM-01
STM-01 is an investigational biologic therapy derived from neonatal cardiac progenitor cells. The therapy is designed to harness the regenerative activity of the cells’ secretome, which contains naturally occurring bioactive factors with anti-inflammatory, angiogenic, anti-fibrotic, and tissue-repair properties. By modulating biological pathways involved in inflammation, fibrosis, angiogenesis, and tissue repair, STM-01 is being developed as a potential treatment for serious cardiovascular and neuromuscular diseases.
About Heart Failure with Preserved Ejection Fraction
Heart failure with preserved ejection fraction is a complex clinical syndrome characterized by signs and symptoms of heart failure despite preserved left ventricular ejection fraction. HFpEF accounts for approximately half of all heart failure and is associated with substantial impairment in exercise capacity and quality of life, frequent hospitalization, and loss of functional independence. Chronic systemic inflammation associated with common comorbidities, including obesity, diabetes, hypertension, and chronic kidney disease, may contribute to coronary microvascular dysfunction, myocardial stiffness, and fibrosis in HFpEF.
About Secretome Therapeutics
Secretome Therapeutics is a clinical-stage biotechnology company developing regenerative medicines derived from proprietary neonatal cardiac progenitor cell technology for the treatment of serious diseases with significant unmet medical need. The company’s platform leverages the regenerative potential of the cellular secretome to develop therapies that target inflammation, fibrosis, and tissue repair across multiple disease areas.