Hypoplastic Left Heart Syndrome (HLHS) Research Program

We are testing Lomecel-B as a potential combinatorial therapy candidate to surgical intervention for HLHS. The scientific goal underlying this study builds on surgical advances of the past thirty years, and is intended to address remaining obstacles to improving long-term cardiac function in HLHS patients.
HLHS is a congenital birth defect in which the left ventricle (one of the pumping chambers of the heart) is either severely underdeveloped or missing. As a consequence, babies born with this condition have severely diminished systemic blood flow, which requires children to undergo a complex, three stage heart reconstruction surgery process over the course of the first 5 years of their lives. While these children can now live into adulthood, early mortality is still extremely high in this population due to right ventricle failure, which is not meant for the increased load demanded for systemic circulation (blood circulation throughout the body). As such, there is an important unmet medical need to improve right ventricular function in these patients to improve both short-term and long-term outcomes.
We believe that Lomecel-B has potential as a combinatorial therapy with HLHS surgery to improve both short- and long-term clinical outcomes. We are evaluating whether a direct injection in the heart can improve right ventricle function by promoting regenerative and repair responses. In animal studies, this combinatorial approach resulted in a 10 – 15% improvement in right ventricle function.

Results from the ELPIS Phase 1 Trial

This study met the primary safety endpoint:

• No major adverse cardiac events (MACE), nor any treatment-related infections during the first month post-treatment.

• 100% of infants treated with Lomecel-B survived free of heart transplant, with follow-up ranging two to 3.5 years after cardiac surgery that included injection with Lomecel-B.

• This finding showed the potential of Lomecel-B for improving long-term clinical outcomes in HLHS patients.

• Based on these findings, In November of 2021, FDA granted Rare Pediatric Disease Designation (RPD) to Longeveron’s Lomecel-B for treatment of HLHS, as a drug for a “rare pediatric disease,” as defined in section 529(a)(3) of the Federal Food, Drug, and Cosmetic Act (FD&C Act) (21 U.S.C. 360ff(a)(3)).


Alzheimer's Research Program

AD is the leading form of dementia. This disease affects millions of Americans, leads to early mortality, and creates a tremendous burden on families and society that costs the U.S. hundreds of billions of dollars annually in direct costs and lost productivity.
Inflammation in the brain – a process called neuroinflammation – is a a key feature of AD. This pro-inflammatory state appears essential for the clinical manifestation of dementia resulting from AD. In addition to affecting the brain tissue itself, neuroinflammation also impairs the blood vessels in the brain and the exchange barrier between the blood and the brain, called the blood-brain barrier (BBB). Ultimately, these pathological processes lead to the structural changes in the brain and resulting dementia.

We are testing Lomecel-B as a potential treatment for AD based on the hypothesis that its multiple possible MOAs can simultaneously address multiple features of AD. Preclinical studies show that MSCs can potentially reduce AD-associated brain inflammation, improve the function of blood vessels in the brain, and reduce brain damage due to AD progression, and promote regenerative responses. We have completed a multicenter, randomized, placebo-controlled Phase 1 safety study of subjects with mild AD.

Results from the Alzheimer’s Disease Phase 1 Trial

The phase 1 trial, funded in part by an Alzheimer’s Association Part the Cloud Challenge on Neuroinflammation grant, used a randomized, placebo-controlled double-blind design testing single i.v. infusion of Lomecel-B 20 million cells (“low-dose”; (n=15)), Lomecel-B 100 million cells (“high-dose”; n=10)), or placebo (n=8). Subjects were followed for 52 weeks post-infusion.

Key summary findings:

• Lomecel-B infusion was well-tolerated in this trial, with no treatment-related serious adverse events observed throughout the 1-year follow-up, including no indications of amyloid-related imaging abnormalities (ARIA) as assessed by magnetic resonance imaging (MRI);

• The average Mini Mental State Exam (MMSE) score, which is a measure of cognitive function, declined more slowly in the low-dose Lomecel-B group compared to the placebo group. At 13 weeks after infusion, the low-dose Lomecel-B group MMSE score was higher (better) compared to placebo (difference of 2.69 ± 1.39 points; p=0.0182; 2-sided 95% CI 0.51 – 4.97);

• At 26 weeks post-infusion, patients in the low-dose Lomecel-B arm showed a significantly higher (better) average score on the Quality of Life in Alzheimer Disease (QOL-AD) compared to placebo (difference of 3.85 ± 1.943 points; p=0.0444; 2-sided 95% CI 0.13 – 9.12);

• At 26 weeks post-infusion, the Alzheimer's Disease Cooperative Study Activities of Daily Living (ADCS-ADL), a measure of competence in basic and instrumental activities of daily living, was significantly higher (better) in the low-dose Lomecel-B group compared to placebo (difference of 6.95 ± 3.46 points; p=0.0118; 95% CI 1.99 – 13.94);  

• Biomarkers:  

• Subjects receiving Lomecel-B had significantly increased serum levels of several pro-vascular biomarkers (VEGF, IL4, and IL-6) relative to the placebo group post-infusion.  

• There was a significant increase in D-dimer in the high-dose, but not low-dose, Lomecel-B arm versus placebo;

• Subjects receiving Lomecel-B had significantly increased serum levels of several anti-inflammatory cytokines (sIL-2Rα, IL-4, IL-10 and IL-12) relative to the placebo group post-infusion;

• There were no significant changes in the Lomecel-B arms versus the change in placebo for any of neuronal-related biomarkers examined;

MRIs showed a significant increase in change in left hippocampus volume in the high-dose Lomecel-B arm versus the change in placebo group at Week 13 (p=0.0311). By Week 26, the difference was no longer significant. The low dose Lomecel-B arm showed no significant difference versus placebo.  


Aging Frailty is a clinically-defined and extreme form of unsuccessful aging. It is readily recognized by the hallmark signs of weakness, slowness, fatigue, unintentional weight loss, and low activity. Those with Aging Frailty are disproportionately compromised in their ability to cope with every day and acute stressors, are at high vulnerability to disease and injury, and are at increased risk for poor outcomes and death after surgery. Even normally “minor” insults (e.g., minor infection) can have devastating consequences, and lead to a spiral of decline to debility in these patients.
The necessity for identifying patients with Aging Frailty is well-acknowledged in the geriatric community, and the treatment of Aging Frailty and promotion of healthful aging are recognized priorities of the National Academy of Medicine and NIA/NIH. Despite the pressing need for interventions, there are no FDA-approved therapies that can slow down, reverse, or prevent Aging Frailty.

Aging Frailty Research Program

Biological Underpinnings of Aging Frailty

Aging Frailty is a multifaceted biologically-driven process that is distinct from normal aging. While all of the biological mechanisms underlying frailty are still being elucidated, it is thought to involve a low-level chronic pro-inflammatory state referred to as inflammaging. This loss of control over inflammation can be attributed to an imbalance between levels of inflammatory promoters and anti-inflammatory mediators, as well as diminished capacity to restore equilibrium once an inflammatory stimulus has subsided. The ultimate result is measurable elevated serum levels of pro-inflammatory signaling molecules, such as tumor necrosis factor-α (TNF-α), and diminished anti-inflammatory mediators, such as interleukin-10 (IL-10). In particular, serum TNF-α positively correlates to Aging Frailty severity.
Inflammation can contribute to the physical decline in Aging Frailty through multiple mechanisms, including detrimental effects on muscles, bone tissue, the immune system, cardiovascular function, and cognition. In muscle cells, pro-inflammatory mediators such as TNF-α stimulate catabolic biochemical pathways that break down muscle tissue, which can explain the clinically observed atrophy, decreased strength and endurance, and increased exhaustion seen in Aging Frailty. Inflammation can also severely diminish immune system function, and accelerate the aging-related decline in the immune system, known as immunosenescence. This ultimately leads to an immune system that is hyporesponsive, making these patients highly vulnerable to disease and cancer.
Aging Frailty (and aging in general) is also characterized by reductions in the number and function of circulating MSCs. Therefore, treatments that can positively affect and/or replenish these endogenous stem cell functions could be of therapeutic value for Aging Frailty.
The culmination of these organ system declines can explain the common clinical manifestations of Aging Frailty, such as sarcopenia and cachexia, and forms the basis for the resulting heightened vulnerability to injury, disease, adverse health outcomes, and mortality.

Lomecel-B for the Potential Treatment of Aging Frailty 

We are evaluating Lomecel-B as a therapy for Aging Frailty because the potential mechanisms of action may suitably address many of the features and underpinnings of this condition. Foremost, Lomecel-B has the potential to reduce inflammation associated with Aging Frailty, and to promote an anti-inflammatory state by releasing anti-inflammatory molecules, which can promote physiological restoration to a more normal state. As our early clinical data show, Lomecel-B may be able to improve aspects of physical functioning, as well as immune function.

Metabolic Syndrome Research Program


We have an ongoing Phase 1 sub-study exploring whether Lomecel-B can improve the Metabolic Syndrome, and if the Metabolic Syndrome presents confounding issues for this treatment approach in Aging Frailty patients. This sub-study primarily focuses upon blood-based biomarker changes, and non-invasive evaluation of vascular (blood vessel) functioning.

The Metabolic Syndrome is a clinically-defined condition (ICD-10: code 277.7) that increases the chances of developing cardiovascular disease (CVD) and Type II diabetes mellitus (T2DM). It is also known as X syndrome, insulin resistance syndrome, cardiometabolic syndrome, and Reaven’s syndrome. The Metabolic Syndrome is defined as a cluster of risk factors for which at least three of the following five criteria must be met.


Elevated serum triglycerides.


Reduced high-density lipoprotein (good cholesterol).


Elevated blood pressure.


Elevated fasting glucose.


Increased waist circumference (central or apple-shaped obesity).

The Metabolic Syndrome is associated with vascular dysfunction and damage, and a proinflammatory state marked by elevated serum levels of C-reactive protein (CRP), interleukin-6 (IL-6), and D-dimer. Obesity also directly contributes to this proinflammatory state and the Metabolic Syndrome.
The incidence of the Metabolic Syndrome has reached epidemic proportions and continues to increase, as the overall prevalence in the U.S. is approximately 35% of the total population aged 18 and older, or over 80 million people.
Lomecel-B may be a potential candidate for the Metabolic Syndrome through multiple potential mechanisms of action that include the potential to reduce associated inflammation and improve vascular function. Preclinical studies support the clinical benefits of allogeneic MSC therapy for treating the Metabolic Syndrome, which resulted in improvements in vascular function, atherosclerosis, and glucose homeostasis.


Acute Respiratory Distress Syndrome (ARDS) Research Program


We are conducting a multicenter, double-blinded, randomized, placebo-controlled trial for ARDS due to COVID-19 or influenza virus infection.


ARDS can be rapidly induced by a variety of insults, such as coronavirus and influenza virus infection. Approximately 150,000 people experience ARDS in the U.S. annually, with a mortality rate of about 40%. These numbers are increasing as a result of COVID-19, which could become a seasonal epidemic. Older persons, those with Aging Frailty, and those with the Metabolic Syndrome, are at significantly increased risk for severely poor outcomes from ARDS due to viral infection, including prolonged hospitalization and death.


Viral infection leading to ARDS can results in severe inflammation called a “cytokine storm”, most pronounced by severely elevated serum levels of C reactive protein (CRP) and interleukin-6 (IL-6). This in turn leads to disruption of the lung cell layers (the endothelial and epithelial barriers), and consequently, to severe inhibition of pulmonary exchange. ARDS can result in long-term adverse effects on patients, such as lung scarring (fibrosis). As now widely appreciated due to COVID-19, there is a dearth of treatment options available for ARDS, and first-line defense measures often have sub-optimal palliative effects.