Pulmatrix and Eos SENOLYTIX Announce $19 Million Merger to Advance Anti-Aging Mitochondrial Therapies
Key Insights
Pulmatrix will acquire Eos SENOLYTIX (search) in a merger creating a first-in-class anti-aging biotechnology company focused on gerotherapeutic peptides targeting mitochondrial dysfunction.
The combined company will advance PTC-2105, a lead clinical candidate for sarcopenia (search) and sarcopenic obesity (search) that demonstrated improved body composition and physical function in preclinical studies.
A concurrent $19 million financing will support development of Eos's proprietary MitoXcel platform, which targets aging mechanisms through mitochondrial membrane potential (search) modulation.
Pulmatrix, Inc. (Nasdaq: PULM) and Eos SENOLYTIX (search), Inc. announced a definitive merger agreement on March 26, 2026, creating a combined company focused on developing first-in-class gerotherapeutic peptides targeting mitochondrial dysfunction in aging-related diseases. The merged entity will operate as Eos SENOLYTIX, Inc. and is expected to trade on Nasdaq under the ticker symbol "EOSX."
The transaction includes concurrent private financings totaling $19 million in aggregate gross proceeds to support advancement of Eos's proprietary MitoXcel platform, including its lead clinical candidate PTC-2105 for sarcopenia (search) and sarcopenic obesity (search). Following the merger closure, pre-merger Pulmatrix stockholders are expected to own approximately 6% of the combined company, while pre-merger Eos stockholders will own approximately 94%.
Novel Approach to Age-Related Disease
The combined company will position itself as a leader in gerotherapeutics—medicines that target the root biological mechanisms of aging to improve healthspan. Unlike GLP-1 receptor (search) agonists that focus solely on weight reduction and are associated with both fat and lean mass loss, gastrointestinal side effects, and rapid weight regain following discontinuation, PTC-2105 targets underlying aging-associated mitochondrial dysfunction.
In preclinical studies, PTC-2105 demonstrated dramatic improvements in body composition, including reductions in fat mass greater than seen with GLP-1s, increases in lean mass, and improvements in physical function without reduced food intake or rebound weight gain following discontinuation in animals approaching one year of treatment with once-weekly subcutaneous injection.
MitoXcel Platform Technology
Eos's proprietary MitoXcel platform leverages AI-driven mitochondrial peptide design to improve body composition by increasing lean mass while reducing harmful abdominal/visceral fat, without directly targeting muscle or fat regulatory pathways. The platform supports a shift in obesity (search) treatment, redefining healthy weight loss as the achievement of optimal body composition rather than simply optimal BMI.
PTC-2105 is a mitochondrial-targeted geropeptide designed to both enhance mitochondrial efficiency and selectively induce apoptotic self-elimination of senescent cells. Eos's lead clinical candidates, PTC-2105 and PTC-2107 (search), have demonstrated the ability to rejuvenate naturally aged mice via two separate mechanisms through a single, aging-specific target: the mitochondrial membrane potential (search) (MMP), also called the "Δψm."
These mechanisms include the return of mitochondrial function efficiency in aging cells almost immediately back to their younger, more efficient phenotype, and the profound elimination of senescent cells throughout every organ in the body, including the brain, reducing their negative systemic inflammatory effects.
Addressing Unmet Medical Need
Sarcopenia (search) and sarcopenic obesity (search) represent a large and growing unmet medical need, characterized by progressive loss of muscle mass and function in aging populations, often accompanied by obesity (search), affecting tens of millions globally. These conditions are associated with increased frailty, morbidity, and healthcare burden, with no approved therapies currently available.
While GLP-1 receptor (search) agonists reduce fat, approximately 25-40% of weight loss is lean mass, underscoring the need for therapies that lead to healthy weight loss improving overall body composition. By targeting mitochondrial dysfunction and senescent cells, Eos's MitoXcel platform has potential applicability across multiple age-related diseases beyond sarcopenia (search), including metabolic, cognitive and neurodegenerative, and mitochondrial disorders.
Leadership and Strategic Vision
"We believe the focus in obesity (search) will shift from percentage body weight loss to the composition of that weight loss, including effects on visceral fat and lean mass, which are important predictors of overall health and long-term survival," said Dr. Kevin Slawin, Founder and Chief Executive Officer of Eos, who will lead the merged entity as CEO. "In multiple well-controlled preclinical studies, PTC-2105 reduced overall and visceral fat and increased lean mass in naturally aged mice, while also driving significant improvements across multiple measures of physical function."
Dr. Slawin is a physician-scientist and serial biotechnology entrepreneur with decades of experience in translational medicine, drug development and company formation. He was the founder of Bellicum Pharmaceuticals (search), Inc., an early pioneer in CAR T cell therapies, and currently leads multiple life sciences ventures focused on aging biology and mitochondrial therapeutics.
Peter B. Ludlum, Chief Executive Officer of Pulmatrix, stated: "Eos's innovative approach to targeting mitochondrial dysfunction and senescent cells represents a compelling scientific and strategic opportunity that builds on the recent approval of FORZINITY (elamipretide), the first FDA-approved mitochondrial-targeted therapeutic."
The proposed merger has been unanimously approved by the boards of directors of both companies and is expected to close in mid-2026, subject to customary closing conditions, including stockholder approval and SEC registration statement effectiveness.