LEKSUM: New Study Indicates Efficacy of Multiple Doses of Extracellular Vesicles to Address Muscle Myopathy

Key Takeaways

New studies reinforce earlier findings of positive results from the use of multiple doses of EVs.
Additional scientific data supports Leksum's hypothesis regarding its LK-ICU program.
The scientific team intends to follow-up with detailed single muscle fiber contractile and muscle fiber size measurements.

BOSTON, Massachusetts, June 24, 2025; A new study by Leksum LLC (Leksum) successfully demonstrates that multiple doses of extracellular vesicles (EVs) could mitigate the risk of lung injury for patients placed on mechanical ventilation (MV) while in intensive care units (ICU).

Early results show significant improvement in both size and function of diaphragm muscle fibers after one dose of EVs. Although the new data is preliminary, additional improvement has been achieved from two doses. The study was conducted at Leksum's new one-of-a-kind laboratory located at SLU, Uppsala, Sweden, which uniquely replicates the effects of MV on muscle tissue in ICU conditions.

The positive results following a second dose of EVs support the hypothesis of Professor Lars Larsson, Leksum’s Chief Scientific Officer, regarding the efficacy of EVs derived from bone marrow mesenchymal stromal cells (BM-MSCs) to combat lung injury and diaphragm muscle dysfunction associated with immobilized patients subject to MV. Dr. Larrson stated, "If these preliminary results hold true, they indicate an almost complete preservation of both diaphragm muscle fiber size and function." Leksum’s scientific team will follow-up with detailed single muscle fiber contractile and muscle fiber size measurements as it prepares for Phase I trials in Europe.

Findings at day five after multiple doses of extracllular vesicles (EV’s):

Fiber cross-sectional area (CSA) and specific force (SF) measurements for specimens receiving two doses of EVs were 93% and 94%, respectively, compared with control fibers (0-day). For specimens not receiving treatment, previous studies showed CSA and SF measurements of 57% and 52%, respectively, after five days.
Great stability of hemodynamic parameters, respiratory peak pressure, and peripheral oxygen saturation (SpO2 = 97-99%).
No accumulation of mucus in the mouth around the tracheal tube - accumulation of mucus is typically observed on the first or second day of MV in control subjects and on the fourth and fifth day with a single dose of EVs.
At the dissection: the lungs appeared in very good condition according to visual inspection (i.e., they looked like controls); the blood also looked highly oxygenated.
The diaphragm muscle, at dissection microscope, appeared in very good condition compared with samples after five days without intervention; in particular, the thickness appeared preserved.

This latest research is the fifth study investigating the effect of EVs on single muscle fiber size and force generation capacity (specific force, maximum force normalized to fiber cross-sectional area). The team's previous studies successfully demonstrated the efficacy of EVs derived from BM-MSCs in combatting lung injury associated with MV, i.e., targeting a potential pathophysiological mechanism underlying Ventilator Induced Diaphragm Dysfunction (VIDD).

MV is a life-saving intervention. However, it often results in a delayed and complicated weaning process due to diaphragm muscle dysfunction, which is associated with higher mortality and morbidity rates. Mitigating the negative effects of MV promises to enhance the quality of life for millions of patients suffering from muscle myopathy and related conditions while reducing the expense of the weaning process, totals for which are estimated to be upwards of $100 billion a year (US & EUR).

About Leksum
Leksum LLC, based in Boston, Massachusetts with its primary laboratory at SLU, Uppsala, Sweden, is an early-stage life sciences company developing advanced biologic therapies to address acquired muscle myopathies. The company is preparing to enter into Phase I/IIa studies related to its LK-ICU program, which encompasses therapies addressing muscle myopathies resulting from the use of mechanical ventilation in ICUs, in particular with immobilized patients. Leksum's scientific team is also researching additional skeletal muscle conditions including sarcopenia, cancer cachexia, and muscle-loss due to the use of weight-loss drugs (i.e., GLP-1s).

Key Takeaways

New studies reinforce earlier findings of positive results from the use of multiple doses of EVs.
Additional scientific data supports Leksum's hypothesis regarding its LK-ICU program.
The scientific team intends to follow-up with detailed single muscle fiber contractile and muscle fiber size measurements.

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Quotes

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If these preliminary results hold true, they indicate an almost complete preservation of both diaphragm muscle fiber size and function.

Lars Larsson, MD/PhD — Chief Scientific Officer

If these preliminary results hold true, they indicate an almost complete preservation of both diaphragm muscle fiber size and function.

5202

https://cdn.filestackcontent.com/5iHe8RplSKCa52zo8svX

Professor Larsson, formerly of the Karolinska Institute, Sweden, now at SLU, Uppsala, Sweden, and winner of the 2017 Distinguished Scientist award from the Society for Experimental Biology and Medicine, is Leksum’s Chief Scientific Officer. His muscle research spans four decades. He has worked at the Karolinska Institute which awards the Nobel Prize for Medicine and Physiology, the University of Uppsala, the University of Wisconsin-Madison, and Penn State University. He has lectured at Harvard University, Oxford University, the Pennsylvania State University (main campus), Hershey Medical Center, Mayo Clinic (Rochester, MN), University of Michigan (Ann Arbor), Kentucky University, Wayne State University, Carnegie Mellon University, University of Vermont, University of Iowa, University of Texas AM, University of Florida, Berkeley University, University of Texas-Galveston, University of Texas Southwestern, McGill University, Tokyo University, Hiroshima University, Melbourne University, University of Western Australia Perth, Martin Luther-University Halle-Wirtenberg, Műnster University, Amsterdam University, Bonn University, Warsaw University, University of Florence, Padova University, Venetian Institute of Molecular Medicine, King´s College, University of Liverpool, University of Newcastle, University of Manchester, Zhejiang University School of Medicine, and various Scandinavian Universities (University of Copenhagen, Lund University, University of Gothenburg, Oslo University, Linköping University, Örebro University, Karolinska Institute, Uppsala University, University of Jyväskylä, Åbo Akademi, Umeå University). Professor Larsson has published over 250 peer-reviewed scientific papers on multiple aspects of his work documenting his team’s extensive and successful research results. Professor Larsson has also delivered invited presentations at Eli Lilly and Company, Regeneron Pharmaceuticals, and Cytokinetics. The head of muscle at a Big Pharma company describes Professor Larsson as the world’s leading authority on muscle wasting in the ICU for the last 20 years. He has personally diagnosed over 20,000 patients with neuromuscular disorders, including diagnosing the first-ever patient with ICU Critical Illness Myopathy (CIM) in Sweden in 1995. His work has enabled a detailed understanding of the mechanisms underlying the impaired muscle function and muscle wasting associated with aging and in the ICU including in ventilator-induced specific muscle diseases. He has focused on physiological and pathophysiological changes of the molecular motor protein myosin and its associated proteins and taken a translational approach combining experimental animal models with clinical studies in patients and healthy control subjects to develop effective and safe therapeutic interventions. Professor Larsson has studied the regulation of muscle contraction at the motor protein and muscle cell levels and in the 3D organization of myonuclei in single muscle fibers in short single muscle fiber segments obtained from humans with the percutaneous muscle biopsy technique or from different experimental animal models.

Related Bios

Lars Larsson, MD/PhD

Chief Scientific Officer

Professor Larsson, formerly of the Karolinska Institute, Sweden, now at SLU, Uppsala, Sweden, and winner of the 2017 Distinguished Scientist award from the Society for Experimental Biology and Medicine, is Leksum’s Chief Scientific Officer. His muscle research spans four decades. He has worked at the Karolinska Institute which awards the Nobel Prize for Medicine and Physiology, the University of Uppsala, the University of Wisconsin-Madison, and Penn State University. He has lectured at Harvard University, Oxford University, the Pennsylvania State University (main campus), Hershey Medical Center, Mayo Clinic (Rochester, MN), University of Michigan (Ann Arbor), Kentucky University, Wayne State University, Carnegie Mellon University, University of Vermont, University of Iowa, University of Texas AM, University of Florida, Berkeley University, University of Texas-Galveston, University of Texas Southwestern, McGill University, Tokyo University, Hiroshima University, Melbourne University, University of Western Australia Perth, Martin Luther-University Halle-Wirtenberg, Műnster University, Amsterdam University, Bonn University, Warsaw University, University of Florence, Padova University, Venetian Institute of Molecular Medicine, King´s College, University of Liverpool, University of Newcastle, University of Manchester, Zhejiang University School of Medicine, and various Scandinavian Universities (University of Copenhagen, Lund University, University of Gothenburg, Oslo University, Linköping University, Örebro University, Karolinska Institute, Uppsala University, University of Jyväskylä, Åbo Akademi, Umeå University).

Professor Larsson has published over 250 peer-reviewed scientific papers on multiple aspects of his work documenting his team’s extensive and successful research results. Professor Larsson has also delivered invited presentations at Eli Lilly and Company, Regeneron Pharmaceuticals, and Cytokinetics. The head of muscle at a Big Pharma company describes Professor Larsson as the world’s leading authority on muscle wasting in the ICU for the last 20 years.

He has personally diagnosed over 20,000 patients with neuromuscular disorders, including diagnosing the first-ever patient with ICU Critical Illness Myopathy (CIM) in Sweden in 1995. His work has enabled a detailed understanding of the mechanisms underlying the impaired muscle function and muscle wasting associated with aging and in the ICU including in ventilator-induced specific muscle diseases. He has focused on physiological and pathophysiological changes of the molecular motor protein myosin and its associated proteins and taken a translational approach combining experimental animal models with clinical studies in patients and healthy control subjects to develop effective and safe therapeutic interventions.

Professor Larsson has studied the regulation of muscle contraction at the motor protein and muscle cell levels and in the 3D organization of myonuclei in single muscle fibers in short single muscle fiber segments obtained from humans with the percutaneous muscle biopsy technique or from different experimental animal models.

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Contacts

Niles Chura, CEO, Leksum LLC

info@leksum.com