A Pioneering Biotech Promises to Revolutionize Medicine with a Human Protein that Boosts the Body’s Immune System

Susan L. Levinson, PhD
BioAegis Therapeutics
5 min readOct 6, 2022


BioAegis Therapeutics expects to unlock the healing powers of gelsolin and develop new treatments for disease.

As the world recovers from the COVID-19 pandemic, scientists are still busy trying to unlock the secrets of the human body’s immune system. Their goal is not only to find new ways to combat infection, but also to treat the countless autoimmune and inflammatory disorders that affect millions of people globally. These conditions range the gamut — from neurodegenerative disease, diabetes and rheumatoid arthritis to ulcerative colitis.

The stakes are high, considering autoimmune diseases — conditions where your immune system mistakenly attacks healthy cells in your body — are on the rise worldwide. These inflammatory attacks cause significant pain and disability. According to new research from National Institutes of Health and their collaborators, they are seeing an uptick in the prevalence of antinuclear antibodies — a biomarker of autoimmunity — in the U.S. especially among males, adults over 50 and adolescents.

It’s not surprising that hundreds of biotech startups are looking for ways to address this growing health crisis. Up until now, standard treatments for autoimmune disorders and inflammatory diseases have been immunosuppressive medicines like steroids that reduce symptoms by restricting the immune response. But these drugs can have harmful side effects, and long-term use can potentially increase the risk of developing deadly infections, cancers and bone loss.

Body Heal Thyself

BioAegis Therapeutics has a novel approach that could create a new paradigm to address a wide range of inflammatory as well as infectious and degenerative diseases. BioAegis is developing what is known as a Host-Directed Therapeutic (HDT) around plasma gelsolin (pGSN), a protein found in the blood that is a master regulator of inflammation. HDTs have the advantage of harnessing the body’s own system to treat disease. Plasma gelsolin’s role is to keep inflammation localized to the site of injury, while boosting, rather than suppressing the body’s ability to clear pathogens and fight infection.

BioAegis’ scientific co-founder, Dr. Thomas Stossel, former president of the American Society of Hematology and professor at Harvard Medical School, discovered and named gelsolin. In his studies he found it is a naturally occurring protein in the human body’s immune system. When people get very ill, their gelsolin levels go down, and that often leads to debilitating medical conditions and disease.

Dr. Stossel co-founded BioAegis, along with CEO Susan Levinson and COO Valerie Ceva, who both left leadership roles at Big Pharma, and VP Steven Cordovano, former life science hedge fund manager. Their goal: to recreate the protein in the lab and commercialize this new approach to combat a wide spectrum of inflammatory health conditions.

Since then, the company has developed a recombinant human gelsolin product that is manufactured to be identical to the natural human protein. The company benefits from over 40 patents issued for the use of gelsolin to fight infection, inflammatory disease, renal failure, multiple sclerosis, and neurologic diseases.

What is remarkable is that gelsolin is pathogen agnostic, meaning it can treat any infection whether it is viral or bacterial in the body, and it may be useful for many types of inflammatory health conditions. In addition, clinical trials have shown gelsolin therapy to be safe even at the highest doses tested. Unlike steroids and other anti-inflammatory agents, gelsolin is non-immunosuppressive.

It is expected that BioAegis’ product will first be rolled out to treat severe pneumonia and sepsis in the U.S. and abroad. There are currently no therapies aimed directly at the overly exuberant inflammatory host response to infection or severe injury. A spotlight has been focused on these conditions since the pandemic began as the medical community has looked for new and innovative ways to address the high death rate among patients infected with the coronavirus.

Clinical Studies and Ongoing Research

The future looks promising. To date, BioAegis has conducted Phase 1 and Phase 2 clinical trials with its gelsolin treatment for patients hospitalized with pneumonia and severe COVID pneumonia. In the months ahead, the company will be conducting additional clinical trials in the U.S. Since this is a naturally occurring human protein, it is not surprising that no safety issues were seen in these studies.

Recombinant gelsolin was effective in many animal studies of inflammatory disease. In very intriguing studies done at the Harvard School of Public Health, gelsolin given to mice infected with serious drug resistant infections, boosted the immune system and improved animal survival. In fact, gelsolin made ineffective antibiotics work again. This could address the increasing global problem of antimicrobial resistance.

The company’s research has gained recognition from the Biomedical Advanced Research and Development Authority (BARDA). Recently, the government agency awarded BioAegis with a contract to advance the development of their plasma gelsolin therapy for patients with sepsis and severe infection. The goal is to find a new treatment option for sepsis in an era of superbugs — strains of bacteria, viruses, parasites and fungi — resistant to most existing antibiotics and other medications commonly used to treat inflection. Each year at least 1.7 million adults in the U.S. develop sepsis and nearly 270,000 die as a result, the CDC reports.

The BARDA contract is the latest in a series of collaborations the company has forged with leading research and academic institutions in the U.S. and Europe including the National Institute of Allergy and Infectious Diseases, Vanderbilt University and Northwestern University. The company continues to pursue its understanding of how the protein works with leading investigators around the world.

Positioned For Success

BioAegis recently closed a $22 million institutional equity funding round bringing the total amount of capital raised to $50 million. To date, over 250 investors worldwide have helped fund the company’s product research and development. The new financing has already accelerated BioAegis’ pipeline, unlocking the potential for gelsolin to treat additional indications.

The BioAegis team and its many investors are optimistic about the potential of this mighty protein to treat infectious and inflammatory diseases and address the significant unmet needs in critical care environments.

Our hope is that in the not-to-distant future gelsolin can be an essential tool used to cure disease and save lives,” says BioAegis CEO Levinson. “This breakthrough could really revolutionize modern medicine.

Links to Studies:
Autoimmunity may be rising in the United States (https://www.nih.gov/news-events/news-releases/autoimmunity-may-be-rising-united-states)
BioAegis Therapeutics Reports Favorable Safety and Pharmacokinetic Results in its Phase 1b/2a Dose-Escalation Study of Recombinant Human Plasma Gelsolin with Highest Doses Ever Administered to Patients
Recombinant Human Plasma Gelsolin Stimulates Phagocytosis while Diminishing Excessive Inflammatory Responses in Mice with Pseudomonas aeruginosa Sepsis



Susan L. Levinson, PhD
BioAegis Therapeutics

CEO, BioAegis Therapeutics Inc. — A clinical stage private company focused on developing therapies for infectious, inflammatory and degenerative diseases.