Human polyclonal antibodies show promise as effective treatment

SIOUX FALLS, SD, USA I December 21, 2017 I SAB Biotherapeutics (SAB), a clinical-stage biopharmaceutical development company, announced today its first-in-human trial of new immunotherapy approach has shown efficacy in antibiotic-resistant bacteria based on a recent paper published online in Clinical Infectious Diseases.

“This study provides the first clinical evidence showing the human polyclonal antibody therapeutic–produced from our natural DiversitAb immunotherapy platform–is safe, and provides an option for recalcitrant infection resistant bacteria where antibiotics and multiple other therapies were ineffective,” said Eddie J. Sullivan, PhD, SAB Biotherapeutics president and CEO.

“This is an important step in furthering the development of this platform technology in infectious disease, including anti-microbial resistance,” he continued.

The patient.

The trial, conducted at Brigham and Women’s Hospital, involved a patient who suffered from a chronic infection caused by antibiotic-resistant bacteria. Mycoplasma hominis can be an infectious pathogen in immunosuppressed individuals. The patient was diagnosed with M. hominis septic polyarthritis in 2009 and was treated with multiple courses of antibiotics with no improvement. A target-specific human polyclonal antibody was pursued as a potentially more effective therapeutics strategy.

The science.

SAB’s new immunotherapy approach–The DiversitAb platform–leverages transchromosomal (Tc) bovine™ that have been genetically designed to produce fully human polyclonal antibodies (IgG) in response to a bacteria, virus or toxin. To create the targeted treatment, SAB vaccinated a Tc bovine with inactivated isolates of the patient’s bacteria (M. hominis). After 10 days the antibodies began circulating in the bovine blood stream and were harvested in plasma over several weeks.

The treatment.

The plasma was purified in the company’s cGMP manufacturing facilities to isolate the antibodies–designated SAB-136. The patient–the first to be treated with human polyclonal IgG harvested from Tc bovine–received infusions to combat the infection.

The result.

After one year, the high-dose therapy resulted in reduced M. hominis burden and improved clinical parameters. The infusions were well tolerated and with no significant adverse events. Safety was assessed with laboratory values, physical exam and subjective reports. Therapeutic efficacy was evaluated with samples collected from the primary infection site, and laboratory studies to monitor inflammation as well as a patient journal.

“This research demonstrates the potential for expanding treatment for immune deficient patients suffering from infections, which may have low coverage in current antibody replacement therapies,” said Duane Wesemann, MD, PhD, a physician in the Rheumatology, Immunology and Allergy department at BWH and an Assistant Professor of Medicine, Harvard Medical School and principal investigator on the study.

“The use of DiversitAb platform begins to explore the relevancy for other patient populations in the setting of chronic, multi-drug resistant infections or viral infections for which there is no effective treatment or prevention strategy,” he added.

SAB’s first two immunotherapies targeting seasonal influenza and MERS-CoV are in clinical trials, with other infectious disease, oncology and autoimmune targets in development.

“With the advancements of modern medicine–and even recent immunotherapies–there are still many human health conditions without solutions,” concluded Sullivan. “Our hope is that our platform can provide a new rapid response and effective treatment for many of these patients.”

About SAB Biotherapeutics, Inc.

SAB Biotherapeutics, Inc. (SAB), headquartered in Sioux Falls, S.D. is a clinical-stage, biopharmaceutical development company leading the science and manufacturing of antibody therapeutics. Utilizing some of the most advanced antibody science in the world, SAB is delivering the world’s first large-scale platform to create immunoglobulins. This natural production platform holds the potential for treatment of public health problems, rare conditions, long-term diseases and global pandemic threats.

SOURCE: SAB Biotherapeutics