Advancement to Phase 3 is major milestone for SAB’s unique DiversitAb immunotherapy platform that produces fully-human polyclonal antibodies without human donors

Both doses of SAB-185 tested in Phase 2 met pre-defined efficacy goal at interim analysis

SIOUX FALLS, SD, USA I September 24, 2021 I SAB Biotherapeutics (SAB), a clinical-stage biopharmaceutical company with a novel immunotherapy platform that produces specifically targeted, high-potency, fully-human polyclonal antibodies without the need for human donors, today announced that an independent Data Safety Monitoring Board (DSMB) has completed its prespecified interim analysis data review of the safety and efficacy of SAB-185 in the Phase 2 portion of the ACTIV-2 trial and has recommended advancement to Phase 3. SAB-185 is a fully-human, specifically-targeted, broadly-neutralizing polyclonal antibody therapeutic candidate for the treatment of non-hospitalized patients with mild to moderate COVID-19. It is being assessed in the ACTIV-2 trial funded and conducted by the National Institute of Allergy and Infectious Diseases (NIAID), part of the US National Institutes of Health (NIH) in collaboration with the AIDS Clinical Trials Group. SAB-185 is advancing to the Phase 3 trial based on meeting pre-defined graduation criteria.

“Advancement of SAB-185 to Phase 3 is a major milestone for our DiversitAb™ immunotherapy platform, which uniquely produces fully-human targeted polyclonal antibodies that have broad applicability to treating other infectious diseases and medical conditions,” said Eddie J. Sullivan, PhD, co-Founder, President, and Chief Executive Officer of SAB Biotherapeutics. “The recent publication of nonclinical data demonstrating SAB-185’s potent neutralization of multiple emerging SARS-CoV-2 variants provided additional evidence that SAB-185 has the potential to become a valuable therapy for mild to moderate COVID-19. We now look forward to the completion of the Phase 3 trial and if successful, the opportunity to make SAB-185 widely available to the many COVID-19 patients battling this persistent and evolving disease.”

Both the low and high doses of SAB-185 tested in Phase 2 met the pre-defined efficacy goal for advancement to Phase 3 and appeared safe at the interim analysis. NIAID and SAB researchers are finalizing the preferred dose to assess in Phase 3.

The Phase 3 portion of the ACTIV-2 trial is a randomized, unblinded, active comparator-controlled adaptive platform study that will assess the clinical safety and efficacy of SAB-185 compared to active control monoclonal antibody treatment in people with mild to moderate COVID-19 who are at higher risk for progression to hospitalization, enrolling approximately 600 participants to receive the investigational agent SAB-185 and 600 to receive an active comparator. The primary outcome measures of the Phase 3 trial will include safety and non-inferiority for the prevention of a composite endpoint of either hospitalization or death from any cause through study day 28.

For more information on the Phase 3 trial, please visit clinicaltrials.gov (Identifier: NCT04518410).

On June 22, 2021, SAB announced a planned merger with Big Cypress Acquisition Corp. (NASDAQ: BCYP). The transaction is expected to close in the fourth quarter of 2021.

About SAB-185
SAB-185 is a fully-human polyclonal antibody therapeutic entering a Phase 3 study for the treatment of non-hospitalized patients with mild to moderate COVID-19. It was developed in collaboration with the US government using SAB’s novel proprietary DiversitAb™ Rapid Response Antibody Program, as part of the Countermeasures Acceleration Group, formerly Operation Warp Speed. In nonclinical studies, the novel therapeutic candidate has shown potent neutralization of the Munich, Washington and other variant strains, including Delta and Lambda. Preclinical data has also indicated that SAB-185 is significantly more potent than human-derived convalescent immunoglobulin G (IgG).

Direct support for the development of SAB-185 is provided by the US Department of Defense’s (DoD) Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense (JPEO-CBRND) on behalf of the Office of the Assistant Secretary of Defense for Health Affairs (OASD(HA)) and the Defense Health Agency (DHA) and the Biomedical Advanced Research and Development Authority (BARDA), part of the Department of Health and Human Services (DHHS) Office of the Assistant Secretary for Preparedness and Response, under contract #MCDC 2019-448.

About SAB Biotherapeutics, Inc.
SAB Biotherapeutics, Inc. (SAB) is a clinical-stage, biopharmaceutical company advancing a new class of immunotherapies leveraging fully human polyclonal antibodies. SAB has applied advanced genetic engineering and antibody science to develop transchromosomic (Tc) Bovine™ herds that produce fully-human antibodies targeted at specific diseases, including infectious diseases such as COVID-19 and influenza, immune system disorders including type 1 diabetes and organ transplantation, and cancer. SAB’s versatile DiversitAb™ platform is applicable to a wide range of serious unmet needs in human diseases. It produces natural, specifically targeted, high-potency, human polyclonal immunotherapies. SAB is currently advancing multiple clinical programs and has a number of collaborations with the US government and global pharmaceutical companies. For more information on SAB, visit: http://www.sabbiotherapeutics.com and follow @SABBantibody on Twitter.

SOURCE: SAB Biotherapeutics