5 October 2021 - - The first patient has been dosed with SAB-185 in the Phase 3 ACTIV-2 COVID-19 trial, US-based biopharmaceutical company SAB Biotherapeutics said.

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.

The candidate is being assessed in the ACTIV-2 trial led by the National Institute of Allergy and Infectious Diseases (NIAID), part of the US National Institutes of Health in collaboration with the AIDS Clinical Trials Group.

SAB-185 is the second agent to graduate to Phase 3 and the first polyclonal antibody therapeutic candidate in ACTIV-2, which is evaluating multiple investigational agents to treat early symptomatic COVID-19 in non-hospitalized individuals.

SAB-185 advanced from Phase 2 to the Phase 3 portion of the ACTIV-2 trial based on meeting pre-defined graduation criteria.

The interim analysis demonstrated that both the lower and higher doses of SAB-185 tested in Phase 2 met the pre-defined efficacy goal for advancement to Phase 3 and appeared safe. SAB researchers in consultation with NIAID have determined the lower dose of SAB-185 (3,840 Units/kg) will be assessed in Phase 3.

The Phase 3 portion of the ACTIV-2 trial is a randomized, unblinded, active comparator-controlled adaptive platform non-inferiority study that is assessing 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.

It is 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 include safety and non-inferiority for the prevention of a composite endpoint of either hospitalization or death from any cause through study day 28.

On June 22, 2021, SAB announced a planned merger with Big Cypress acquisition Corp. (NASDAQ: BCYP). The transaction is expected to close in 4Q21.

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.

Direct support for the development of SAB-185 is provided by the US Department of Defense's 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 and the Biomedical Advanced Research and Development Authority (BARDA), part of the Department of Health and Human Services Office of the Assistant secretary for Preparedness and Response, under contract #MCDC 2019-448.

SAB Biotherapeutics, Inc. 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 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.