Benzinga | Dec 1, 2021 07:09AM EST

SAB Biotherapeutics Announces SAB-176 Met Its Primary Endpoint In Phase 2a Challenge Study In Adults Infected With Influenza Virus

Topline data show SAB-176 achieved statistically significant reductions in viral load and clinical symptoms and it appeared safe and well-tolerated

Second clinical proof of concept achieved by DiversitAb(tm) platform in past two months

Positive clinical results confirm that SAB's fully-human polyclonal antibodies can be broadly neutralizing to both known and unknown viral variants--a valuable feature when addressing rapidly mutating pathogens

SAB plans to further evaluate SAB-176 in a Phase 2 influenza clinical trial slated to begin in 2Q 2022

SIOUX FALLS, S.D., Dec. 01, 2021 (GLOBE NEWSWIRE) -- SAB Biotherapeutics (NASDAQ:SABS), (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 SAB-176, its investigational therapeutic for the treatment of seasonal influenza, achieved statistically significant (p = 0.026) reductions in viral load and clinical signs and symptoms compared to placebo in a Phase 2a challenge study. In the study, SAB-176 appeared to be safe and well-tolerated. SAB-176 is a quadrivalent fully human polyclonal antibody therapeutic candidate designed for the treatment of moderate to severe Type A and B seasonal influenza viruses.

"We are highly encouraged by these topline results showing that treatment with SAB-176 achieved statistical significance in reducing influenza viral load and clinical signs and symptoms in treated subjects, despite the small size of this first Phase 2 study. These data suggest that SAB-176 has the potential to be an effective treatment for this prevalent, highly-mutating virus that resurfaces annually and is a major source of hospitalizations and deaths," said Tom Luke, MD, Chief Medical Officer of SAB Biotherapeutics. "These trial results support advancing SAB-176 as a potential treatment for seasonal influenza through further clinical studies, and we look forward to sharing additional data as it becomes available."

"These positive efficacy data for SAB-176 represent the second clinical proof of concept achieved by our DiversitAb(tm) platform in the past two months," said Eddie J. Sullivan, PhD, Co-Founder, President, and Chief Executive Officer of SAB Biotherapeutics. "In September our investigational COVID-19 therapy SAB-185 met the pre-defined efficacy goal for advancement from Phase 2 to Phase 3 in the NIH-sponsored ACTIV-2 trial. These back-to-back clinical successes for our first two pipeline products give us confidence that the DiversitAb(tm) platform is clinically validated. They reinforce our commitment to advancing this unique platform, with its demonstrated ability to rapidly generate therapeutic candidates for highly mutating pathogen targets with ongoing resurgence and pandemic potential, including influenza and COVID-19."

About SAB-176 Challenge Study

The Phase 2a challenge study, initiated in June 2021, was a randomized, double-blind, placebo-controlled study evaluating the safety and treatment efficacy of SAB-176 in 60 healthy adults challenged with a pandemic influenza virus strain (pH1N1). Participants were randomized to receive either SAB-176 (25 mg/kg dose) or placebo and were intranasally inoculated with pandemic H1N1 (2009/California) virus, and nasopharyngeal swabs were taken 8 days after inoculation.

The primary endpoint of the study was reduction of the nasopharyngeal viral load of subjects treated with SAB-176 (expressed as area under the curve, or AUC) compared to those receiving placebo over an 8-day timepoint as measured by qRT-PCR. SAB-176 met the primary endpoint of significantly reducing patient pH1N1 influenza viral load in the treated subjects (p = 0.026, one sided).

A secondary endpoint of the challenge study was reduction of clinical flu signs and symptoms in the subjects receiving active treatment (n=8) compared to placebo controls (n=12) for those who had signs and symptoms. SAB-176 achieved statistical significance in meeting the secondary endpoint at Day 4 (p = 0.013, one sided) in symptomatic patients. Additional analyses of secondary endpoint data are underway.

In this study SAB-176 also appeared to be safe and well tolerated. No SAB-176-related serious adverse events (SAEs) were observed, and most adverse events were mild to moderate. Based on these positive efficacy and safety results, SAB plans to further evaluate SAB-176 in advanced clinical trials.

"One remarkable aspect of these results is that SAB's Tc Bovine(tm) were not immunized to the specific influenza virus strain that was used in the challenge study," added Christoph Bausch, PhD, Chief Scientific Officer of SAB Biotherapeutics. "Nonetheless, the statistically significant reduction in virus load and symptoms that were achieved confirm that SAB-176 demonstrated high cross reactivity to this pandemic strain. This reinforces a unique and timely feature of our DiversitAb(tm) platform--the diversity of the human antibodies it produces gives our therapeutics the potential to be broadly neutralizing to both known and unknown viral variants--a very valuable feature when addressing rapidly mutating pathogens."

For more information on the Phase 2a clinical trial, visit clinicaltrials.gov (Identifier NCT04850898).