Synthetic Biologics Announces Washington University School of Medicine in St. Louis IRB Approval of the SYN-004 (ribaxamase) Phase 1b/2a Clinical Protocol

IRB Approval Signals Phase 1b/2a Clinical Trial in Allogeneic HCT Recipients May Proceed as Planned; Enrollment Anticipated to Commence During Q1 2021

ROCKVILLE, Md., Dec. 22, 2020 /PRNewswire/ — Synthetic Biologics, Inc. (NYSE American: SYN), a diversified clinical-stage company leveraging the microbiome to develop therapeutics designed to prevent and treat gastrointestinal (GI) diseases in areas of high unmet need, today announced it has received approval from the Institutional Review Board (IRB) at Washington University School of Medicine in St. Louis (Washington University), to commence the Phase 1b/2a clinical trial of SYN-004 (ribaxamase) in allogeneic hematopoietic cell transplant (HCT) recipients. As a result, the Company expects to commence patient enrollment for the Phase 1b/2a clinical trial in the first quarter of 2021.

The IRB-approved Phase 1b/2a clinical program will be conducted by Washington University and comprise a randomized, double-blinded, placebo-controlled clinical trial of oral SYN-004 in up to 36 evaluable adult allogeneic HCT recipients. The goal of this study is to evaluate the safety, tolerability and potential absorption into the systemic circulation (if any) of 150 mg oral SYN-004 administered to allogeneic HCT recipients who receive an IV beta-lactam antibiotic to treat fever. Study participants will be enrolled into three sequential cohorts, with each receiving a different study-assigned IV beta-lactam antibiotic. Eight participants in each cohort will receive SYN-004 and four will receive placebo.

Safety and pharmacokinetic data for each cohort will be reviewed by an independent Data and Safety Monitoring Committee that will make a recommendation on whether to proceed to the next IV beta-lactam antibiotic. The study will also evaluate potential protective effects of SYN-004 on the gut microbiome as well as generate preliminary information on potential therapeutic benefits and patient outcomes of SYN-004 in allogeneic HCT recipients. Enrollment is expected to begin during the first quarter of 2021, pandemic conditions permitting.

“Approval of the Phase 1b/2a clinical protocol by Washington University’s IRB is an important step in pursuing a potentially more cost-effective development strategy for SYN-004, targeting a highly specialized patient population,” stated Steven A. Shallcross, Chief Executive and Financial Officer of Synthetic Biologics. “Broad spectrum IV beta-lactam antibiotics used to treat infection following conditioning chemotherapy for allogeneic HCT patients is a necessary and oftentimes lifesaving intervention. However, this may have the unintended consequence of causing dysbiosis of the microbiome which may lead to infection by opportunistic pathogens such as C. difficile (CDI) and vancomycin-resistant enterococci (VRE). In previously completed clinical trials, SYN-004 demonstrated a significant reduction in the incidence of CDI and VRE in treated patients versus placebo and has the potential to significantly improve outcomes for allogenic HCT recipients. We expect to commence enrollment of patients in the first quarter of 2021 and look forward to providing further updates as we advance this exciting program.”

The Washington University IRB is a committee established to review and approve research involving human subjects. The purpose of the IRB is to ensure that all human subject research is conducted in accordance with all federal, institutional, and ethical guidelines. The primary goal of an IRB is to safeguard the rights, safety and welfare of participants in research studies.

About SYN-004 (ribaxamase)

SYN-004 (ribaxamase) is an oral prophylactic therapy designed to degrade certain IV beta-lactam antibiotics within the GI tract and maintain the natural balance of the gut microbiome for the prevention of Clostridioides difficile infection (CDI), overgrowth of pathogenic organisms, the emergence of antimicrobial resistance (AMR) and acute graft-versus-host-disease (aGVHD) in allogeneic hematopoietic cell transplant (HCT) recipients. Allogeneic HCT recipients routinely receive long courses of IV beta-lactam antibiotics to treat infection. Antibiotic-mediated damage of the gut microbiome in allogeneic HCT recipients has been strongly associated with adverse outcomes including CDI, vancomycin-resistant enterococci (VRE) colonization and potentially fatal bacteremia and aGVHD. A previously completed placebo-controlled Phase 2b clinical trial of 412 patients demonstrated SYN-004 protected the gut microbiome from antibiotic-mediated dysbiosis. Patients receiving SYN-004 also demonstrated significantly better maintenance and recovery of the gut microbiome as well as lower incidences of new colonization by opportunistic and potentially pathogenic microorganisms such as VRE.

About Synthetic Biologics, Inc.

Synthetic Biologics, Inc. (NYSE American: SYN) is a diversified clinical-stage company leveraging the microbiome to develop therapeutics designed to prevent and treat gastrointestinal (GI) diseases in areas of high unmet need. The Company’s lead candidates are: (1) SYN-004 (ribaxamase) which is designed to degrade certain commonly used intravenous (IV) beta-lactam antibiotics within the gastrointestinal (GI) tract to prevent (a) microbiome damage, (b) Clostridioides difficile infection (CDI), (c) overgrowth of pathogenic organisms, (d) the emergence of antimicrobial resistance (AMR) and (e) acute graft-versus-host-disease (aGVHD) in allogeneic hematopoietic cell transplant (HCT) recipients, and (2) SYN-020, a recombinant oral formulation of the enzyme intestinal alkaline phosphatase (IAP) produced under cGMP conditions and intended to treat both local GI and systemic diseases. For more information, please visit Synthetic Biologics’ website at www.therivabio.com.     

This release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. In some cases forward-looking statements can be identified by terminology such as “may,” “should,” “potential,” “continue,” “expects,” “anticipates,” “intends,” “plans,” “believes,” “estimates,” and similar expressions, and includes statements regarding the Company commencing patient enrollment for the Phase 1b/2a clinical trial in the first quarter of 2021, the potential of SYN-004 to significantly improve outcomes for allogenic HCT recipient and the intended benefits to be derived from SYN-004 and SYN-020. These forward-looking statements are based on management’s expectations and assumptions as of the date of this press release and are subject to a number of risks and uncertainties, many of which are difficult to predict that could cause actual results to differ materially from current expectations and assumptions from those set forth or implied by any forward-looking statements. Important factors that could cause actual results to differ materially from current expectations include, among others, Synthetic Biologics’ ability to commence patient enrollment for the Phase 1b/2a clinical trial in the first quarter of 2021, the ability to  continue to comply with continued listing requirements of the NYSE American, the ability of its product candidates to demonstrate safety and effectiveness, as well as results that are consistent with prior results, Synthetic Biologics’ clinical trials continuing and/or beginning enrollment as expected, a failure to receive the necessary regulatory approvals for commencement of clinical trials and commercialization of Synthetic Biologics’ therapeutics, including approval of proposed trial designs, a failure of Synthetic Biologics’ clinical trials, and those conducted by investigators, for SYN-004 and SYN-020 to be commenced or completed on time or to achieve desired results and benefits, a failure of Synthetic Biologics’ clinical trials to continue enrollment as expected or receive anticipated funding, a failure of Synthetic Biologics to successfully develop, market or sell its products, Synthetic Biologics’ inability to maintain its material licensing agreements, or a failure by Synthetic Biologics or its strategic partners to successfully commercialize products, Synthetic Biologics’ ability to achieve acceptance of its product candidates in the marketplace and the successful development, marketing or sale of Synthetic Biologics’ products by competitors that render Synthetic Biologics’ products obsolete or non-competitive, the continued maintenance and growth of Synthetic Biologics’ patent estate, Synthetic Biologics becoming and remaining profitable, Synthetic Biologics’ ability to obtain or maintain the capital or grants necessary to fund its research and development activities, a loss of any of Synthetic Biologics’ key scientists or management personnel and other factors described in Synthetic Biologics’ Form 10-K and 10-K/A for the year ended December 31, 2019 and its other filings with the SEC, including subsequent periodic reports on Forms 10-Q and 8-K. The information in this release is provided only as of the date of this release, and Synthetic Biologics undertakes no obligation to update any forward-looking statements contained in this release on account of new information, future events, or otherwise, except as required by law.

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SOURCE Synthetic Biologics, Inc.