Allarity Therapeutics announces plans to test antiviral activity of stenoparib drug

Reviewed by Emily Henderson, B.Sc.Jan 27 2021

Allarity Therapeutics of Hørsholm, Denmark, today announced plans to further test the antiviral activity of stenoparib, its PARP inhibitor, against SARS-CoV-2 lineage B.1.1.7, also known as Coronavirus Variant B117 (the "British variant"), at the COVID-19 Testing Service Center (CTSC) of Northern Arizona University's Pathogen and Microbiome Institute (PMI), a leading U.S. infectious disease testing center.

The virus variant was labeled "Variant of Concern 202012/01" by Public Health England (PHE), an agency of the UK Department of Health and Social Care, in a publication on December 21, 2020, after it was found to have spread rapidly within the UK, and the PHE assessed that this variant has a substantially increased transmissibility compared with other coronavirus variants.

This variant has also been identified in the U.S. in several states, and the Centers for Disease Control confirms that this variant spreads more easily and quickly than other variants.

Based on previous positive pre-clinical test results with stenoparib as a treatment of SARS-CoV-2, announced on August 26, 2020, Allarity will now work with scientists at PMI to test the similar ability of stenoparib to block the infection and replication of SARS-CoV-2 lineage B.1.1.7.

Results of the previous series of pre-clinical studies for SARS-CoV-2 were recently published in the peer-reviewed journal mBio, showing that stenoparib inhibits SARS-CoV-2 as a single agent. In addition, stenoparib in combination with remdesivir was active in inhibiting coronavirus in vitro.

The concentration of stenoparib required for virus inhibition was lower in the combination study than in the single-agent study. The two drugs target the virus through unique but different mechanisms of action. The study was led by NAU assistant professor and director of CTSC C. Todd French, working with PMI researchers, staff, and students including Nathan Stone and Sierra Jaramillo.

Stenoparib (formerly 2X-121, E7449) is a small molecule, targeted inhibitor of Poly ADP-Ribose Polymerase (PARP), a key DNA damage repair enzyme active in tumors, which was originally developed by the pharmaceutical company Eisai.

Besides investigating whether stenoparib has therapeutic potential as a possible treatment of SARS-CoV-2 and the British variant (lineage B.1.1.7), Allarity Therapeutics is also currently evaluating stenoparib for the treatment of advanced ovarian cancer in Phase 2 clinical trial at the Dana-Farber Cancer Institute in Boston, Mass., using a DRP® companion diagnostic to guide patient enrollment and improve therapeutic outcome.

"We are excited to be one of the first few companies to be working on a possible treatment for the new variant by further testing, pre-clinically, the therapeutic potential of stenoparib against the British variant of Coronavirus, given the positive results of our prior preclinical tests of the drug as an anti-viral treatment for SARS-Cov-2," said Steve R. Carchedi, CEO of Allarity Therapeutics.

"We intend to work with the FDA and NIH, as well as other regulatory agencies and funding sources, to advance stenoparib as soon as possible into clinical trials for the treatment of COVID-19 and/or the British variant. Exploring our novel drug as a promising new treatment for COVID-19 underscores our company's commitment to developing new therapies for the improvement of patient care, and we are pleased to do whatever we can to provide a meaningful impact on solutions to this global pandemic."

It is important that clinicians have multiple tools for treating patients, and our laboratory testing facility can help by validating the effectiveness of drugs against the SARS-CoV-2. In this case, we are taking a cancer drug and repurposing it to fight COVID-19."

C. Todd French, Assistant Professor and Director of COVID-19 Testing Service Center, Northern Arizona University

Paul Keim, NAU Regents' Professor and PMI executive director, said "The emergence of SARS-CoV-2 variants is a challenge to our current approaches to COVID-19. They necessitate the validation of our diagnostics, vaccines, and therapeutics against a panel of these new and dangerous strains. B.1.1.7, in particular, has to be included in order for us to choose the right approaches and drugs for this disease."

Allarity Therapeutics has applied for stenoparib to become a part of what is popularly known as Operation Warp Speed, a partnership among components of the U.S. government, including the Department of Health and Human Services (HHS), the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH) and the Biomedical Advanced Research and Development Authority (BARDA.

Specifically, Allarity has submitted a phase 2/3 protocol through the BARDA portal, and if this proposal is successful it may lead to a fully or partially government-funded development process of stenoparib as a treatment of SARS-Cov-2.