Moleculin Biotech, Inc., a clinical stage pharmaceutical company with a broad portfolio of drug candidates targeting significant unmet needs in the treatment of tumours and viruses, announced that its research team has discovered that a molecule within its portfolio of antimetabolites has displayed significant in vitro antiviral activity against SARS-CoV-2. Independent laboratory testing of the new drug candidate, called "WP1096," has now repeatedly demonstrated a therapeutic index of greater than 10, which is considered by our team to be an industry-standard commercialization threshold for in vitro performance of antiviral drugs.

Walter Klemp, Chairman and CEO of Moleculin, stated, "While we continue to see encouraging progress with WP1122 in preparation for clinical trials for the potential treatment of COVID-19, we have also continued our antiviral drug discovery program to expand the range of potential therapies. Our efforts led to a new discovery that we believe can be a game-changer. WP1096 and its close analog, WP1097, are structurally slightly different agents within the WP1122 portfolio. However, small structural changes unexpectedly resulted in high levels of antiviral activity and potentially a unique mode of action. The in vitro performance is significant enough that we simply must now consider proceeding with the necessary preclinical support for these additional molecules for antiviral clinical trials in addition to the lead molecule, WP1122."

Mr. Klemp continued, "The in vitro therapeutic index of WP1096 against SARS-CoV-2 appears to meet the level needed to support preclinical studies aimed to fully assess the commercial potential of WP1096. That alone is compelling data, but the unexpected performance of both WP1096 and WP1097 may be the result of mechanistic differences from the rest of our antimetabolite portfolio, which has pushed us to evaluate their potential in other viruses and related diseases like HIV, Zika, Dengue Fever and others."

Mr. Klemp concluded, "This was an unexpected discovery and one that really demands an adaptive change in development strategy on our part. While we continue our preclinical development work on WP1122, including in vivo testing for SARS-CoV-2, we are now expanding our program by adding these two new molecules as well. We anticipate it will take at least twelve months of development work to assess clinical potential for these new molecules and file an Investigational New Drug (IND) application to the US Food and Drug Administration. In the meantime, we expect to be communicating more in vitro test results for activity in additional viruses in the near future."