SyneuRx Announces Final Results of Phase 2 Clinical Trial of COVID-19 Oral Antiviral Candidate Pentarlandir® (SNB01)

Positive results show Pentarlandir is safe and effective in patients with mild-to-moderate COVID-19

LOS ANGELES & NEW TAIPEI CITY, Taiwan–(BUSINESS WIRE)–SyneuRx™ International (TPEX:6575), a global biotech company focused on the development of new classes of drugs for COVID-19 and multiple major central nervous system disorders, today announced results from its phase 2 clinical trial evaluating the efficacy and safety of SNB01 (Pentarlandir), a novel COVID-19 oral antiviral candidate.

Eighty-nine participants suffering from breakthrough or unvaccinated cases of COVID-19 were randomized evenly into high-dose, low-dose, and placebo groups. The phase 2 study showed that Pentarlandir can reduce the inflammation caused by COVID and improve overall health. In five out of six inflammatory markers studied, Pentarlandir treatment groups showed either statistical signals of greater reductions in the inflammatory markers or a clear trend of greater reductions. Many secondary endpoints also showed encouraging trends. In particular, the Pentarlandir treatment groups exhibited greater improvement in overall health status. In terms of clinical symptoms, Pentarlandir groups were associated with a greater reduction in total COVID-19 symptoms in the longer run (between two to eight weeks after randomization) than the placebo group. On average, Pentarlandir groups were associated with fewer days of worsening symptoms in half of the 24 COVID symptoms measured.

Pentarlandir was very well tolerated in both high- and low-dose groups with no serious adverse event. There were a limited number of adverse events overall (15%), most of which were mild in intensity. Only a few cases (4%) were related to the treatment drug. Higher dose treatment did not elicit more treatment-related adverse events. There were no cases of hospitalization, death, or discontinuation of the study due to adverse events.

“We are strongly encouraged by the findings of this successful proof-of-concept study. These findings not only help us better design the forthcoming phase 3 study, but also have great clinical implications,” said Emil Tsai, M.D., Ph.D., M.A.S., founder and CEO of SyneuRx. “Pentarlandir shows potential to treat COVID and/or prevent multisystem inflammatory syndrome, a very serious condition associated with COVID. The study results have also brought promise to the recent call for new COVID-19 treatment options as concerns of rebounds and resistance to existing antivirals emerge.”

Tsai continued, ”We expect that COVID stays around in the long-term and inflicts morbidity and mortality on millions, much like what OC43 and H1N1 have been doing in the human population for many years. And there will be more zoonotic illnesses to come. We are committed to evaluating the potential of targeting the protease inhibitor and other potential crucial drug targets to address the ongoing challenge of treatment resistance in vulnerable patients. By looking at the structure of these targets, with an eye to where resistant variants might develop, we intend to improve upon the current standard of care.”

SyneuRx is expected to launch the phase 3 study in the coming months. An optimal dose will be selected and the scope will expand to evaluate Pentarlandir’s broad-spectrum antiviral activity in inhibiting SARS-CoV-2 as well as influenza viruses, including rigorous safety assessments, to be ready for the potential coinciding surges of flu and COVID-19.

To learn more about the Pentarlandir clinical trial, visit (NCT Number: NCT04911777).

For more information about SyneuRx, visit

About Pentarlandir

Working through years of research into how several debilitating central nervous system diseases operate, SyneuRx scientists arrived at the theory that regulatory enzymes such as protease would be a critically important ”drug target” for these types of illnesses, which coincidentally is also a target for several virally caused diseases such as HIV and hepatitis. Researchers decided to test all the compounds in the company’s patent portfolio against protease and discovered that several SyneuRx-developed compounds were potent protease blockers, of which the compound that became Pentarlandir proved to be the most safe and efficacious in preclinical tests. SyneuRx confirmed its ability to block coronavirus replication in multiple, rigorous cellular studies and it also proved to maintain an excellent safety profile, which made Pentarlandir an ideal candidate to go into clinical development. SyneuRx has found Pentarlandir also may block replication of several influenza viruses in cellular assay. The company continues to test the efficacy of Pentarlandir against other potentially lethal viral strains.

About SyneuRx

SyneuRx International (TPEX:6575) is a clinical-stage global biotech company focused on the development of new classes of drugs for COVID-19 and multiple major central nervous system (CNS) disease conditions. Founded in 2013, SyneuRx is poised to bring change-making pharmaceuticals to market with a robust, promising pipeline of seven investigational drugs for CNS disorders and two for COVID-19 – eight of which are currently in phase 2 and phase 3 clinical trials with the U.S. Food and Drug Administration. The company’s mission is to infuse a scientific and humanistic approach into its research and development of safe, effective, and accessible therapies for patients suffering from disorders such as schizophrenia, dementia, and depression, as well as COVID-19 and other RNA-encoded viruses. Dedicated to taking a safety-first approach with its research and development by focusing on well-established lead compounds as well as natural sources and plant substances to treat or prevent illness, SyneuRx has received Breakthrough Therapy Designations and Orphan Drug Designations from the FDA for two of its novel CNS therapeutics. To learn more, visit

Disclosure Notice

The information contained in this release is as of July 31, 2022. SyneuRx assumes no obligation to update forward-looking statements contained in this release as the result of new information or future events or developments. This release contains forward-looking information about SyneuRx’s efforts to combat COVID-19 as well as flu and the company’s investigational oral antiviral candidate Pentarlandir® (including qualitative assessments of available data, potential benefits, expectations for clinical trials, advanced purchase agreements, the anticipated timing of data readouts, regulatory submissions, regulatory approvals or authorizations, planned investment and anticipated manufacturing, distribution and supply), involving substantial risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. Risks and uncertainties include, among other things, the uncertainties inherent in research and development, including the ability to meet anticipated clinical endpoints, commencement and/or completion dates for clinical trials, regulatory submission dates, regulatory approval dates and/or launch dates, as well as risks associated with preclinical and clinical data, including the possibility of unfavorable new preclinical, clinical or safety data and further analyses of existing preclinical, clinical or safety data; the ability to produce comparable clinical or other results including efficacy, safety and tolerability profile observed to date, in additional studies or in larger, more diverse populations following commercialization; the risk that preclinical and clinical trial data are subject to differing interpretations and assessments, including during the peer review/publication process, in the scientific community generally, and by regulatory authorities; whether regulatory authorities will be satisfied with the design of and results from these and any future preclinical and clinical studies; whether and when any drug applications or submissions to request emergency use or conditional marketing authorization for any potential indications for Pentarlandir may be filed in any jurisdictions and if obtained, whether or when such emergency use authorization or licenses will expire or terminate; whether and when regulatory authorities in any jurisdictions may approve any such applications for Pentarlandir, which will depend on myriad factors, including making a determination as to whether the product’s benefits outweigh its known risks and determination of the product’s efficacy and, if approved, whether it will be commercially successful; decisions by regulatory authorities impacting labeling or marketing, manufacturing processes, safety and/or other matters that could affect the availability or commercial potential of Pentarlandir, including development of products or therapies by other companies; risks related to the availability of raw materials for Pentarlandir; the risk that we may not be able to create or scale up manufacturing capacity on a timely basis or maintain access to logistics or supply channels commensurate with global demand, which would negatively impact our ability to supply the estimated numbers of courses of Pentarlandir within the projected time periods; whether and when additional purchase agreements will be reached; the risk that demand for any products may be reduced or no longer exist; uncertainties regarding the impact of COVID-19 on SyneuRx’s business, operations and financial results; and competitive developments.


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