Potential for significant clinical impact.

AT-527 has a unique mechanism of action, with dual targets including chain termination (RdRp) and NiRAN inhibition, which has the potential to create a high barrier to resistance.

A scientist operating an analytical instrument in a laboratory environment.


AT-527 addresses the key challenges of the COVID-19 pandemic and beyond.

For the treatment of COVID-19, we need transformational solutions, and we believe that oral, safe, direct-acting antivirals can play an essential role worldwide. The value and global health impact of a direct-acting antiviral is to rapidly inhibit viral replication in the early phase of infection, which has the effect of reducing disease progression and curtailing the spread of infection.

While vaccines will play an important role in mitigating the COVID-19 pandemic, we will need treatment options to stay ahead of the virus. To treat patients who are waiting to or do not want to be immunized and for patients for whom the vaccine does not create protective immunity, direct-acting antivirals are and will remain an essential complement to vaccines.

AT-527 is an oral, direct-acting antiviral drug candidate.

AT-527 is being evaluated for easy and early administration to reduce burden and duration of disease. AT-527 has the potential to be used for pre- and post-exposure prophylaxis, to reduce transmission and to impact long-term COVID sequelae.

Similar to Tamiflu®

Complementary medical intervention to vaccination similar to the influenza paradigm (Tamiflu®)

Significant advantages vs antibodies

Significant advantages vs antibodies:

  • convenient for patients and healthcare workers
  • global reach
  • manufacture
  • scale-up
  • cost
Effective vs. mutations

Highly-conserved target has potential to enable antiviral activity in the presence of multiple variants

anticipated to be effective again st future coronaviruses

Antiviral activity against potential future coronaviruses beyond SARS-CoV-2 anticipated

Key Profile Features of AT-527

Safety Icon

Generally safe and well tolerated (no drug related SAEs or discontinuations) in studies being conducted for the treatment of COVID-19 and studies conducted in HCV.

Excellent Oral Bioavailability Icon
Excellent Oral Bioavailability

High solubility promotes rapid absorption.

Convenient Delivery Icon
Convenient Delivery

Designed for QD or BID (twice daily) oral administration.

Manufacturing Icon

Efficient and scalable manufacture of drug product.

COVID-19 Clinical Trials

To learn more about our current clinical trials evaluating AT-527 for the treatment of coronavirus disease (COVID-19), please use the links below:

Study to Evaluate the Effects of AT-527 in Non-Hospitalized Adult Patients With Mild or Moderate COVID-19

Safety and Efficacy of AT-527 in Subjects With Moderate Coronavirus Disease (COVID-19) [hospitalized setting]