Are your patients at increased risk of severe illness from COVID-19? 

We are investigating an oral antiviral study medication in high-risk adult and adolescent participants with COVID-19. 

For many, a COVID-19 diagnosis can still have a significant impact on their daily lives and well-being.  

While clinical trials have shown that some COVID-19 treatments have demonstrated a reduction in the risk of hospitalization and death for participants at higher risk of severe disease,1 there remains a need for additional COVID-19 treatment options that do not require administration in a healthcare setting, are not limited by drug interactions, and can be taken by people who may not be candidates for other treatments.  

Pfizer ASPIRE-HR is a phase 3 clinical trial evaluating an orally administered antiviral study medication. 

This clinical trial will assess the safety, efficacy, and tolerability of an antiviral study medication compared with placebo in non-hospitalized, symptomatic adult and adolescent participants with COVID-19 who are at high risk of progressing to severe illness. 

This antiviral study medication may have the potential to be a COVID-19 treatment for those with limited treatment options, if the clinical trial is successful and the investigational medication is approved by regulators. 

Watch this video to learn more about an antiviral study medication and the ASPIRE-HR clinical trial: 

Participant eligibility

This clinical trial is enrolling non-hospitalized participants who:  

  • Are adults (18+) or adolescents (12+)
  • Have COVID-19 and developed signs or symptoms within the last 5 days
  • Have risk factors for severe illness or complications from COVID-19, including:
    • BMI ≥30 kg/m2
    • Current smoker
    • Chronic lung disease
    • Asthma requiring daily prescribed therapy
    • Cardiovascular disease
    • Type 1 or Type 2 diabetes
    • Mild to moderate renal impairment
    • Neurodevelopmental disorders
    • Sickle cell disease
    • Moderate immunosuppression
  • May not be able or willing to take currently approved treatments for COVID-19
  • Have not received a COVID-19 vaccine in the last 4 months

Additional requirements apply. Only Principal Investigators can determine eligibility.   

About the clinical trial

Eligible participants will be randomized 1:1 to receive an oral antiviral study medication or placebo twice daily for 5 days (10 total doses). Participants may also receive permitted standard of care treatments for COVID-19. 

Participants will be in the study for approximately 24 weeks, including screening, treatment, and follow-up. Participants will need to attend at least 12 appointments, some of which may be conducted via telemedicine.   

There is no cost to participate, and health insurance is not required. Participants will receive compensation for completing clinical trial activities. 

Together, we can make a difference.

People are often introduced to clinical trials through conversations with their healthcare providers. We appreciate you taking the time to have discussions with your patients and their loved ones who may be interested in contributing to research.  

Should any of your patients take part in this clinical trial, they will have the option to remain under your medical care for all non-study-related needs. 

Thank you for considering your patients for this clinical trial.   

Antiviral study medication mechanism of action

This antiviral study medication is a selective inhibitor of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro), a virally encoded enzyme that is critical to the SARS-CoV-2 replication cycle.

We are researching whether an antiviral study medication effectively inhibits viral replication, and whether its lower potential for drug-drug interactions may benefit participants who take other medications for overlapping health conditions. 

This antiviral study medication is investigational and has not been approved by any health authority.

Do you have patients with COVID-19 in your care?

To learn more about Pfizer’s Antiviral COVID-19 Clinical Trials and how to refer patients, please complete the contact form and a member of the Pfizer team will contact you.  

Contact Form

Thank you for considering Pfizer’s Antiviral COVID-19 Clinical Trials for your patients. 

Site finder

Find an ASPIRE-HR study site near you 

The ASPIRE-HR clinical trial is taking place in multiple countries worldwide. 

To find your nearest study site, please enter your postal code and select the optimal distance to view on the map from the drop-down menu: 

      References

      1. Centers for Disease Control and Prevention. COVID-19 Treatment Clinical Care for Outpatients. CDC. Published December 20, 2024. Accessed March 28, 2025. 

      https://www.cdc.gov/covid/hcp/clinical-care/outpatient-treatment.html