MDX2301 in healthy adults and adults at higher risk for severe COVID-19

A Phase 1a/b Randomized, Double-Blind, Placebo-Controlled Dose Escalation Study Evaluating MDX2301 in Healthy Adults and Adults at Higher Risk for Severe COVID-19

Phase 1 Interventional ModeX Therapeutics, An OPKO Health Company · NCT07445971

This study will try single and repeat doses of MDX2301 given by IV, IM, or SC to see if they are safe and trigger neutralizing activity in healthy adults and adults at higher risk for severe COVID-19.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment80 (estimated)
Ages18 Years to 64 Years
SexAll
SponsorModeX Therapeutics, An OPKO Health Company Industry-sponsored
Locations2 sites (Las Vegas, Nevada and 1 other locations)
Trial IDNCT07445971 on ClinicalTrials.gov

What this trial studies

This is a first-in-human, Phase 1, interventional trial testing MDX2301 delivered by intravenous, intramuscular, or subcutaneous routes. Participants include healthy adults and adults 18–64 with one or more risk factors for severe COVID-19, who will receive single doses of MDX2301 or placebo and a repeat IM or SC dose about three months later. The study measures safety, tolerability, pharmacokinetics, anti-drug antibody formation, and neutralizing activity. Dosing is done at two U.S. clinical research sites and includes normal saline placebo control.

Who should consider this trial

Good fit: Adults 18–64 who are either healthy or have at least one listed higher-risk condition (for example asthma, diabetes, chronic lung or kidney disease, cardiac disease, stable HIV, cystic fibrosis, sickle cell disease, or thalassemia) and are clinically stable may qualify.

Not a fit: People younger than 18 or older than 64, those with recent or unstable hospitalizations or uncontrolled illness, or those who cannot attend the required clinic visits are unlikely to be eligible or to benefit from participation.

Why it matters

Potential benefit: If successful, MDX2301 could offer a passive immunization option to reduce the risk or severity of COVID-19 in vulnerable adults.

How similar studies have performed: Other monoclonal antibody and passive immunization approaches have shown benefit in preventing or reducing severe COVID-19, so this trial builds on that prior clinical experience.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria

Healthy Adults

1. Participant is a healthy male or female, 18 to 64 years of age.
2. Participant is in good health in the opinion of the investigator.

   Adults at Higher Risk for Developing Severe COVID-19:
3. Participant is a male or female, 18 to 64 years of age.
4. Participant is at higher risk for developing severe COVID-19, with 1 or more of the following risk factors:

   1. Asthma
   2. Diabetes
   3. Cerebrovascular disease, which affects blood flow to the brain.
   4. Chronic kidney disease
   5. Chronic lung disease
   6. Cardiac disease
   7. Chronic liver disease
   8. Cystic fibrosis
   9. HIV clinically stable on antiretroviral therapy for at least 6 months prior to screening.
   10. Sickle cell disease or thalassemia
5. Participant is clinically stable with no clinically significant abnormalities.
6. Participant has not been hospitalized within the 12 months prior to screening or is not expected to be hospitalized during the study due to underlying medical conditions.

   All Participants
7. Female participants of childbearing potential must have a negative urine pregnancy test.
8. Female participants of childbearing potential must agree to follow instructions for a highly effective birth control method.
9. Participant is able to understand and sign the informed consent form prior to undergoing any study procedures.
10. Participant is willing and able to comply with scheduled visits and procedures.

Exclusion Criteria:

Healthy Adults

1. Participant has any chronic or significant medical condition that, in the opinion of the investigator, might compromise the participant's safety or interfere with evaluation of the study drug.
2. Participant has evidence of active HIV, hepatitis B, or hepatitis C infections at screening.

   Adults at Higher Risk for Severe COVID-19:
3. Participant has any serious disease, condition, or disorder that, in the opinion of the investigator, might compromise the participant's safety or interfere with evaluation of the study drug or interpretation of study results, or may lead to hospitalization or death within the study period.
4. Participant has evidence of active hepatitis B or hepatitis C infections at screening.

   All Participants
5. Participant has abnormal vital signs, ECG findings, or laboratory values at Screening or Day -1.
6. Participant tests positive for SARS-CoV-2 infection at screening.
7. Participant self-reports having COVID-19 or received COVID-19 antiviral for prophylaxis or treatment prior to Day 1.
8. Participant has received a SARS-CoV-2 vaccine prior to dosing.
9. Participant has received a monoclonal antibody (mAb) for SARS-CoV-2 or convalescent plasma for SARS-CoV-2 prior to Day 1.
10. Participant has received or is expected to receive for the duration of the study immunoglobulin, blood-derived products, high-dose systemic corticosteroids, or other immunosuppressant drugs within 6 months prior to Day 1.
11. Participant is pregnant, breastfeeding, or seeking pregnancy while on the study.
12. Participant with a known clinically significant bleeding disorder that would prohibit the participant from receiving an IV infusion or IM or SC injection.
13. Participant had major surgery within 30 days prior to Day 1.
14. Participant has donated blood prior to screening.
15. Participant has any skin condition and/or tattoo that may interfere with the evaluation of safety at the injection site.
16. Participant has a history of alcoholism or illicit drug use prior to screening or a positive test for drugs of abuse at screening or on Day -1.
17. Participant is a current smoker or user of other nicotine containing products on a daily basis.
18. Participant has received an investigational product within 30 days prior to Day 1.
19. Participant has a known hypersensitivity to any components of MDX2301, any of its excipients or closely related compounds.

    For All Participants, Temporary Exclusions for Randomization on Day 1 if Remains within the Screening Window:
20. Participant has any acute illness, within 3 days of Day 1.
21. Participant has vital signs considered by the investigator to be clinically significant prior to study drug administration.
22. Participant has had close contact with anyone confirmed to have SARS-CoV-2 infection within the 7 days prior to Day 1.
23. Any acute drug therapy prescribed by a physician within 7 days prior to Day 1.

Where this trial is running

Las Vegas, Nevada and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions COVID -19COVID-19
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.