COVID-19Phase 2Ta1NCT04428008
Thymosin Alpha 1 to Prevent COVID-19 Infection in Renal Dialysis Patients
A Phase 2 study testing Thymalfasin in people with COVID-19, run by William B. Ershler, MD at 1 site in United States.
Trial summary
Thymalfasin (thymosin alpha 1 or Ta1), the active pharmaceutical ingredient in ZADAXIN® injection, is a 28-amino acid synthetic peptide, identical to natural Ta1 produced by the thymus gland. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- COVID-19
- What is being tested?
- Thymalfasin
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 189 participants
- Where
- 1 siteUnited States
- Study dates
- 12 Jan 2021to 19 Jan 2023
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 18 or greater
- Signed informed consent
- End-stage renal disease (ESRD) who receive hemodialysis 2 or more times each week and are expected to continue on dialysis indefinitely.
Who cannot join
- Patients on short-term hemodialysis, such as those with transient renal dysfunction associated with acute illness who are projected to have return in renal function
- Patients for whom renal transplantation is anticipated within the next six months
- Patients with an anticipated survival of less than 3 months
- Patients with symptoms that might be attributable to COVID-19 infection
- Patients who test positive for SARS-CoV2
- Patients with active infectious disease requiring antibiotics
Show all 15Show fewer
- Patients with hospitalization within the previous 3 months for acute myocardial infarction or congestive heart failure
- Patients with advanced malignancy receiving cytotoxic chemotherapy
- Patients with a Karnofsky Performance Scale score of less than 60
- Patients with prior history of solid organ (kidney, liver, heart, lung, pancreas) or bone marrow transplant
- Patients with active autoimmune disease on immunosuppressive medication
- Patients receiving Plaquenil
- Participation in an investigational drug or device trial in previous 30 days
- History of allergy or intolerance to Ta1
- Any other medical or psychiatric condition that, in the opinion of the Investigator, would compromise patient safety or interfere with the objectives of the protocol or completion of the protocol treatment
Trial locations and contacts
1 site in 1 country.
United States1 site
Clinical Research Consultants
Kansas City, Kansas, 64111
About this study
Official title: A Pilot Trial of Thymalfasin (Ta1) to Prevent COVID-19 Infection in Renal Dialysis Patients
Thymalfasin (thymosin alpha 1 or Ta1), the active pharmaceutical ingredient in ZADAXIN® injection, is a 28-amino acid synthetic peptide, identical to natural Ta1 produced by the thymus gland. Ta1 is a biological response modifier which activates various cells of the immune system, and is therefore expected to have clinical benefits in disorders where immune responses are impaired or ineffective, including acute and chronic viral and bacterial infections, cancers, and vaccine non-responsiveness. Patients with end-stage renal disease (ESRD) on hemodialysis, in addition to their intrinsic kidney disease and frequent burden of comorbidities, also have increased risk of exposure to communicable diseases as they are treated several times each week at hemodialysis centers with several other patients and clinic staff in attendance. The majority of patients are over 60 years of age and many are receiving immunosuppressive medications. Accordingly, ESRD patients are particularly susceptible to COVID-19 infection. Ta1 has been shown to be safely administered to hemodialysis patients. It is our hypothesis that a course of Ta1 administered to individuals with ESRD will reduce the rate and severity of infection with COVID-19.
Read the detailed description
Patients with end-stage renal disease (ESRD) on hemodialysis, in addition to their intrinsic kidney disease and frequent burden of comorbidities, also have increased risk of exposure to communicable diseases as they are treated several times each week at hemodialysis centers with several other patients and clinic staff in attendance. The majority of patients are over 60 years of age and many are receiving immunosuppressive medications. Accordingly, ESRD patients are particularly susceptible to COVID-19 infection.
Thymalfasin (thymosin alpha 1, Ta1) is a naturally occurring peptide that has been evaluated for its immunomodulatory activities and related therapeutic potential in several conditions and diseases, including infectious disease and cancer. ZADAXIN, a synthetic form of Ta1, been has been used clinically in pilot studies for treatment of severe acute respiratory syndrome (SARS) and other lung infections including acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disorder (COPD), as well as infections after bone marrow transplant]. Larger clinical trials have shown significant efficacy for treatment of severe sepsis and hepatitis B, along with certain cancers such as melanoma, hepatocellular, and lung cancer. Ta1 has also demonstrated improvement in response to vaccines in the elderly and in patients immunocompromised by renal disease. The beneficial clinical effects of Ta1 result from activation of toll-like receptor (TLR) 9 in dendritic and other immune system cells, resulting in augmentation of T helper (Th1) function, natural killer (NK) cell activity, and increased antibody responses to T-cell dependent antigens. Importantly, Ta1 also leads to an increase in IL-10 producing regulatory T cells, which create feedback inhibition of cytokine production, hence dampening immune response and preventing a pro-inflammatory cytokine storm.
It is our hypothesis that a course of Ta1 administered to individuals at high risk for COVID-19 infection (hemodialysis patients) will reduce the rate of COVID-19 infection and severity of infection with COVID-19, compared to untreated individuals in the same hemodialysis units with comparable risk. The study will also evaluate the need for hospitalization in those patients who do not become infected with COVID-19.
- Conditions
- COVID-19
- Being tested
- Thymalfasin
- Keywords
- COVID-19, Thymalfasin, Thymosin alpha 1, ZADAXIN, Hemodialysis
- Medical subject headings
- COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ThymalfasinDrug
Also called Thymosin alpha 1, Ta1, ZADAXIN
Synthetic 28 amino acid peptide
| Study group | Role | What they receive |
|---|---|---|
| Active arm | Experimental | 1.6 mg thymalfasin in 1 mL subcutaneous injection twice weekly after dialysis for 8 weeks Receives: Drug: Thymalfasin |
| Control arm | No intervention | Standard care |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With COVID-19 Infection
Number of subjects who become infected with COVID-19 over the course of the study
Measured: 6 months
Secondary outcomes (3)
Hospitalization
Number of participants who were hospitalized
Measured: 6 months
Non-COVID-19 Infections
Number of participants with non-COVID-19 infections
Measured: 6 months
Mortality
Number of subjects who died
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jun 2020
- Study start12 Jan 2021
- Primary completion19 Jan 2023
- Study completion19 Jan 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for COVID-19Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Subjects will be centrally randomized to receive either study treatment drug (Ta1) or no Ta1. Randomization will be stratified by site.
- Masking
- None (open label)
- Enrolment
- 189 participants (actual)
Sponsor and investigators
- Lead sponsor
- William B. Ershler, MD
- Sponsor type
- University, hospital or other
- Collaborators
- Davita Clinical Research
- Responsible party
- Sponsor-investigator, William B. Ershler, MD, Ershler, William B., MD
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04428008
- Sponsor's protocol ID
- ACW-1221958-1
- Acronym
- Ta1
- Status last verified
- Apr 2026
- First submitted
- 7 Jun 2020
- Last updated
- 21 Apr 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Pilot Trial of Thymalfasin (Ta1) to Prevent COVID-19 Infection in Renal Dialysis Patients
- ClinicalTrials.gov ID
- NCT04428008
- Acronym / sponsor ID
- Ta1 / ACW-1221958-1
- Conditions
- COVID-19
- Keywords
- COVID-19, Thymalfasin, Thymosin alpha 1, ZADAXIN, Hemodialysis
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 189 participants (actual)
- Lead sponsor
- William B. Ershler, MDUniversity, hospital or other
- Collaborators
- Davita Clinical Research
- Study start
- 12 Jan 2021 (actual)
- Primary completion
- 19 Jan 2023 (actual)
- Study completion
- 19 Jan 2023 (actual)
- First posted
- 11 Jun 2020 (actual)
- Results
- Posted 21 Apr 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Thymalfasin (thymosin alpha 1 or Ta1), the active pharmaceutical ingredient in ZADAXIN® injection, is a 28-amino acid synthetic peptide, identical to natural Ta1 produced by the thymus gland. Ta1 is a biological response modifier which activates various cells of the immune system, and is therefore expected to have clinical benefits in disorders where immune responses are impaired or ineffective, including acute and chronic viral and bacterial infections, cancers, and vaccine non-responsiveness. Patients with end-stage renal disease (ESRD) on hemodialysis, in addition to their intrinsic kidney disease and frequent burden of comorbidities, also have increased risk of exposure to communicable diseases as they are treated several times each week at hemodialysis centers with several other patients and clinic staff in attendance. The majority of patients are over 60 years of age and many are receiving immunosuppressive medications. Accordingly, ESRD patients are particularly susceptible to COVID-19 infection. Ta1 has been shown to be safely administered to hemodialysis patients. It is our hypothesis that a course of Ta1 administered to individuals with ESRD will reduce the rate and severity of infection with COVID-19.
Detailed description
Patients with end-stage renal disease (ESRD) on hemodialysis, in addition to their intrinsic kidney disease and frequent burden of comorbidities, also have increased risk of exposure to communicable diseases as they are treated several times each week at hemodialysis centers with several other patients and clinic staff in attendance. The majority of patients are over 60 years of age and many are receiving immunosuppressive medications. Accordingly, ESRD patients are particularly susceptible to COVID-19 infection.
Thymalfasin (thymosin alpha 1, Ta1) is a naturally occurring peptide that has been evaluated for its immunomodulatory activities and related therapeutic potential in several conditions and diseases, including infectious disease and cancer. ZADAXIN, a synthetic form of Ta1, been has been used clinically in pilot studies for treatment of severe acute respiratory syndrome (SARS) and other lung infections including acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disorder (COPD), as well as infections after bone marrow transplant]. Larger clinical trials have shown significant efficacy for treatment of severe sepsis and hepatitis B, along with certain cancers such as melanoma, hepatocellular, and lung cancer. Ta1 has also demonstrated improvement in response to vaccines in the elderly and in patients immunocompromised by renal disease. The beneficial clinical effects of Ta1 result from activation of toll-like receptor (TLR) 9 in dendritic and other immune system cells, resulting in augmentation of T helper (Th1) function, natural killer (NK) cell activity, and increased antibody responses to T-cell dependent antigens. Importantly, Ta1 also leads to an increase in IL-10 producing regulatory T cells, which create feedback inhibition of cytokine production, hence dampening immune response and preventing a pro-inflammatory cytokine storm.
It is our hypothesis that a course of Ta1 administered to individuals at high risk for COVID-19 infection (hemodialysis patients) will reduce the rate of COVID-19 infection and severity of infection with COVID-19, compared to untreated individuals in the same hemodialysis units with comparable risk. The study will also evaluate the need for hospitalization in those patients who do not become infected with COVID-19.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Subjects will be centrally randomized to receive either study treatment drug (Ta1) or no Ta1. Randomization will be stratified by site.
| Arm | Type | Receives |
|---|---|---|
| Active arm | Experimental | Drug: Thymalfasin1.6 mg thymalfasin in 1 mL subcutaneous injection twice weekly after dialysis for 8 weeks |
| Control arm | No intervention | –Standard care |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Age 18 or greater
- Signed informed consent
- End-stage renal disease (ESRD) who receive hemodialysis 2 or more times each week and are expected to continue on dialysis indefinitely.
Key exclusion criteria (15 listed)
- Patients on short-term hemodialysis, such as those with transient renal dysfunction associated with acute illness who are projected to have return in renal function
- Patients for whom renal transplantation is anticipated within the next six months
- Patients with an anticipated survival of less than 3 months
- Patients with symptoms that might be attributable to COVID-19 infection
- Patients who test positive for SARS-CoV2
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ThymalfasinAlso: Thymosin alpha 1, Ta1, ZADAXINSynthetic 28 amino acid peptide | Drug | Active arm |
Primary outcome
Number of Participants With COVID-19 Infection
Time frame: 6 months
Number of subjects who become infected with COVID-19 over the course of the study
3 secondary outcomes
Hospitalization
Time frame: 6 months
Non-COVID-19 Infections
Time frame: 6 months
Mortality
Time frame: 6 months
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Apr 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Thymalfasin in people with COVID-19, run by William B. Ershler, MD at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 21 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 21 Apr 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants With COVID-19 Infection (time frame: 6 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Apr 2026.