A Phase 2 interventional study of Paxlovid 5 days and Paxlovid 10 days in COVID-19 and Immunodeficiency, sponsored by ANRS, Emerging Infectious Diseases. Recruiting at 18 sites in 3 countries. Open to participants aged 16 Years and older. Per ClinicalTrials.gov, last updated 2026-02-23.
Sponsored by ANRS, Emerging Infectious Diseases · Phase 2, Interventional, and Treatment
The overall purpose of the trial is to evaluate the efficacy and safety of possible combination antiviral therapy DAA (remdesivir + nirmatrelvir/r)∞ versus the reference monotherapy (nirmatrelvir/r alone) and to assess the efficacy and safety of increasing the nirmatrelvir/r course from 5- to 10 days in immunocompromised patients diagnosed with asymptomatic or mild to moderate COVID-19.
This is a randomized, controlled, factorial, superiority trial to evaluate the viral efficacy of DAA (nirmatrelvir/r) + DAA (remdesivir)∞ versus nirmatrelvir/r alone and of 5 days versus 10 days of nirmatrelvir/r in immunocompromised patients diagnosed with asymptomatic or mild to moderate COVID-19.
The primary objective is to assess whether (i) a combination antiviral therapy of two DAA (nirmatrelvir/r + remdesivir)∞ And/or (ii) an increase in nirmatrelvir/r duration from 5 to 10 days improves viral efficacy by decreasing the SARS-CoV-2 positivity rate by real time RT-PCR (CT\<32) in nasopharyngeal swabs at D10.
Patients will be eligible if they are immunocompromised, have confirmed asymptomatic SARS-CoV-2 infection or mild to moderate COVID-19, regardless of symptoms onset, provided that they have no contra-indication to any of the study drugs.
A total of 256 patients will be included in France and Switzerland.
Participants not eligible for randomisation or who refuse to participate to the trial for any reason will be proposed to be included in an exploratory non comparative cohort (maximum 97 participants).
7,640 studies on the registry are indexed under COVID-19; 488 are open to participants now.
This study's planned enrollment of 256 is above the median of 100 across 4,099 interventional studies indexed under COVID-19.
Browse COVID-19 studies →ANRS, Emerging Infectious Diseases is the lead sponsor of 212 studies on the registry; 40 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Pregnant or breastfeeding female
Drug: Paxlovid 5 days
Drug: Paxlovid 10 days
Drug: Paxlovid 5 days · Drug: Veklury
Drug: Paxlovid 10 days · Drug: Veklury
Nirmatrelvir/r 300mg/100 mg bid will be given for 5 days, orally. Nirmatrelvir/r is a combination of two molecules: nirmatrelvir which is a protease inhibitor (against 3CL) and ritonavir which has a booster role. Nirmatrelvir/r (marketed by Pfizer under the brand name Paxlovid®) is indicated for the treatment of COVID-19 in adults who do not require supplemental oxygen and who are at increased risk for progressing to severe COVID-19.
Also known as: Nirmatrevlir/ritonavir
Nirmatrelvir/r 300mg/100 mg bid will be given for 10 days, orally.
Also known as: Nirmatrevlir/ritonavir
Remdesivir "flash", 200mg, intravenous. Remdesivir (marketed by Gilead under de brand name Veklury®) is indicated in patients with pneumonia requiring supplemental oxygen (inpatients), as well as in outpatients who are at increased risk of progressing to severe COVID-19. The mode of action characterize remdesivir as a direct-acting antiviral compound.
Also known as: remdesivir
Percentage of patients with SARS-CoV-2 viral load (threshold cicle (Ct) <32) by real-time RT-PCR in nasopharyngeal swabs at Day 10 after treatment initiation.
SARS-CoV-2 viral load is measured in nasopharyngeal swabs by real-time RT-PCR
Time frame: Day 10
Percentage of patients with SARS-CoV-2 viral load (threshold cicle <32 CT) by real-time RT-PCR in nasopharyngeal swabs at Day5, Day14 and Day21 after treatment initiation
SARS-CoV-2 viral load is measured in nasopharyngeal swabs by real-time RT-PCR
Time frame: Day5, Day14 and Day21
Percentage of patients with detectable SARS-CoV-2 viremia at Day5, Day10 and Day14
SARS-CoV-2 viremia is measured from plasma samples by real-time RT-PCR
Time frame: Assessed for 14 days from the date of randomisation at Day5, Day10 and Day14
Decrease of SARS-CoV-2 viral load measured by copies/ml by nasopharyngeal swab at Day5, Day10, Day14, Day21 and in blood samples at Day5, Day10 and Day14 comparatively to screening
SARS-CoV-2 viral load is measured in nasopharyngeal swabs and in blood samples by real-time RT-PCR
Time frame: Day5, Day10, Day14, Day21
Number of de novo emergence of mutations on nasopharyngeal RT-PCR at Day5, Day10, Day14 and Day21 comparatively to screening
Emergence of mutations is measured in nasopharyngeal swabs by genotyping techniques
Time frame: Day5, Day10, Day14 and Day21
Time to first negative SARS-CoV-2 RT-PCR (CT<32) until Day90
SARS-CoV-2 viral load is measured in nasopharyngeal swabs by real-time RT-PCR
Time frame: Day90
Absence of ability to cultivate virus from viral cultures from nasopharyngeal swabs at Day5, Day10 and Day21
Viral culture is performed from nasopharyngeal swabs samples
Time frame: Day5, Day10 and Day21
Percentage of patients with sustained resolution or abatement of symptoms defined as a FLU-PRO-Plus score ≤1 at Day5, Day10, Day14, Day21 and Day28
FLU-PRO-Plus score is measured via an arithmetic formula
Time frame: Day5, Day10, Day14, Day21 and Day28
All-cause hospitalization and/or death at Day28
Outcome measured during patients medical follow-up
Time frame: Day28
Hospitalization at Day28
Outcome measured during patients medical follow-up
Time frame: Day28
Death at Day28
Outcome measured during patients medical follow-up
Time frame: Day28
Rate of Post-COVID19 condition at Day90 according to the WHO October 2021 definition
Rate of Post-COVID19 condition at Day90 according to the WHO October 2021 definition: o Post COVID-19 condition occurs in individuals with a history of probable or confirmed SARS-CoV-2 infection, usually 3 months from the onset of COVID-19 with symptoms that last for at least 2 months and cannot be explained by an alternative diagnosis. Common symptoms include fatigue, shortness of breath, cognitive dysfunction but also others and generally have an impact on everyday functioning. Symptoms may be new onset following initial recovery from an acute COVID-19 episode or persist from the initial illness. Symptoms may also fluctuate or relapse over time.
Time frame: Day 90
Percentage of participants with an adverse event (AE) or serious adverse event (SAE) or AE leading to treatment discontinuation up to Day28
Outcome measured during patients medical follow-up
Time frame: Day 28
Adherence to nirmatrelvir/r with patient-reported adherence and nirmatrelvir/r residual plasma dosage at Day5 and Day10
Outcome measured by patient-reported adherence and drug residual dosage using dried spot (DBS)
Time frame: Day5 and Day10
Number of DDIs who led to dosage adjustment of other patient's drugs
Outcome measured during patients medical follow-up
Time frame: Assessed up to Day 10 from randomisation
Percentage of patients with specific retreatment patients (by antiviral antiinflammatory drugs or convalescent plasma through Day90
Outcome measured during patients medical follow-up
Time frame: Day90
To assess the phenotypic resistance (IC50 increase) against treatment for viral strains cultured from nasopharyngeal swabs
Outcome measured in nasopharyngeal swabs by phenotyping techniques
Time frame: Day5, Day10, Day14, Day21
Immunosuppressors residual concentrations, if applicable
Outcome measures in participants' blood samples
Time frame: as needed
Plan to share: Undecided
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ANRS, Emerging Infectious Diseases