A Phase 3 interventional study of Pritelivir and Investigator's choice in HSV Infection, sponsored by AiCuris Anti-infective Cures AG. Completed at 70 sites in 15 countries. Open to participants aged 16 Years and older. Per ClinicalTrials.gov, last updated 2026-06-12.
Sponsored by AiCuris Anti-infective Cures AG · Phase 3, Interventional, and Treatment
Randomized, open-label, multi-center, comparative trial to assess the efficacy and safety in immunocompromised subjects with acyclovir resistant or acyclovir susceptible mucocutaneous HSV infection, treated with pritelivir 100 mg once daily (following a loading dose of 400 mg as first dose to rapidly reach steady-state plasma concentration) or investigators choice, which can be either foscarnet 40 mg/kg every 8 hours or 60 mg/kg every 12 hours, or Cidofovir iv 5 mg/kg body weight given once weekly, or Cidofovir 1% or 3% topical applied 2 to 4 times daily, or Imiquimod 5% topical 3 times per week) (provided the drug is nationally approved).
The trial comprises 5 Parts, Part A, B, C, D, E and F.
Part A and Part B (Phase 2) have been finalised.
Part B is an open-label, multi-center design to assess the efficacy and safety of pritelivir in subjects with ACV-resistant-mucocutaneous HSV and who either:
developed foscarnet resistance/intolerance during treatment in Part A (no improvement after at least 5 days of foscarnet therapy or intolerance to foscarnet requiring cessation of foscarnet treatment).
Parts C, D, E and F (Phase 3).
This trial part is designed to show superiority of pritelivir against Investigator's Choice in obtaining clinical cure, ie, number of subjects with all lesions healed within 28 days.
Part D is an open-label, multi-center design to assess the efficacy and safety of pritelivir in subjects with ACV-R mucocutaneous HSV episodes and who in addition either:
Part F is an open-label, multi-center design to assess the efficacy and safety of pritelivir in subjects with ACV-R mucocutaneous HSV episodes and who in addition either:
Dosing of trial medication:
Pritelivir oral tablet as single daily doses of 100 mg (following a loading dose of 400 mg as first dose)
Comparator per investigator's choice (provided the drug listed below is nationally approved):
Foscarnet intermittent infusions of 40 mg/kg every 8 hours or 60 mg/kg every 12 hours (to be adjusted in case of renal impairment) for a minimum of 1 hour duration, or Cidofovir iv infusion of 5 mg/kg body weight given once weekly, or Cidofovir 1% or 3% topical treatment, applied 2 to 4 times daily, or Imiquimod 5% topical treatment, 3 times per week.
Duration of treatment:
Until all mucocutaneous HSV lesions are healed or up to 28 days, whichever is earlier.
A prolongation up to a maximum of 42 days may be possible depending on the clinical progress.
166 studies on the registry are indexed under Herpes Simplex; 12 are open to participants now.
This study's enrollment of 158 is above the median of 66 across 113 interventional studies indexed under Herpes Simplex.
Browse Herpes Simplex studies →AiCuris Anti-infective Cures AG is the lead sponsor of 9 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Part C inclusion criteria
men and women of any ethnic group aged ≥16 years.
In Canada, Germany, Belgium:
Immunocompromised (due to conditions including but not limited to infection, hematopoietic cell or solid organ transplantation, and chronic use of immunosuppressive treatment) men and women of any ethnic group aged >18 years.
Part D and F inclusion criteria
All inclusion criteria as for Part C, except for inclusion criterion 2, which is replaced by:
2. ACV-R and foscarnet-R mucocutaneous HSV infection based on clinical failure or positive genotypic/phenotypic resistance testing for current lesion or documented intolerance to iv foscarnet requiring cessation of foscarnet treatment or precluding foscarnet treatment.
Subjects will be able to enter Part F only after closure of enrollment in Part D.
Part E inclusion (Part E is not being conducted in Germany)
All inclusion criteria as for Part C, except for inclusion criterion 2, which is replaced by:
2. Recurrent mucocutaneous HSV infection considered ACV-S.
Part C exclusion criteria
Having received an drug in an investigational drug trial unter certain conditions.
Part D (complete) exclusion criteria
All exclusion criteria as for Part C, except criterion 12, which is replaced by:
Participation in a clinical trial without receiving other investigational drugs (eg, follow-up phase of a trial, observational study) is permitted.
Part E exclusion criteria (Part E is not being conducted in Germany)
All exclusion criteria in Part E are identical to those in Part C with the addition of:
13. Having used acyclovir, valacyclovir, or famciclovir within 3 days prior to starting pritelivir.
Part F exclusion criteria All exclusion criteria for Part D plus 13. Part D open for enrollment
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Oral tablets, 100mg/day (400mg loading dose on day 1) for up to 28 days and potential prolongation for up to additional 14 days
Drug: Pritelivir
Investigator's Choice: Foscarnet iv, 40 mg/kg tid or 60mg/kg bid or Cidofovir iv, 5 mg/kg body weight given once weekly or Cidofovir 1% or 3%, topically applied 2 to 4 times daily or Imiquimod 5%, topically applied 3 times per week, for up to 28 days and potential prolongation for up to additional 14 days.
Drug: Investigator's choice
Oral tablets, 100mg/day (400mg loading dose on day 1) for up to 28 days and potential prolongation for up to additional 14 days
Drug: Pritelivir
Oral tablets, 100mg/day (400mg loading dose on day 1) for up to 28 days and potential prolongation for up to additional 14 days
Drug: Pritelivir
100 mg oral tablets
Foscarnet iv, 40 mg/kg BW tid or 60mg/kg bid or Cidofovir iv, 5 mg/kg BW given once weekly or Cidofovir 1% or 3%, topically applied 2 to 4 times daily or Imiquimod 5%, Solution for iv infusion or topical application
Also known as: Foscarnet or Cidofovir or Imiquimod
Efficacy measured by cure rate
Number of subjects cured (all lesions healed as assessed by the Investigator) during the treatment period of up to 28 days relative to the total number of subjects treated with trial medication in the respective treatment group.
Time frame: Up to a maximum of 28 days
Efficacy measured by cure rate
Number of subjects cured (all lesions healed as assessed by the Investigator) during the treatment period of up to 42 days relative to the total number of subjects treated with trial medication in the respective treatment group.
Time frame: Up to a maximum of 42 days
Efficacy measured by time to lesion healing
Time to lesion healing, defined as complete epithelization of the mucocutaneous HSV lesion(s) within the treatment period and no appearance of new lesions, as assessed by the Investigator.
Time frame: Up to a maximum of 42 days
Efficacy measured by recurrence rate
Recurrence rate at 2 months following PoTV assessed by telephone, defined as number of subjects with a recurrence as assessed by the Investigator following 2/3 months after PoTV relative to the total number of subjects assessed for recurrence at the respective telephone call per treatment.
Time frame: At 2 months following post treatment visit, from randomization up to a maximum of 108 days
Efficacy measured by recurrence rate
Recurrence rate at 3 months following PoTV assessed by telephone, defined as number of subjects with a recurrence as assessed by the Investigator following 2/3 months after PoTV relative to the total number of subjects assessed for recurrence at the respective telephone call per treatment.
Time frame: At 3 months following post treatment visit, from randomization up to a maximum of 139 days
Efficacy measured by pain rate
Number of days with pain at lesion site relative to the total number of days with analyzable pain data through daily subject self-reporting
Time frame: Up to a maximum of 42 days
Efficacy measured by time to pain cessation at site of lesion
Starting at first dose of trial medication until pain is no longer reported by the subject (date and time)
Time frame: Up to a maximum of 42 days
Efficacy measured by average pain score
Using a single-dimensional scale assessing pain intensity through daily subject self-reporting
Time frame: Up to a maximum of 42 days
Efficacy measured by clinical shedding rate
Number of HSV positive swabs per subject relative to the total number of swabs collected per subject from lesion swabs taken from HSV lesion(s)
Time frame: From date of randomization until the date of first documented healing, assessed up to a maximum of 42 days
Efficacy measured by time to cessation of shedding
Number of days until swabs taken are negative
Time frame: Up to a maximum of 42 days
Efficacy measured by mean log number of HSV DNA copies
Mean log number of HSV DNA copies on HSV DNA positive swabs from lesion(s) as detected by quantitative real-time PCR (polymerase chain reaction).
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Efficacy measured by resistance to trial medication
Resistance to trial medication for lesions not healed within the treatment period or newly appeared lesions under treatment before or at the PoTV.
Time frame: From date of randomization until the date of post treatment visit, assessed up to a maximum of 73 days
Safety measured by number of subjects developing chronic kidney disease
Chronic kidney disease
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by percentage of subjects developing chronic kidney disease
Chronic kidney disease
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by percentage of subjects developing acute Kidney Injury
Acute Kidney Injury (AKI) stage \>1 of KDIGO (Kidney Disease: Improving Global Outcome) criteria (increase in serum creatinine by 2.0 to 2.9 times compared to baseline or urine output \<0.5 mL/kg/h for \>12 hours)
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by percentage of subjects developing renal impairment
Renal impairment
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by percentage of subjects developing electrolyte abnormality
All abnormal values
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by percentage of subjects developing seizures
All seizures
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by percentage of subjects developing anemia
Haemoglobin measurement
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by adverse events
Incidence of Adverse Events
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by haematology
Incidence of abnormal hematologic laboratory test results
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by lymphadenopathy
Incidence of lymphadenopathy measured by physical examination
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by CRP (C reactive protein )
Incidence of CRP increase
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by cutaneous adverse events
Incidence of cutaneous adverse events by physical examination
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by (a)PTT (partial thromboplastin time)
Incidence of (a)PTT increase
Time frame: From date of randomization until the date of safety follow-up visit, assessed up to a maximum of 73 days
Safety measured by discontinuation rate
Number of subjects discontinuing pritelivir or 'Inverstigator's Choice' due to AE(s) or intolerance relative to the total number of subjects treated with pritelivir or foscarnet, respectively
Time frame: Up to a maximum of 42 days
Plan to share: No
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This study is completed, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Pritelivir
AiCuris Anti-infective Cures AG