Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Recruiting

Study on the Effect of Acyclovir in ICU Patients with Pneumonia and Herpes Simplex Virus Type 1 Detected in Lung Fluid

Verified siteRegistered drug
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on patients who are in the intensive care unit and require ventilation due to a type of lung infection known as pneumonia. The study is particularly interested in cases where the herpes simplex virus type 1 (HSV-1) is found in the lungs. The treatment being tested is called acyclovir, which is given through an infusion directly into the bloodstream. Acyclovir is an antiviral medication that is commonly used to treat infections caused by viruses.

The purpose of the study is to understand how acyclovir affects the health outcomes of these patients, specifically looking at survival rates over a 30-day period. Participants in the study will receive either acyclovir or a placebo, and their progress will be monitored over time. The study will also track other factors such as the number of days patients can breathe without the help of a machine, the length of their stay in the hospital, and their overall quality of life during and after the treatment.

Throughout the study, researchers will collect data to see if acyclovir helps reduce the presence of HSV-1 in the lungs and improves the patients' recovery. The study aims to provide valuable insights into the potential benefits of using acyclovir for patients with pneumonia and HSV-1, ultimately helping to improve treatment strategies for these serious conditions.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Participation begins after meeting specific criteria: age 18 or older, requiring respiratory support, detection of herpes simplex virus type 1 in bronchoalveolar lavage, and having pneumonia. Consent must be provided by the patient or a legal representative.

  2. Step 2

    Treatment administration

    The treatment involves the administration of aciclovir, a medication given intravenously. The dosage and frequency are determined by the medical team based on individual needs.

  3. Step 3

    Monitoring and assessment

    Throughout the trial, various health parameters are monitored. These include the number of days without the need for ventilation, days without vasopressor medication, and changes in organ function scores. The length of stay in the intensive care unit and hospital is also recorded.

  4. Step 4

    Evaluation of outcomes

    The primary outcome measured is the 30-day survival rate. Secondary outcomes include the number of days without delirium or coma, microbiological cure, and quality of life assessments at different intervals up to 180 days.

  5. Step 5

    Completion of the trial

    The trial is expected to conclude by December 31, 2026. Final assessments will include long-term survival rates and overall quality of life.

Who can join the trial?

5 criteria

  • Must be **18 years or older**.
  • Must need **help with breathing**, either through a machine or other support.
  • Must have a test showing **herpes simplex virus type 1 (HSV-1)** in the lungs, with at least **1,000 copies per milliliter**.
  • Must have **pneumonia**, which is an infection in the lungs. This can be caught from the community or healthcare settings, including when on a breathing machine.
  • Must have **consent** given by the patient or their legal representative, which means agreeing to participate in the study.

Who cannot join the trial?

7 criteria

  • Patients who are not in the intensive care unit.
  • Patients who are not on a ventilator.
  • Patients who do not have pneumonia.
  • Patients who do not have the herpes simplex virus type 1 (HSV-1) detected in their bronchoalveolar lavage (BAL). The BAL is a test that involves washing out the lungs to collect a sample for testing.
  • Patients who are not within the specified age range for the study.
  • Patients who do not belong to the specific clinical trial group required for the study.
  • Patients who are not considered part of a vulnerable population.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

Acyclovir is a medication used in this clinical trial to treat patients with lower respiratory tract infections who are on ventilators. The trial is investigating whether using acyclovir can improve the outcomes for these patients, specifically looking at whether it can reduce the 30-day mortality rate. Acyclovir is commonly used to treat infections caused by the herpes simplex virus, and in this study, it is being tested to see if it can help patients with respiratory infections where the herpes simplex virus is detected in their lungs.

What is already known about the treatment

Acyclovir – Acyclovir is typically administered orally or intravenously, depending on the severity of the infection. It is well-established in medical literature as an antiviral medication primarily used to treat infections caused by herpes simplex virus (HSV). In the context of this clinical trial, it is being investigated for its effects on patients in intensive care units who are on ventilation and have pneumonia with HSV-1 detected in their bronchoalveolar lavage. Acyclovir works by inhibiting the viral DNA polymerase enzyme, which prevents the virus from replicating. It is classified as an antiviral drug.

Investigated diseases

  • Pneumonia

    Pneumonia is an infection that inflames the air sacs in one or both lungs, which may fill with fluid or pus. It can be caused by bacteria, viruses, or fungi, and leads to symptoms such as cough, fever, chills, and difficulty breathing. The disease can range from mild to severe, with progression depending on the individual's health and the type of organism causing the infection. In severe cases, especially in hospitalized patients, pneumonia can lead to complications like respiratory failure. It is particularly concerning in patients who are already on ventilation, as it can exacerbate their condition.

  • Herpes Simplex Virus Type 1 (HSV-1) Infection

    HSV-1 is a common virus that typically causes oral herpes, leading to cold sores or fever blisters around the mouth. However, it can also infect other parts of the body, including the respiratory tract, especially in individuals with weakened immune systems. In the context of intensive care units, HSV-1 can be detected in the bronchoalveolar lavage of patients, indicating a possible respiratory infection. The virus can remain dormant in the body and reactivate under certain conditions, leading to recurrent symptoms. Its presence in the respiratory system can complicate the clinical picture, particularly in patients with existing lung conditions.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-504322-19-00Protocol codeZKSJ0153Estimated enrolment710 patientsSponsorFriedrich-Schiller-Universitaet Jena

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

ClinicalTrials.eu

Every clinical trial in Europe, in plain language.

Explore the full ecosystem of clinical research in Europe.

Search trials

Legal notice · Published by CTIN POLAND sp. z o.o., ul. rtm. Witolda Pileckiego 67/109, 02-781 Warsaw, Poland · KRS 0001111334 · REGON 528919042 · NIP 9512598637

© 2026 Clinical Trials EU – European Clinical Trials Information Network

GDPR compliance, ISO 9001 and ISO 27001 certified (LL-C Certification)

On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).