PANDORA: Evaluation of Platelet-rich Plasma in Non-tumoural Odour Disorders: a Descriptive Pilot Study. (PANDORA)

March 17, 2026 updated by: Hospices Civils de Lyon
This is a prospective, single-center, single-arm, non-comparative descriptive pilot study evaluating autologous platelet-rich plasma (PRP) injections in adults with persistent (>6 months) non-tumoural olfactory dysfunction, either age-related degenerative olfactory dysfunction (DOD) or post-traumatic olfactory dysfunction (DOPT). Participants receive three PRP injections over 4 weeks (Day 0, Day 14, Day 28), with follow-up visits at Month 3 and Month 6 after the first injection. Olfactory function is assessed using the Sniffin' Sticks Test (TDI score). Patient-reported outcomes include SNOT-22 and a visual analog scale (VAS) for perceived olfactory impairment. Safety is assessed through adverse event collection.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Prospective consecutive recruitment in an ENT department at Hôpital Lyon Sud (Hospices Civils de Lyon). Eligible participants are enrolled into one of two diagnostic cohorts (DOD or DOPT), and analyses are performed separately by cohort. PRP is prepared from autologous venous blood using a standardized preparation system and injected under endoscopic guidance in the olfactory cleft area (superior nasal septum mucosa). Follow-up assessments are performed at baseline and at Months 3 and 6 after the first injection.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • France
      • Pierre-Bénite, France, 69310

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria

  • Adults with persistent (>6 months) non-tumoural olfactory dysfunction: age-related degenerative olfactory dysfunction (DOD) or post-traumatic olfactory dysfunction (DOPT).
  • Objective olfactory impairment confirmed by Sniffin' Sticks Test (TDI ≤ 30.5/48).
  • MRI within the last 6 months after onset excluding tumoural etiology or central cause.
  • Normal nasal endoscopy.
  • Affiliated to a social security system (or equivalent).
  • Written informed consent.

Exclusion Criteria

  • Inflammatory rhinosinus disease (e.g., nasal polyposis) or granulomatosis with polyangiitis.
  • Coagulation disorder.
  • Brain radiotherapy history or ongoing chemotherapy.
  • Olfactory disorder temporally linked to SARS-CoV-2 infection (delay <1 month).
  • History of sinus or skull base surgery (except septoplasty/turbinoplasty/rhinoseptoplasty).
  • Therapeutic-dose anticoagulants.
  • Refusal to discontinue chronic NSAID use if applicable.
  • Pregnancy/labor/breastfeeding.
  • Vulnerable persons (deprived of liberty; legal protection; etc.).
  • Participation in another interventional study with ongoing exclusion period.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: PRP injections
Single arm receiving autologous platelet-rich plasma injections at Day 0, Day 14 (±1), and Day 28 (±1), with follow-up at Months 3 and 6.
Biological: Autologous Platelet-Rich Plasma (PRP) Injection
At each injection visit (Day 0, Day 14 ±1, Day 28 ±1), venous blood is collected and processed to obtain autologous PRP using a standardized preparation system. PRP is injected under endoscopic guidance into the superior nasal septum mucosa near the olfactory cleft, up to a total volume of 4 mL per visit. Participants are monitored after each injection and adverse events are recorded.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Proportion of participants with clinically meaningful improvement in olfactory function (Sniffin' Sticks Test TDI score)
Time Frame: Baseline (Visit 1, prior to first injection) to Month 6 follow-up (Visit 5)
Proportion of participants whose change in olfactory function, measured using the Sniffin' Sticks Test (Threshold, Discrimination, Identification score - TDI), between baseline (Visit 1, prior to the first PRP injection) and the 6-month follow-up visit reaches or exceeds the minimal clinically significant difference (MCID) of 5.5 points on the 48-point TDI scale. The TDI score combines three components: olfactory threshold (T), odor discrimination (D), and odor identification (I).
Baseline (Visit 1, prior to first injection) to Month 6 follow-up (Visit 5)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Occurrence of treatment-related adverse events
Time Frame: From first injection (Day 0) to Month 6 follow-up visit
ccurrence and type of adverse events during the study period. Adverse events will be classified according to the Common Terminology Criteria for Adverse Events (CTCAE v5.0). For each adverse event, the investigator will assess severity and relationship to the experimental treatment.
From first injection (Day 0) to Month 6 follow-up visit
Change in olfactory function at Month 3 (TDI score)
Time Frame: Baseline (Visit 1) to Month 3 follow-up (Visit 4)
Change in olfactory function measured by the Sniffin' Sticks Test (TDI score) between baseline (Visit 1, before the first injection) and the Month 3 follow-up visit.
Baseline (Visit 1) to Month 3 follow-up (Visit 4)
Change in olfactory function at Month 6 (TDI score)
Time Frame: Baseline (Visit 1) to Month 6 follow-up (Visit 5)
Change in olfactory function measured by the Sniffin' Sticks Test (TDI score) between baseline (Visit 1, before the first injection) and the Month 6 follow-up visit.
Baseline (Visit 1) to Month 6 follow-up (Visit 5)
Change in quality of life (SNOT-22 score)
Time Frame: Baseline (Visit 1) to Month 6 follow-up (Visit 5)
Change in quality of life assessed using the Sino-Nasal Outcome Test (SNOT-22) questionnaire between baseline and Month 6. The SNOT-22 score ranges from 0 to 110, with higher scores indicating greater symptom burden. A minimal clinically significant difference is considered to be 8.9 points.
Baseline (Visit 1) to Month 6 follow-up (Visit 5)
Change in patient-reported olfactory impairment (Visual Analog Scale)
Time Frame: Baseline (Visit 1) to Month 6 follow-up (Visit 5)
Change in patient-reported olfactory impairment assessed using a Visual Analog Scale (VAS) ranging from 0 (no discomfort) to 10 (unbearable discomfort) between baseline and Month 6.
Baseline (Visit 1) to Month 6 follow-up (Visit 5)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hospices Civils de Lyon

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 11, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 11, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 16, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 20, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 17, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 69HCL24_1192
  • 2025-A02847-42 (Other Identifier: ID RCB)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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