Skip to main content
OpenTrials
Not Yet Recruiting

NCT Number: NCT07473830

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

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.

Not Yet Recruiting

Trial opening soon.

Get Notified

Key information

Conditions

Olfactory Dysfunction Age-related Degenerative Olfactory Dysfunction Anosmia Nervous System Diseases Neurologic Manifestations Olfaction Disorders Pathological Conditions, Signs and Symptoms Post-traumatic Olfactory Dysfunction Sensation Disorders Signs and Symptoms

Age range

18 year–99 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Autologous Platelet-Rich Plasma (PRP) Injection

Biological

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.

Primary outcomes

  1. 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).

Secondary outcomes

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  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.

Study contacts

Contact information is provided by the study sponsor or research team.

MAxime FIEUX, Dr

CONTACT

[email protected]

0033 4 72 66 64 15 ext. +33

Sponsors and collaborators

Lead sponsor

Hospices Civils de Lyon

Other

Registry information

Acronym: PANDORA

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
Mar 16, 2026
Registry last updated
Mar 20, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.