Prospector 2

2025-520888-41-00 Therapeutic use (Phase IV) Ongoing, recruiting

Start 10 Dec 2025 · Status Ongoing, recruiting · 2 EU/EEA countries · 2 sites

Overview

Sponsor-declared trial summary

Phase Therapeutic use (Phase IV)
Status Ongoing, recruiting
Participants planned 712
Countries 2
Sites 2

Penicillin allergy

Evaluate the efficacy of prolonged oral penicillin challenge (5 days) over single dose penicillin challenge for ascertainment of true penicillin allergy (i.e. immune mediated allergy).

Key facts

Sponsor
Gentofte Hospital, Austin Health
Participant type
Patients
Age range
18-64 years, 65+ years
Gender
Male and Female
Therapeutic area
Diseases [C] - Immune System Diseases [C20]
Trial duration
10 Dec 2025 → ongoing
Decision date (initial)
2025-10-28
Transition trial
No
Low-intervention
No
Rare-disease indication
No
Vulnerable population
No
Funding sources
no external funding

External identifiers

EU CT number
2025-520888-41-00
WHO UTN
U1111-1319-6129

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Diagnosis

Evaluate the efficacy of prolonged oral penicillin challenge (5 days) over single dose penicillin challenge for ascertainment of true penicillin allergy (i.e. immune mediated allergy).

Conditions and MedDRA coding

Penicillin allergy

VersionLevelCodeTermSystem organ class
20.0 LLT 10013661 Drug allergy 10021428
20.0 LLT 10001738 Allergy 10021428
20.0 LLT 10034292 Penicillin allergy 10021428
22.0 LLT 10082424 Allergy to antibiotic 10021428
20.1 PT 10053462 Allergy test 100000004848
23.0 LLT 10083817 Oral drug challenge test 10022891

Study design 1 period

#TitleAllocationBlindingRoles blindedArms
1 PROSPECTOR-2
International multi-center, double blinded, placebo-controlled, parallel 2-arm, superiority randomised clinical trial
 Randomised Controlled Double [{"id":176446,"code":4,"name":"Analyst"},{"id":176448,"code":5,"name":"Carer"},{"id":176449,"code":1,"name":"Subject"},{"id":176447,"code":2,"name":"Investigator"}] control (placebo): If recruited to the control arm, the participant will receive no further therapeutic doses, but will receive oral placebo twice daily (BD) for 5 days, commencing the day following the hospital administered single dose
Intervention: If recruited to the intervention arm, the participant will then receive a 5-day course of oral amoxicillin 500mg twice daily (BD) frequency, commencing the day following the hospital administered single dose (Day 1).

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 6

  1. Adult patients referred to the outpatient allergy clinic or inpatient allergy service (with a non-infective diagnosis) for a penicillin allergy history (i.e. amoxicillin or penicillin unspecified)
  2. Adult patients with an immune-mediated penicillin allergy history: 1. Delayed phenotype (> 6 hours post dose) 2. Or unknown timing
  3. Tolerated first dose of an oral amoxicillin challenge
  4. Willing and able to give consent
  5. Willing and able to undergo telehealth or in clinic review post challenge
  6. Outpatients who are not currently receiving, or are not likely to receive, beta-lactam antibiotic therapy during the 14-day study period.

Exclusion criteria 4

  1. Patient age is < 18 years
  2. Any other illness that, in the investigator’s judgement, will substantially increase the risk associated with subject’s participation in this study
  3. Stevens-Johnson Syndrome, Drug Reaction with Eosinophilia and Systemic Symptoms or Acute Generalized Exanthematous Pustulosis or Toxic Epidermal Necrolysis to penicillin’s or aminocephalosporins
  4. Concurrent use of antihistamines or systemic steroid therapy (> 10 mg daily)

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

  1. Positive oral challenge (i.e. immune mediated reaction up to and including day 7 following the first test dose, number and percentage of participants), as adjudged by independent blinded panel

Secondary endpoints 4

  1. Positive oral challenge (i.e. immune mediated reaction up to and including day 14 following the first test dose, number and percentage of participants), as adjudged by independent blinded panel
  2. Non-inferiority of single dose challenge to prolonged challenge (risk difference with two-sided 95% confidence interval using 10% as clinically relevant non-inferiority margin)
  3. Time to positive oral challenge
  4. Quality of life (measured by Drug Hypersensitivity Quality of Life Questionnaire (DrHy-Q) at day 0 and 90

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Amoxicillin

PRD12493417 · Product

Active substance
Amoxicillin Trihydrate
Substance synonyms
AMOXYCILLIN TRIHYDRATE
Pharmaceutical form
CAPSULE
Route of administration
ORAL
Max daily dose
1000 mg milligram(s)
Max total dose
5000 mg milligram(s)
Max treatment duration
5 Day(s)
Authorisation status
Not Authorised
MA holder
REGION HOVEDSTADENS APOTEK
Paediatric formulation
No
Orphan designation
No

Placebo 1

Capsugel Belgium N.V Empty hard gelatin capsules size AA Elong, DB-caps Part number G7ECL000020 see IMPD

N/A · Product

Other product name
N/A
Pharmaceutical form
N/A
ATC code
N/A — N/A
Marketing authorisation
N/A
MA holder
N/A
MA country
Iceland
Paediatric formulation
No

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Gentofte Hospital

22 Total trials 10 Recruiting 9 Ended
Commercial
Sponsor organisation
Gentofte Hospital
Address
Gentofte Hospitalsvej 1
City
Hellerup
Postcode
2900
Country
Denmark

Scientific contact point

Organisation
Gentofte Hospital
Contact name
Lene Heise Garvey

Public contact point

Organisation
Gentofte Hospital
Contact name
Lene Heise Garvey

Third parties 2

OrganisationCity, countryDuties
Region Hovedstaden
ORG-100003705
 Frederiksberg, Denmark On site monitoring
Universitair Ziekenhuis Antwerpen
ORG-100009995
 Edegem, Belgium On site monitoring

Austin Health

Sponsor organisation
Austin Health
Address
P. O. Box 5555, 145 Studley Road 145 Studley Road
City
Heidelberg
Postcode
3084
Country
Australia

Scientific contact point

Organisation
Austin Health
Contact name
Jason Trubiano

Public contact point

Organisation
Austin Health
Contact name
Jason Trubiano

Sponsor responsibilities

Article 77 compliance
Gentofte Hospital
Contact point sponsor
Gentofte Hospital
Article 77 implementation
Gentofte Hospital

Locations

2 EU/EEA countries · 2 investigational sites

By country

CountryMS statusPlanned subjectsSites
Belgium Authorised, recruitment pending 80 1
Denmark Ongoing, recruiting 80 1
Rest of world
South Africa, Canada, United States, Australia, Hong Kong
 — 552 —

Investigational sites

Belgium

1 site · Authorised, recruitment pending
Universitair Ziekenhuis Antwerpen
immunology, allergy and rheumatology, Drie Eikenstraat 655, 2650, Edegem

Denmark

1 site · Ongoing, recruiting
Gentofte Hospital
Allergy Clinic, Department of Dermatology and Allergy, Gentofte Hospitalsvej 1, 2900, Hellerup

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Country Trial startTrial end Recruitment startRecruitment end Early termination
Denmark 2025-12-10 2025-12-10

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 27 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

TypeTitleVersion
Protocol (for publication) D1 updated PROSPECTOR 2 protocol for European sites clean version 4.0
Protocol (for publication) D1 updated PROSPECTOR 2 protocol for European sites track changes version 1
Protocol (for publication) D4 Drug hypersensitivity QOL questionnaire 1
Protocol (for publication) D4 Drug hypersensitivity QOL questionnaire_Danish 1
Protocol (for publication) D4 Drug hypersensitivity QOL questionnaire_Dutch 1
Protocol (for publication) D4 Patient instruction card Danish 1
Protocol (for publication) D4 patient instruction card Dutch 1
Protocol (for publication) D4 Telephone follow up questionnaire 1
Protocol (for publication) D4 telephone follow up questionnaire Danish 1
Protocol (for publication) D4 Telephone follow up questionnaire dutch 1
Protocol (for publication) Summary of changes protocol RFI I 1
Recruitment arrangements (for publication) K1 recruitment arrangements 3.0
Recruitment arrangements (for publication) K1 Recruitment arrangements 1
Recruitment arrangements (for publication) K2 recruitment poster for waiting room 1.00
Subject information and informed consent form (for publication) D4 Telephone follow up questionnaire dutch 2
Subject information and informed consent form (for publication) D4 Telephone follow up questionnaire dutch track changes 2
Subject information and informed consent form (for publication) L1 subject information and informed consent Dutch 5.0
Subject information and informed consent form (for publication) L1 Subject information and informed consent Dutch track changes 1
Subject information and informed consent form (for publication) L1 subject information and informed consent English 4.0
Subject information and informed consent form (for publication) L1 subject information and informed consent form 2.00
Subject information and informed consent form (for publication) L1 subject information and informed consent French 4.0
Subject information and informed consent form (for publication) L2 Participants rights in a clinical trial National Ethical Committee 1
Summary of Product Characteristics (SmPC) (for publication) G2 SmPC for Amoxicillin Aurobindo 500 mg capsules US 1
Synopsis of the protocol (for publication) D1_Protocol synopsis_DA 2025-520888-41-00 2.1
Synopsis of the protocol (for publication) D1_Protocol synopsis_DE 2025-520888-41-00 1
Synopsis of the protocol (for publication) D1_Protocol synopsis_FR 2025-520888-41-00 1
Synopsis of the protocol (for publication) D1_Protocol synopsis_NL 2025-520888-41-00 1

Application history

2 submissions — initial application plus substantial / non-substantial modifications

#TypeCodeSubmittedReference MSConclusionDecision date
1 INITIAL IN 2025-07-07 Denmark Acceptable
2025-10-27
 2025-10-28
2 SUBSTANTIAL MODIFICATION SM-1 2026-03-30 Acceptable 2026-05-26