New Antibiotic Treatment Options for Uncomplicated Anogenital Gonorrhoea Infections - a Double-blind Randomized Controlled Non-inferiority Trial
Phase: PHASE3
Conditions: Gonorrhea
Sponsor: Public Health Service of Amsterdam

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ACADEMICAL MEDICAL CENTER (AMC) – PUBLIC HEALTH SERVICE (GGD) AMSTERDAM 
New antibiotic treatment 
options for 
uncomplicated 
anogenital gonorrhoea   
(NABOGO trial) 
a double-blind randomized clinical non-
inferiority trial 
 
 
 
 
 
 
 
 
This document contains the protocol of a double blinded randomized controlled non-inferiority trial 
investigating registered antibiotics as new treatment options for uncomplicated anogenital gonorrhoea. 
In this protocol the rationale and the study procedures are described in detail.  

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PROTOCOL TITLE: New antibiotic treatment options for uncomplicated anogenital gonorrhoea 
infections – a double-blind randomized clinical non-inferiority trial 
Protocol ID 
new antibiotic treatment options for uncomplicated 
anogenital gonorrhoea 
Short title 
NABOGO 
EudraCT number  
2017-000176-28 
Version 
2.0 
Date 
May 10th 2017 
Study coordinator 
 
M.M. de Laat, MD, PhD student 
STI Outpatient Clinic, Public Health Service Amsterdam 
and Department of Dermatology, Academic Medical 
Center, University of Amsterdam 
Principal investigator 
 
Prof. dr. H.J.C. de Vries, MD 
Dermato-venerologist, STI Outpatient Clinic, Public 
Health Service Amsterdam and Department of 
Dermatology, Academic Medical Center, University of 
Amsterdam  
Project members 
Dr. Sylvia Bruisten 
Molecular microbiology, Department of Infectious 
Diseases, Public Health Service (GGD) Amsterdam 
Dr. A.P. van Dam, MD  
Microbiology, Department Infectious Diseases, Public 
Health Service (GGD) Amsterdam  
Dr. A. Hogewoning, MD 
Dermatology, Head of department STI Outpatient clinic 
Public Health Service (GGD) Amsterdam 
Dr. M. Knol 
Senior epidemiologist, RIVM, National Institute for 
Public Health and the Environment, Centre for 
Infectious Disease Control Netherlands (CIb),  
Epidemiology and Surveillance Unit (EPI) 
Prof. dr. R.A.A. Mathot, MD 
Pharmacology, Department pharmacology, Academic 
Medical Center, University of Amsterdam 
Prof. dr. J.M. Prins, MD 

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Internal Medicine and Infectious Diseases, Head of 
Department Internal Medicine, Academic Medical 
Center, University of Amsterdam 
Dr. M.F. Schim van der Loeff, MD 
Senior epidemiologist, Department research and 
prevention of infectious diseases, Public Health 
Service Amsterdam 
Dr. C.M. Wind, MD 
Dermatology Leiden University Medical Center 
Sponsor  
Academic Medical Center, Amsterdam 
Contractor 
Public Health Services, Amsterdam 
Subsidising party 
ZonMW, project number: 84801 5001 
Independent expert 
Dr. G. Sonder, MD 
Senior epidemiologist, biologist, Head of Department 
of Infectious Diseases, Public Health Service  
Amsterdam 
Laboratory sites  
Public Health Laboratory, Department of Infectious 
Diseases, Public Health Service Amsterdam 
Pharmacy  
AMC Pharmacy 
Dr. E.M. Kemper, pharmacologist 

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PROTOCOL SIGNATURE SHEET 
Name 
Signature 
Date 
Head of Department: 
 
Prof. dr. R. Hoekzema, MD 
dermatologist, head of 
department Dermatology, 
Academic Medical Center 
Amsterdam 
 
Principal Investigator: 
 
Prof. dr. H.J.C. de Vries, MD 
dermatologist, head of 
department STI clinic, Public 
Health Services Amsterdam 
and Academic Medical Center 
Amsterdam 
 
 
 
 
 

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TABLE OF CONTENTS 
1. 
INTRODUCTION AND RATIONALE ............................................................................................... 4 
2. 
OBJECTIVES .................................................................................................................................. 6 
3. 
STUDY DESIGN .............................................................................................................................. 7 
4. 
STUDY POPULATION .................................................................................................................... 8 
4.1 
Population (base)..................................................................................................................... 8 
4.2 
Inclusion criteria ....................................................................................................................... 8 
4.3 
Exclusion criteria...................................................................................................................... 8 
4.4 
Sample size calculation ......................................................................................................... 10 
5. 
TREATMENT OF SUBJECTS ....................................................................................................... 11 
5.1 
Investigational product/treatment .......................................................................................... 11 
5.2 
Use of co-intervention ............................................................................................................ 11 
5.3 
Escape medication ................................................................................................................ 11 
6. 
INVESTIGATIONAL PRODUCT .................................................................................................... 12 
6.1 
Name and description of investigational  product(s) ............................................................. 12 
6.2 
Summary of findings from non-clinical studies ...................................................................... 12 
6.3 
Summary of findings from clinical studies ............................................................................. 12 
6.4 
Summary of known and potential risks and benefits ............................................................. 12 
6.5 
Description and justification of route of administration and dosage ...................................... 13 
6.6 
Dosages, dosage modifications and method of administration ............................................. 13 
6.7 
Preparation and labelling of Investigational Medicinal Product ............................................. 16 
6.8 
Drug accountability ................................................................................................................ 16 
7. 
METHODS ..................................................................................................................................... 17 
7.1 
Study endpoints ..................................................................................................................... 17 
7.1.1 
Main study endpoint....................................................................................................... 17 
7.1.2 
Secondary study parameters/endpoints ........................................................................ 17 
7.2 
Randomization, blinding and treatment allocation ................................................................. 18 
7.3 
Study procedures................................................................................................................... 18 
7.4 
Withdrawal of individual subjects........................................................................................... 21 
7.5 
Replacement of individual subjects after withdrawal ............................................................. 21 
7.6 
Follow-up of subjects withdrawn from treatment ................................................................... 21 
7.7 
Premature termination of the study ....................................................................................... 21 
8. 
SAFETY REPORTING .................................................................................................................. 22 
8.2 
AEs, SAEs and SUSARs ....................................................................................................... 22 
8.2.1 
Adverse events (AEs) .................................................................................................... 22 
8.2.2 
Serious adverse events (SAEs) ..................................................................................... 22 
8.2.3 
Suspected unexpected serious adverse reactions (SUSARs) ...................................... 22 
8.3 
Annual safety report .............................................................................................................. 23 
8.4 
Follow-up of adverse events .................................................................................................. 24 
8.5 
Data Safety Monitoring Board (DSMB) / Safety Committee .................................................. 24 
9. 
STATISTICAL ANALYSIS ......................................................................................................... 25 
9.1 
Primary study parameters ..................................................................................................... 25 
9.2 
Secondary study parameters ................................................................................................. 25 

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9.3 
Interim analysis ...................................................................................................................... 26 
10. 
ETHICAL CONSIDERATIONS .................................................................................................. 27 
10.1 
Regulation statement ............................................................................................................. 27 
10.2 
Recruitment and consent ....................................................................................................... 27 
10.3 
Objection by minors or incapacitated subjects (if applicable) ............................................... 27 
10.4 
Benefits and risks assessment, group relatedness ............................................................... 27 
10.5 
Compensation for injury ......................................................................................................... 28 
10.6 
Incentives ............................................................................................................................... 28 
11. 
ADMINISTRATIVE ASPECTS, MONITORING AND PUBLICATION ....................................... 29 
11.1 
Handling and storage of data and documents ....................................................................... 29 
11.2 
Monitoring and Quality Assurance......................................................................................... 29 
11.3 
Amendments .......................................................................................................................... 29 
11.4 
Annual progress report .......................................................................................................... 29 
11.5 
End of study report ................................................................................................................ 29 
11.6 
Public disclosure and publication policy ................................................................................ 30 
12. 
STRUCTURED RISK ANALYSIS .............................................................................................. 31 
12.1 
Potential issues of concern .................................................................................................... 31 
12.2 
Synthesis ............................................................................................................................... 35 
13. 
REFERENCES .......................................................................................................................... 37 

0 
 
LIST OF ABBREVIATIONS AND RELEVANT DEFINITIONS  
ABR 
ABR form, General Assessment and Registration form, is the application form that 
is required for submission to the accredited Ethics Committee (In Dutch, ABR = 
Algemene Beoordeling en Registratie) 
AMC 
AMR 
AE 
Academic Medical Center  
Antimicrobial Resistance 
Adverse Event 
AR 
Adverse Reaction 
CA 
Competent Authority 
CCMO 
Central Committee on Research Involving Human Subjects; in Dutch: Centrale 
Commissie Mensgebonden Onderzoek 
CV 
Curriculum Vitae 
DALY 
DSMB 
EMA 
Disability Adjusted Life Years 
Data Safety Monitoring Board 
European Medicines Agency 
ESC 
Extended Spectrum Cephalosporin 
EudraCT 
European Drug Regulatory Affairs Clinical Trials  
FDA 
GCP 
HIV 
Food and Drug Administration 
Good Clinical Practice 
Human Immunodeficiency Virus 
IB 
Investigator’s Brochure 
IC 
IM 
Informed Consent 
Intramuscular(ly) 
IMP 
Investigational Medicinal Product  
IMPD 
Investigational Medicinal Product Dossier  
ITT 
IV 
METC  
Intention To Treat analysis 
Intravenous(ly) 
Medical research ethics committee (MREC); in Dutch: medisch ethische toetsing 
commissie (METC) 
MIC 
MITT 
MSM 
NAAT 
Ng 
Minimum Inhibitory Concentration 
Modified Intention To Treat analysis 
Men who have sex with men 
Nucleic Acid Amplification Test 
Neisseria gonorrhoeae 

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PP 
POC 
RCT 
(S)AE 
Per Protocol analysis 
Point-of-Care (test) 
Randomized Controlled Trial 
(Serious) Adverse Event  
SPC 
Summary of Product Characteristics (in Dutch: officiële productinfomatie IB1-tekst) 
Sponsor 
The sponsor is the party that commissions the organisation or performance of the 
research, for example a pharmaceutical company, academic hospital, scientific 
organisation or investigator. A party that provides funding for a study but does not 
commission it is not regarded as the sponsor, but referred to as a subsidising 
party. 
STI 
SUSAR 
Sexually Transmitted Infection 
Suspected Unexpected Serious Adverse Reaction 
TOC 
Wbp 
Test of Cure 
Personal Data Protection Act (in Dutch: Wet Bescherming Persoonsgevens) 
WHO 
WMO 
World Health Organization 
Medical Research Involving Human Subjects Act (in Dutch: Wet Medisch-
wetenschappelijk Onderzoek met Mensen 
 
 
 
 

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SUMMARY 
Rationale: Antimicrobial resistance (AMR) to extended spectrum cephalosporins (ESC) among 
Neisseria gonorrhoeae (Ng) is a major public health concern. With no alternative antimicrobial 
treatment options for gonorrhoea and only a few new drugs in the development pipeline, it is 
important to test existing antibiotics for their efficacy in gonorrhoea treatment.  
Objective: This project aims to identify new treatment modalities for uncomplicated gonorrhoea using 
the registered drugs ertapenem, fosfomycin and gentamicin.  
Study design: A double blinded randomized controlled non-inferiority trial with four treatment arms.  
Study population: Patients with anogenital gonorrhoea visiting the sexually transmitted infections 
(STI) outpatient clinic of the Public Health Services Amsterdam, aged 18 years and older, both female 
and male, with a variety of ethnic backgrounds. The highest prevalence of gonorrhoea is seen among 
men who have sex with men (MSM).  
Intervention: Fivehunderd forty-eight patients are randomly assigned to one of four treatment arms. 
They will receive either ceftriaxone 500mg intramuscularly (IM) or ertapenem 1000mg IM or 
gentamicin 5mg/kg IM with a maximum of 400mg (in two doses) supplemented with an oral placebo, 
or receive fosfomycin 6g oral suspension supplemented with an intramuscular placebo. 
Main study endpoint: The bacterial eradication capacity of the study antimicrobials at the included 
infection site using an RNA-based Nucleic Acid Amplification Test (NAAT) 7-14 days after treatment.  
Nature and extent of the burden and risks associated with participation, benefit and group 
relatedness: With 78 million new cases of gonorrhoea in adults aged 15-49 years, gonorrhoea is the 
second most bacterial STI worldwide. Persistent Ng infections may cause severe reproductive tract 
inflammation and irreversible damage with infertility as a result. Moreover gonorrhoea also increases 
the risk of human immunodeficiency virus (HIV) transmission. When untreatable gonorrhoea becomes 
reality, an increase will be seen in both the burden of disease and costs for society.   
The drugs in this study are all widely used antimicrobials. The most important side effects are nephro- 
and ototoxicity associated with gentamicin. However, limited research has been done on the safety of 
a single dose intramuscular injection of gentamicin. We expect that a single dose intramuscular 
injection will not harm young and healthy participants. For safety reasons and to monitor the renal 
function, we will measure renal function before and after treatment. Patients with renal impairment are 
not eligible to take part in this study.  
The burden of participation to this study comprises a double instead of a single intramuscular 
injection, because the injectable volume of gentamicin will be too large (6-10 ml) for a single injection. 
At the same time all participants receive an oral suspension, a finger prick to draw blood for point-of-
care (POC) serum creatinin test, one extra visit at day 7 for follow-up with another NAAT and keeping 
a diary between treatment and follow-up visit after 7 days. A subset of approximately 160 participants 

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will additionally be asked to give two to three blood samples (total volume: 9 – 13.5 ml) for the 
purpose of estimating the population pharmacokinetics, which will be used for a PK/PD analysis in 
order to aid the optimization of treatment regimes.   
 
 

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1. INTRODUCTION AND RATIONALE 
With 78 million new cases of gonorrhoea in adults aged 15–49 years, gonorrhoea is the second most 
common bacterial sexually transmitted infection worldwide (STI)[1]. Persistent infections may cause 
severe genital and reproductive tract inflammation and irreversible damage with infertility as a result.  
Moreover, gonorrhoea increases the transmission of human immunodeficiency virus (HIV)[2]. The 
most recent global report of the World Health Organization (WHO) on antimicrobial resistance (AMR) 
published in 2014, specifically mentions treatment failures of gonorrhoea due to resistance to 
extended spectrum cephalosporins (ESCs) in 10 countries. ESCs are the treatment of last resort for 
gonorrhoea. Furthermore, decreased susceptibility to ESCs is reported in 36 countries including the 
Netherlands[3, 4]. It is anticipated to be only a matter of time before gonococci with full resistance to 
the ESCs spread internationally. Consequently, gonorrhoea may become untreatable unless new 
drugs become available or existing drugs that are presently not used for treatment of gonorrhoea are 
tested for their efficacy in gonorrhoea infections[5-7].  
The threat of untreatable gonorrhoea infections is of global concern because there will be a major 
impact on disease control efforts due to prolonged infections, increased prevalence of serious 
complications, and also non-urogenital gonococcal diseases such as neonatal infections and 
disseminated gonococcal infections will become much more common. In addition, untreated 
gonorrhoea is associated with an increased risk of acquisition and transmission of HIV infection[2]. 
Based on the 2008 global estimates of incident gonococcal infections, the estimate for global 
disability- adjusted life years (DALYs) due to gonorrhoea is approximately 440,000[8]. Antimicrobial 
resistance in gonorrhoea will further increase this burden and cost for society. Financial costs for 
health services and individual patients will increase[9]. 
This project aims to identify new treatment modalities for uncomplicated gonorrhoea using the 
registered drugs, ertapenem, fosfomycin and gentamicin, which have not yet been proven clinically 
effective against gonorrhoea. Although ertapenem is, like ceftriaxone, a beta-lactam antibiotic, so far 
Ng strains with resistance to ceftriaxone had much lower minimum inhibitory concentrations (MICs) for  
ertapenem. For this reason, ertapenem is very likely also an effective antibiotic against ESC-resistant 
strains. The efficacy of ertapenem in other extended spectrum β-lactamase (ESBL) producing gram-
negative bacteria’s is previously proven[10-12]. Both fosfomycin and gentamicin have modes of action 
very different from ceftriaxone, and their efficacy against gonorrhoea will be unrelated to the strains’ 
susceptibility for ceftriaxone. Yuan et al. performed a randomized controlled trial (RCT) in which a 
three-dose regimen of 3 g fosfomycin was compared to dual regimen of ceftriaxone and azithromycin. 
In this trial, efficacy of both regimens for treatment of uncomplicated gonococcal urethritis in men was 
shown[13]. However, a non-inferior effectiveness of fosfomycin compared to ceftriaxone plus 
azithromycin could not be concluded. This study was limited by the small sample size and by the use 
of different test modalities for diagnosis (gram stain) and test of cure (culture and/or RNA-based 
Nucleic Acid Amplification Test (NAAT)). Gentamicin has been used for the treatment of gonorrhoea 
in some developing countries for decades [14-16]. However, the effect had never been evaluated in 
an RCT. A two-arm dual therapeutic regimen trial is ongoing in the UK comparing gentamicin with 

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ceftriaxone, plus azithromycin in both arms[17]. As mentioned by Kirkcaldy et al, a limitation of an 
RCT with dual therapeutic arms containing azithromycin is that it is not possible to evaluate the 
efficacy of the second antibiotic since high-dose azithromycin has demonstrated excellent efficacy 
against azithromycin susceptible gonorrhoea as mono-therapy[18]. Besides, several studies have 
now conclusively shown that the formerly assumed synergistic effect of a combination of extended 
spectrum cephalosporin plus azithromycin in fact does not exist[19-23]. We will therefore compare 
mono-therapeutic regimes since this will allow a true evaluation of the eradicative capacity of each 
single antibiotic on gonorrhoea.  
We propose a non-inferiority, double-blinded randomized controlled trial to determine if one or more of 
the experimental treatment options against uncomplicated anogenital gonorrhoea are a good 
alternative for the current gold standard therapy in the Netherlands (500 mg ceftriaxone intramuscular 
(IM)), based on a test of cure, disappearance of symptoms and frequency and severity of adverse 
events.  
It is important to consider that the efficacy of an antimicrobial agent is dependent on the relationship 
between the MIC for the microorganism and the exposure of the microorganism to the agent in the 
patient. Therefore, we also aim to study the pharmacokinetic and pharmacodynamic properties of 
gentamicin, ertapenem and ceftriaxone (IM administered) and fosfomycin (orally administered). By 
combining pharmacokinetic data with antimicrobial susceptibility data (MIC) of circulating Neisseria 
gonorrhoeae (Ng) strains, Monte Carlo simulations will be performed to predict treatment efficacy 
under various antimicrobial resistance prevalence conditions, both now and in the near future[24]. 
 
 

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2. OBJECTIVES 
 
Primary objectives 
To determine the bacterial eradication capacity of ertapenem, fosfomycin and gentamicin compared 
to the reference treatment (ceftriaxone) in uncomplicated anogenital gonococcal infections (at one 
included infection site) by molecular test of cure (TOC) 7-14 days after treatment.  
 
Secondary objectives 
1. To determine the bacterial eradication capacity of the experimental treatment options (ertapenem, 
fosfomycin and gentamicin) compared to the reference treatment (ceftriaxone) in uncomplicated 
anogenital gonococcal infections by molecular test of cure after 7-28 days.  
2. To determine the bacterial eradication capacity of experimental treatment options compared to the 
reference treatment at infection sites other than the included infection site (also including pharyngeal 
gonorrhoea) by molecular test of cure after 7-28 days.  
3. To determine the type, frequency and severity of adverse events of the experimental treatment 
options compared to the reference treatment.  
4. To determine the in vitro antimicrobial susceptibility (in MIC) of the experimental and reference 
treatment in all Ng strains collected at all infected anatomical sites of each participant at inclusion and 
in case of a positive test of cure.  
5. To determine the time to disappearance of symptoms at the included infection site in the first 14  
days after treatment, for the experimental treatment compared to the reference treatment.  
6. To determine the clinical and demographic predictors for treatment failure (see chapter 7 for 
definition).  
7. To determine the population pharmacokinetics of ceftriaxone, gentamicin and ertapenem  
administered intramuscularly, and fosfomycin administered orally.  
 
 

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3. STUDY DESIGN 
A double-blinded randomized controlled single center non-inferiority trial with three experimental arms 
and one reference arm. The expected duration of the study is 36 months, of which 18 months are 
needed for recruitment. The study will be conducted at the sexually transmitted infections (STI) 
outpatient clinic of the Public Health Service in Amsterdam.   
All participants are requested to participate in a subset for a pharmacological analysis as well until we 
have included 160 participants. Following randomization we aim to include approximately 40 
participants in each treatment arm for this additional subset. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
* estimated numbers 
Figure 1. Flow chart of study design and sample size. 
 
Patients visiting STI Outpatient 
Clinic Amsterdam 
Meeting inclusion criteria  
Meeting exclusion criteria 
Reference therapy 
(N = 137)* 
Experimental arm 1 
(N = 137)* 
Experimental arm 2 
(N = 137)* 
Experimental arm 3 
(N = 137)* 
Subset for pharmacological 
analysis (N = 160;  
40 participants of each arm) 
Randomization  
(N = 548)*
Post-randomisation exclusions based 
on negative baseline NAAT (N = 55)*  
Loss to follow-up (N = 55)* 
Protocol violations 
Per protocol population 
Intention to treat population (N = 438)* 
Not meeting inclusion 
criteria 
Not meeting exclusion criteria 

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4. STUDY POPULATION 
 
4.1 Study population 
Patients of the STI Outpatient Clinic Amsterdam with an uncomplicated anogenital Ng infection will be 
included in this study. At the STI clinic in Amsterdam we diagnosed 2230 new gonorrhoea patients in 
2016, or approximately 185 per month. Of these, 2033 patients were male and 197 were female, ages 
ranged between 15 years and 73 years old with a variety in ethnic backgrounds. Of all gonorrhoea 
cases 28.1% were coinfected with other bacterial STI. Of all anatomical infection sites, in 2016, the 
anorectal site was most frequently infected (1218 anorectal infections among MSM, 84 anorectal 
infections among females), followed by the pharyngeal infection site (1026 pharyngeal infections 
among MSM, 58 pharyngeal infections among females). The urogenital infection was the least 
infected site (476 urogenital infections among MSM, 144 urogenital infections among heterosexual 
males, 143 cervical/vaginal infections among females) at the STI clinic in Amsterdam [Annual report 
STI clinic Public Health Service (GGD) Amsterdam, 2016].  
4.2 Inclusion criteria 
In order to be eligible to participate in this study, a subject must meet all of the following criteria:  
- 
18 years or older 
- 
Anorectal, cervical/vaginal or urethral Ng infection, diagnosed by the following: 
o 
Ng-positive Gram-stained smear (intracellular Gram-negative diplococci and 
leukocytes) and/or 
o 
Positive for Ng by nucleic acid amplification test (NAAT) (Aptima Combo 2) and/or 
o 
Positive for Ng by culture 
- 
Provide samples from the included infection site for NAAT and direct culture immediately 
before treatment 
- 
Willing to abstain from anal, vaginal and oral sex until the test of cure (TOC)-visit, or use 
condoms during sex 
- 
Willing and able to return for a TOC-visit 7-14 days after treatment 
- 
Provide informed consent 
- 
Able to swallow liquid and accept intramuscular injections 
 
4.3 Exclusion criteria 
A potential participant who meets any of the following criteria will be excluded from participation in this 
study 
 
Pre-randomisation: 
- 
Suspicion of a complicated Ng infection based on signs and/or symptoms indicating pelvic 
inflammatory disease (PID), epididymitis, prostatitis or gonococcal arthritis* 
                                                     
 

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- 
Another (sexually transmitted) infection or a suspicion of another infection for which 
antimicrobial therapy is indicated  
- 
Pregnancy, having a wish to become pregnant or breastfeeding (tested at inclusion visit) 
- 
Not able to read/understand Dutch or English 
- 
HIV infection if: 
o 
Newly diagnosed HIV infection (upon the inclusion visit) and/or 
o 
CD4+ cell-count <200 cells/µL (as reported by the patient) 
- 
Known allergy or adverse reactions to ceftriaxone, ertapenem, fosfomycin or gentamicin 
- 
Known renal impairment (based on estimated GFR using Cockroft and Gault formula using 
serum creatinin measured with a point-of-care (POC) test; cut off value renal impairment 
eGFR ≤ 50 ml/min) 
- 
Known liver cirrhosis (based on history) 
- 
Known congestive heart failure (based on history) 
- 
Known myasthenia gravis 
- 
Known hearing loss or balance disorder, confirmed by an ear-nose-throat (ENT)-doctor or for 
which an ENT doctor has been consulted and a diagnostic process is still in progress (based 
on history) 
- 
Concurrent use of any of the following medication:  
o 
systemic antibacterial antimicrobials other than nitrofurantoin or metronidazole 
o 
systemic immunosuppressive drugs 
o 
systemic valproic acid 
o 
systemic metoclopramide  
- 
Use of any antimicrobial therapy other than nitrofurantoin or metronidazole in the two weeks 
prior to study enrollment (based on history) 
- 
Previous enrollment in the study 
- 
Concurrent participation in other non-observational medical research 
- 
Unlikely to adhere to the study protocol 
 
Post-randomisation: 
Exclusion of participants from the intention to treat analysis (ITT): 
- 
Negative result of Ng NAAT of sample collected on T0 (the day of treatment): 
1. Negative NAAT in spite of positive gram stain. 
2. Positive NAAT on prestudy visit but spontaneous clearance of the infection in the time 
period between first test and return visit for treatment (=study inclusion visit). A novel 
sample for NAAT will be collected on the study inclusion visit just before administration of  
treatment; if these results are Ng-negative a participant will be excluded of ITT.  
Exclusion of per protocol analysis (PP):  
- 
Exclusion of ITT 
- 
Use of non-study related antibiotics after inclusion prior to TOC visit 
- 
Other protocol violations 

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4.4 Sample size calculation  
To calculate the sample size for this non-inferiority trial we used the R function nBinomial of the 
package gsDesign. This function computes sample size using the method of Farrington and Manning 
for a trial to test the difference between two binomial event rates[25]. The following parameters were 
used in the calculation: 98% treatment success in control and experimental arms, 10% non-inferiority 
δ-margin (a commonly used margin), 90% power, two-sided α-level of 0.0083 (including Bonferroni 
adjustment for three comparisons). This results in a sample size of 109 participants per treatment 
arm. Considering a loss-to-follow-up rate of 10% (participants not returning for TOC or exclusion 
criteria) and considering a post hoc exclusion of 10% due to false-positive gram stains and self-
clearance, we require 137 included participants per treatment arm. Thus, a total of 548 participants 
should be included.  
 
In order to estimate the population pharmacokinetics, we will measure blood concentration of the 
administered antimicrobial in 160 participants at two or more various time points[26]. As a result of the 
randomization, it is expected that approximately 40 participants will be included per treatment arm. 
With the collected data reliable population pharmacokinetic-pharmacodynamic models will be derived 
for Monte Carlo simulations.  
 
4.4.1. Recruitment duration 
At the STI clinic in Amsterdam we diagnosed 1667 new anogenital gonorrhoea cases in 2016, which 
is approximately 138 per month. Assuming that 71.9% of them does not have a bacterial co-infection 
and will  be eligible to participate in this trial and assuming that 30% of invited patients consent to 
participate and does not meet exclusion criteria, we may expect 30 inclusions per month. To allow for 
a slow inclusion of 25 per month, we will need a recruitment period of 548/25 = 22 months.  
 
4.5 Patient registration  
Inclusion of participants will be performed by either a research nurse or the research coordinator. 
After obtaining written informed consent, the research coordinator will keep the informed consent 
form. A study number will be generated at inclusion and stored on a coding list. All participants 
receive a ‘study identification card’ with contact information of the study team and a personal study 
number of which should be kept by the participant. This ‘study identification card’ does not contain 
any personal information of the participant.  
 
 

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5. TREATMENT OF SUBJECTS 
 
5.1 Investigational treatment 
Participants will be treated with either one of three experimental therapies (intramuscular gentamicin 
and ertapenem and oral fosfomycin) or the reference therapy (intramuscular ceftriaxone). Participants 
and the treating health professional will be blinded for the treatment allocation. For blinding purposes, 
those receiving intramuscular therapy (gentamicin will be administered in two intramuscular injections, 
when allocated to the ertapenem or ceftriaxone group participants will be given one intervention 
intramuscular injection and one placebo intramuscular injection) will receive a placebo oral solution 
and; those receiving oral therapy (fosfomycin) will receive two placebo intramuscular injections.  
 
5.2 Use of co-intervention 
There will be no use of co-intervention. Nevertheless participants are asked to refrain from sexual 
intercourse or use condoms between treatment and follow-up visit in order to minimize the occurrence 
of re-infection.  
 
5.3 Escape medication 
In case of an objectified treatment failure (see chapter 7.1.1 for definition), patients are retreated with 
the current reference therapy in an increased dose, ceftriaxone 1000mg intramuscular, plus 
azithromycin 1000mg orally. Ceftriaxone is currently still 100% effective in the Netherlands. However, 
in the case of clinical treatment failure it is possible that one received ceftriaxone 500mg. Besides, it is 
possible that antimicrobial susceptibility testing at inclusion indicates decreased susceptibility or  
resistance to ceftriaxone. For this reason, we chose to double the dose of ceftriaxone and to add 
azithromycin to the escape medication regime.  
 
 
 

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6. INVESTIGATIONAL PRODUCT 
 
6.1 Names and description of investigational medicinal products 
There will be three arms consisting of experimental treatments and one control arm consisting of the 
current reference treatment.  
- 
Reference treatment: single dose ceftriaxone 500 mg IM, dissolved in 2 ml lidocaine 1% 
supplemented with 0.9% NaCl until 10 ml (2 x 5 ml). 
- 
Experimental arm 1: single dose ertapenem 1000 mg IM, dissolved in 3.2 ml lidocaine 1% 
supplemented with 0.9% NaCl until 10 ml (2 x 5 ml). 
- 
Experimental arm 2: gentamicin 5 mg/kg IM injection once (solution 40 mg/ml), if indicated 
supplemented with 0.9% NaCl until 10 ml (2 x 5 ml). Maximum gentamicin dose is 400 mg 
because this is diluted in 10ml which is the maximum volume for 2 intramuscular injections. 
- 
Experimental arm 3: fosfomycin 6 gram trometamol orally once. 
- 
Placebo intramuscular injection: 5 ml or 10 ml (2 x 5 ml) 0.9% NaCl (when receiving oral therapy 
10 ml 0.9% NaCl will be administered, and when receiving ertapenem or ceftriaxone 5 ml 0.9% 
NaCl will be administered).  
- 
Placebo oral suspension: orange lemonade. 
 
6.2 Summary of findings from non-clinical studies 
See summary of product characteristics. 
 
6.3 Summary of findings from clinical studies 
See summary of product characteristics. 
 
6.4 Summary of known and potential risks and benefits 
Ceftriaxone 
Ceftriaxone is the standard therapy for Ng infections in the Netherlands. There is no resistance 
among Ng strains to ESCs reported in the Netherlands and ceftriaxone is well tolerated. Thus, in this 
trial ceftriaxone will not cause any additional risks in comparison to the general population with 
gonorrhoea. Consequently there is no need for extra measures to reduce expected risks.  
Ertapenem 
Ertapenem is safely used for several indications worldwide both in intramuscular and intravenous 
form (for more detailed information see chapter 12.1) [27]. In Europe, ertapenem is not yet registered 
as intramuscular injection, however it is safely used intravenously [28]. We do not expect any harm 
from a single intramuscular dose in our young and relative healthy population. Because of the 
influence of ertapenem on the valproic acid plasma levels, patients using valproic acid are excluded 
from this trial.  
Fosfomycin 
Fosfomycin is safely used for several indications worldwide. The usual dose of oral fosfomycin in 

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13 
 
urinary tract infections is a single dose of 3g. Based on Monte Carlo simulations to predict effective 
treatment dosage, 6g is expected to be effective in gonococcal infections. Since intravenous doses 
are administered up to 24g in 2-3 doses per day, we do not expect toxicity from a 6g oral dose. A few 
clinical studies have been performed on (either intramuscular or oral) fosfomycin in patients with 
uncomplicated gonococcal urethritis, none of these studies reported any severe events [13, 29, 30]. 
Participants of this trial are assured not to take metoclopramide in the first 7 days. In case of the 
intake of metoclopramide on the day of inclusion or in case of the intention to take metoclopramide in 
the following days, patients are excluded from this study.  
Gentamicin 
Since gentamicin is widely used for different indications and earlier research on a single dose 
intramuscular injection of 240-280mg [18, 31-34] in patients with gonorrhoea did not show any severe 
side effects, the hypothesis is that it is an efficient and safe product for this indication. There is limited 
knowledge on the prevalence of nephro- and ototoxicity as a result of a single dose gentamicin [35]. 
For this reason, renal function will be measured before treatment administration and people with an 
impaired renal function will be excluded from this study. Additionally, at the follow-up visit 7-14 days 
after treatment, renal function will again be tested in order to follow the effects of a single dose 
gentamicin on renal function. Also hearing problems and balance disorder will be evaluated before 
and after treatment.  
6.5 Description and justification of route of administration and dosage 
Ceftriaxone, ertapenem and gentamicin will be administered intramuscularly, as oral administration is 
not possible. Furthermore, intravenous administration is less comfortable for patients, not necessary 
and not possible at the STI outpatient clinic. In Europe, ertapenem is only registered for intravenous 
administration. In the United States of America (USA) ertapenem is approved by Food and Drug 
Administration (FDA) both for intravenous and intramuscular administration for various indications 
[27]. Fosfomycin oral suspension is available and preferred in the light of patient comfort and time 
management.  
 
For blinding purposes there are two treatment modalities: either therapeutic treatment will be 
administered intramuscularly (ceftriaxone, ertapenem or gentamicin) and placebo (orange lemonade) 
will be administered orally, or therapeutic treatment will be administered as an oral suspension 
(fosfomycin) and placebo (0.9% NaCl) will be administered intramuscularly. Solutions of ceftriaxone, 
ertapenem and gentamicin are colorless to light-yellow and have a similar visual appearance as 
placebo. Fosfomycin oral solution contains an orange/mandarin flavoring agent. Taste is comparable 
to the placebo orange lemonade. 
  
6.6 Dosages, dosage modifications and method of administration 
Dosages for ertapenem, fosfomycin and gentamicin are based on Monte Carlo simulations using 
pharmacokinetic information from literature [36-48], and MIC data of Ng strains isolated in Amsterdam 
Dosage of ceftriaxone is according to current Dutch STI guidelines [49]. 

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14 
 
Monte Carlo simulations of 5 mg/kg gentamicin (max 400 mg) IM demonstrated a median maximal 
concentration (Cmax) of 16 mg/L (95% CI: 8-22 mg/L (see figure 2). With a MIC of 1 the ratio 
Cmax/MIC is well above 10 which is considered a PD target for gentamicin. 
0
6
1 2
1 8
2 4
0
4
8
1 2
1 6
2 0
2 4
2 8
G e n ta m ic in  4 0 0  m g  im
tim e  (h )
g e n ta m ic in  c o n c  (m g /L )
 
Figure 2: Monte Carlo simulation of 5 mg/kg (max 400 mg) gentamicin IM  
 
Monte Carlo simulations of 1000 mg ertapenem IM resulted in unbound concentrations 9.6 hours 
above MIC in 100% of the patients with MIC up to 0.25 mg/L (Figure 3). This is well above the MIC90 
observed in our outpatient clinic (0.016 mg/L) 
 

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15 
 
0 .0 0 1
0 .0 1
0 .1
1
1 0
0
2 0
4 0
6 0
8 0
1 0 0
M IC  (m g /L )
%  p e rc n ta g e  p a tie n ts  9 .6  h o u r T > M IC
M IC 5 0
G G D
M IC 9 0
G G D
E rta p e n e m  1 0 0 0  m g  im
   
Figure 3: Monte Carlo simulation of 1000 mg ertapenem IM  
 
Monte Carlo simulations of 6 gram oral fosfomycin resulted in concentrations above an MIC of 10 
mg/L during an 8-hour period for 95% of the patients. Lopez Gracia reported a similar exposure after 
a single IM dose of 4 gram; in this study this dose produced 100% eradication [29]. 
0
6
1 2
1 8
2 4
0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
F o s fo m y c in  6  g  p o
tim e  (h )
fo fs fo m y c in  c o n c  (m g /L )
 
 Figure 4: Monte Carlo simulation of 6 gram oral fosfomycin  
 
 

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16 
 
6.7 Preparation and labeling of Investigational Medicinal Product 
This study will be performed in a double-blinded fashion. The patient, study nurse and the study 
coordinator will be blinded to treatment allocation.  
 
The medication will be prepared by an independent medical doctor from the STI clinic. When a patient 
is included in the study, this independent physician performs the randomization and prepares the 
medication according to the allocated treatment arm. Subsequently, the blinded medication is 
delivered to the study coordinator or study nurse, who will administer the blinded medication to the 
participant. A list will be kept by the independent medical doctor with the participant study ID linked to 
the allocated study arm. Four to five medical doctors from the STI clinic will be trained to function as 
an independent treatment preparer.  
 
6.8 Drug accountability 
Ceftriaxone, fosfomycin and gentamicin are registered at the European Medicines Agency (EMA) in 
this form and mode of administration and therefore will be available from any pharmacy. However, as 
stated before, ertapenem is only registered at the EMA for IV administration. The IV formulation is 
used for IM administration in the USA and this method is FDA approved for several indications. We 
will use the IV formulation likewise for IM administration. Batch numbers of medication used will be 
recorded. 
For intramuscular placebo we will use 0.9% NaCl and for oral placebo we will use orange lemonade 
(private label of Albert Heijn).  
 
 
 

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7. METHODS 
7.1 Study endpoints 
7.1.1 Primary endpoint 
Bacterial eradication of Ng infection at the included infection site, based on a test of cure (TOC) using 
an RNA-based NAAT (Aptima Combo 2 assay) at the follow-up visit 7-14 days after treatment (T7).   
 
An exceptional group contains participants who receive escape medication because of a suspected 
persistent Ng infection based on persisting symptoms and a positive Gram stain 3-6 days after 
treatment administration. These cases will be considered as ‘treatment failures’ without the 
performance of a test of cure, because a NAAT will not be reliable less than 7 days after treatment 
administration. 
A positive test of cure can be the result of a persistent infection and thus failure of the administered 
treatment, or can be a result of a re-infection. Re-infection could be either with the same Ng species 
(usually from the same partner(s)) or with another Ng species. In order to be able to differentiate 
between a persistent infection (treatment failure) or a re-infection with another Ng species (treatment 
success) we will perform genotyping of the Ng strains [50]. If we find two similar Ng strains we cannot 
differentiate between a persistent infection or a re-infection with the same strain, for this reason we 
follow the result of the test of cure in defining treatment failure or success in the primary analysis. 
7.1.2. Secondary endpoints 
1. Bacterial eradication of Ng infection at the included infection site, based on TOC using an RNA-
based NAAT 7-28 days after treatment. 
2. Bacterial eradication of Ng infection at any infected site(s) not included in the primary endpoint 
analysis, based on a TOC using an RNA-based NAAT 7-28 days after treatment.  
3. Any adverse events (type, frequency and severity) occurring during 28 days following the start of 
treatment.  
4. In vitro MICs of all Ng strains for all study antimicrobials, determined by e-test on culture at 
inclusion (before treatment, T0) and at the TOC follow-up visit (T7). 
5.  
a. Symptoms of Ng infection (such as pain, irritation/itch, redness, any discharge, bleeding, 
changed defecation pattern and/or swelling) from treatment to TOC visit (7-14 days). 
b. Time (in days) from the start of treatment to disappearance of symptoms of Ng infection. 
c. Signs of Ng infection (such as mucosal fragility, redness, discharge, bleeding and/or swelling) 
assessed at physical examination if indicated based on symptoms, at T0 and T7.  
6. Pharmacokinetic characteristics of study drugs in peripheral blood up to 24 hours after 
administration.  
 
 
 

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7.2 Randomization, blinding and treatment allocation 
7.2.1 Randomization 
Participants will be randomized in a 1:1:1:1 ratio to the four treatment arms. Randomization will be 
performed using random permuted blocks assuring equal distribution to all treatment arms. The length 
of the blocks will be random to avoid any selection bias (8-12 participants per block). A computer 
randomization program ALEA, which is validated for use in GCP trials and will be provided by the 
AMC Clinical Research Unit, will perform allocation.  
 
7.2.2 Blinding 
This study will be performed in a double-blinded fashion. The patient, study nurse and the study 
coordinator will be blinded to treatment allocation.  
 
There will be an independent medication preparer available for randomization, treatment allocation, 
preparation and blinding of medication. When a patient is included in the study, the medication 
preparer performs the randomization and prepares the medication according to the allocated 
treatment arm. The independent medication preparer will deliver the blinded medication to the study 
coordinator or study nurse, who subsequently will administer the medication to the participant. A list 
will be kept by the independent medication preparer with the participant study ID linked to the 
allocated study arm. Medical doctors and nurses from the STI clinic will be trained to function as an 
independent treatment preparer.  
 
7.2.3 Treatment administration 
All participants receive two intramuscular injections of 5 ml in the upper outer quadrant of each 
gluteus maximus muscle and a liquid substance that they will drink under direct observation at the day 
of inclusion.  
 
7.2.4 Indication for breaking the randomization code  
An AE that needs further treatment by a medical doctor could be an indication for breaking the 
randomization code in a particular participant. The appearance of a SAE that is determined to be 
related to the study treatment is also an indication for deblinding the treatment allocation in a 
particular participant.   
 
7.3 Study procedures 
All participants will receive standard care including counseling, contact tracing, partner notification,  
and diagnostics for other STIs if indicated.  
 
 
 

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19 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 5. Flowchart of study procedures 
 
Participants who contact the STI clinic in less than 7 days after treatment administration because of 
persisting or worsening symptoms, will be evaluated by the study coordinator. If indicated, a gram 
stain will be repeated. If the gram stain is negative after treatment administration, a watchful waiting 
policy will be followed regarding the Ng infection and the participant will be advised to come back at 
the follow-up visit 7 days after treatment administration. Further diagnostics can be initiated for other 
(suspected) diseases. When the repeated gram stain is positive >48 h after treatment administration, 
samples will be collected for NAAT and culture, and eventually the study physician decides whether to 
treat with escape medication or not. Ng-RNA may still be detectable within 7 days after treatment, 
even when the infection has been effectively treated [51]. This means that a positive NAAT within 7 
days is not a reliable indication of treatment failure. If escape treatment is given and the NAAT is 
negative, this case will be considered as treatment failure in the intention to treat (ITT), but will be 
excluded from the per protocol analysis. When escape treatment is given and the culture is positive, 
this case will be regarded as a treatment failure in both the ITT- and per protocol (PP) analysis.  
Gram-stain (complaints) 
STI consultation (no complaints) 
1. questionnaire and physical examination 
2. collect samples for Ng NAAT and culture 
3. finger prick (for POC serum creatinin test) 
4. randomization 
5. receive treatment and placebo 
6. receive diary and instruction for at home 
7. subset: 2x venapunction (for PK analysis) 
collect samples for NAAT; wait for results 
T0 
Follow-up visit: 
- NAAT (TOC) and culture 
- POC serum creatinin test 
- evaluate symptoms 
- evaluate adverse events 
- physical examination if 
indicated 
Post hoc exclusion 
(self- clearance) 
Posthoc exclusion 
(false positive) 
Final contact (per email) for evaluation by a digital questionnaire 
T30
T7 
1. questionnaire and physical examination 
2. repeat samples for Ng NAAT and culture 
3. finger prick (for POC serum creatinin test) 
4. randomization 
5. receive treatment and placebo 
6. receive diary and instruction for at home 
7. subset: 2x venapunction (for PK analysis) 
Return for 
- NAAT and culture 
- treatment with escape 
medication 

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Each participant (until a total of 160 participants is reached) will be requested to return for the 
collection of a peripheral blood sample at two or three random time points distributed over the 
following options: 0.5, 1, 2, 4, 6, 8 or 24h after treatment administration. With the collected data a 
reliable population pharmacokinetic model will be derived for Monte Carlo simulations. For the 
pharmacokinetic study a maximum of 13.5 ml blood will be obtained by venipuncture.  
Questionnaire 
The following information will be obtained by a questionnaire at the day of inclusion and at the follow-
up visit at day 7-14: symptoms (pain, irritation/itch, redness, discharge, bleeding, and/or swelling, 
duration of symptoms), sexual behavior, and at the follow-up visit and by an e-questionnaire at day 30 
(a link to a secured digital questionnaire will be sent by email): any adverse events (in particular rash 
and hearing problems, vestibular problems or tinnitus).  The e-questionnaire at day 30 will also 
contain an evaluation of the experiences of participating in this trial.  
 
Diary 
All participants are requested to keep a diary to record the presence of complaints (either symptoms 
and adverse events).  
 
Physical examination 
Signs (mucosal fragility, redness, discharge, bleeding and/or swelling) at physical examination of the 
included infection site are scored by a study nurse, study physician or clinician during clinic visits at 
the day of inclusion (T0) and at the follow-up visit for TOC (T7) if indicated based on symptoms. 
 
Laboratory tests  
- 
Anal, pharyngeal and vaginal swabs and urine for RNA-based NAAT (Aptima Combo 2 
assay) at T0, at T7, and in case of treatment failure another NAAT just before the 
administration of escape medication and 7-14 days later a second test of cure. The RNA-
based NAAT is the test of first choice for test of cure because of its high specificity and 
superior sensitivity compared to bacterial culture[52]. It has recently been recommended to 
perform the test no sooner than 7 days after treatment [51]. 
- 
Anal, cervical, pharyngeal and urethral swabs for culture at T0, at T7 and in case of treatment 
failure additional cultures will be performed just before the administration of escape 
medication and 7-14 days afterwards. 
- 
In case of a Ng-positive culture at T0 and T7, strain identification of both the Ng strains will be 
performed by genotyping in order to identify whether these strains are genetically identical. 
- 
MIC values of ceftriaxone, ertapenem, fosfomycin and gentamicin for all Ng strains by Etest. 
EUCAST certified breakpoints of MIC values for Neisseria gonorrhoeae do not exist for 
ertapenem, fosfomycin and gentamicin. For this reason, it is not possible to draw any 
conclusions on susceptibility/resistance before the analysis.  
- 
Finger prick to collect a drop of blood (around 30 µL)  for a point-of-care serum creatinin test 
at T0 and at T7 will be performed in order to test for renal impairment (an exclusion criterion 

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21 
 
and possible adverse event of gentamicin). Renal impairment is defined by a eGFR ≤50 
ml/min (calculated with Cockroft-Gault).  
- 
In a subset of participants, a venapunction to collect 4,5 ml blood at two or three time points 
(0.5, 1, 2, 4, 6, 8 or 24h after treatment administration) in which plasma concentration of the 
antibiotics will be measured. The maximal volume is 13.5 ml. 
 
Re-infections: to minimize the risk of re-infections  
All participants are requested to abstain from sexual intercourse until their TOC visit, or consistently 
use condoms, and report their behavior in a diary.  
 
7.4 Withdrawal of individual subjects 
Subjects can leave the study at any time for any reason without any consequences. The investigator 
can decide to withdraw a subject from the study for urgent medical reasons (e.g. an urgent medical 
condition which requires treatment with a known interaction with one of the study drugs).  
 
7.5 Replacement of individual subjects after withdrawal 
This longitudinal study has a relative short follow-up period. Patients who are lost to follow-up or who 
are post-hoc excluded from analyses (see section 3, 4.3 and 4.4) will not be replaced if the proportion 
of included participants lost and/or post-hoc excluded does not exceed the expected 20% (see 
section 3, 4.3 and 4.4). If it does exceed the expected 20% when recruitment is still ongoing, we will 
replace them by new inclusions until at least 438 analysable patients are included. 
 
7.6 Follow-up of subjects withdrawn for treatment 
If subjects are withdrawn from the study, follow-up will take place in order to evaluate adverse events. 
Furthermore, patients will still be able to routinely visit the STI clinic.  
 
7.7 Premature termination of study 
If during interim analysis a treatment success is found among < 60% of the participants in  one 
treatment arm, this arm will be terminated. Besides, we will stop a treatment arm early if any patient 
dies, if any patient requires emergency surgery, or if any patient suffers a permanent and irreversible 
disability, and it can be shown that this event was related to participation in this trial.  
 

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8. SAFETY REPORTING 
 
8.1 Temporary halt for reasons of subject safety 
In accordance to section 10, subsection 4, of the WMO, the sponsor will suspend the study if there is 
sufficient ground that continuation of the study will jeopardize participant health or safety.  The 
sponsor will notify the accredited METC without undue delay of a temporary halt including the reason 
for such an action. The study will be suspended pending a further positive decision by the accredited 
METC. The investigator will take care that all participants are kept informed. 
 
8.2 AEs, SAEs and SUSARs 
8.2.1 Adverse events (AEs) 
Adverse events are defined as any undesirable experience occurring to a participant during the study, 
whether or not considered related to the trial procedure or the experimental intervention. All adverse 
events reported by the subject or observed by the investigators, meeting all of the following criteria 
will be recorded: 
- Severity: grade 3 and 4, or grade 1 and 2 lasting longer than 1 week, graded by the CTCAE 
(Common Terminology Criteria for Adverse Events, v4.03, June 2010). 
- Causality: there needs to be a reasonable suspicion of the AE being an effect of the medical 
treatment of uncomplicated anogenital gonorrhoea.   
- Time window: between the moment of inclusion and the day 30 follow-up visit. 
8.2.2 Serious adverse events (SAEs) 
A serious adverse event is any untoward medical occurrence or effect that results in death or; 
- 
Is life threatening (at the time of the event); 
- 
Requires hospitalization or prolongation of existing inpatients’ hospitalization; 
- 
Results in persistent or significant disability or incapacity; 
- 
Any other important medical event that did not result in any of the outcomes listed above 
due to medical or surgical intervention but could have been based upon appropriate 
judgment by the investigator. 
An elective hospital admission will not be considered as a serious adverse event. 
Medically significant serious adverse events considered related to the investigational product by the 
investigator will be reported through the web portal ToetsingOnline to the accredited METC that 
approved the protocol within 7 days of first knowledge. Line-listings of all other SAEs will be reported 
in the annual safety report. 
 
8.2.3 Suspected unexpected serious adverse reactions 
Adverse reactions are all untoward and unintended responses to an investigational product related to 
any dose administered. 

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Unexpected adverse reactions are SUSARs if the following three conditions are met: 
1. the event must be serious (see chapter 9.2.2); 
2. there must be a certain degree of probability that the event is a harmful and an undesirable 
reaction to the medicinal product under investigation, regardless of the administered dose; 
3. the adverse reaction must be unexpected, that is to say, the nature and severity of the adverse 
reaction are not in agreement with the product information as recorded in: 
- 
Summary of Product Characteristics (SPC) for an authorised medicinal product; 
- 
Investigator’s Brochure for an unauthorised medicinal product. 
 
The sponsor will report expedited the following SUSARs through the web portal ToetsingOnline  to the 
METC: 
 
SUSARs that have arisen in the clinical trial that was assessed by the METC; 
 
SUSARs that have arisen in other clinical trials of the same sponsor and with the same 
medicinal product, and that could have consequences for the safety of the subjects 
involved in the clinical trial that was assessed by the METC. 
The remaining SUSARs are recorded in an overview list (line-listing) that will be submitted once every 
half year to the METC. This line-listing provides an overview of all SUSARs from the study medicine, 
accompanied by a brief report highlighting the main points of concern.  
The expedited reporting of SUSARs through the web portal ToetsingOnline is sufficient as notification 
to the competent authority. 
The expedited reporting will occur not later than 15 days after the sponsor has first knowledge of the 
adverse reactions. For fatal or life threatening cases the term will be maximal 7 days for a preliminary 
report with another 8 days for completion of the report.  
8.3. Annual Safety report  
In addition to the expedited reporting of SUSARs, the sponsor will submit, once a year throughout the 
clinical trial, a safety report to the accredited METC, competent authority, and competent authorities 
of the concerned Member States.  
This safety report consists of  
- a list of all suspected (unexpected or expected) serious adverse reactions, along with an aggregated 
summary table of all reported serious adverse reactions, ordered by organ system, per study; 
- a report concerning the safety of the subjects, consisting of a safety analysis and an evaluation of 
the balance between the efficacy and the harmfulness of the medicine under investigation; 
- a list of all medically non-significant serious adverse events and all serious adverse events 
considered unrelated to the investigational product.    
 
 

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8.4 Follow-up of adverse events 
All AEs will be followed until they have abated, or until a stable situation has been reached. 
Depending on the event, follow-up may require additional tests or medical procedures as indicated, 
and/or referral to the general physician or a medical specialist may be required.  
 
8.5 Data safety monitoring board (DSMB) 
We expect the additional risks of participating in this study to be low-moderate. In case of moderate 
extra risks the use of a Data Safety Monitoring Board (DSMB) could be determined per study. In this 
study a DSMB will be installed to timely detect possible inefficacy of one or more experimental 
treatment arms. The included antimicrobials are widely used for other indications and there is ample 
experience with these drugs suggesting minimal safety risks. Nevertheless, if a SAE or important AE 
occurs, the investigators first evaluate whether a relation to the study medication is probable and 
whether deblinding is indicated. Subsequently, the investigators propose their plan to the DSMB who 
will eventually recommend on  how to proceed. Detailed information on the DSMB procedures can be 
found in the DSMB-charter (K5).  
 
 

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25 
 
9. STATISTICAL ANALYSIS 
Descriptive demographic and clinical data (including symptoms and signs) will be compared between 
the treatment groups at baseline.  
9.1 Primary study parameters 
If a single patient is infected with Neisseria gonorrhoeae at more than one anatomical site, only one 
site will be included in the primary analysis. Because the prevalence of cervical infections is much 
lower than urethral or rectal infections, cervical infections will preferentially be included over rectal 
infections in the same patient. The order of inclusion of multiple infected sites will be: 1) cervical 
infections, 2) urethral infections and 3) anal infections. 
 
Both a per protocol analysis (PP) and an intention to treat analysis (ITT) will be performed. In this 
non-inferiority trial, the primary approach to between group comparative analysis would be by per 
protocol analysis. An intention to treat analysis will be less conservative because of the risk of dilution 
in treatment effect and consequently an increased risk of false rejection of the null hypothesis. 
However, an ITT analysis is important in order to preserve the value of randomization and better 
reflect clinical practice.  
 
For the evaluation of the primary clinical outcome variable (treatment success), the risk difference 
between each of the experimental treatments and the reference treatment will be calculated. The 
confidence interval around this risk difference will be calculated using the R function ci.pd of the R 
package Epi. This package uses the Newcombe method to estimate the interval for the difference 
between independent proportions [53]. If the lower limit of the confidence interval around the risk 
difference between an experimental treatment and the reference treatment does not exceed -10% 
(the predefined non-inferiority margin), the experimental treatment will be declared to be non-inferior 
to the reference treatment. Following Bonferroni correction for three comparisons as a result of the 
four treatment groups, we will calculate a two-sided 98.3% confidence interval around the risk 
difference.  
We will perform a sensitivity analysis in which participants with a positive TOC based on a re-infection 
(proven by non-identical genetic type determined by genotyping) will be coded as treatment success 
instead of treatment failure.  
9.2 Secondary study parameters 
Secondary outcomes (eradication capacity of study drugs up to 28 days and eradication capacity of 
study drugs at different infection sites not included in primary objective) will be analyzed using 
equivalent methods as above.  
Adverse event analysis will be descriptive. Frequency counts and percentages of the prespecified 
main categories of AEs will be presented by treatment arm.  

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26 
 
Explorative analyses will be performed to assess determinants of treatment failure and the existence 
of adverse events using univariate logistic regression analysis. Variables that are associated with 
treatment failures or adverse events will be included into a multivariable logistic regression model.  
Antimicrobial susceptibility (in MIC) will be measured for all Ng strains obtained the day of inclusion 
(T0) and at the TOC visit (T7). Drug concentrations will be assessed in peripheral blood samples  
collected from 160 participants at two or three different time points distributed over the following time 
points: 0.5, 1, 2, 4, 6, 8 or 24 hours after treatment gift. The pharmacokinetic and antimicrobial 
susceptibility data of circulating Ng strains will be combined, and Monte Carlo simulations will be 
performed in order to predict treatment efficacy under various antimicrobial resistance prevalence 
conditions.  
9.3 Interim analysis 
One interim analysis will be performed by the Data Safety Monitoring Board (DSMB) in order to timely 
tackle the exposure to a significantly less effective agent. After one third of all planned inclusions, the 
proportion of treatment failures in the three experimental treatment arms will be calculated. When in 
one arm 40% or more of the participants were not successfully treated (i.e. less than 60% have a 
negative TOC), this agent will be considered ineffective and the arm will be terminated. This 
proportion of treatment failure is considered clinically unacceptable by the research team. When 
assuming a cure rate of 98% in the reference treatment, we calculated that with a number of 36 
participants per treatment arm (approximately one third of the final number of participants per 
treatment arm), the confidence interval (using the ‘Newcombe method’) around the risk difference 
between the experimental treatment (cure rate 60%) and the reference treatment (cure rate 98%) will 
be -52% to -24%. This would mean that the experimental treatment is highly significantly worse than 
the reference treatment. The upper limit is even far under the non-inferiority margin of -10%.  
If required, the DSMB will analyze safety of participants on an ad hoc basis and guide 
recommendation for continuation of the study or early termination because of clear harm to the 
participant. We will stop the study early if any patient dies, if any patient requires emergency surgery, 
or if any patient suffers a permanent and irreversible disability, and it can be shown that this event 
was related to participation in the clinical trial. 
 
 
 

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10. ETHICAL CONSIDERATIONS 
 
10.1 Regulation statement 
This project will be conducted according to the principles of the Declaration of Helsinki (64th WMA 
General Assembly, Fortaleza, October 2013) and in accordance with the Medical Research Involving 
Human Subjects Act (WMO) of Dutch law.  
10.2 Recruitment and consent 
Recruitment will take place among gonorrhoea patients visiting the STI outpatient clinic of the Public 
Health Service (GGD) in Amsterdam and will be performed by the local team of nurses and 
physicians. If a patient is interested in participation, further information will be given either by the 
research nurse or the study coordinator both verbally and in a written patient information brochure. 
Two main pathways in establishing the diagnosis of a Ng infection can be distinguished, depending 
on the reason for consultation. As is shown in figure 5, part of the gonorrhoea patients consulting the 
STI clinic have symptoms suggestive for gonorrhoea. In these patients a gram stain is done 
immediately. If the gram stain is positive for gram negative diplococci (suggesting Neisseria 
gonorrhoeae) a preliminary diagnosis is established, and these patients are immediately treated for 
gonorrhoea. Gonorrhoea patients without symptoms have to wait 2-10 days for the results of the 
NAAT before they receive treatment. For the first group we offer a time period of 2 hours to read the 
patient information brochure and consider participation of the study. The latter group will receive a 
digital version of the patient information brochure, together with the gonorrhoea diagnosis and the 
advice to make an appointment for treatment at the STI clinic. The latter patient group will have at 
least 24 hours to consider participation.  
Written informed consent will be obtained by the research nurse or the study coordinator. The patient 
information brochure, including the informed consent form, are attached to this document in the 
appendices (E1).  
10.3 Objection by minors or incapacitated subjects 
Not applicable.  
10.4 Benefits and risk assessments 
Considering the pattern of development of resistance to previous first line treatment regimes for 
gonorrhoea on one side and, the emergence of Ng strains with decreased susceptibility or even 
resistance to ESCs on the other side, it is expected that gonorrhoea may become untreatable in the 
near future. For this reason, there is an urgent need to find alternative treatment options. Previous 
research suggests that ertapenem, fosfomycin and gentamicin might be effective and safe options. 
However, this is not yet proven by well-designed and robust trials in uncomplicated anogenital 
gonorrhoea cases. The most important risk for participants in this study is thus inefficacy of one of the 
treatment options, and therefore a delay in the administration of efficacious treatment. To minimize 
this risk, we will install a DSMB to perform an interim analysis on treatment efficacy. In the case of 
disproportional numbers of treatment failure in a treatment arm, we will preliminary terminate this arm. 

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Furthermore, there is always a risk of adverse events in medication trials. Since ceftriaxone, 
ertapenem, fosfomycin and gentamicin are registered and have been safely used for several 
indications for decades, we expect the risk of serious adverse events to be minimal. However, 
nephro- and ototoxicity are known side effects of gentamicin, in particular among patients receiving 
multiple (high) dosages  of gentamicin and among patients with renal impairment. Although the effects 
of a single dose of gentamicin have not been structurally  investigated, we do expect this risk to be 
low in our relatively healthy study population receiving a single intramuscular dose. The 
consequences of nephro- and ototoxicity are considered serious, therefore we will examine the renal 
function (by performing a point-of-care serum creatinin test) and symptoms of ototoxicity (by 
questionnaire) before and after the admission of treatment. We will exclude patients with renal 
impairment defined by an eGFR ≤50 ml/min (Cockroft-Gault). A disadvantage of participation is the 
administration of an additional intramuscular injection and an oral suspension. Albeit the risk of 
pain/bleeding/infection at injection site is very low, it is increased as a result of two IM injections 
instead of one. In conclusion, the most important benefit for anyone at risk for  STIs is: the aim to 
assure treatment options for gonorrhoea in the near future. A benefit for participants is a TOC (not 
otherwise done) and thus assurance of bacterial eradication. 
10.5 Compensation for injury 
The sponsor has a liability insurance which is in accordance with article 7 of the WMO. The sponsor 
(also) has an insurance which is in accordance with the legal requirements in the Netherlands (Article 
7 WMO). This insurance provides cover for damage to research subjects through injury or death 
caused by the study. The insurance applies to the damage that becomes apparent during the study or 
within 4 years after the end of the study. 
10.6 Incentives 
All 160 participants that consent to participate in the subset for the pharmacological analysis will 
receive a reimbursement of 30 euros to compensate for the inconvenience of 2 – 3 vena punctures 
and 1 – 3 return visits within the first 24 hours.  
 
 

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11. ADMINISTRATIVE ASPECTS, MONITORING AND PUBLICATION 
11.1 Handling and storage of data and documents 
Clinical data and patient samples will be stored according to the standard procedures of the STI 
outpatient clinic. Electronic patient files are accessible to all medical personnel of the STI outpatient 
clinic with access and codes to the computer system. All data gained from the study questionnaires 
will be stored in a separate file using a unique project ID, which is allocated to each participant at 
study inclusion. The study coordinator will maintain a list linking study ID’s to electronic patient file 
identifiers. This list will be kept in a locked filing cabinet with restricted access. Information gained 
from the data collection and analysis of this trial will be available for inspection on request by the 
participating physicians, the METC, the DSMB, the monitoring board, the funder and the regulatory 
health authorities.  
11.2 Monitoring and Quality Assurance 
Monitoring of accuracy and quality of the research data and performance of the research is 
compulsory for this study. The CRU of the AMC will organize and perform the monitoring. A detailed 
monitoring plan will be composed in collaboration with the CRU.  
 
11.3 Amendments 
A ‘substantial amendment’ is defined as an amendment to the terms of the METC application, or to 
the protocol or any other supporting documentation, that is likely to affect to a significant degree: 
- the safety or physical or mental integrity of the subjects of the trial; 
- the scientific value of the trial; 
- the conduct or management of the trial; or 
- the quality or safety of any intervention used in the trial. 
 
All substantial amendments will be notified to the METC and to the competent authority. Non-
substantial amendments will not be notified to the accredited METC and the competent authority, but 
will be recorded and filed by the sponsor.  
11.4 Annual progress report 
The investigator will submit a summary of the progress of the trial to the accredited METC once a 
year. Information will be provided on the date of inclusion of the first subject, numbers of subjects 
included and numbers of subjects that have completed the trial, serious adverse events/ serious 
adverse reactions, other problems, and amendments.  
11.5 Temporary halt and (prematurely) end of study report 
The sponsor will notify the accredited METC and the competent authority of the end of the study 
within a period of 90 days. The end of the study is defined as the last contact with the last patient (30 
days after the last participant has received treatment). The sponsor will notify the METC immediately 
of a temporary halt of the study, including the reason of such an action. In case the study is ended 

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prematurely, the sponsor will notify the accredited METC and the competent authority within 15 days, 
including the reasons for the premature termination.  Within one year after the end of the study, the 
investigator will submit a final study report with the results of the study, including any 
publications/abstracts of the study, to the accredited METC and the Competent Authority.  
11.6 Public disclosure and publication policy 
This trial will be registered at clinicaltrials.gov and EudraCT. It is our intention to publish study 
outcomes in the most appropriate peer-reviewed scientific journals and at scientific congresses. Both 
the sponsor and the subsiding party support the intention to disclose the results of this trial. 
Authorship will follow the guidelines defined by the international Committee of Medical Journal 
Editors.  
 
 

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12. STRUCTURED RISK ANALYSIS 
12.1 Potential issues of concern 
Ertapenem 
a. Level of knowledge about mechanism of action 
The mechanism of action of ertapenem is well known. Ertapenem is one of the β-lactam 
antimicrobials, it is rapidly bactericidal and derives its activity from binding to specific penicillin 
binding proteins (PBP) and subsequent blocking of cell wall synthesis[28]. 
 
b. Previous exposure of human beings with the test product 
Ertapenem is widely used in patients with the following moderate to severe infections caused by 
susceptible bacteria: complicated intra-abdominal infections, complicated skin infections, 
community acquired pneumonia, complicated urinary tract infections, acute pelvic infections[28]. In 
Europe, ertapenem is only registered as intravenous treatment, however in the USA it is safely 
administered either intravenously and intramuscularly for the previously mentioned indications [27]. 
As far as we know, there are no clinical trials investigating the efficacy and safety of ertapenem in 
patients infected with Neisseria gonorrhoeae.   
c. Can the primary or secondary mechanism be induced in animals and/or in ex-vivo human cell 
material? 
Not applicable.  
d. Selectivity of the mechanism to target tissue in animals and/or human beings 
Non-clinical data reveal no special hazard for humans based on conventional studies of safety, 
pharmacology, repeated-dose toxicity, genotoxicity and toxicity to reproduction and development. 
Decreased neutrophil counts, however, occurred in rats that received high doses of ertapenem, 
which was not considered a significant safety issue. Long-term studies in animals have not been 
performed in order to evaluate the carcinogenic potential of ertapenem [28].  
e. Analysis of potential effect 
Previous research showed that ertapenem 1000mg is a safe, well tolerated and effective agent 
against urinary tract infections [54-58]. Based on PK/PD simulations using MIC values of Ng 
strains from the STI clinic in Amsterdam, we expect that ertapenem 1000mg single dose will be 
effective against gonorrhoea as well (unpublished data, June 2014, correspondence with R.A.A. 
Mathot). The following serious adverse events are reported rarely: antibiotic-associated 
pseudomembranous colitis and  seizures (in elderly patients and those with pre-existing central 
nervous system disorders). Other, commonly reported (>1/100 - <1/10), adverse events are: 
diarrhoea, nausea, rash, headache, elevations in ALT, AST, alkaline phosphatase and platelet 
count. Of note, these data are based on patients using multiple doses of ertapenem, it is thus 
expected that the prevalence and severity of adverse events will be lower in our patients. The only 
explicit contra-indication is an anaphylactic reaction to any β-lactam antibacterial agent [28]. 

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f. Pharmacokinetic considerations 
Ertapenem is highly bound to plasma proteins. In healthy young adults the plasma half-life is 4 
hours. There are inadequate data on the safety and efficacy of ertapenem in patients with 
advanced renal impairment to support a dose recommendation. Therefore, ertapenem should not 
be used in these patients [28].  
g. Study population 
The average population consulting the STI outpatient clinic in the city center of Amsterdam is 
young and has limited health concerns. A large proportion of this population is HIV positive, but in 
most of them this is well treated.  
h. Interaction with other products 
Co-administration of valproic acid with carbapenem agents may result in a decreased level of 
valproic acid falling below therapeutic range. This can lead to inadequate seizure control.  
 
i. Predictability of effect 
There are no markers available to predict the effect of ertapenem.  
j. Can effects be managed? 
In case of treatment failure, participants receive a doubled dose of ceftriaxone (1000mg) plus 
azithromycin 1000mg. Research subjects can always contact the STI outpatient clinic and the 
study coordinator in case of any questions or uncertainties. At the STI outpatient clinic a case with 
emergency medication (for instance, for anaphylactic reaction or seizures) is available. If 
necessary participants can be referred to a specialist in the hospital.  
Fosfomycin 
a. Level of knowledge about mechanism of action 
The mechanism of action of fosfomycin is well known. Fosfomycin is a fosfonic acid derivate which 
exhibits bactericidal activity by inhibiting cell wall synthesis through inhibition of fosfoenolpyruvate 
transferase. This enzyme is involved in the first phase of peptidoglycan synthesis in both Gram-
negative and Gram-positive bacteria. At the same time, fosfomycin inhibits adhesion of bacteria to 
the bladder mucosa and consequently prevents re-infection. Because of the distinctive 
mechanisms of fosfomycin, there is minimal cross-resistance with other antimicrobials [59-61].  
b. Previous exposure of human beings with the test product 
Fosfomycin-Trometamol is widely used in humans for the treatment of urinary tract infections and 
is a registered medicinal product at EMA. Three clinical studies have been performed to study the 
effect of fosfomycine in uncomplicated gonococcal urethritis. In these studies no severe adverse 
events were reported [13, 29, 62]. 
c. Can the primary or secondary mechanism be induced in animals and/or in ex-vivo human cell 
material? 
Not applicable.  

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d. Selectivity of the mechanism to target tissue in animals and/or human beings 
Oral fosfomycin is metabolized after absorption to the free acid fosfomycin, which will be 
eliminated in urine and faeces. It is mainly distributed to the kidneys, bladder wall, prostate and 
seminal vesicles. Preclinical data, based on conventional studies with single and repeated toxicity 
studies, genotoxicity studies and reproduction and development studies do not reveal any special 
risks for human beings.  
e. Analysis of potential effect 
The previously mentioned clinical trials investigating the efficacy of multiple dosed fosfomycin in 
patients infected with Neisseria gonorrhoeae, showed promising cure rates [13, 29, 62]. Based on 
Monte Carlo simulations with antimicrobial susceptibility data of Ng, it is calculated that single-
dosed fosfomycin in a dose of 6g is potentially effective (unpublished data, June 2014, 
correspondence with R. Mathot or C. Wind). Common adverse events of fosfomycin are mild and 
often self-limiting, including diarrhea, nausea, abdominal pain and headache. The only explicit 
contra-indication is an anaphylactic reaction to fosfomycin in the past [60, 63].  
f. Pharmacokinetic considerations 
The maximal plasma concentration is reached in 2 hours after intake. The half-life is 6 hours. 
fosfomycin is completely eliminated by the kidneys. Higher levels of fosfomycin concentration are 
found in urine than the MIC in peripheral blood samples after 24-48 hours[63].  
g. Study population 
The average population consulting the STI outpatient clinic in the city center of Amsterdam is 
young and has limited health concerns. A high number of this population is HIV positive, but in 
most of them this is well treated. 
h. Interaction with other products 
The serum concentration and urinary excretion of fosfomycin are decreased by co-administration 
of metoclopramide, but otherwise it has limited drug interactions[60]. A simultaneous intake with 
food delays fosfomycin absorption, following a decrease in peak plasma and urine [63]. 
i. Predictability of effect 
There are no markers available to predict the effect of fosfomycin. 
j. Can effects be managed? 
In case of treatment failure, participants receive a doubled dose of ceftriaxone (1000mg) plus 
azithromycin 1000mg . Research subjects can always contact the STI outpatient clinic and the 
study coordinator in case of any questions or uncertainties. At the STI outpatient clinic a case with 
emergency medication (for instance, for anaphylactic reaction or seizures) is available. If 
necessary participants can be referred to a specialist in the hospital. 
Gentamicin 
a. Level of knowledge about mechanism of action 

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The mechanism of action of gentamicin is well known. Gentamicin is a bactericide antibiotic that 
inhibits the synthesis of proteins by binding to the 30S subunit of the bacterial ribosome. 
Gentamicin is known to be effective in a large amount of pathogen Gram-positive and Gram-
negative bacteria [35]. 
b. Previous exposure of human beings with the test product 
Gentamicin is a widely used antibiotic for several indications and is a registered medicinal product 
at EMA. In different developing countries, gentamicin is being used for the treatment of gonorrhoea 
for decades [14, 15, 64].  
c. Can the primary or secondary mechanism be induced in animals and/or in ex-vivo human cell 
material? 
Not applicable 
d. Selectivity of the mechanism to target tissue in animals and/or human beings 
After intramuscular admission, gentamicin is well distributed to body tissue and body fluids. 
However, low concentrations are found in cerebrospinal liquor, sputum and pleural and peritoneal 
fluids. Gentamicin passes both peritoneal and placental membranes. Preclinical safety research 
did not reveal any specific risks for human beings [35].  
e. Analysis of potential effect 
See 12.1b. Additionally, Felarca et al. found the adequate (efficient and safe) dose of gentamicin 
for the treatment of gonorrhoea[31], subsequently several studies have been enrolled using a dose 
of 240-280mg gentamicin IM with cure rates between 94-100%[18, 32-34]. Also, the susceptibility 
for gentamicin of Neisseria Gonorrhoeae strains is widely investigated in Ng strains from different 
regions[14, 18, 34, 65-68].  Limited research on adverse events of gentamicin in patients with 
gonorrhoea showed no nephrotoxicity and ototoxicity after a single dose intramuscular injection 
[31-34, 69].  
f. Pharmacokinetic considerations 
Gentamicin is not metabolized in the human body and it is eliminated in its active form. In patients 
with a normal renal function, the half-life is between 2-3 hours. In patients with impaired renal 
function, the half-life is reduced based on the remaining renal function. Toxic dosages can cause 
renal impairment and/or neurological damage [35].  
g. Study population 
The average population consulting the STI outpatient clinic in the city center of Amsterdam is 
young and has limited health concerns. A high number of this population is HIV positive, but in 
most of them this is well treated. Therefore, we expect that the rate of participants with renal 
impairment or other chronic diseases will be low. However, because of the limited knowledge on 
adverse-events after one single dose of gentamicin, the renal function will be tested on forehand in 
all possible participants and people with renal impairment will be excluded from the study. Also 

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pregnant women will be excluded from this study, since little is known on the effects of pregnancy 
[35].  
h. Interaction with other products 
There are no drug-interactions known with gentamicin. However, attention needs to be paid to 
nephro- and ototoxic medicines, because this effect could be increased when simultaneously using 
gentamicin [35]. For this reason, we will evaluate the renal function and we will exclude 
participants with renal impairment.  
i. Predictability of effect 
There are no markers in order to predict the effect of gentamicin.  
j. Can effects be managed? 
In case of treatment failure, participants receive a doubled dose of ceftriaxone (1000mg) plus 
azithromycin 1000mg . Research subjects can always contact the STI outpatient clinic and the 
study coordinator in case of any questions or uncertainties. At the STI outpatient clinic a case with 
emergency medication (for instance, for anaphylactic reaction or seizures) is available. If 
necessary participants can be referred to a specialist in the hospital. 
12.2 Synthesis 
Ceftriaxone 
Ceftriaxone is the standard therapy for gonorrhoea infections in the Netherlands, given the current 
efficacy-rate of 100% and the mild adverse events that are reported. For this reason, chapter 12.1 is 
not indicated for this product. Furthermore, in this trial Ceftriaxone will not cause any risks in 
comparison to the general population with gonorrhoea. Consequently there is no need for extra 
measures to reduce expected risks.  
Ertapenem 
Ertapenem is safely used for several indications worldwide both in intramuscular and intravenous 
form. In Europe ertapenem is not yet registered as intramuscular injection, however it is safely used 
intravenously. We do not expect any harm from a single intramuscular dose in our young and 
relatively healthy population. Because of the influence of Ertapenem on the valproic acid plasma 
levels, patients using valproic acid are excluded from this trial.  
Fosfomycin 
Fosfomycin is safely used for several indications worldwide. A few clinical studies with (either 
intramuscular or oral) Fosfomycin have been performed in patients with uncomplicated gonococcal 
urethritis, none of these studies reported any severe events. Participants of this trial are assured not 
to take metoclopramide at the first 7 days. In case of the intake of metoclopramide on the day of 
inclusion or in case of the intention to take metoclopramide in the following days, patients are 
excluded from this study.  

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Gentamicin 
Since a single intramuscular dose of gentamicin is used for gonorrhoea in Malawi [14, 70] for decades 
and effectiveness is reported in different studies, we can expect that it is an efficient and safe product 
for this indication. Because of limited knowledge on the prevalence of nephro- and ototoxicity as a 
result of the single dose gentamicin, renal function will be measured before treatment is given and 
people with an impaired renal function will be excluded from this study. This is determined by a point-
of-care serum creatinin test before administration of treatment. Additionally, at the follow-up visit 7-14 
days after treatment, renal function will again be tested in order to evaluate the effects of a single 
dose gentamicin on renal function. Also deafness and balance disorder will be evaluated before and 
after treatment in order to look for ototoxicity after a single dose injection of gentamicin.  
 
 
 
 
 

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13. REFERENCES 
1. 
Newman, L., et al., Global Estimates of the Prevalence and Incidence of Four Curable 
Sexually Transmitted Infections in 2012 Based on Systematic Review and Global Reporting. 
PLoS One, 2015. 10(12): p. e0143304. 
2. 
Jarvis, G.A. and T.L. Chang, Modulation of HIV transmission by Neisseria gonorrhoeae: 
molecular and immunological aspects. Curr HIV Res, 2012. 10(3): p. 211-7. 
3. 
van Dam, A.P., et al., Verified clinical failure with cefotaxime 1g for treatment of gonorrhoea in 
the Netherlands: a case report. Sex Transm Infect, 2014. 90(7): p. 513-4. 
4. 
Wind, C.M., et al., Trends in antimicrobial susceptibility for azithromycin and ceftriaxone in 
Neisseria gonorrhoeae isolates in Amsterdam, the Netherlands, between 2012 and 2015. 
Euro Surveill, 2017. 22(1). 
5. 
Camara, J., et al., Molecular characterization of two high-level ceftriaxone-resistant Neisseria 
gonorrhoeae isolates detected in Catalonia, Spain. J Antimicrob Chemother, 2012. 67(8): p. 
1858-60. 
6. 
Kirkcaldy, R.D., G.A. Bolan, and J.N. Wasserheit, Cephalosporin-resistant gonorrhea in North 
America. JAMA, 2013. 309(2): p. 185-7. 
7. 
Unemo, M. and W.M. Shafer, Antibiotic resistance in Neisseria gonorrhoeae: origin, evolution, 
and lessons learned for the future. Ann N Y Acad Sci, 2011. 1230: p. E19-28. 
8. 
Organization, W.H., Antimicrobial resistance: global report on surveillance. 2014. 
9. 
Ndowa, F. and M. Lusti-Narasimhan, The threat of untreatable gonorrhoea: implications and 
consequences for reproductive and sexual morbidity. Reprod Health Matters, 2012. 20(40): p. 
76-82. 
10. 
Fong, J.J., L. Rose, and E.A. Radigan, Clinical outcomes with ertapenem as a first-line 
treatment option of infections caused by extended-spectrum beta-lactamase producing gram-
negative bacteria. Ann Pharmacother, 2012. 46(3): p. 347-52. 
11. 
Rattanaumpawan, P., et al., Efficacy and safety of de-escalation therapy to ertapenem for 
treatment of infections caused by extended-spectrum-beta-lactamase-producing 
Enterobacteriaceae: an open-label randomized controlled trial. BMC Infect Dis, 2017. 17(1): 
p. 183. 
12. 
Collins, V.L., et al., Efficacy of ertapenem for treatment of bloodstream infections caused by 
extended-spectrum-beta-lactamase-producing Enterobacteriaceae. Antimicrob Agents 
Chemother, 2012. 56(4): p. 2173-7. 
13. 
Yuan, Z., et al., Randomized controlled clinical trial on the efficacy of fosfomycin trometamol 
for uncomplicated gonococcal urethritis in men. Clin Microbiol Infect, 2016. 22(6): p. 507-12. 
14. 
Brown, L.B., et al., Neisseria gonorrhoeae antimicrobial susceptibility in Lilongwe, Malawi, 
2007. Sex Transm Dis, 2010. 37(3): p. 169-72. 
15. 
Kamanga, G., C. Mhango, and L. Brown, Viewpoint: Gentamicin for treatment of gonococcal 
urethritis in Malawi. Malawi Med J, 2010. 22(3): p. 63-4. 
16. 
Lee, H., K. Lee, and Y. Chong, New treatment options for infections caused by increasingly 
antimicrobial-resistant Neisseria gonorrhoeae. Expert Rev Anti Infect Ther, 2016. 14(2): p. 
243-56. 
17. 
Brittain, C., et al., Gentamicin versus ceftriaxone for the treatment of gonorrhoea (G-TOG 
trial): study protocol for a randomised trial. Trials, 2016. 17(1): p. 558. 
18. 
Kirkcaldy, R.D., et al., The efficacy and safety of gentamicin plus azithromycin and 
gemifloxacin plus azithromycin as treatment of uncomplicated gonorrhea. Clin Infect Dis, 
2014. 59(8): p. 1083-91. 
19. 
Furuya, R., et al., In vitro synergistic effects of double combinations of beta-lactams and 
azithromycin against clinical isolates of Neisseria gonorrhoeae. J Infect Chemother, 2006. 
12(4): p. 172-6. 
20. 
Furuya, R., et al., In vitro activities of antimicrobial combinations against clinical isolates of 
Neisseria gonorrhoeae. J Infect Chemother, 2013. 19(6): p. 1218-20. 
21. 
Sathia, L., et al., Pharyngeal gonorrhoea - is dual therapy the way forward? Int J STD AIDS, 
2007. 18(9): p. 647-8. 
22. 
Pereira, R., M.J. Cole, and C.A. Ison, Combination therapy for gonorrhoea: in vitro synergy 
testing. J Antimicrob Chemother, 2013. 68(3): p. 640-3. 
23. 
Wind, C.M., H.J. de Vries, and A.P. van Dam, Determination of in vitro synergy for dual 
antimicrobial therapy against resistant Neisseria gonorrhoeae using Etest and agar dilution. 
Int J Antimicrob Agents, 2015. 45(3): p. 305-8. 

C1 - METC Protocol NABOGO versie 2.0 d.d. 10-05-2017 
  
 
 
 
38 
 
24. 
Mouton, J.W., et al., The role of pharmacokinetics/pharmacodynamics in setting clinical MIC 
breakpoints: the EUCAST approach. Clin Microbiol Infect, 2012. 18(3): p. E37-45. 
25. 
Farrington, C.P. and G. Manning, Test statistics and sample size formulae for comparative 
binomial trials with null hypothesis of non-zero risk difference or non-unity relative risk. Stat 
Med, 1990. 9(12): p. 1447-54. 
26. 
Sheiner, L.B. and S.L. Beal, Evaluation of methods for estimating population 
pharmacokinetics parameters. I. Michaelis-Menten model: routine clinical pharmacokinetic 
data. J Pharmacokinet Biopharm, 1980. 8(6): p. 553-71. 
27. 
Merck&Co., I., Investigator's Brochure ertapenem 2011. 
28. 
Merck&Co., I., Summary of product characteristics Ertapenem. 
Geneesmiddeleninformatiebank, College ter Beoordeling van Geneesmiddelen, 2011. 
29. 
Lopez-Gracia, J., Treatment of acute and subacute gonococcal urethritis with fosfomycin. 
Chemotherapy, 1977. 23 Suppl 1: p. 293-300. 
30. 
Tesh, L.D., et al., Neisseria gonorrhoeae and fosfomycin: Past, present and future. Int J 
Antimicrob Agents, 2015. 46(3): p. 290-6. 
31. 
Felarca, A.B., E.M. Laqui, and L.M. Ibarra, Gentamicin in gonococcal urethritis of Filipino 
males: dosage and response. J Infect Dis, 1971. 124 Suppl: p. S287-92. 
32. 
Hantschke, D., et al., Treatment of gonorrhoea with single injections of gentamicin. Br J Vener 
Dis, 1973. 49(1): p. 62-4. 
33. 
Hira, S.K., et al., Efficacy of gentamicin and kanamycin in the treatment of uncomplicated 
gonococcal urethritis in Zambia. Sex Transm Dis, 1985. 12(1): p. 52-4. 
34. 
Tan, N.J., et al., Gentamicin in the treatment of infections due to penicillinase-producing 
gonococci. Br J Vener Dis, 1980. 56(6): p. 394-6. 
35. 
BV, C., Summary of product characteristics Gentamicin sulphate. 
Geneesmiddeleninformatiebank, College ter Beoordeling van Geneesmiddelen, 2014. 
36. 
Majumdar, A.K., et al., Pharmacokinetics of ertapenem in healthy young volunteers. 
Antimicrob Agents Chemother, 2002. 46(11): p. 3506-11. 
37. 
Chen, M., et al., Comparative pharmacokinetics and pharmacodynamic target attainment of 
ertapenem in normal-weight, obese, and extremely obese adults. Antimicrob Agents 
Chemother, 2006. 50(4): p. 1222-7. 
38. 
Wittau, M., et al., Pharmacokinetics of ertapenem in colorectal tissue. Chemotherapy, 2011. 
57(5): p. 437-48. 
39. 
Burkhardt, O., et al., Underdosing of ertapenem in critically ill patients with pneumonia 
confirmed by Monte Carlo simulations. Int J Antimicrob Agents, 2010. 35(1): p. 96-7. 
40. 
Borsa, F., et al., Comparative pharmacokinetics of tromethamine fosfomycin and calcium 
fosfomycin in young and elderly adults. Antimicrob Agents Chemother, 1988. 32(6): p. 938-
41. 
41. 
Goto, M., et al., Fosfomycin kinetics after intravenous and oral administration to human 
volunteers. Antimicrob Agents Chemother, 1981. 20(3): p. 393-7. 
42. 
Sauermann, R., et al., Antibiotic abscess penetration: fosfomycin levels measured in pus and 
simulated concentration-time profiles. Antimicrob Agents Chemother, 2005. 49(11): p. 4448-
54. 
43. 
Segre, G., et al., Pharmacokinetic profile of fosfomycin trometamol (Monuril). Eur Urol, 1987. 
13 Suppl 1: p. 56-63. 
44. 
Choi, J.S., C.K. Kim, and B.J. Lee, Administration-time differences in the pharmacokinetics of 
gentamicin intravenously delivered to human beings. Chronobiol Int, 1999. 16(6): p. 821-9. 
45. 
Chung, M., R. Costello, and S. Symchowicz, Comparison of netilmicin and gentamicin 
pharmacokinetics in humans. Antimicrob Agents Chemother, 1980. 17(2): p. 184-7. 
46. 
Rosario, M.C., et al., Population pharmacokinetics of gentamicin in patients with cancer. Br J 
Clin Pharmacol, 1998. 46(3): p. 229-36. 
47. 
Staatz, C.E., C. Byrne, and A.H. Thomson, Population pharmacokinetic modelling of 
gentamicin and vancomycin in patients with unstable renal function following cardiothoracic 
surgery. Br J Clin Pharmacol, 2006. 61(2): p. 164-76. 
48. 
Xuan, D., D.P. Nicolau, and C.H. Nightingale, Population pharmacokinetics of gentamicin in 
hospitalized patients receiving once-daily dosing. Int J Antimicrob Agents, 2004. 23(3): p. 
291-5. 
49. 
Dam, A.P.v., LCI-richtlijn gonorroe. 2013. 
50. 
Heymans, R., et al., Evaluation of Neisseria gonorrhoeae multiple-locus variable-number 
tandem-repeat analysis, N. gonorrhoeae Multiantigen sequence typing, and full-length porB 

C1 - METC Protocol NABOGO versie 2.0 d.d. 10-05-2017 
  
 
 
 
39 
 
gene sequence analysis for molecular epidemiological typing. J Clin Microbiol, 2012. 50(1): p. 
180-3. 
51. 
Wind, C.M., et al., Test of Cure for Anogenital Gonorrhoea Using Modern RNA-Based and 
DNA-Based Nucleic Acid Amplification Tests: A Prospective Cohort Study. Clin Infect Dis, 
2016. 62(11): p. 1348-55. 
52. 
Bignell, C., M. Unemo, and S.T.I.G.E.B. European, 2012 European guideline on the diagnosis 
and treatment of gonorrhoea in adults. Int J STD AIDS, 2013. 24(2): p. 85-92. 
53. 
Newcombe, R.G., Interval estimation for the difference between independent proportions: 
comparison of eleven methods. Stat Med, 1998. 17(8): p. 873-90. 
54. 
Arguedas, A., et al., Safety and tolerability of ertapenem versus ceftriaxone in a double-blind 
study performed in children with complicated urinary tract infection, community-acquired 
pneumonia or skin and soft-tissue infection. Int J Antimicrob Agents, 2009. 33(2): p. 163-7. 
55. 
Burkhardt, O., H. Derendorf, and T. Welte, Ertapenem: the new carbapenem 5 years after first 
FDA licensing for clinical practice. Expert Opin Pharmacother, 2007. 8(2): p. 237-56. 
56. 
Jimenez-Cruz, F., et al., A prospective, multicenter, randomized, double-blind study 
comparing ertapenem and ceftriaxone followed by appropriate oral therapy for complicated 
urinary tract infections in adults. Urology, 2002. 60(1): p. 16-22. 
57. 
Livermore, D.M., et al., Activity of ertapenem against Neisseria gonorrhoeae. J Antimicrob 
Chemother, 2004. 54(1): p. 280-1. 
58. 
Tomera, K.M., et al., Ertapenem versus ceftriaxone followed by appropriate oral therapy for 
treatment of complicated urinary tract infections in adults: results of a prospective, 
randomized, double-blind multicenter study. Antimicrob Agents Chemother, 2002. 46(9): p. 
2895-900. 
59. 
Hendlin, D., et al., Phosphonomycin, a new antibiotic produced by strains of streptomyces. 
Science, 1969. 166(3901): p. 122-3. 
60. 
Michalopoulos, A.S., I.G. Livaditis, and V. Gougoutas, The revival of fosfomycin. Int J Infect 
Dis, 2011. 15(11): p. e732-9. 
61. 
Reffert, J.L. and W.J. Smith, Fosfomycin for the treatment of resistant gram-negative bacterial 
infections. Insights from the Society of Infectious Diseases Pharmacists. Pharmacotherapy, 
2014. 34(8): p. 845-57. 
62. 
Rodriguez, A., et al., Bacteriological evaluation of fosfomycin in clinical studies. 
Chemotherapy, 1977. 23 Suppl 1: p. 247-58. 
63. 
BV, Z., Summary of product characteristics Monuril. Geneesmiddeleninformatiebank, College 
ter Beoordeling van Geneesmiddelen, 2014. 
64. 
Dowell, D. and R.D. Kirkcaldy, Effectiveness of gentamicin for gonorrhoea treatment: 
systematic review and meta-analysis. Sex Transm Infect, 2012. 88(8): p. 589-94. 
65. 
Bala, M., et al., Gentamicin Susceptibility among a Sample of Multidrug-Resistant Neisseria 
gonorrhoeae Isolates in India. Antimicrob Agents Chemother, 2016. 60(12): p. 7518-7521. 
66. 
Bala, M., et al., Gentamicin in vitro activity and tentative gentamicin interpretation criteria for 
the CLSI and calibrated dichotomous sensitivity disc diffusion methods for Neisseria 
gonorrhoeae. J Antimicrob Chemother, 2016. 71(7): p. 1856-9. 
67. 
Chisholm, S.A., et al., An evaluation of gentamicin susceptibility of Neisseria gonorrhoeae 
isolates in Europe. J Antimicrob Chemother, 2011. 66(3): p. 592-5. 
68. 
Hjelmevoll, S.O., et al., Phenotypic and genotypic properties of Neisseria gonorrhoeae 
isolates in Norway in 2009: antimicrobial resistance warrants an immediate change in national 
management guidelines. Eur J Clin Microbiol Infect Dis, 2012. 31(6): p. 1181-6. 
69. 
Jackson, G.G. and G. Arcieri, Ototoxicity of gentamicin in man: a survey and controlled 
analysis of clinical experience in the United States. J Infect Dis, 1971. 124 Suppl: p. S130-7. 
70. 
Daly, C.C., et al., Development of an antimicrobial susceptibility surveillance system for 
Neisseria gonorrhoeae in Malawi: comparison of methods. J Clin Microbiol, 1997. 35(11): p. 
2985-8.