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    Clinical Trial Results:
    A Phase 3, Randomized, Active-Controlled, Double-Blind Clinical Study to Evaluate the Efficacy and Safety of Oral Islatravir Once-Monthly as Preexposure Prophylaxis in Cisgender Men and Transgender Women Who Have Sex With Men, and Are at High Risk for HIV-1 Infection

    Summary
    EudraCT number
    		 2020-003309-79
    Trial protocol
    		 FR   Outside EU/EEA  
    Global end of trial date
    04 Aug 2023

    Results information
    Results version number
    		 v2(current)
    This version publication date
    01 May 2025
    First version publication date
    14 Feb 2024
    Other versions
    		 v1
    Version creation reason

    Trial information

    		 Close Top of page
    Trial identification
    Sponsor protocol code
    MK-8591-024
    Additional study identifiers
    ISRCTN number
    		 -
    US NCT number
    		 NCT04652700
    WHO universal trial number (UTN)
    		 -
    Sponsors
    Sponsor organisation name
    Merck Sharp & Dohme LLC
    Sponsor organisation address
    126 East Lincoln Avenue, P.O. Box 2000, Rahway, NJ, United States, 07065
    Public contact
    Clinical Trials Disclosure, Merck Sharp & Dohme LLC, ClinicalTrialsDisclosure@msd.com
    Scientific contact
    Clinical Trials Disclosure, Merck Sharp & Dohme LLC, ClinicalTrialsDisclosure@msd.com
    Paediatric regulatory details
    Is trial part of an agreed paediatric investigation plan (PIP)
    Yes
    EMA paediatric investigation plan number(s)
    		 EMEA-002938-PIP01-20
    Does article 45 of REGULATION (EC) No 1901/2006 apply to this trial?
    No
    Does article 46 of REGULATION (EC) No 1901/2006 apply to this trial?
    No
    Results analysis stage
    Analysis stage
    Final
    Date of interim/final analysis
    04 Aug 2023
    Is this the analysis of the primary completion data?
    Yes
    Primary completion date
    04 Aug 2023
    Global end of trial reached?
    Yes
    Global end of trial date
    04 Aug 2023
    Was the trial ended prematurely?
    Yes
    General information about the trial
    Main objective of the trial
    The purpose of this study is to evaluate the safety and tolerability of oral islatravir (ISL) once monthly (QM) as Preexposure Prophylaxis (PrEP) in cisgender men who have sex with men and transgender women who have sex with men and who are at high risk of HIV-1 infection with 48 or 96 weeks of treatment and a follow-up of ≥42 days. Due to decreased lymphocyte and CD4+ T-cell counts across the ISL program, blinded dosing was halted on 10-Dec-2021, with no further enrollment. Thus, no participants <18 years of age were randomized. Assessments conducted prior to then are designated as Part 1. In Part 2, participants from Part 1 were switched to open-label PrEP therapy with emtricitabine/tenofovir disoproxil (FTC/TDF) or emtricitabine/tenofovir alafenamide (FTC/TAF) while continuing in the study. In Part 3, the study was unblinded to original randomized intervention group, and participants were permitted to continue receiving unblinded FTC/TDF or FTC/TAF until the end of the study.
    Protection of trial subjects
    This study was conducted in conformance with Good Clinical Practice standards and applicable country and/or local statutes and regulations regarding ethical committee review, informed consent, and the protection of human subjects participating in biomedical research.
    Background therapy
    		 -
    Evidence for comparator
    		 -
    Actual start date of recruitment
    15 Mar 2021
    Long term follow-up planned
    No
    Independent data monitoring committee (IDMC) involvement?
    Yes
    Population of trial subjects
    Number of subjects enrolled per country
    Country: Number of subjects enrolled
    France: 12
    Country: Number of subjects enrolled
    Japan: 26
    Country: Number of subjects enrolled
    South Africa: 59
    Country: Number of subjects enrolled
    Thailand: 68
    Country: Number of subjects enrolled
    United States: 277
    Country: Number of subjects enrolled
    Peru: 52
    Worldwide total number of subjects
    494
    EEA total number of subjects
    12
    Number of subjects enrolled per age group
    In utero
    0
    Preterm newborn - gestational age < 37 wk
    0
    Newborns (0-27 days)
    0
    Infants and toddlers (28 days-23 months)
    0
    Children (2-11 years)
    0
    Adolescents (12-17 years)
    0
    Adults (18-64 years)
    492
    From 65 to 84 years
    2
    85 years and over
    0

    Subject disposition

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    Recruitment
    Recruitment details
    		 -

    Pre-assignment
    Screening details
    		 Participants were randomized at 23 study sites in France, Japan, Peru, South Africa, and the United States.

    Period 1
    Period 1 title
    Part 1: Blinded Study Medication
    Is this the baseline period?
    		 Yes
    Allocation method
    Randomised - controlled
    Blinding used
    		 Double blind
    Roles blinded
    		 Subject, Investigator, Assessor

    Arms
    Are arms mutually exclusive
    Yes

    Arm title
    		 Part 1: ISL & Parts 2 & 3: FTC/TDF or FTC/TAF
    Arm description
    		 Participants received 60 mg tablet of ISL once monthly (QM) plus placebo to FTC/TDF tablet once daily (QD) or placebo to FTC/TAF tablet QD in Part 1. Participants then received open-label FTC/TDF or FTC/TAF in Parts 2 and 3.
    Arm type
    		 Experimental

    Investigational medicinal product name
    Islatravir
    Investigational medicinal product code
    Other name
    MK-8591
    Pharmaceutical forms
    Tablet
    Routes of administration
    Oral use
    Dosage and administration details
    ISL 60 mg tablet, QM, orally for up to24 months, Part 1 only

    Investigational medicinal product name
    Placebo to FTC/TAF
    Investigational medicinal product code
    Other name
    Pharmaceutical forms
    Tablet
    Routes of administration
    Oral use
    Dosage and administration details
    Placebo FTC/TAF 0 mg tablets QD, orally for up to 24 months

    Investigational medicinal product name
    Placebo to FTC/TDF
    Investigational medicinal product code
    Other name
    Pharmaceutical forms
    Tablet
    Routes of administration
    Oral use
    Dosage and administration details
    Placebo FTC/TDF 0 mg tablets QD, orally for up to 24 months

    Investigational medicinal product name
    FTC/TAF
    Investigational medicinal product code
    Other name
    Descovy Emtricitabine/Tenofovir Alafenamide
    Pharmaceutical forms
    Tablet
    Routes of administration
    Oral use
    Dosage and administration details
    Participants receive 200/25 mg of FTC/TAF combination tablet, QD, orally for up to 24 months

    Arm title
    		 Parts 1 to 3: FTC/TDF or FTC/TAF
    Arm description
    		 Participants received 200/245 mg or 200/300 mg of FTC/TDF combination tablet QD or 200/25 mg of FTC/TAF combination tablet QD at investigator's discretion plus placebo to ISL tablet QM in Part 1. Participants continued to receive open-label FTC/TDF or FTC/TAF in Parts 2 and 3.
    Arm type
    		 Active comparator

    Investigational medicinal product name
    FTC/TDF
    Investigational medicinal product code
    Other name
    Truvada Emtricitabine/Tenofovir Disoproxil Fumarate
    Pharmaceutical forms
    Tablet
    Routes of administration
    Oral use
    Dosage and administration details
    Participants receive 200/245 mg of FTC/TDF combination tablet, QD, orally for up to 24 months

    Investigational medicinal product name
    Placebo to ISL
    Investigational medicinal product code
    Other name
    Pharmaceutical forms
    Tablet
    Routes of administration
    Oral use
    Dosage and administration details
    Placebo ISL 0 mg tablets QM, orally for up to 24 months.

    Number of subjects in period 1
    		Part 1: ISL & Parts 2 & 3: FTC/TDF or FTC/TAF Parts 1 to 3: FTC/TDF or FTC/TAF
    Started
    328
    166
    Completed
    308
    160
    Not completed
    20
    6
         Consent withdrawn by subject
    12
    4
         Adverse event, non-fatal
    1
    -
         Lost to follow-up
    7
    2
    Period 2
    Period 2 title
    Parts 2 and 3: Open-Label FTC TDF or TAF
    Is this the baseline period?
    		 No
    Allocation method
    Not applicable
    Blinding used
    		 Not blinded

    Arms
    Are arms mutually exclusive
    Yes

    Arm title
    		 Part 1: ISL & Parts 2 & 3: FTC/TDF or FTC/TAF
    Arm description
    		 Participants received 60 mg tablet of ISL once monthly (QM) plus placebo to FTC/TDF tablet once daily (QD) or placebo to FTC/TAF tablet QD in Part 1. Participants then received open-label FTC/TDF or FTC/TAF in Parts 2 and 3.
    Arm type
    		 Active comparator

    Investigational medicinal product name
    FTC/TDF
    Investigational medicinal product code
    Other name
    Truvada Emtricitabine/Tenofovir Disoproxil Fumarate
    Pharmaceutical forms
    Tablet
    Routes of administration
    Oral use
    Dosage and administration details
    Participants receive 200/245 mg of FTC/TDF combination tablet, QD, orally for up to 24 months

    Investigational medicinal product name
    FTC/TAF
    Investigational medicinal product code
    Other name
    Descovy Emtricitabine/Tenofovir Alafenamide
    Pharmaceutical forms
    Tablet
    Routes of administration
    Oral use
    Dosage and administration details
    Participants receive 200/25 mg of FTC/TAF combination tablet, QD, orally for up to 24 months

    Arm title
    		 Parts 1 to 3: FTC/TDF or FTC/TAF
    Arm description
    		 Participants received 200/245 mg or 200/300 mg of FTC/TDF combination tablet QD or 200/25 mg of FTC/TAF combination tablet QD at investigator's discretion plus placebo to ISL tablet QM in Part 1. Participants continued to receive open-label FTC/TDF or FTC/TAF in Parts 2 and 3.
    Arm type
    		 Active comparator

    Investigational medicinal product name
    FTC/TDF
    Investigational medicinal product code
    Other name
    Truvada Emtricitabine/Tenofovir Disoproxil Fumarate
    Pharmaceutical forms
    Tablet
    Routes of administration
    Oral use
    Dosage and administration details
    Participants receive 200/245 mg of FTC/TDF combination tablet, QD, orally for up to 24 months

    Investigational medicinal product name
    FTC/TAF
    Investigational medicinal product code
    Other name
    Descovy Emtricitabine/Tenofovir Alafenamide
    Pharmaceutical forms
    Tablet
    Routes of administration
    Oral use
    Dosage and administration details
    Participants receive 200/25 mg of FTC/TAF combination tablet, QD, orally for up to 24 months

    Number of subjects in period 2 [1]
    		Part 1: ISL & Parts 2 & 3: FTC/TDF or FTC/TAF Parts 1 to 3: FTC/TDF or FTC/TAF
    Started
    306
    154
    Completed
    0
    0
    Not completed
    306
    154
         Consent withdrawn by subject
    39
    23
         Physician decision
    -
    2
         Study terminated by Sponsor
    227
    119
         Not reported
    6
    1
         Lost to follow-up
    34
    9
    Notes
    [1] - The number of subjects starting the period is not consistent with the number completing the preceding period. It is expected the number of subjects starting the subsequent period will be the same as the number completing the preceding period.
    Justification: Period 1 was not completed prior to moving to open-label Parts 2 and 3.

    Baseline characteristics

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    Baseline characteristics reporting groups
    Reporting group title
    Part 1: ISL & Parts 2 & 3: FTC/TDF or FTC/TAF
    Reporting group description
    		 Participants received 60 mg tablet of ISL once monthly (QM) plus placebo to FTC/TDF tablet once daily (QD) or placebo to FTC/TAF tablet QD in Part 1. Participants then received open-label FTC/TDF or FTC/TAF in Parts 2 and 3.

    Reporting group title
    Parts 1 to 3: FTC/TDF or FTC/TAF
    Reporting group description
    		 Participants received 200/245 mg or 200/300 mg of FTC/TDF combination tablet QD or 200/25 mg of FTC/TAF combination tablet QD at investigator's discretion plus placebo to ISL tablet QM in Part 1. Participants continued to receive open-label FTC/TDF or FTC/TAF in Parts 2 and 3.

    Reporting group values
    		 Part 1: ISL & Parts 2 & 3: FTC/TDF or FTC/TAF Parts 1 to 3: FTC/TDF or FTC/TAF Total
    Number of subjects
    		 328 166 494
    Age categorical
    Units: Subjects
        In utero
    		 0 0 0
        Preterm newborn infants (gestational age < 37 wks)
    		 0 0 0
        Newborns (0-27 days)
    		 0 0 0
        Infants and toddlers (28 days-23 months)
    		 0 0 0
        Children (2-11 years)
    		 0 0 0
        Adolescents (12-17 years)
    		 0 0 0
        Adults (18-64 years)
    		 327 165 492
        From 65-84 years
    		 1 1 2
        85 years and over
    		 0 0 0
    Age Continuous
    Units: years
        arithmetic mean (standard deviation)
    		 29.6 ( 9.6 ) 29.5 ( 9.2 ) -
    Sex: Female, Male
    Units: Participants
        Female
    		 0 0 0
        Male
    		 328 166 494
    Race (NIH/OMB)
    Units: Subjects
        American Indian or Alaska Native
    		 2 0 2
        Asian
    		 70 31 101
        Native Hawaiian or Other Pacific Islander
    		 2 0 2
        Black or African American
    		 83 41 124
        White
    		 135 71 206
        More than one race
    		 35 20 55
        Unknown or Not Reported
    		 1 3 4
    Ethnicity (NIH/OMB)
    Units: Subjects
        Hispanic or Latino
    		 111 51 162
        Not Hispanic or Latino
    		 214 111 325
        Unknown or Not Reported
    		 3 4 7

    End points

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    End points reporting groups
    Reporting group title
    Part 1: ISL & Parts 2 & 3: FTC/TDF or FTC/TAF
    Reporting group description
    		 Participants received 60 mg tablet of ISL once monthly (QM) plus placebo to FTC/TDF tablet once daily (QD) or placebo to FTC/TAF tablet QD in Part 1. Participants then received open-label FTC/TDF or FTC/TAF in Parts 2 and 3.

    Reporting group title
    Parts 1 to 3: FTC/TDF or FTC/TAF
    Reporting group description
    		 Participants received 200/245 mg or 200/300 mg of FTC/TDF combination tablet QD or 200/25 mg of FTC/TAF combination tablet QD at investigator's discretion plus placebo to ISL tablet QM in Part 1. Participants continued to receive open-label FTC/TDF or FTC/TAF in Parts 2 and 3.
    Reporting group title
    Part 1: ISL & Parts 2 & 3: FTC/TDF or FTC/TAF
    Reporting group description
    		 Participants received 60 mg tablet of ISL once monthly (QM) plus placebo to FTC/TDF tablet once daily (QD) or placebo to FTC/TAF tablet QD in Part 1. Participants then received open-label FTC/TDF or FTC/TAF in Parts 2 and 3.

    Reporting group title
    Parts 1 to 3: FTC/TDF or FTC/TAF
    Reporting group description
    		 Participants received 200/245 mg or 200/300 mg of FTC/TDF combination tablet QD or 200/25 mg of FTC/TAF combination tablet QD at investigator's discretion plus placebo to ISL tablet QM in Part 1. Participants continued to receive open-label FTC/TDF or FTC/TAF in Parts 2 and 3.

    Primary: Number of Participants Who Experienced an Adverse Event (AE) During Blinded Treatment

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    End point title
    		 Number of Participants Who Experienced an Adverse Event (AE) During Blinded Treatment [1]
    End point description
    An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The number of participants who experienced an AE will be reported for each treatment arm.
    End point type
    Primary
    End point timeframe
    Up to approximately 10.5 months
    Notes
    [1] - No statistical analyses have been specified for this primary end point. It is expected there is at least one statistical analysis for each primary end point.
    Justification: Per protocol, only descriptive statistics are presented.
    End point values
    		 Part 1: ISL & Parts 2 & 3: FTC/TDF or FTC/TAF Parts 1 to 3: FTC/TDF or FTC/TAF
    Number of subjects analysed
    328
    166
    Units: Participants
    211
    128
    No statistical analyses for this end point

    Primary: Number of Participants Who Discontinued from Blinded Study Treatment Due to an AE

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    End point title
    		 Number of Participants Who Discontinued from Blinded Study Treatment Due to an AE [2]
    End point description
    An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The number of participants who experienced an AE will be reported for each treatment arm.
    End point type
    Primary
    End point timeframe
    Up to approximately 9 months
    Notes
    [2] - No statistical analyses have been specified for this primary end point. It is expected there is at least one statistical analysis for each primary end point.
    Justification: Per protocol, only descriptive statistics are presented.
    End point values
    		 Part 1: ISL & Parts 2 & 3: FTC/TDF or FTC/TAF Parts 1 to 3: FTC/TDF or FTC/TAF
    Number of subjects analysed
    328
    166
    Units: Participants
    1
    0
    No statistical analyses for this end point

    Secondary: Number of Participants with Confirmed HIV-1 infection

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    End point title
    		 Number of Participants with Confirmed HIV-1 infection
    End point description
    The number of participants with confirmed HIV-1 infections during the blinded treatment period is presented.
    End point type
    Secondary
    End point timeframe
    Up to approximately 10.5 months
    End point values
    		 Part 1: ISL & Parts 2 & 3: FTC/TDF or FTC/TAF Parts 1 to 3: FTC/TDF or FTC/TAF
    Number of subjects analysed
    328
    166
    Units: Participants
    0
    0
    No statistical analyses for this end point

    Adverse events

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    Adverse events information
    Timeframe for reporting adverse events
    Entire Study: Blinded Treatment (Part 1) + Open-Label Standard-of-Care Treatment (Parts 2 & 3) [Up to approximately 26 months]
    Adverse event reporting additional description
    Data are presented separately for Part 1 (randomized blinded treatment) and Parts 2 & 3 (open-label standard-of-care preexposure prophylaxis [PrEP] periods). Open-label PrEP treatment was pooled per protocol as standard-of-care treatment (FTC/TAF as available only for US sites, FTC/TDF as brand [200/300 mg] or generic [200/245 mg]).
    Assessment type
    		 Systematic
    Dictionary used for adverse event reporting
    Dictionary name
    		 MedDRA
    Dictionary version
    26.0
    Reporting groups
    Reporting group title
    Part 1: ISL
    Reporting group description
    		 Participants received blinded 60 mg tablet of ISL QM plus placebo to FTC/TDF tablet QD or placebo to FTC/TAF tablet QD in Part 1.

    Reporting group title
    Part 1: FTC/TDF or FTC/TAF
    Reporting group description
    		 Participants received blinded FTC/TDF (200/245 mg or 200/300 mg) or FTC/TAF (200/25 mg) QD and placebo to ISL QM in Part 1.

    Reporting group title
    Parts 2 & 3: Open-label PrEP (FTC/TDF or FTC/TAF in Part 1)
    Reporting group description
    		 Participants received open-label FTC/TDF or FTC/TAF (based on regional availability) QD in Parts 2 and 3 (after blinded FTC/TDF or FTC/TAF in Part 1).

    Reporting group title
    Parts 2 & 3: Open-label PrEP (ISL in Part 1)
    Reporting group description
    		 Participants received open-label FTC/TDF or FTC/TAF (based on regional availability) QD in Parts 2 and 3 (after blinded ISL in Part 1).

    Serious adverse events
    		 Part 1: ISL Part 1: FTC/TDF or FTC/TAF Parts 2 & 3: Open-label PrEP (FTC/TDF or FTC/TAF in Part 1) Parts 2 & 3: Open-label PrEP (ISL in Part 1)
    Total subjects affected by serious adverse events
         subjects affected / exposed
    6 / 328 (1.83%)
    1 / 166 (0.60%)
    5 / 154 (3.25%)
    18 / 306 (5.88%)
         number of deaths (all causes)
    0
    0
    0
    0
         number of deaths resulting from adverse events
    0
    0
    0
    0
    Injury, poisoning and procedural complications
    Alcohol poisoning
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Jaw fracture
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Ulna fracture
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Nervous system disorders
    Epilepsy
         subjects affected / exposed
    1 / 328 (0.30%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 1
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Amnesia
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Gastrointestinal disorders
    Proctitis
         subjects affected / exposed
    1 / 328 (0.30%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    0 / 306 (0.00%)
         occurrences causally related to treatment / all
    0 / 1
    0 / 0
    0 / 0
    0 / 0
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Psychiatric disorders
    Acute psychosis
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Substance-induced psychotic disorder
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Suicidal ideation
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    1 / 154 (0.65%)
    0 / 306 (0.00%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 1
    0 / 0
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Infections and infestations
    Cellulitis
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    COVID-19
         subjects affected / exposed
    1 / 328 (0.30%)
    1 / 166 (0.60%)
    1 / 154 (0.65%)
    8 / 306 (2.61%)
         occurrences causally related to treatment / all
    0 / 1
    0 / 1
    0 / 1
    0 / 8
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Appendicitis
         subjects affected / exposed
    1 / 328 (0.30%)
    0 / 166 (0.00%)
    2 / 154 (1.30%)
    0 / 306 (0.00%)
         occurrences causally related to treatment / all
    0 / 1
    0 / 0
    0 / 2
    0 / 0
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Pneumonia
         subjects affected / exposed
    1 / 328 (0.30%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    0 / 306 (0.00%)
         occurrences causally related to treatment / all
    0 / 1
    0 / 0
    0 / 0
    0 / 0
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Peritonsillar abscess
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Folliculitis
         subjects affected / exposed
    1 / 328 (0.30%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    0 / 306 (0.00%)
         occurrences causally related to treatment / all
    0 / 1
    0 / 0
    0 / 0
    0 / 0
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Pyelonephritis acute
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Dengue fever
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Upper respiratory tract infection
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    1 / 154 (0.65%)
    0 / 306 (0.00%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 1
    0 / 0
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Viral infection
         subjects affected / exposed
    0 / 328 (0.00%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Metabolism and nutrition disorders
    Hyperglycaemia
         subjects affected / exposed
    1 / 328 (0.30%)
    0 / 166 (0.00%)
    0 / 154 (0.00%)
    1 / 306 (0.33%)
         occurrences causally related to treatment / all
    0 / 1
    0 / 0
    0 / 0
    0 / 1
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Frequency threshold for reporting non-serious adverse events: 5%
    Non-serious adverse events
    		 Part 1: ISL Part 1: FTC/TDF or FTC/TAF Parts 2 & 3: Open-label PrEP (FTC/TDF or FTC/TAF in Part 1) Parts 2 & 3: Open-label PrEP (ISL in Part 1)
    Total subjects affected by non serious adverse events
         subjects affected / exposed
    120 / 328 (36.59%)
    88 / 166 (53.01%)
    104 / 154 (67.53%)
    230 / 306 (75.16%)
    Investigations
    CD4 lymphocytes decreased
         subjects affected / exposed
    1 / 328 (0.30%)
    3 / 166 (1.81%)
    6 / 154 (3.90%)
    24 / 306 (7.84%)
         occurrences all number
    1
    3
    10
    29
    Nervous system disorders
    Headache
         subjects affected / exposed
    14 / 328 (4.27%)
    10 / 166 (6.02%)
    9 / 154 (5.84%)
    18 / 306 (5.88%)
         occurrences all number
    14
    10
    11
    23
    Gastrointestinal disorders
    Haemorrhoids
         subjects affected / exposed
    3 / 328 (0.91%)
    2 / 166 (1.20%)
    8 / 154 (5.19%)
    12 / 306 (3.92%)
         occurrences all number
    3
    2
    9
    12
    Diarrhoea
         subjects affected / exposed
    19 / 328 (5.79%)
    9 / 166 (5.42%)
    11 / 154 (7.14%)
    14 / 306 (4.58%)
         occurrences all number
    21
    11
    11
    14
    Respiratory, thoracic and mediastinal disorders
    Cough
         subjects affected / exposed
    5 / 328 (1.52%)
    3 / 166 (1.81%)
    5 / 154 (3.25%)
    16 / 306 (5.23%)
         occurrences all number
    5
    3
    5
    17
    Oropharyngeal pain
         subjects affected / exposed
    6 / 328 (1.83%)
    7 / 166 (4.22%)
    9 / 154 (5.84%)
    13 / 306 (4.25%)
         occurrences all number
    6
    8
    10
    15
    Infections and infestations
    Chlamydial infection
         subjects affected / exposed
    0 / 328 (0.00%)
    2 / 166 (1.20%)
    7 / 154 (4.55%)
    17 / 306 (5.56%)
         occurrences all number
    0
    2
    9
    19
    COVID-19
         subjects affected / exposed
    35 / 328 (10.67%)
    21 / 166 (12.65%)
    37 / 154 (24.03%)
    69 / 306 (22.55%)
         occurrences all number
    36
    21
    41
    79
    Oropharyngeal gonococcal infection
         subjects affected / exposed
    16 / 328 (4.88%)
    11 / 166 (6.63%)
    24 / 154 (15.58%)
    41 / 306 (13.40%)
         occurrences all number
    18
    11
    29
    55
    Nasopharyngitis
         subjects affected / exposed
    14 / 328 (4.27%)
    7 / 166 (4.22%)
    11 / 154 (7.14%)
    27 / 306 (8.82%)
         occurrences all number
    14
    8
    12
    33
    Latent syphilis
         subjects affected / exposed
    2 / 328 (0.61%)
    0 / 166 (0.00%)
    3 / 154 (1.95%)
    18 / 306 (5.88%)
         occurrences all number
    2
    0
    3
    22
    Influenza
         subjects affected / exposed
    4 / 328 (1.22%)
    6 / 166 (3.61%)
    14 / 154 (9.09%)
    14 / 306 (4.58%)
         occurrences all number
    4
    7
    15
    19
    Pharyngeal chlamydia infection
         subjects affected / exposed
    2 / 328 (0.61%)
    1 / 166 (0.60%)
    2 / 154 (1.30%)
    18 / 306 (5.88%)
         occurrences all number
    2
    1
    2
    18
    Syphilis
         subjects affected / exposed
    10 / 328 (3.05%)
    7 / 166 (4.22%)
    15 / 154 (9.74%)
    19 / 306 (6.21%)
         occurrences all number
    10
    7
    15
    20
    Proctitis gonococcal
         subjects affected / exposed
    13 / 328 (3.96%)
    15 / 166 (9.04%)
    30 / 154 (19.48%)
    51 / 306 (16.67%)
         occurrences all number
    14
    16
    41
    63
    Proctitis chlamydial
         subjects affected / exposed
    20 / 328 (6.10%)
    14 / 166 (8.43%)
    27 / 154 (17.53%)
    65 / 306 (21.24%)
         occurrences all number
    25
    14
    37
    81
    Upper respiratory tract infection
         subjects affected / exposed
    10 / 328 (3.05%)
    8 / 166 (4.82%)
    17 / 154 (11.04%)
    31 / 306 (10.13%)
         occurrences all number
    10
    8
    20
    32

    More information

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    Substantial protocol amendments (globally)
    Were there any global substantial amendments to the protocol? Yes
    Date
    Amendment
    07 Jun 2021
    AM1: The purpose of this amendment was to update the statistical methods for primary and secondary objectives.
    06 Dec 2021
    AM2: The purpose of this amendment was to increase frequency of monitoring of lymphocytes and to add C4+ T-cell monitoring.
    24 Feb 2022
    AM3: The purpose of this amendment was to halt dosing of blinded study intervention and to give participants the option to receive daily FTC/TDF or FTC/TAF.
    03 Aug 2022
    AM4: The purpose of this amendment was to add Part 3 to unblind each participant's Part 1 study intervention and monitor safety.

    Interruptions (globally)
    Were there any global interruptions to the trial? Yes
    Date
    Interruption
    Restart date
    10 Dec 2021
    Dosing of blinded study intervention was halted on 10-Dec-2021 due to findings of decreased lymphocyte and CD4+ T-cell counts.
    -

    Limitations and caveats
    Limitations of the trial such as small numbers of subjects analysed or technical problems leading to unreliable data.
    None reported
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    The status and protocol content of GB trials is no longer updated since 1 January 2021. For the UK, as of 31 January 2021, EU Law applies only to the territory of Northern Ireland (NI) to the extent foreseen in the Protocol on Ireland/NI. Legal notice
    As of 31 January 2023, all EU/EEA initial clinical trial applications must be submitted through CTIS . Updated EudraCT trials information and information on PIP/Art 46 trials conducted exclusively in third countries continues to be submitted through EudraCT and published on this website.

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