Exploring the long-term safety of antiretroviral treatment interruptions as part of HIV cure and remission clinical trials
| ISRCTN | ISRCTN51060377 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN51060377 |
| Integrated Research Application System (IRAS) | 357550 |
| Sponsor | Imperial College London |
| Funders | ViiV Healthcare, St Mary's Development Trust, NIHR Imperial Biomedical Research Centre |
- Submission date
- 02/11/2026
- Registration date
- 13/11/2026
- Last edited
- 05/11/2026
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Infections and Infestations
Plain English summary of protocol
Background and study aims
Antiretroviral therapy (ART) can control HIV and improve health for people living with HIV but it cannot cure HIV. There are several strategies that are being investigated towards HIV cure or remission. The only way to see if any treatment is effective is to temporarily stop ART. This process is called an analytical treatment interruption (ATI).
In the past, people were not closely monitored during studies that involved an ATI and significant drops in CD4 counts (that are needed for immune function) were allowed before ART was restarted. This type of ATI has been associated with worse health outcomes.
To make ATIs safe, current studies choose participants at lower risk of complications. Participants are closely monitored during ATI with frequent blood tests. There are strict criteria for when ART should be restarted. However, the long-term health outcomes for these modern ATI trials are unknown.
The COAST study is looking at the long-term health and quality of life of people living with HIV who did or did not previously take part in modern ATI trials.
Who can participate?
1. People aged 18 years and over living with HIV who have taken part in a clinical trial that involved an analytical treatment interruption according to modern ATI consensus guidelines (ATI-group)
2. People aged 18 years and over living with HIV who have not taken part in a clinical trial that involved an analytical treatment interruption and are matched to the ATI participants (non-ATI group)
What does the study involve?
Part A: Retrospective data collection from clinical records with or without information regarding a participants time in an ATI trial obtained directly from the ATI study sponsor.
Part B: Additional data collection directly from participants with or without the completion of a series of quality of life questionnaires (electronic).
Data will be collected at COAST study entry and again every 2 years out to 10 years per participant (pending additional funding).
What are the possible benefits and risks of participating?
This study is purely observational with no intervention. Consent and study visits (for Part B) can be done remotely. There are no direct benefits or risks of taking part.
Where is the study run from?
Imperial College London (UK)
When is the study starting and how long is it expected to run for?
December 2026 to October 2030
Who is funding the study?
1. ViiV Healthcare (UK)
2. St Mary’s Development Trust (UK)
3. NIHR Imperial Biomedical Research Centre (UK)
Who is the main contact?
1. Dr Tamara Elliott, tamara.elliott04@imperial.ac.uk
2. Maathini Balachandran, m.balachandran@imperial.ac.uk
Contact information
Principal investigator, Scientific, Public
Imperial College London
South Kensington Campus
Exhibition Road
London
SW7 2AZ
United Kingdom
| Phone | +44 (0)2075947393 |
|---|---|
| tamara.elliott04@imperial.ac.uk |
Study information
| Primary study design | Observational |
|---|---|
| Observational study design | Case-control study |
| Scientific title | Clinical outcomes after structured interruption of antiretroviral therapy |
| Study acronym | COAST |
| Study objectives | |
| Ethics approval(s) |
Approved 26/10/2026, North East - Newcastle & North Tyneside 2 Research Ethics Committee (2 Redman Place, Stratford, London, E20 1JQ, United Kingdom; +44 (0)207 972 2503; newcastlenorthtyneside2.rec@hra.nhs.uk), ref: 26/NE/0164 |
| Health condition(s) or problem(s) studied | Human immunodeficiency virus (HIV) |
| Methodology | Observational study with data collection as a combination of: 1. Review of clinical records 2. Direct consultation with participants +/- completion of a series of quality of life questionnaires 3. Directly from original ATI study sponsors for information during the time a participant was in the clinical trial |
| Intervention type | Other |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) | |
| Completion date | 31/10/2030 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 100 Years |
| Sex | All |
| Target sample size at registration | 1800 |
| Key inclusion criteria | Cases (analytical treatment interruption [ATI]) cohort): Any individual living with HIV who has taken part in a clinical trial that involved an analytical treatment interruption (ATI) according to modern ATI consensus guidelines Controls (non-ATI cohort): Any individual living with HIV who has not had an ATI as part of a clinical trial and matched to cases |
| Key exclusion criteria | Does not meet the inclusion criteria |
| Date of first enrolment | 01/12/2026 |
| Date of final enrolment | 31/10/2028 |
Locations
Countries of recruitment
- United Kingdom
- England
- Scotland
- Belgium
- Denmark
- Germany
- Netherlands
- Norway
- South Africa
- Spain
- Thailand
Study participating centres
Guy's Hospital
Great Maze Pond
London
SE1 9RT
England
Pond Street
London
NW3 2QG
England
80 Newark Street
London
E1 2ES
England
London
WC1E 6JB
England
369 Fulham Road
London
SW10 9NH
England
Lyndhurst Road
Worthing
BN11 2DH
England
Crumpsall
Manchester
M8 5RB
England
Edinburgh
Lothian
EH4 2XU
Scotland
St Marys Hospital
South Wharf Road
London
W2 1BL
England
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|
Editorial Notes
05/11/2026: Study's existence confirmed by the HRA.
