The CASBAH Study
| ISRCTN | ISRCTN16138250 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN16138250 |
| Integrated Research Application System (IRAS) | 361365 |
| Central Portfolio Management System (CPMS) | 71848 |
| Grant code | HT94252430004 |
| Sponsor | Imperial College London |
| Funder | U.S. Army Medical Research Acquisition Activity |
- Submission date
- 17/12/2025
- Registration date
- 11/03/2026
- Last edited
- 11/03/2026
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Infections and Infestations
Plain English summary of protocol
Background and study aims
HIV treatment with antiretroviral therapy (ART) works very well to keep the virus under control, but it does not cure HIV. People need to take ART every day for life because the virus can hide in certain cells and return if treatment stops. Researchers are looking for new ways to control HIV without daily tablets. One option is using special proteins called broadly neutralising antibodies (bNAbs), which can fight HIV in different ways. Early studies show that a single infusion of these antibodies can keep HIV levels low in the blood for months, but we do not know if they also protect the brain and spinal fluid. This study will find out if bNAbs can stop HIV from multiplying in these areas, which could help prevent brain damage and offer a new treatment approach.
Who can participate?
People with HIV who are already taking part in other research studies where they have stopped daily ART and may be receiving bNAbs.
What does the study involve?
Including screening, participants will attend four visits over about a year. Two visits will be at their usual research department and will include questions about brain health, memory and thinking tests, a questionnaire, blood samples, and a lumbar puncture (spinal tap). One visit will be to an imaging centre for a brain MRI scan. The final visit will be either in person or by phone.
What are the possible benefits and risks of participating?
The study may help researchers learn more about new HIV treatments, but it is unlikely to benefit participants directly. Risks include discomfort or side effects from procedures such as blood tests, lumbar puncture, and MRI scans. These will be explained in detail before joining.
Where is the study run from?
St Mary’s Hospital, London (UK).
When is the study starting and how long is it expected to run for?
January 2026 to February 2028
Who is funding the study?
The U.S. Army Medical Research Acquisition Activity.
Who is the main contact?
n.doyle@imperial.ac.uk
Contact information
Public
Department of Infectious Disease
Imperial College London
Exhibition Road
London
SW7 2AZ
United Kingdom
| Phone | +44 (0)20 7594 3351 |
|---|---|
| n.doyle@imperial.ac.uk |
Scientific, Principal investigator
Clinical Trials Centre
Winston Churchill Wing
Praed Street
London
W2 1NY
United Kingdom
 ORCID ID |
0000-0002-5847-8416 |
|---|---|
| Phone | +44 (0)20 3312 1603 |
| a.winston@imperial.ac.uk |
Study information
| Primary study design | Observational |
|---|---|
| Observational study design | Cross sectional study |
| Scientific title | Central Nervous System Health of Broadly Neutralising Antibodies and Interruption of Antiretroviral Therapy in Persons with HIV |
| Study acronym | CASBAH |
| Study objectives | Study aim - To assess parameters of brain health in persons with HIV who have stopped daily oral antiretroviral therapy, with or without the administration of broadly neutralising antibodies (bNAb). |
| Ethics approval(s) |
Approved 16/12/2025, North West - Haydock Research Ethics Committee (2 Redman Place, Stratford, London, E20 1JQ, United Kingdom; -; haydock.rec@hra.nhs.uk), ref: 25/NW/0367 |
| Health condition(s) or problem(s) studied | Human immunodeficiency virus [HIV] disease |
| Intervention | This is a prospective, observational, single-centre clinical study. Twenty (20) persons with HIV, who have stopped daily oral antiretroviral therapy and are participating in a clinical trial which involves the administration of bNAbs, will be enrolled. Potentially eligible participants will be asked to provide their informed consent and attend their routine research clinic for a Screening visit. At this visit, potential participants will: Be asked some questions about themself, their physical and mental health and any medications they take or have taken in the past. If it has not been recorded recently via their parent bNAb study, their height, weight and blood pressure will be measured. They will have a physical examination if they are experiencing any symptoms. They will be asked some questions about their brain health. They will complete some brain function (cognitive) tests. They will complete a questionnaire about their mental and emotional health and wellbeing. If they haven't had their HIV viral load measured within the last 4 weeks, blood will be collected to measure this at this visit. Following the Screening visit, eligible participants will return for a follow-up visit, which consists of 2 parts - brain imaging and lumbar puncture examination. These visits can be done on the same day or within 30 days of each other. These visits should take place within 12 months of the Screening visit. The first part will take place at an imaging facility, which is in a different location from their routine research clinic. They will have an MRI (magnetic resonance imaging) brain scan and have a blood sample collected. Following this, they will attend their routine research clinic, where: They will be asked some questions about their brain health. They will complete some brain function (cognitive) tests. They will complete a questionnaire about their mental and emotional health and wellbeing. They will have another blood sample collected. They will undergo a lumbar puncture examination and have some cerebrospinal fluid (CSF) collected. Individuals may participate in the study on more than one occasion if their health circumstances relating to the primary endpoint assessment change. |
| Intervention type | Other |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) |
|
| Completion date | 28/02/2028 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 99 Years |
| Sex | All |
| Target sample size at registration | 20 |
| Key inclusion criteria | 1. Documented HIV-1 infection 2. Full capacity to provide signed informed consent 3. Participating in a clinical trial which involves the administration of bNAbs 4. Has received at least one infusion of a bNAb or placebo 5. Able to comply with the study procedures in the opinion of the investigator |
| Key exclusion criteria | 1. Cerebral infections (including AIDS defining illnesses) 2. Contraindication for MRI examination (e.g. claustrophobia, metal implants, physically unable to lie flat) 3. Contraindication to lumbar-puncture examination (at the discretion of the investigator) |
| Date of first enrolment | 16/03/2026 |
| Date of final enrolment | 30/11/2027 |
Locations
Countries of recruitment
- United Kingdom
- England
Study participating centre
London
W12 0HS
England
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Data sharing statement to be made available at a later date |
| IPD sharing plan |
Editorial Notes
17/12/2025: Trial's existence confirmed by the National Institute for Health and Care Research (NIHR) (UK).
