Extended-release Pharmacotherapy for Opioid Use Disorder (EXPO)
Research type
Research Study
Full title
Extended-release Pharmacotherapy for Opioid Use Disorder (EXPO): An Open Label Randomised Controlled Trial of Injectable Depot Maintenance Buprenorphine versus Standard-Of-Care Oral Maintenance Opioid Agonist/Partial Opioid Agonist Medication, with Personalised Psychosocial Intervention
IRAS ID
255522
Contact name
Mike Kelleher
Contact email
Sponsor organisation
King's College London
Eudract number
2018-004460-63
Duration of Study in the UK
3 years, 0 months, 0 days
Research summary
In England, there are at last 350,000 people in need of treatment for opioid drug addiction (mainly illicit heroin). These people suffer a considerable personal and social disease burden which is associated with substantial societal costs. In the NHS we have longstanding oral replacement medication therapies (methadone liquid and buprenorphine tablets). Up to 40-50% of patients discontinue early in treatment and do not obtain any clinically meaningful benefit.
The EXPO Trial is a randomised controlled trial of extended-release buprenorphine maintenance medication to treat addiction to opioid drugs (mainly illicit heroin). Opioid addiction is a persistent and debilitating condition. In the NHS, the front-line medication therapies are: daily oral methadone and sublingual tablet buprenorphine (standard-of-care). There are around 150,000 people enrolled in MET or BUP in 1,000 NHS and NGO clinics.
On average, treatment associated with reductions in illicit drugs use, drug injecting, overdose, and crime. However, up to 50% of patients drop out; often within a month and with many experiencing a repeating cycle of treatment admission and discontinuation. In EXPO, we will determine the effectiveness of an extended-release formulation of buprenorphine (XR-BUP) compared to standard-of-care medication in specialist NHS addictions clinics, and also determine the effectiveness of XR-BUP with a tailored psychosocial intervention, building on a successfully completed study at the co-ordinating centre in South London. In the EXPO study, the XR-BUP medication is an called Sublocade (Indivior). Developed, trialled and now used in clinical practice in the USA, this is a monthly subcutaneous injectable medication. Study participation will be offered to patients already enrolled in treatment as well new admissions to each clinic. Findings from EXPO will make a vital practice contribution to effective patient care for opioid use disorder.
Lay summary of study results: Methadone and buprenorphine that is taken orally is commonly used to treat opioid use disorder but there is a form of buprenorphine that's injected under the skin and lasts longer. There is currently limited research comparing its effectiveness to the standard treatments taken orally yet.
The EXPO Trial was a real-world study comparing standard opioid use disorder treatments taken orally (SoC) with a newer form of higher strength-slower releasing buprenorphine injection (BUP-XR). Adults at 5 addiction treatment clinics across England and Scotland were randomly assigned to continue their usual oral daily medication or BUP-XR for 24 weeks. The main aim was to see how many days participants didn’t use opioids during weeks 2–24. Safety was also assessed, and a cost analysis was done to compare the cost of the treatments against the number of days participants remained opioid free whilst considering various factors that affect people with opioid use disorder and society.
Between August 9, 2019, and November 2, 2021, 314 participants were randomly assigned, by a computer, to receive standard oral treatments or the higher strength-slower releasing buprenorphine injection (BUP-XR). Those in the BUP-XR group remained opioid-free for a longer average time (123.43 days) compared to the SoC group (104.37 days).
Although, more side effects occurred in the BUP-XR group, they were mostly mild to moderate pain from the injection. There were no serious side effects that were linked to the treatments. When looking at the cost of the treatments against each other, BUP-XR had a higher cost but was more cost-effective for participants with more opioid addiction severity or on treatment for over 28 days at the start of the study.
In comparison to the standard daily oral treatment, the monthly BUP-XR injection was better in providing more opioid free days, with a similar safety record. BUP-XR wasn't cost-effective against the current standard oral treatments overall but demonstrated better effectiveness at a lower cost to treat participants with more severe opioid use disorder or those on longer-term treatment. However, more research is needed to see if BUP-XR shows more improvement for patients with opioid use disorder over a longer period.
REC name
London - Brighton & Sussex Research Ethics Committee
REC reference
19/LO/0483
Date of REC Opinion
1 Jul 2019
REC opinion
Further Information Favourable Opinion