COMPARED RETENTION RATES BETWEEN PATIENTS TREATED WITH BUVIDAL IN FRANCE vs. SUBLINGUAL BUPRENORPHINE (OPALE-2 STUDY)

BACKGROUND Buvidal is the only formulation of long-acting buprenorphine currently available in Europe. One of the main expected achievements of long-acting formulations of buprenorphine is to enhance adherence, and to increase retention into treatment [1]. 
PATIENTS & METHODS The OPALE-2 study is a national, observational, retrospective study, conducted in 12 French addiction centers. The medical files of all patients treated with Buvidal, since the marketing of the medication in 2021, were examined, to collect the following parameters: sociodemographic features (i.e., age, sex, level of education, family and occupational status), baseline features of opioid and other substance use, and baseline medications and comorbidities. Retention (i.e., maintenance of Buvidal treatment in the center), was investigated at six months. We compared the retention rate of patient treated with Buvidal in France, to a reference rate (47.0%) obtained in a large observational study in patients treated using sublingual buprenorphine [2]. The comparison was conducted using a Pearson’s chi-squared test. The OPALE-2 study was funded by Camurus, and the protocol was reported to the Health Data Hub on Feb 2023, based on the reference French ethics procedure for analyzing retrospective data in medical records (MR-004 procedure).  
RESULTSIn total, 73 patients (mean age: 44.5 ± 11.1 years; percentage of males: 76.7%) were included in the intermediate analyses of the study. At six months, 53 (72.6%) patients were still on Buvidal in the initial center, which was found statistically greater that the similar retention rate (47.0%) found for patients receiving sublingual buprenorphine (p<0.01). Descriptive statistics of the complete population, and factors of adherence for Buvidal will be displayed in the e-Poster.  
CONCLUSIONBased on the preliminary analyses of the OPALE-2 study, retention on Buvidal at six months is higher than that found in patients treated with sublingual forms of buprenorphine. Final analyses will be refined, using a larger sample and adjusted models. 
 
REFERENCES
[1] Vorspan F, Hjelmström P, Simon N, Benyamina A, Dervaux A, Brousse G, Jamain T, Kosim M, Rolland B. What place for prolonged-release buprenorphine depot-formulation Buvidal® in the treatment arsenal of opioid dependence? Insights from the French experience on buprenorphine. Expert Opin Drug Deliv. 2019 Sep;16(9):907-914.
[2] Williams AR, Mauro CM, Feng T, Wilson A, Cruz A, Olfson M, Crystal S, Samples H, Chiodo L. Performance Measurement for Opioid Use Disorder Medication Treatment and Care Retention. Am J Psychiatry. 2023 Jun 1;180(6):454-457.