History of the discovery, development, and FDA-approval of buprenorphine medications for the treatment of opioid use disorder.

Buprenorphine-based medications were first approved by the United States Food and Drug Administration in 2002 for the treatment of opioid dependence, or opioid use disorder (OUD) as the condition is presently known. This regulatory milestone was the outcome of 36 years of research and development, which also led to the development and approval of several other new buprenorphine-based medications. In this short review, we first describe the discovery and early development stages of buprenorphine. Second, we review key steps that led to the development of buprenorphine as a drug product. Third, we explain the regulatory approval of several buprenorphine-based medications for the treatment of OUD. We also discuss these developments in the context of the evolution of regulations and policies that have progressively improved OUD treatment availability and efficacy, although challenges remain in removing system-level, provider-level, and local-level barriers to quality treatment, to integrating OUD treatment into routine care and other settings, to reducing disparities in access to treatment, and to optimizing person-centered outcomes.

Current Perspectives on Selective Dopamine D3 Receptor Antagonists/Partial Agonists as Pharmacotherapeutics for Opioid and Psychostimulant Use Disorders.

Over three decades of evidence indicate that dopamine (DA) D3 receptors (D3R) are involved in the control of drug-seeking behavior and may play an important role in the pathophysiology of substance use disorders (SUD). The expectation that a selective D3R antagonist/partial agonist would be efficacious for the treatment of SUD is based on the following key observations. First, D3R are distributed in strategic areas belonging to the mesolimbic DA system such as the ventral striatum, midbrain, and ventral pallidum, which have been associated with behaviors controlled by the presentation of drug-associated cues. Second, repeated exposure to drugs of abuse produces neuroadaptations in the D3R system. Third, the synthesis and characterization of highly potent and selective D3R antagonists/partial agonists have further strengthened the role of the D3R in SUD. Based on extensive preclinical and preliminary clinical evidence, the D3R shows promise as a target for the development of pharmacotherapies for SUD as reflected by their potential to (1) regulate the motivation to self-administer drugs and (2) disrupt the responsiveness to drug-associated stimuli that play a key role in reinstatement of drug-seeking behavior triggered by re-exposure to the drug itself, drug-associated environmental cues, or stress. The availability of PET ligands to assess clinically relevant receptor occupancy by selective D3R antagonists/partial agonists, the definition of reliable dosing, and the prospect of using human laboratory models may further guide the design of clinical proof of concept studies. Pivotal clinical trials for more rapid progression of this target toward regulatory approval are urgently required. Finally, the discovery that highly selective D3R antagonists, such as R-VK4-116 and R-VK4-40, do not adversely affect peripheral biometrics or cardiovascular effects alone or in the presence of oxycodone or cocaine suggests that this class of drugs has great potential in safely treating psychostimulant and/or opioid use disorders.

Buprenorphine exposure levels to optimize treatment outcomes in opioid use disorder.

The severity of the ongoing opioid crisis, recently exacerbated by the COVID-19 pandemic, emphasizes the importance for individuals suffering from opioid use disorder (OUD) to have access to and receive efficacious, evidence-based treatments. Optimal treatment of OUD should aim at blocking the effects of illicit opioids while controlling opioid craving and withdrawal to facilitate abstinence from opioid use and promote recovery. The present work analyses the relationship between buprenorphine plasma exposure and clinical efficacy in participants with moderate to severe OUD using data from two clinical studies (39 and 504 participants). Leveraging data from placebo-controlled measures assessing opioid blockade, craving, withdrawal and abstinence, we found that buprenorphine plasma concentrations sustained at 2-3 ng/ml (corresponding to ≥70% brain mu-opioid receptor occupancy) optimized treatment outcomes in the majority of participants, while some individuals (e.g., injecting opioid users) needed higher concentrations. Our work also included non-linear mixed effects modeling and survival analysis, which identified a number of demographic, genetic and social factors modulating treatment response and retention. Altogether, these findings provide key information on buprenorphine plasma levels that optimize clinical outcomes and increase the likelihood of individual treatment success. NLM identifiers: NCT02044094, NCT02357901.

The introduction of a novel formulation of buprenorphine into organized health systems.

Background: Effective medications for opioid use disorder (MOUD) are underutilized. This exploratory study used real-world data to analyze US distribution patterns of buprenorphine extended-release (BUP-XR) within organized health systems (OHS), including the Veterans Health Administration (VHA), Indian Health Service (IHS), criminal justice system (CJS), and integrated delivery networks (IDNs). Methods: National BUP-XR distribution data within each OHS were available from WNS Global Services and were evaluated from July 2019 through July 2020. BUP-XR distribution data by OHS subtype (VHA, IHS, CJS, IDN) and state were aggregated and reported. Results: The total distribution of BUP-XR increased from 6,721 units in the second half of 2019 (H2'19) to 12,925 in the first half of 2020 (H1'20). OHS distribution increased from H2'19 to H1'20 in every subtype but was primarily driven by IDN distribution growth. IDNs accounted for 73% of total units in H2'19 and continued to grow in H1'20. In H1'20, IDNs accounted for 78%, VHA for 12%, CJS for 6%, and IHS for 4%. IDN distribution for BUP-XR increased from 4,911 to 10,100 units, showing the highest growth rate of 106% within all OHS subtypes. The states with the highest total BUP-XR distribution over the 12-month period were Massachusetts (4,534), Pennsylvania (3,773), and California (1,866). Conclusions: Overall distribution of BUP-XR, as a treatment option for OUD, is increasing; however, access to MOUD varies greatly across OHS subtypes and geography. Identifying and overcoming barriers to appropriate MOUD use is critical in addressing the opioid crisis.

Assessment of craving in opioid use disorder: Psychometric evaluation and predictive validity of the opioid craving VAS.

BACKGROUND: This work evaluated the psychometric properties of the single-item Opioid Craving Visual Analog Scale (OC-VAS) for opioid use disorder (OUD). METHODS: Psychometric evaluation of the OC-VAS (range: 0-100 mm) was supported by Subjective Opiate Withdrawal Scale (SOWS) item 16 and total score, Clinical Opiate Withdrawal Scale (COWS) scores, and the 36-Item Short-Form Health Survey, using data from phase 3 study (NCT02357901; N = 487) participants who received randomized treatment and completed the OC-VAS at screening. Descriptive properties, test-retest reliability, construct validity, known-groups validity, and responsiveness were assessed. Interpretation of meaningful change and predictive validity were also explored. RESULTS: Descriptive properties for the OC-VAS at screening did not provide evidence of problematic floor/ceiling effects or missingness. The test-retest reliability was established by weekly intraclass correlations >0.70. At the screening and end of the study, the strong positive correlations between OC-VAS and SOWS Total/Item 16 score and the significant OC-VAS differences among COWS severity groups supported construct validity and known-groups (discriminating ability) validity, respectively. The associations between the changes in OC-VAS and in supporting measures/opioid use from screening to the end of the study demonstrated responsiveness and the ability to detect change in clinical status. During the induction and randomization treatment periods, significant relationships were identified between OC-VAS score and subsequent opioid use. CONCLUSIONS: This psychometric evaluation of the OC-VAS performed on a large OUD patient population provides evidence to support its use to measure the severity of opioid craving and its ability to predict opioid use.

Treating Opioid Use Disorder With a Monthly Subcutaneous Buprenorphine Depot Injection: 12-Month Safety, Tolerability, and Efficacy Analysis.

BACKGROUND: BUP-XR (RBP-6000 or SUBLOCADE) is the first Food and Drug Administration-approved subcutaneously administered monthly extended-release buprenorphine medication for the treatment of moderate or severe opioid use disorder. The primary objective of this phase III study was to assess the long-term safety, tolerability, and efficacy of BUP-XR. METHODS: This open-label multicenter study in adults with moderate or severe opioid use disorder enrolled 257 participants from a previously conducted placebo-controlled, double-blind phase III study (rollover group) and 412 de novo participants not previously treated with BUP-XR. Participants received an initial injection of BUP-XR 300 mg and subsequent monthly 300 mg or 100 mg flexible doses. By study end, participants received up to 12 injections. RESULTS: Overall, 66.8% of participants reported more than 1 treatment-emergent adverse event (TEAE). Injection-site TEAEs (13.2% of participants) were mostly mild or moderate in severity. There were no clinically meaningful changes in safety assessments. An integrated analysis of the double-blind and open-label study participants showed that the incidence of TEAEs, including injection-site TEAEs, was lower in the second 6 months of treatment versus the first 6 months. After 12 months of treatment, 61.5% of the rollover participants and 75.8% of the de novo participants were abstinent. Retention rates after 12 months were 50.6% for the participants who initiated BUP-XR in the double-blind study and 50.5% for de novo participants. CONCLUSIONS: This study demonstrates that the clinical benefits and acceptable safety profile of BUP-XR demonstrated in the 6-month double-blind study are sustained over a 12-month open-label study, with lower incidence of TEAEs in the second 6 months of treatment.

Recovery From Opioid Use Disorder (OUD) After Monthly Long-acting Buprenorphine Treatment: 12-Month Longitudinal Outcomes From RECOVER, an Observational Study.

OBJECTIVES: While evidence has mounted regarding the short-term effectiveness of pharmacotherapy for opioid use disorder (OUD), little is known about longer-term psychosocial, economic, and health outcomes. We report herein 12-month outcomes for an observational study enrolling participants who had previously taken part in a long-acting buprenorphine subcutaneous injection (BUP-XR) trial for moderate to severe OUD. METHODS: The RECOVER (Remission from Chronic Opioid Use: Studying Environmental and SocioEconomic Factors on Recovery; NCT03604861) study enrolled participants from 35 US community-based sites. Self-reported sustained opioid abstinence over 12 months and self-reported past-week abstinence at 3-, 6-, 9-, and 12-month visits were assessed. Multiple regression models assessed the association of BUP-XR duration with abstinence, controlling for potential confounders. Withdrawal, pain, health-related quality of life, depression, and employment at RECOVER baseline and 12-month visits were also compared to values collected before treatment in the BUP-XR trial. RESULTS: Of 533 RECOVER participants, 425 completed the 12-month visit (average age 42 years; 66% male); 50.8% self-reported sustained 12-month and 68.0% past-week opioid abstinence. In multiple regressions, participants receiving 12-month versus ≤2-month BUP-XR treatment duration had significantly higher likelihood of sustained opioid abstinence (75.3% vs 24.1%; P = 0.001), with similar results for past-week self-reported abstinence over time. During RECOVER, participants had fewer withdrawal symptoms, lower pain, positive health-related quality of life, minimal depression, and higher employment versus pre-trial visit. CONCLUSIONS: RECOVER participants reported positive outcomes over the 12-month observational period, including high opioid abstinence and stable or improved humanistic outcomes. These findings provide insights into the long-term impact of pharmacotherapy in OUD recovery.

Effects of monthly buprenorphine extended-release injections on patient-centered outcomes: A long-term study.

INTRODUCTION: The physical, social, psychological, and economic burden of opioid use disorder (OUD) is substantial. As of the year 2019, the predominant focus of OUD research was outcomes such as retention and abstinence. We report herein the effects of extended-release buprenorphine (BUP-XR), the first FDA-approved subcutaneously injected, monthly treatment for OUD, on patient-centered outcomes. MATERIALS AND METHODS: Patient-centered outcomes were collected during an open-label safety study of participants with OUD (NCT# 02510014) evaluating BUP-XR. Measures collected during the study included the EQ-5D-5L, SF-36v2, Treatment Effectiveness Assessment (TEA), Addiction Severity Index-Lite (ASI-Lite), employment/insurance status questionnaire, and Medication Satisfaction Questionnaire (MSQ). Changes from baseline to end of study week 49 were analyzed using mixed models for repeated measures. "Baseline" was defined as the value collected prior to the first BUP-XR injection. Results presented are for those participants who initiated treatment on BUP-XR during the open-label study and were eligible to receive up to 12 injections. RESULTS: Four hundred twelve participants were included in analyses; 206 participants discontinued BUP-XR prematurely. Mean EQ-5D-5L scores remained stable from baseline to end of study. Statistically significant improvements from baseline to end of study were noted for the SF-36v2 mental component summary score (difference = 5.0, 95%CI: 3.5-6.5) and 7 of 8 domain scores (P < .05 for all comparisons); the SF-36v2 physical component summary remained stable from baseline to end of study. The TEA total score (difference = 9.3 points, 95%CI: 8.0-10.5) and 4 of 4 domain scores (difference = 2-3 points per domain) significantly improved from baseline to end of study. Significant improvements (P < .05 for all comparisons) on the ASI-Lite were seen for all problem areas except alcohol use from baseline to end of study. Employment rate increased 7% whereas health insurance status remained stable from baseline to end of study. Medication satisfaction measured using the MSQ was >88% at end of study. CONCLUSIONS: Treatment with BUP-XR monthly injections for up to 12 months in this cohort of treatment-seeking individuals with OUD led to positive PCOs and high treatment satisfaction, which correspond to personal recovery.

Monthly Extended-Release Risperidone (RBP-7000) in the Treatment of Schizophrenia: Results From the Phase 3 Program.

PURPOSE/BACKGROUND: The Phase 3 program for RBP-7000, a once-monthly subcutaneous (SC) extended-release risperidone formulation approved for treatment of schizophrenia, consisted of a double-blind placebo-controlled trial (previously reported) and a 52-week open-label study of monthly RBP-7000 120 mg. The primary objective of the open-label study was to evaluate the long-term safety and tolerability of RBP-7000 in adults with schizophrenia. A secondary objective was to assess long-term maintenance of effectiveness. METHODS/PROCEDURES: The 52-week Phase 3 open-label study (NCT02203838) enrolled 92 rollover participants from the double-blind trial (NCT02109562) and 408 stable (Positive and Negative Syndrome Scale [PANSS] total score, ≤70) de novo participants. Participants received up to 13 monthly SC injections of RBP-7000 120 mg. Safety assessments included treatment-emergent adverse events, injection-site assessments, vital signs, laboratory and ECG parameters, extrapyramidal symptoms, and suicidality. Clinical outcomes included the PANSS and Clinical Global Impression-Severity. FINDINGS/RESULTS: Overall, 367 participants (73.4%) reported 1 or more treatment-emergent adverse event; the most common were injection-site pain (13.0%) and weight increase (12.8%). Most participants (>80%) experienced no injection-site reactions. No clinically meaningful changes were observed in laboratory or electrocardiogram values, vital signs, extrapyramidal symptoms, or suicidality. Over 12 months of exposure, mean PANSS scores continued to improve in rollover participants and remained stable among de novo participants. Mean Clinical Global Impression-Severity scores remained stable among all participants. IMPLICATIONS/CONCLUSIONS: Except for anticipated injection-site reactions, RBP-7000 demonstrated a favorable safety and tolerability profile similar to oral risperidone. Notably, PANSS scores continued to improve for participants from the pivotal study and remained stable for de novo participants.

Patient-reported outcomes in schizophrenia patients treated with once-monthly extended-release risperidone in a long-term clinical study.

PURPOSE: RBP-7000 (PERSERIS™) is a once-monthly subcutaneous extended-release risperidone formulation approved by the United States Food and Drug Administration for the treatment of schizophrenia in adults. The objective of this study was to describe the long-term impact of RBP-7000 on health-related quality of life (HRQoL), subjective well-being, treatment satisfaction and medication preference in patients with schizophrenia. PATIENTS AND METHODS: HRQoL was derived from a 52-week multicentre Phase III single-arm open-label outpatient study that assessed the safety and efficacy of RBP-7000 (120 mg) in patients with schizophrenia. HRQoL was measured using the EuroQol EQ-5D-5L and Short-Form Survey SF-36 version 2; well-being using the Subjective Well-being Under Neuroleptic Treatment - Short Version (SWN-S); satisfaction using the Medication Satisfaction Questionnaire and medication preference using the Preference of Medication questionnaire. RESULTS: Of 482 participants at baseline, 234 remained through the end of study (EOS; week 52). Mean HRQoL and well-being scores remained stable between baseline (EQ-5D-5L index: 0.83; SF-36v2 Physical Component Score: 50; SF-36v2 Mental Component Score: 46; total SWN-S score: 89) and EOS (EQ-5D-5L index: 0.86; SF-36v2 Physical Component Score: 49; SF-36v2 Mental Component Score: 47; total SWN-S score: 90). The proportion of participants reporting satisfaction increased between week 4 (66%) and EOS (81%), with a similar trend for the preference of RBP-7000 over previous treatment (week 4: 66%; EOS: 72%). Sensitivity analyses suggested a minor effect of dropout on characterization of change over time in patient-reported outcomes (PRO) measures. CONCLUSION: Study participants attained mean HRQoL scores near that of the general US population. Over two-thirds reported high satisfaction with and preference for RBP-7000 across the study period. Additional research is needed to confirm whether these PRO translate into improved outcomes such as adherence and ultimately fewer relapses in patients with schizophrenia.

Measuring recovery in opioid use disorder: clinical utility and psychometric properties of the Treatment Effectiveness Assessment.

Purpose: The Treatment Effectiveness Assessment (TEA) is a patient-centered instrument for evaluating treatment progress and recovery from substance use disorders, including opioid use disorder (OUD). We assessed the TEA's reliability and validity and determined minimal clinically important differences (MIDs) in participants with moderate to severe OUD. Patients and methods: The TEA measures change in four single-item domains (substance use, health, lifestyle, community involvement) from treatment initiation across the duration of a treatment program. Self-reported responses range from 1 ("none or not much") to 10 ("much better") with items summed to a total score ranging from 4-40. We assessed floor and ceiling effects, internal consistency, test-retest reliability, known-groups validity (ANOVA stratified by current health status [36-Item Short Form Health Survey item 1]), convergent/divergent validity, and MIDs using data from a phase 3, open-label clinical trial of buprenorphine extended-release monthly injection for subcutaneous use (BUP-XR). Participants with OUD completed the TEA at screening and before monthly injections for up to 12 months. Results: Among 410 participants (mean age 38 years; 64% male), the mean baseline (pre-injection 1) TEA total score was 25.4 (SD 9.7), with <10% of participants at the measure floor and 10%-20% at the ceiling across domains. Internal consistency was high (Cronbach's α=0.90), with marginal test-retest reliability (intraclass correlation coefficient =0.69). Mean TEA total score consistently increased from baseline (n=410; mean 25.4 [SD 9.7]) to end of study (n=337; 35.0 [6.7]) and differentiated between current health status groups (P<0.001); it was weakly correlated with other measures of health-related quality of life/severity. MIDs ranged from 5-8 for the TEA total score across anchor- and distribution-based approaches. Conclusion: The TEA exhibited acceptable reliability and validity in a cohort of participants with moderate to severe OUD treated with BUP-XR. Given its brevity and psychometric properties, the TEA is a promising tool for use in clinical practice and research.

Patient-centered Outcomes in Participants of a Buprenorphine Monthly Depot (BUP-XR) Double-blind, Placebo-controlled, Multicenter, Phase 3 Study.

OBJECTIVE: Opioid use disorder (OUD) is associated with physical, social, psychological, and economic burden. This analysis assessed the effects of RBP-6000, referred to as BUP-XR (extended-release buprenorphine), a subcutaneously injected, monthly buprenorphine treatment for OUD compared with placebo on patient-centered outcomes measuring meaningful life changes. METHODS: Patient-centered outcomes were collected in a 24-week, phase 3, placebo-controlled study assessing the efficacy, safety, and tolerability of BUP-XR 300/300 mg (6 × 300 mg) and 300/100 mg (2 × 300 mg followed by 4 × 100 mg) injections in treatment-seeking participants with moderate-to-severe OUD. Measures included the EQ-5D-5L, SF-36v2, Medication Satisfaction Questionnaire, employment/insurance status, and healthcare resource utilization (HCRU). Changes from baseline to end of study were compared across treatment arms, using mixed models for repeated measures. RESULTS: Participants receiving BUP-XR (n = 389) versus placebo (n = 98) had significantly greater changes from baseline on the EQ-5D-5L index (300/300 mg: difference = 0.0636, P = 0.003), EQ-5D-5L visual analog scale (300/300 mg: difference = 5.9, P = 0.017; 300/100 mg: difference = 7.7, P = 0.002), and SF-36v2 physical component summary score (300/300 mg: difference = 3.8, P < 0.001; 300/100 mg: difference = 3.2, P = 0.002). Satisfaction was significantly higher for participants receiving BUP-XR 300/300 mg (88%, P < 0.001) and 300/100 mg (88%, P < 0.001) than placebo (46%). Employment and percentage of insured participants increased by 10.8% and 4.1% with BUP-XR 300/300 mg and 10.0% and 4.7% with 300/100 mg but decreased by 12.6% and 8.4% with placebo. Participants receiving BUP-XR compared with placebo had significantly fewer hospital days per person-year observed. CONCLUSIONS: These results show the feasibility of measuring patient-centered life changes in substance use disorder clinical studies. Participants receiving up to 6 monthly injections of BUP-XR, compared with placebo, reported better health, increased medication satisfaction, increased employment, and decreased healthcare utilization.

Efficacy and safety of a monthly buprenorphine depot injection for opioid use disorder: a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: RBP-6000, referred to as BUP-XR (extended-release buprenorphine), is a subcutaneously injected, monthly buprenorphine treatment for opioid use disorder. BUP-XR provides sustained buprenorphine plasma concentrations to block drug-liking of abused opioids over the entire monthly dosing period, while controlling withdrawal and craving symptoms. Administration of BUP-XR in a health-care setting also mitigates abuse, misuse, diversion, and unintentional exposure. We aimed to investigate the efficacy of different BUP-XR dosing regimens in participants with opioid use disorder. METHODS: This randomised, double-blind, placebo-controlled, phase 3 trial was done at 36 treatment centres in the USA. Treatment-seeking adults aged 18-65 years who had moderate or severe opioid use disorder (as defined by the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders) entered an open-label run-in phase of up to 2 weeks' treatment with buprenorphine-naloxone sublingual film. Eligible participants were then randomly assigned (4:4:1:1) with an interactive voice/web-response system to receive BUP-XR 300 mg/300 mg (six injections of 300 mg), BUP-XR 300 mg/100 mg (two injections of 300 mg plus four injections of 100 mg), or volume-matched placebo every 28 days, and received weekly individual drug counselling. No supplemental buprenorphine was allowed. The primary efficacy endpoint was participants' percentage abstinence from opioid use, defined as the percentage of each participant's negative urine samples and self-reports of illicit opioid use from week 5 to week 24, analysed in the full analysis set. Safety was assessed in all participants who received at least one dose of BUP-XR or placebo. This study is registered with ClinicalTrials.gov, number NCT02357901. FINDINGS: From Jan 28, 2015, to Nov 12, 2015, 1187 potential participants were screened, 665 entered run-in, and 504 received BUP-XR 300 mg/300 mg (n=201), BUP-XR 300 mg/100 mg (n=203), or placebo (n=100). Mean participants' percentage abstinence was 41·3% (SD 39·7) for BUP-XR 300 mg/300 mg and 42·7% (38·5) for 300 mg/100 mg, compared with 5·0% (17·0) for placebo (p<0·0001 for both BUP-XR regimens). No compensatory non-opioid drug use was observed during BUP-XR treatment. The most common adverse events were headache (17 [8%] participants in the BUP-XR 300 mg/300 mg group vs 19 [9%] participants in the BUP-XR 300 mg/100 mg group vs six [6%] participants in the placebo group), constipation (16 [8%] vs 19 [9%] vs 0), nausea (16 [8%] vs 18 [9%] vs five [5%]), and injection-site pruritis (19 [9%] vs 13 [6%] vs four [4%]). The BUP-XR safety profile was consistent with other buprenorphine products for treatment of opioid use disorder, except for injection-site reactions, which were reported in more than 5% of all participants who received BUP-XR, but were mostly mild and not treatment-limiting. INTERPRETATION: Participants' percentage abstinence was significantly higher in both BUP-XR groups than in the placebo group. Treatment with BUP-XR was also well tolerated. The availability of this monthly formulation, delivered by health-care providers, represents an advance in treatment for opioid use disorder that enhances the benefits of buprenorphine by delivering sustained, optimal exposure, while reducing risks of current buprenorphine products. FUNDING: Indivior.

Remission from chronic opioid use-Studying environmental and socio-economic factors on recovery (RECOVER): Study design and participant characteristics.

Few opioid use disorder (OUD) treatment studies measure meaningful life changes during long-term recovery, focusing instead on retention and abstinence. Here, we report on the design and participant characteristics of the RECOVER study, a study exploring life changes in persons with OUD for up to 24 months following participation in a Phase III trial evaluating buprenorphine extended-release monthly injection for subcutaneous use (known as RBP-6000 during development). This multisite, observational, cohort study tracks clinical, environmental, and socio-economic changes using self-administered assessments, urine drug screens (UDS), and public databases. Outcomes include demographics (e.g., patient characteristics, employment history, criminal history), lifetime and recent OUD drug use and treatment, and current health and resource use. Demographic and psychosocial characteristics are compared to a national, population-based study. RECOVER participants (N = 533) tend to be single, white, males aged 26 years or older. Mean age at first opioid use was 21.7 years; lifetime substance-related overdose was 24.2%. At first assessment, 334 (62.7%) participants reported past 7-day and 296 (55.5%) reported past 28-day opioid abstinence. Five hundred UDS were collected at the first assessment; buprenorphine (90.6%), marijuana (45.2%), and opiates (34.4%) were most commonly identified. Two hundred forty-nine (47.2%) participants reported full- or part-time employment. Participants were like a national sample with differences found for age, race/ethnicity, employment, education, and health-related quality of life. We hope that further research using this approach can provide data supporting the patient-centered development of OUD treatments and be adopted by substance use disorder studies to incorporate recovery-related, life-activity outcomes.

Exposure-response analysis after subcutaneous administration of RBP-7000, a once-a-month long-acting Atrigel formulation of risperidone.

AIMS: A new, long-acting, subcutaneous (SC) formulation of risperidone (RBP-7000) has been developed for the treatment of schizophrenia to address issues of non-adherence associated with oral risperidone treatment. The objective of this work was to establish an exposure-response relationship between total active moiety (AM) plasma exposure (risperidone + 9-hydroxy-risperidone) and Positive and Negative Syndrome Scale (PANSS) or Clinical Global Impression severity (CGI-S) scores using data from a registration trial. METHODS: This was a Phase 3 randomized, double-blind, placebo-controlled, multicenter study in 354 patients to evaluate the efficacy, safety and tolerability of RBP-7000 (90 mg and 120 mg). Non-linear mixed effects modelling was used to develop an integrated population pharmacokinetic/pharmacodynamic (PK/PD) model that included a joint PK model for risperidone and 9-hydroxy-risperidone with placebo and drug-effect models to establish the relation between total AM exposure and PANSS or CGI-S scores. RESULTS: CYP2D6 poor and intermediate metabolizers had lower formation rates of 9-hydroxy-risperidone (94% and 76% lower, respectively) compared to the extensive CYP2D6 metabolizers. The maximum placebo-corrected relative decrease in PANSS score from baseline following RBP-7000 treatment was 5.4%, half of which could be achieved at plasma concentrations of 4.6 ng ml-1 of the total AM. A proportional odds model for the CGI-S score related the total AM plasma concentration to the probability of improving/worsening scores over time. CONCLUSIONS: Exposure-response analysis was established between total AM concentrations and PANSS and CGI-S scores, with good precision in parameter estimates. CYP2D6 phenotype on risperidone metabolism was the only identified covariate.

Quantitative determination of buprenorphine, naloxone and their metabolites in rat plasma using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry.

A rapid and sensitive LC-MS/MS method was developed and validated for the simultaneous determination of buprenorphine and its three metabolites (buprenorphine glucuronide, norbuprenorphine and norbuprenorphine glucuronide) as well as naloxone and its metabolite naloxone glucuronide in the rat plasma. A hydrophilic interaction chromatography column and a mobile phase containing acetonitrile and ammonium formate buffer (pH 3.5) were used for the chromatographic separation. Mass spectrometric detection was achieved by an electrospray ionization source in the positive mode coupled to a triple quadrupole mass analyzer. The calibration curves for the six analytes displayed good linearity over the concentration range 1.0 or 5.0-1000 ng/mL. The intra and inter-day precision (CV) ranged from 2.68 to 16.4% and from 9.02 to 14.5%, respectively. The intra- and inter-day accuracy (bias) ranged from -14.2 to 15.2% and from -9.00 to 4.80%, respectively. The extraction recoveries for all the analytes ranged from 55 to 86.9%. The LC-MS/MS method was successfully applied to a pharmacokinetic study of buprenorphine-naloxone combination in rats.

Improving the oral bioavailability of buprenorphine: an in-vivo proof of concept.

OBJECTIVES: The aim of this study was to improve the oral bioavailability of buprenorphine by inhibiting presystemic metabolism via the oral co-administration of 'Generally Recognized as Safe' compounds, thus providing an orally administered drug product with less variability and comparable or higher exposure compared with the sublingual route. METHODS: The present studies were performed in Sprague Dawley rats following either intravenous or oral administration of buprenorphine/naloxone and oral co-administration of 'Generally Recognized as Safe' compounds referred to as 'adjuvants'. Plasma samples were collected up to 22 h postdosing followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis. KEY FINDINGS: The adjuvants increased Cmax (21 ± 16 ng/ml vs 75 ± 33 ng/ml; 3.6-fold) and AUC(0-22 h) (10.6 ± 8.11 µg min/ml vs 22.9 ± 11.7 µg min/ml; 2.2-fold) values of buprenorphine (control vs adjuvant-treated, respectively). The absolute oral bioavailability of buprenorphine doubled (from 1.24% to 2.68%) in the presence of the adjuvants. CONCLUSIONS: One may suggest that the adjuvant treatment most likely inhibited the presystemic metabolic enzymes, thus decreasing the intestinal 'first-pass effect' on buprenorphine. Additional studies are now required to further explore the concept of inhibiting presystemic metabolism of buprenorphine by adjuvants to potentially increase the oral bioavailability of buprenorphine.

1,2,4-Triazolyl 5-Azaspiro[2.4]heptanes: Lead Identification and Early Lead Optimization of a New Series of Potent and Selective Dopamine D3 Receptor Antagonists.

A novel series of 1,2,4-triazolyl 5-azaspiro[2.4]heptanes with high affinity and selectivity at the dopamine (DA) D3 receptor (D3R) is described. Some of these compounds also have high selectivity over the hERG channel and were characterized with respect to their pharmacokinetic properties both in vitro and in vivo during lead identification and early lead optimization phases. A few derivatives with overall favorable developability characteristics were selected for further late lead optimization studies.

Health-related quality of life in acute schizophrenia patients treated with RBP-7000 once monthly risperidone: An 8-week, randomized, double-blind, placebo-controlled, multicenter phase 3 study.

BACKGROUND: There is increased interest in the impact of new long-acting treatments on health-related quality of life (HRQoL) in patients with schizophrenia. The aim of this study was to evaluate the impact of treatment with subcutaneous injections of RBP-7000, a new sustained-release formulation of risperidone, compared with placebo on health status, subjective well-being, treatment satisfaction, and preference of medicine in subjects with acute schizophrenia. METHODS: HRQoL data were derived from an 8-week double-blind, randomized, placebo-controlled, phase 3 study that assessed efficacy, safety, and tolerability of once monthly RBP-7000 (90mg and 120mg) compared with placebo in subjects with acute schizophrenia (n=337). HRQoL was measured with the EuroQol EQ-5D-5L, well-being using the Neuroleptic Treatment-Short Version (SWN-S), satisfaction using the Medication Satisfaction Questionnaire (MSQ), and preference using the Preference of Medicine Questionnaire (POM). RESULTS: The EQ-5D-5L VAS increased significantly in the RBP-7000 120mg group compared to Placebo (p=0.0212). In RBP-7000 120mg, subjects reported significant improvements in SWN-S physical functioning (p=0.0093), social integration (p=0.0368), and total score (p=0.0395). Subjects were significantly more satisfied with RBP-7000 versus placebo (90mg p=0.0009, 120mg p=0.0006) and preferred RBP-7000 over their previous medication (90mg p<0.0001, 120mg p=0.0619). CONCLUSIONS: Significantly greater improvements in HRQoL and overall well-being were demonstrated in patients randomized to RBP-7000 compared to placebo. The effect was more pronounced in the RBP-7000 120mg group. Patient satisfaction improved significantly and patient preference for their medicine favored RBP-7000 90mg and 120mg versus Placebo.

1,2,4-Triazolyl octahydropyrrolo[2,3-b]pyrroles: A new series of potent and selective dopamine D3 receptor antagonists.

A novel series of 1,2,4-triazolyl octahydropyrrolo[2,3-b]pyrroles showing high affinity and selectivity at the DA D3 receptor is reported here. Compounds endowed with high selectivity over the hERG channel were identified and their pharmacokinetic properties thoroughly analyzed. A few derivatives with appropriate developability characteristics were selected for further studies and progression along the screening cascade. In particular, derivative 60a, (DA D3 pKi=8.4, DA D2 pKi=6.0 and hERG fpKi=5.2) showed a balanced profile and further refinements are in progress around this molecule.