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Indivior Presents Modelling Data on Interaction Between Buprenorphine and Fentanyl in Opioid-Naïve and Opioid-Tolerant Subjects at the 2021 American Conference of Pharmacometrics

Data explain how buprenorphine has the potential to reduce the frequency and magnitude of fentanyl-induced respiratory depression and apnea

Richmond, VA, November 8, 2021 - Indivior PLC (LON: INDV) announces the presentation of modelling data describing the competitive interaction of buprenorphine, a treatment for opioid use disorder (OUD), and fentanyl, an increasingly abused opioid, at the µ-opioid receptor (MOR) at the Twelfth American Conference of Pharmacometrics (ACoP12), taking place virtually from November 8-12, 2021.

According to the Centers for Disease Control and Prevention (CDC), more than 96,779 people died from drug overdose in the 12-month period ending March 2021. Approximately 61,230 of these deaths were attributed to synthetic opioids such as fentanyl.1

Modelling Buprenorphine Effect on Fentanyl-induced Respiratory Depression in Opioid-naïve and Opioid-tolerant Subjects explains how buprenorphine has the potential to reduce fentanyl-induced respiratory depression and apnea.2 Population pharmacokinetic/pharmacodynamic (PK/PD) modelling was conducted to characterize buprenorphine-fentanyl interaction at MORs and its resulting effect on ventilation.2 This modelling suggested that clinically relevant exposures to buprenorphine has the potential to limit fentanyl binding to MORs and thereby possibly reduce the frequency and magnitude of respiratory depression induced by fentanyl in opioid-tolerant (OT) subjects.2

“This modelling study further enhances our understanding of the competitive interaction between buprenorphine and fentanyl,” said Christian Heidbreder, Chief Scientific Officer, Indivior. “The study results provide early clinical insights into the role that high sustained buprenorphine plasma concentrations may have in reducing fentanyl-induced respiratory depression and apnea. Because of these promising data, additional study is warranted.”


About the Study

In this two-period crossover, single-center study, 14 opioid-naïve healthy volunteers (HV) and 8 OT subjects received on 2 separate occasions intravenous placebo and buprenorphine infusion targeting buprenorphine plasma concentrations of 0.2 or 0.5 ng/mL in HVs and 1, 2 or 5 ng/mL in OT subjects.1 Upon reaching target concentrations, participants received up to 4 escalating intravenous doses of fentanyl (HV: 0.075–0.35 mg/70 kg; OT: 0.25–0.70 mg/70 kg).  Minute ventilation was measured under isohypercapnic conditions and serial blood samples were collected to assess buprenorphine and fentanyl plasma concentrations. Simulation studies were conducted to investigate the effects of a larger range of fentanyl bolus doses (up to 5 mg/70 kg) that may be representative of fentanyl unintentional overdoses.2


About Indivior

Indivior is a global pharmaceutical company working to help change patients’ lives by developing medicines to treat substance use disorders (SUD) and serious mental illnesses. Our vision is that all patients around the world will have access to evidence-based treatment for the chronic conditions and co-occurring disorders of SUD. Indivior is dedicated to transforming SUD from a global human crisis to a recognized and treated chronic disease. Building on its global portfolio of opioid use disorder treatments, Indivior has a pipeline of product candidates designed to both expand on its heritage in this category and potentially address other chronic conditions and cooccurring disorders of SUD. Headquartered in the United States in Richmond, VA, Indivior employs more than 800 individuals globally and its portfolio of products is available in over 40 countries worldwide. Visit to learn more. Connect with Indivior on LinkedIn by visiting

Forward-Looking Statements

This announcement contains certain statements that are forward-looking. By their nature, forward looking statements involve risks and uncertainties as they relate to events or circumstances that may or may not occur in the future. Actual results may differ materially from those expressed or implied in such statements because they relate to future events. Forward-looking statements include, among other things, statements regarding the Indivior Group’s financial guidance for 2021, and its medium- and long term growth outlook, its operational goals, its product development pipeline and statements regarding ongoing litigation and other statements containing the words "subject to", "believe", "anticipate", "plan", "expect", "intend", "estimate", "project", "may", "will", "should", "would", "could", "can", the negatives thereof, variations thereon and similar expressions.

Various factors may cause differences between Indivior's expectations and actual results, including, among others (including those described in the risk factors described in the most recent Indivior PLC Annual Report and in subsequent releases): factors affecting sales of Indivior Group’s products and financial position; the outcome of research and development activities; decisions by regulatory authorities regarding the Indivior Group’s drug applications or authorizations; the speed with which regulatory authorizations, pricing approvals and product launches may be achieved, if at all; the outcome of post approval clinical trials; competitive developments; difficulties or delays in manufacturing and in the supply chain; disruptions in or failure of information technology systems; the impact of existing and future legislation and regulatory provisions on product exclusivity; trends toward managed care and healthcare cost containment; legislation or regulatory action affecting pharmaceutical product pricing, reimbursement or access; challenges in the commercial execution; claims and concerns that may arise regarding the safety or efficacy of the Indivior Group’s products and product candidates; risks related to legal proceedings, including compliance with the U.S. Department of Justice Resolution and Settlement Agreements, noncompliance with which could result in potential exclusion from participating in U.S. Federal health care programs; the ongoing investigative and antitrust litigation matters; the opioid national multi-district litigation and securities class action litigation; the Indivior Group’s ability to protect its patents and other intellectual property; the outcome of patent infringement litigation relating to Indivior Group’s products, including the ongoing ANDA lawsuits; changes in governmental laws and regulations; issues related to the outsourcing of certain operational and staff functions to third parties; risks related to the evolving COVID-19 pandemic and the potential impact of COVID-19 on the Indivior Group’s operations and financial condition, which cannot be predicted with confidence; uncertainties related to general economic, political, business, industry, regulatory and market conditions; and the impact of acquisitions, divestitures, restructurings, internal reorganizations, product recalls and withdrawals and other unusual items.

Consequently, forward-looking statements speak only as of the date that they are made and should be regarded solely as our current plans, estimates and beliefs. You should not place undue reliance on forward-looking statements. We cannot guarantee future results, events, levels of activity, performance or achievements. Except as required by law, we do not undertake and specifically decline any obligation to update, republish or revise forward-looking statements to reflect future events or circumstances or to reflect the occurrences of unanticipated events.


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  1. Ahmad FB, Rossen LM, Sutton P. Provisional drug overdose death counts. National Center for Health Statistics; 2021 (last updated 10/3/2021).
  2. Olofsen E, Hyke Algera M, Moss L et al. (2021) Modeling Modelling Buprenorphine Effect on Fentanyl-induced Respiratory Depression in Opioid-naïve and Opioid-tolerant Subjects. ACoP 2021