A single center, open-label SUBLOCADE treatment extension study in which up to 25 participants diagnosed with moderate to severe opioid use disorder (OUD) could be enrolled.

This study is being conducted to assess the longer-term safety of an abbreviated initiation protocol of SUBLOCADE in subjects who have completed the INDV-6000-403 study. It is also to provide treatment to these individuals while they seek longer-term treatment arrangements, as on average it can take an individual with opioid use disorder (OUD) 6 months between seeking treatment and achieving an appointment at a provider in the United States (US).

Subjects who have completed the end of treatment (EOT) procedures for the INDV-6000-403 study may be eligible for participation. It is planned that the EOT visit for INDV-6000-403, which will occur approximately 28 days after the subject's first dose of SUBLOCADE, and Day 1 for INDV-6000-404 will occur within 2 days of the EOT visit, and that EOT assessments will serve as the screening assessments for this study.

On Day 1, eligible subjects will receive a subcutaneous (SC) injection of 300 mg SUBLOCADE. Subjects will return to the clinic for subsequent injections approximately every 4 weeks for a total of up to 5 injections. Adverse events and concomitant medications will be captured throughout the study, female subjects of childbearing potential will receive urine pregnancy tests and all subjects will have urine drug screening (UDS) and evaluation of the previous injection site performed. Subjects will otherwise be treated in accordance with local standard of care, and SUBLOCADE doses will be based on the medical judgment of the Investigator.

Inclusion Criteria:

• Signed the informed consent form (ICF) and have the ability to comply with the requirements and restrictions listed therein.
• Completed the EOT Visit for the INDV-6000-403 Study.
• Is an appropriate candidate in the opinion of the Investigator or medically qualified sub-Investigator.

Exclusion Criteria:

• Subject compliance issues during participation in the INDV-6000-403 study which, in the opinion of the Investigator, could potentially compromise subject safety.
• Subjects who are unable, in the opinion of the Investigator or Indivior, to comply fully with the study requirements including those who are currently incarcerated or pending incarceration legal action.

Adverse events were collected from study Day 1 through end of treatment (EOT), up to Day 141

The goal of the study was to assess the longer term safety of an abbreviated initiation protocol of SUBLOCADE and to provide treatment to these individuals while they seek longer term care arrangements. The COVID-19 pandemic, which began during the study period, potentially affected participant's ability to attend clinic visits.