OBJECTIVES: Standard-of-care for opioid addiction is substitution therapy with methadone, buprenorphine, or buprenorphine/naloxone. As EU5 healthcare budgets tighten, this study explored how emerging brands may gain a foothold in this increasingly generic market, as payers and prescribers balance clinical need with limited funds. METHODS: In February 2015, 253 EU5 psychiatrists were surveyed regarding their prescribing for opioid addiction. In addition, 15 payers/payer-advising KOLs who influence reimbursement at national/regional level were interviewed. RESULTS: Interviewed EU5 payers emphasize that there are high administrative costs involved with providing opioid substitution products to addicted patients, especially for methadone, which generally requires daily clinic visits to allow patients to receive their medication under direct supervision. A substitution therapy requiring less-frequent clinic visits would decrease administrative costs and could be preferred as long as efficacy parameters relative to standard-of-care are maintained. Similarly, surveyed EU5 physicians indicate that potential for abuse or diversion and patient compliance are major considerations for prescribing a new therapy (15% [Spain] to 24% [France] and 28% [UK] and 52% [Spain] of respondents cite these factors, respectively, as a top three consideration). The former could be decreased and the latter increased if therapies were dosed less frequently. A long-acting buprenorphine injection, such as Camurus/Braeburn Pharmaceuticals’ CAM-2038, could, therefore, appeal to both payers and prescribers. Indeed,