The Impact of Suboxone's Market Exclusivity on Cost of Opioid Use Disorder Treatment.

BACKGROUND: Buprenorphine-naloxone is an essential part of the response to opioid poisoning rates in North America. Manipulating market exclusivity is a strategy manufacturers use to increase profitability, as evidenced by Suboxone in the USA. OBJECTIVE: To investigate excess costs of buprenorphine-naloxone due to unmerited market exclusivity (no legal patent or data protection) in Canada. METHODS: Using controlled interrupted time-series, this study examined changes in the cost of buprenorphine-naloxone before and after the first generics were listed on public formularies. Methadone cost was the control. Public data from the Canadian Institute of Health Information in British Columbia, Manitoba, and Saskatchewan were used. All buprenorphine-naloxone and methadone claims (2010-2019) accepted for payment by the provincial drug plan/programme were collected. Primary outcome was mean cost per mg of buprenorphine-naloxone after the first listing of generics. RESULTS: Mean cost per mg of buprenorphine-naloxone before the first listing of generics was $1.21 CAD in British Columbia, $1.27 CAD in Manitoba, and $0.85 CAD in Saskatchewan. Following the introduction of generics, the cost per mg decreased by $0.22 CAD (95% CI - 0.33 to - 0.10; p = 0.0014) in British Columbia, $0.36 CAD (95% CI - 0.58 to - 0.13; p = 0.004) in Manitoba, and $0.27 CAD (95% CI - 0.50 to - 0.05; p = 0.03) in Saskatchewan. Mean cost per mg decreased by $0.26 CAD (95% CI - 0.38 to - 0.13; p = 0.0004) after a third generic was introduced in British Columbia. Excess costs to public formularies during the 4- to 5-year period prior to the listing of generics were $1,992,558 CAD in British Columbia, $80,876 CAD in Manitoba, and $4130 CAD in Saskatchewan. If buprenorphine-naloxone cost $0.61 CAD (mean cost after the third generic entered) instead of $1.21 CAD per mg during the pre-generics period, public payers in British Columbia could have saved $5,016,220 CAD between 2011 and 2015. CONCLUSIONS: Unmerited 6 years of market exclusivity for brand-name buprenorphine-naloxone in Canada resulted in substantial excess costs. There is an urgent need to implement policies that can help reduce costs for high-priority drugs in Canada.