FDA Approves Buprenorphine Extended-Release Subcutaneous Injection for OUD

The Food and Drug Administration (FDA) has approved Brixadi^™ (buprenorphine) extended-release subcutaneous injection for the treatment of moderate to severe opioid use disorder (OUD) in patients who have initiated treatment with a single dose of a transmucosal buprenorphine product or who are already being treated with a transmucosal buprenorphine-containing product.

Brixadi contains buprenorphine, a partial agonist at the mu-opioid receptor and an antagonist at the kappa-opioid receptor; it is supplied in 2 formulations. The weekly injection can be administered to patients who have tolerated a single 4mg dose of a transmucosal buprenorphine‐containing product or those who are currently being treated with a transmucosal buprenorphine-containing product. The monthly injection is appropriate for patients who are currently being treated with a transmucosal buprenorphine-containing product. Brixadi should be used as part of a complete treatment plan that includes counseling and psychosocial support.

The approval was based on data from a phase 3 trial (ClinicalTrials.gov Identifier: NCT02651584) that compared the long-acting subcutaneous treatment to an existing standard of care, sublingual buprenorphine/naloxone, in 428 patients with moderate to severe OUD. Patients were randomly assigned to receive Brixadi plus a sublingual placebo, or active sublingual buprenorphine plus placebo injections, following an initial test dose of transmucosal buprenorphine.

Following titration over the first week, patients were treated with weekly injections over 12 weeks and then switched to monthly injections for an additional 12 weeks. The primary endpoint was the response rate at week 24. Patients were considered responders if they had negative opioid assessments (urinalysis and self-report) at the end of each of the 2 treatment phases.

Results showed that Brixadi met the primary endpoint of noninferiority for responder rate vs daily sublingual buprenorphine/naloxone (16.9% v 14.0%, respectively; P <.001). Treatment with Brixadi also met a key secondary endpoint demonstrating superiority to sublingual buprenorphine/naloxone in the percentage of negative opioid assessments from week 4 to 24 (P =.004). 

The most common adverse reactions reported with Brixadi were injection site reactions (eg, pain, erythema, pruritus), headache, constipation, nausea, insomnia, and urinary tract infection. The prescribing information for Brixadi includes a Boxed Warning associated with a risk for serious harm or death if the product is administered intravenously. Due to this risk, Brixadi is only available through a Risk Evaluation and Mitigation Strategy (REMS) program; treatment should be administered only in a health care setting by a health care provider who is certified in the REMS program.

Brixadi, a Schedule III controlled substance, is supplied as prefilled single-dose syringes in weekly (8mg/0.16mL, 16mg/0.32mL, 24mg/0.48mL, 32mg/0.64mL) and monthly (64mg/0.18mL, 96mg/0.27mL, 128mg/0.36mL) doses. Doses of Brixadi (weekly) cannot be combined to yield an equivalent Brixadi (monthly) dose.

The product is expected to be available in September 2023.

This article originally appeared on MPR