Consequences on economic outcomes of generic versus brand-name drugs used in routine clinical practice: the case of treating peripheral neuropathic pain or generalized anxiety disorder with pregabalin.

Background: Discrepancies are seen between arguments in favor of and against prescribing generic versus brand-name drugs.
Objective: To provide real-world evidence on treatment persistence, economic and clinical outcomes of pregabalin, generic versus brand-name (Lyrica®, Pfizer), routinely used to treat neuropathic pain (NP) or generalized anxiety disorder (GAD).
Methods: Electronic medical records from subjects' first starting treatment with pregabalin between January-2015 and June-2016 were analyzed. Persistence, resources utilization, and costs were assessed, along with remitter and responder rates.
Results: A total of 4860 records were analyzed. Discontinuation was lower with brand-name than with generic in NP (adjusted hazard ratio [HR]: 0.70 [95% CI: 0.58-0.85], p < 0.001) and GAD patients (HR: 0.63 [0.45-0.84], p < 0.001). Adjusted mean total costs were lower with brand-name: €1500 [1428-1573] vs. €2003 [1864-2143] in NP and €1528 [1322-1734] vs. €2150 [1845-2454] in GAD (both p < 0.001). More patients were remitters/ responders with brand-name in NP (55.0% vs. 46.7% and 59.2% vs. 48.4%, respectively; p < 0.001) and GAD (58.6% vs. 48.7% and 64.6% vs. 47.2%, respectively; p < 0.001).
Conclusions: As a consequence of higher persistence in routine practice, patients who first started therapy with pregabalin brand-name versus generic showed better pain or anxiety outcomes at a lower cost to payers in Spain.