Earlier this year, Robert Popovian, Pharm.D.; Anne M. Sydor, Ph.D.; and Peter Pitts conducted an analysis of drug formulary exclusions from the patient’s perspective. The authors noted that pharmacy benefit management companies (PBMs) often determine medication reimbursement rates with formularies. Initially, the formularies were intended to ensure the use of the least-costly, but still effective, medication. Now, however, formularies tend to be designed to maximize concessions, such as rebates.
Currently, the three largest PBMs – CVS Health (Caremark), Cigna (Express Scripts and Ascent Health Services) and United Health (OptumRx) – process more than 75% of retail prescriptions and control more than half of the specialty medicines dispensed in the United States.
These three PBMs announce their formularies and excluded medications on an annual basis. Multiple analyses have been done that have found that there has been an “exponential growth in the number of exclusions” from less than 50 to well over 500 in the last decade. However, the authors of this analysis note that there seems to be no research evaluating whether the exclusions are clinically sound or financially beneficial from a patient’s perspective.
Therefore, the authors of the study analyzed excluded drugs on the only publicly-available national formulary in the United States, the Express Scripts 2022 National Preferred formulary, from the perspective of whether the exclusion benefits patients. To that end, the authors analyzed exclusions of the 2022 publicly available national formulary of the second largest PBM in the United States. They then categorized substitutions as equivalent versus therapeutic and evaluated each exclusion by potential clinical or economic outcomes from a patient perspective.
Of the 53 excluded medications, 68.6% are equivalent substitutions, 29.8% are therapeutic substitutions, and 1.6% had no preferred alternative recommended. Of the 386 equivalent substitutions, 293 brand medicines were excluded in favor of a generic or biosimilar medicine, or a biosimilar favored for another biosimilar. Of the 386 equivalent substitutions, 30 brand medicines were excluded in favor of another brand medicine with the same active generic or biosimilar ingredient; 5 generic or biosimilar medications were excluded in favor of a brand medicine; and 58 brand, biosimilar, or generic drugs were excluded in favor of a different formulation with the same active ingredient.
The authors found that 46% of the 563 exclusions had questionable clinical or financial benefits to patients, potentially requiring prescribers make a choice between treatments that might have adverse financial or medical outcomes for their patients. Therefore, they conclude, because patient co-pays and deductibles are based on retail prices, some formulary exclusions actually result in patients paying substantially more for a preferred drug. The authors posit that additional research is needed to understand how many patients are impacted by these exclusions.