Prostaglandin Coverage and Costs to Medicare and Medicare Beneficiaries, 2009-2017

BACKGROUND: Prostaglandin analogs are the most effective treatment for glaucoma, a common condition among older adults. Despite the availability of generic drugs, the costs associated with these prescription drugs are rising. OBJECTIVE: To characterize Medicare prescription drug plan (PDP) formulary coverage and beneficiary out-of-pocket cost for prostaglandin analogs from 2009 to 2017 and Medicare spending on prostaglandin analogs from 2013 to 2017. METHODS: This study was a retrospective analysis. We used 2009, 2013, and 2017 Medicare PDP formulary, beneficiary cost, and pricing files to determine beneficiary first-prescription out-of-pocket costs and plan coverage (unrestricted, restricted, or not covered) of branded latanoprost 0.005%, travoprost 0.004%, bimatoprost 0.03% and 0.01%, and tafluprost 0.0015% and of generic latanoprost 0.005% and generic bimatoprost 0.03%. We also used Medicare Part D spending data to determine aggregate spend in 2013 and 2017. RESULTS: In 2009, 92% of plans covered branded latanoprost, 83% covered branded bimatoprost; and 49% covered branded travoprost, whereas in 2017, 6% of plans covered branded latanoprost; 95% covered branded bimatoprost; and 96% covered branded travoprost. Although generic latanoprost was universally covered, generic bimatoprost was only covered by 35% of plans in 2017. Median out-of-pocket cost of branded prostaglandins without generic equivalents was $35 (IQR = $29-$40) in 2009, $45 (IQR = $42-$101) in 2013, and $90 (IQR = $45-$159) in 2017. Median out-of-pocket cost of all available generic prostaglandins was $10 (IQR = $5-$33) in 2013 and $10 (IQR = $4-$15) in 2017. In 2013, Medicare spent $733 million on prostaglandin analogs; in 2017, this increased to $1.09 billion, with $943 million (86%) spent on branded prostaglandins and $148 million (14%) spent on generics. CONCLUSIONS: Medicare PDP coverage of branded prostaglandins remained stable from 2009 to 2017. While median beneficiary out-of-pocket costs associated with generic prostaglandins remained stable, those associated with branded prostaglandins increased nearly 3-fold.