Charting the Etanercept Journey: Tracing Cost Dynamics in Poland's Off-Patent Market from Reference Drug Rivalry to Biosimilar Monopoly.

Objectives: To evaluate the pricing of etanercept (ETN) reference and biosimilar drugs in a changing competitive to monopolized market.

Methods: We conducted a comprehensive, retrospective analysis of ETN market competition, specifically changes in tender price based on shifts in market monopoly, including the effects on cost evolution, in the off-patent market in Poland. We included a total of 473 tenders for ETN purchase in dedicated biologic drug reimbursement programs, covering both pre-filled syringes and automatic injectors. This study covers the timeframe from November 2017 to December 2023, throughout which we evaluated a unique setting of ETN market re-monopolization from the perspective of payer, hospital and patient benefits resulting from changing cost calculations.

Results: Between 2017 and 2022, Erelzi was recorded as having the largest total tender volume (59%), with a mean price [per ETN daily defined dose (DDD)] of €7.28, followed by Enbrel (31%, €8.34) and Benepali (10%, €9.45), respectively. Over the last 6 months of waning market competition, the mean price for winning bids was estimated at €5.69. After market re-monopolization by an ETN biosimilar, the mean price of winning bids increased to €8.09, and continued to increase (€9.71) in the last 6 months of available follow-up. In contrast to the competitive era, no significant relationship between tender volume and winning price was recorded after re-monopolization. In the most recent tenders, mean ETN prices increased up to €15.82, nearly tripling the lowest prices of the competitive market period. In the early re-monopolization market, mean annual treatment cost per patient is estimated at over €3800, which exceeds therapy costs in the prior competitive market years, and is expected to increase to over €6200 based on the most recent tenders. On a healthcare system level, this corresponds to over €3.42 million excess costs due to market monopoly. Higher ETN prices resulted in downstream failure of regulatory incentives to promote affordable biologics. Due to higher pricing, hospitals lost over an estimated €2.52 million, with possible risk of treatment restrictions. For the same reason, the public payer achieved comparable savings, allowing for partial coverage of higher reimbursement expenses.

Conclusions: This nation-level scenario of market re-monopolization by a biosimilar drug confirms net loss and excess costs for the healthcare payer, as can be expected from economic theory. The upwards drug repricing and restriction of treatment availability occurs much more rapidly than the decrement in a period of market competition.