The Food and Drug Administration published research late last month that showed greater use of biosimilars by patients covered under Medicare Advantage (MA) plans than traditional or fee-for-service (FFS) Medicare.
Based on claims and encounter data for Medicare recipients from May 2015 through September 2022, the researchers included 20 biosimilars (7 drug categories) typically covered in Medicare parts B (FFS) or C (MA). Thirty-six months of utilization was included for each biosimilar’s calculation of marketshare.
The results, published in JAMA Health Forum, demonstrated that for 6 of the 7 drug categories, biosimilar use was greater in MA compared with FFS Medicare. For example, epoetin alfa biosimilars were utilized 2.3-fold more often in MA than in FFS patients (based on a 5.7-percentage point difference in marketshare). Pegfilgrastim biosimilars had 20% greater marketshare (based on a 3.5-percentage point difference). The increased use in MA for other studied drugs included 80% for infliximab (4.1-point difference), 40% for filgrastim (8.4-point difference), 30% for rituximab (9.4-point difference), and 10% for trastuzumab (6.9-point difference).
On the other hand, bevacizumab biosimilars were used 30% less often by MA members compared with FFS Medicare recipients. The researchers attributed this to a difference in ophthalmic vs. oncologic indications. For ophthalmic prescribing, compounded bevacizumab biosimilars (used as an alternative to ranibizumab) were used 70% less often in MA (based on a <0.1-point difference in marketshare), but for oncologic prescribing, bevacizumab biosimilars were associated with 10% greater use in MA versus FFS (based on 6.9-point difference in marketshare).
These results do raise an interesting point. The pharmaceuticals analyzed in this study are primarily buy-and-bill drugs. It makes sense that given a choice in the FFS reimbursement scheme, providers would favor purchasing the higher-priced originator drug. Medicare Advantage plans, which now cover nearly half of all Medicare beneficiaries, utilize drug formularies to prefer one product over another. In the oncology space in particular, the MA plans (as well commercial health plans) prefer covering biosimilars rather than the reference agents. Since the study was undertaken, the reimbursement rate for biosimilars in Medicare has been increased to the average sales price of the reference product + 8% (from 6%). Has this increased reimbursement offset the buy-and-bill incentive on the part of the physician or provider to purchase the higher cost product in FFS Medicare?
