As of mid-2019, the U.S. market has seen considerable competition from biosimilars in supportive oncology care. The next U.S. biosimilar frontier is therapeutic oncology care, where Genentech’s big trio—Rituxan, Herceptin and Avastin—will likely attempt to hold their ground against biosimilars. Reference product manufacturers and biosimilar manufacturers have been closely monitoring U.S. biosimilar uptake to understand how this market is likely to evolve, but diverse go-to-market and defense strategies may leave us with more questions than answers. As pricing pressure mounts in the U.S., so does pressure on biosimilar uptake, leaving reference product manufacturers and biosimilar manufacturers alike wondering what biosimilar uptake will look like in the therapeutic oncology space, and how much price erosion can be expected due to biosimilar competition.


Here, we provide a point of view on what scenarios we expect to unfold in these two areas with the launch of biosimilars in therapeutic oncology.

The big open question here is whether therapeutic oncology biosimilars will achieve faster or slower uptake than available biosimilars in supportive oncology and immunology. In early 2019, ZS conducted an AdoptionMonitor survey with oncologists and immunologists to better understand their perceptions about biosimilars and expectations of adoption across therapy areas. The survey revealed that, compared to immunologists, oncologists have:

  • A higher likelihood for prescribing biosimilars
  • More interest in quicker formulary inclusion for biosimilars
  • Greater comfort for non-medical switching to biosimilars

These insights suggest that oncologists have a higher anticipation and comfort with biosimilars compared to immunologists and, thus, oncology biosimilars can achieve faster uptake. On the one hand, these results are not surprising given the financial toxicity associated with oncology therapies and the desire of both payers and providers to drive savings from these high-priority budget busters. On the other hand, despite the higher comfort with non-medical switching, the AdoptionMonitor survey revealed that the largest concern related to biosimilars for oncologists was efficacy. From this, perhaps we could conclude that a longer history and broader exposure to existing biosimilars have driven more comfort for oncologists than immunologists, although oncologists might be more hesitant to use biosimilars in the therapeutic setting versus the supportive setting without robust safety and efficacy data.


Payers have shown increasing activity and interest in managing biosimilars, which is fairly new from a historically provider-driven medical benefit space. While payers are building capabilities to more effectively manage medical benefit therapies, we are left to wonder whether they will take a long-term view and try to generate cost savings through driving utilization of lower-cost biosimilars, or whether they will fall into the rebate trap and prioritize short-term cost savings from originators. While this decision will be primarily driven by the available cost savings based on pricing and rebates on individual products, payers have so far either shown reluctance to move away from the reference product or moved back after initial advances towards biosimilars. For example, beginning in July 2019, UnitedHealthcare (UHC) prefers the use of branded Neulasta (pegfilgrastim) over its available biosimilars. At the same time, UHC changed its policy from preferring infliximab biosimilars over the reference product to preferring Remicade, leaving the market wondering whether it will have a consistent strategy towards the adoption of biosimilars. 

List price, or wholesale acquisition cost (WAC), while highly publicized, does little to inform the actual price paid by payers, providers or patients, as rebates and discounts are not reflected in WAC. Instead, when discussing price erosion, we look at net price, or average sales price (ASP), which is a weighted average sales price inclusive of discounts and rebates paid to payers, providers and distributors (excluding 340B institutions, Medicaid and VA). Looking at U.S. biosimilar launches to date, we’ve seen varying degrees of price erosion across reference product and biosimilars. However, in general, the following consistencies have been observed regarding biosimilar pricing strategies:

  • While launch price discounts to the reference products’ wholesale acquisition cost have varied between 15 and 35%, the differences in net price have been much less at around 5 to 10%.
  • Neither reference product nor biosimilar manufacturers have taken significant price increases since facing competition from biosimilars.
  • Most reference products (Amgen’s Neupogen being an exception) and biosimilar manufacturers are eroding their average sales prices (ASPs), indicating increasing discounts and rebates over time.
  • In general, net prices have eroded faster when there are more competitors in the market.

Given what we’ve observed so far, it seems safe to say that price erosion from competition is less specific to therapy but more specific to the competitive situation faced by individual products. To generalize, we’d expect price erosion to be faster when:

  • Multiple products launch within a small window
  • Competitors without differentiated service offerings or existing relationships with payers/providers are forced to rely more heavily on differentiation on price alone

And slower when:

  • Fewer competitors launch
  • Reference product manufacturers prioritize next-generation molecules or shifting to differentiated methods of administration

Recently, Amgen has launched Mvasi (bevacizumab biosimilar) and Kanjinti (trastuzumab biosimilar) at discounts that fall towards the lower end of the range observed so far. Looking forward to the second half of 2019, we may expect faster price erosion than observed so far, particularly due to the number of expected competitors within a short period of time.


Perhaps the biggest question is at what level these prices will stabilize, if at all. Will they stabilize at the 30 to 50% discount level, or will we see 70 to 80% discounts or beyond, as seen in a few EU countries? While the health system is looking to biosimilars to help bring down costs, if prices decline too rapidly or too far, future biosimilar entrants may reassess the commercial viability of the biosimilar molecules in their pipeline. Will manufacturers have the discipline to behave as rational actors, or will the quest for share bottom out the value in these markets?


The biosimilar journey in the U.S. has been long, turbulent and full of doubt, but biosimilars that launched in 2018 and 2019 have all achieved faster uptake than those launched from 2015 to 2017, suggesting that the tides may be turning. The considerable experience with biosimilars in supportive oncology care has improved HCPs’ comfort and awareness. As this comfort and awareness will improve further with the entry of therapeutic oncology care biosimilars, the success of manufacturers will increasingly depend on non-clinical differentiation on price, services and execution. We look to the second half of 2019 and throughout 2020 to define whether the U.S. healthcare system will be inclusive enough to have space both for biosimilars and the reference products.