Since the first EU biosimilar approval for Sandoz’s Omnitrope 12 years ago, the European biosimilar market has been difficult to predict. The dynamic policy and regulatory environment, differing levels of payer control, and variability in go-to-market approaches and manufacturing necessitate a bit of guesswork when it comes to predicting how a given biosimilar will perform. 


Consider the comparison between the launch of infliximab biosimilars and that of rituximab biosimilars.


Infliximab biosimilar uptake in the EU has been a slow process since the launch of Inflectra and Remsima in 2015 largely because of prescribers’ hesitancy to switch their patients’ medication due to efficacy and safety concerns, in addition to restrictive, country-specific prescription recommendations and payer controls. However, in time, infliximab biosimilar uptake caught on, and infliximab biosimilars continue to fight for reference product market share today. As indicated by the recent Sandoz (Zessly) launch, manufacturers continue to believe that there’s potential to further increase infliximab biosimilar penetration in the EU, and that a later entrant has the potential to grab share from existing biosimilars.


After observing infliximab biosimilar’s slow adoption, the market had mixed expectations as to how therapeutic oncology biosimilars would perform. The oncology disease state is sensitive given the acuteness of the disease and the emotional reality that oncology patients, in some cases, are near death. The treatment that these patients receive is oftentimes equally as sensitive, and HCPs may be hesitant to prescribe new products that aren’t identical to tried-and-true reference products. On the other hand, the high cost of treating oncology patients is expected to continue to grow. Oncology biosimilars that launch with sufficient discounts could pave the way for affordable cancer care as the price of reference product oncology treatments continues to climb.


Since the launch of Truxima (Celltrion's rituximab biosimilar) in April 2017, the path for oncology biosimilar adoption has been in sharp contrast to what we have observed for infliximab, with rituximab biosimilar uptake occurring at a rapid rate. In the U.K. alone, rituximab biosimilars already account for 80% of overall rituximab treatment. We have several hypotheses for why this is the case: 

  • By 2017, the market was simply more familiar with biosimilars from the immunology and supportive care experiences. Manufacturers had spent much of that time promoting the safety and interchangeability of biosimilars in general, and several EU countries were already starting to formalize the biosimilar adoption process by introducing quotas for adoption and regulatory pathways for substitution.
  • Biosimilar pricing legislation recently has been put in place to expedite biosimilar uptake. For example, France instituted mandatory biosimilar price cuts in the retail and hospital setting, and the U.K. instated a gainsharing policy to split savings between funders and prescribers.
  • Certain countries are setting biosimilar penetration goals and introducing quotas for adoption. For example, France recently declared its goal of reaching 80% biosimilar penetration by the year 2022, and both Germany and Italy placed quotas on biosimilar adoption to increase biosimilar penetration. Both of these examples showcase the growing desire for widespread biosimilar usage in the EU.
  • Oncologists were positive in their viewpoint. The results of a FirstWord Pharma poll show that EU oncologists are optimistic about biosimilars’ ability to improve patient access to therapies.
  • Discounts observed for rituximab biosimilars have been much steeper compared to the discounts offered for infliximab biosimilars. This opportunity for significant cost savings likely has incentivized payers to push rituximab biosimilar usage. 

Since prescribers and payers have warmly welcomed rituximab biosimilars to the market, oncology reference products will need to enhance their defense strategies to protect market share. As the oncology biosimilar market is still growing and developing, a few reference product defense strategies have been observed thus far: 

  • Roche has been co-promoting the use of Herceptin and Perjeta to help protect combination therapy patients from being switched to trastuzumab biosimilars.
  • Roche also has switched a significant number of IV Herceptin and MabThera patients to the respective subcutaneous (SC) forms. (Approximately 75% of Herceptin patients in the U.K. have already been switched.) Since SC drugs are more convenient for the patient and may cost payers less in the long run (by reducing the amount of time that a patient needs to spend in the hospital), IV biosimilars are less likely to directly compete with SC reference products, and once you have “switched” a patient to SC as well as an institution, it becomes more difficult to switch back. 

Note: Part of why rituximab biosimilar penetration may be so high also could be related to the lower penetration and, therefore, the market preference for SC Rituxan vs. SC Herceptin.)


With the recent launch of Ontruzant (Celltrion's trastuzumab) and other oncology biosimilars gearing up for entry later this year, the question remains: Will the uptake curve observed for rituximab biosimilars hold true for all oncology biosimilars? Furthermore, what will therapeutic oncology biosimilar uptake in the U.S. look like?