Despite having a slow start, biosimilars are now beginning to make headway in the U.S. as more agents enter the market. Today we have 28 approved biosimilars, with 18 of them launched (as of Aug 2020). The vast majority of biosimilars available (15 of them) have indications for oncology patients, which include five for Herceptin (trastuzumab), two for Avastin (bevacizumab), two for Rituxan (rituximab), three for Neulasta (pegfilgrastim), two for Neupogen (filgrastim), and one for Epogen/Procrit (epoetin alfa).
When the first biosimilar, Zarxio, was approved in the U.S. in 2015, stakeholders anxiously awaited to experience the significant cost savings that was highly anticipated from the “new” category of drugs. By 2017, just two years after its launch, Zarxio had crossed the inflection point of having majority market share for the filgrastim molecules, setting a strong tone for oncology supportive care agents. However, the second and third biosimilars approved (for infliximab) proved to have significantly different trajectories. Given the early differences in market dynamics between supportive care agents and disease modifying agents, there was uncertainty as to how oncology therapeutic biosimilars would perform in the U.S.1
Today, the oncology therapeutic biosimilars for bevacizumab, trastuzumab, and rituximab are realizing much faster market adoption compared to the infliximab biosimilars. By June 2020, the bevacizumab biosimilars combined represented approximately 40% market share for bevacizumab molecules, with Mvasi representing approximately 38% alone.1 Trastuzumab and rituximab biosimilars are not too far behind, both capturing over 20% of market share by June 2020.1 Additionally, supportive care pegfilgrastim biosimilars have also reached over 20% market share, representing relatively strong adoption despite the lack of an on-body device administration form.1
More importantly, cost savings benefits from biosimilars in oncology have also been realized by practices, patients, and the overall healthcare system. The entrance of biosimilars alone have impacted the net acquisition cost prices for reference biologics. For example, a recent study looking at CMS reimbursement rates for pegfilgrastim found that Medicare Part B reimbursement for the reference product went from increasing year after year, to stabilizing once the biosimilars entered the market.2 The market pressures created from biosimilars can help create cost savings opportunities without impacting outcomes. This is especially critical in an increasingly value based care world, where biosimilars serves as powerful tools for practices to drive costs savings and achieve success in innovative alternative payment models such as the Oncology Care Model.
However, significant barriers to biosimilar adoption continue to persist, including financial, clinical, and operational considerations. The payer landscape continues to create challenges with enabling provider choice and streamlining product decisions, which create both inventory and workflow inefficiencies within practices. From a clinical standpoint, hesitancies remain with switching patients from reference biologics to biosimilars, and between biosimilars, due to the lack of published data for this scenario. Additionally, terms such as interchangeability and extrapolation continue to be identified as knowledge gaps amongst healthcare providers.3
As a result, a multi-faceted, multi-stakeholder educational approach remains critical to broader uptake of these cost-saving alternatives. For example, a deep understanding of the regulatory approval pathway and terms—such as extrapolation—will help provide greater clarity and confidence in the scientific rigor behind biosimilar approvals. It is important to note that despite it being only 5 years since the launch of the first biosimilar in the U.S., the EU has over 15 years of biosimilar experience, which has resulted in rich data supporting biosimilar utilization, including real world evidence (RWE) and clinical trials. In fact, earlier this year a systematic review comprised of 178 randomized controlled trials and RWE was published, looking at the efficacy, safety, and immunogenicity of switching between reference biologics and biosimilars. The review concluded that based on available switching data, switching from a reference biologic to a biosimilar is not associated with any major efficacy, safety, or immunogenicity issues.4
Physicians, administrators, pharmacists, nurses, patients, and payers are all critical stakeholders who will play a role in determining how quickly biosimilars are adopted in the U.S. Continued development of real world studies, as well peer-to-peer knowledge sharing, will further enable educational tools to be developed to aid in closing knowledge gaps and overcoming certain barriers to biosimilar adoption. With several more oncology biosimilars in the pipeline, these agents will continue to play a key role in lowering the overall costs associated with cancer care. While the U.S. experiences with biosimilars has thus far been slower than anticipated, signs indicate that we may soon see broader uptake – and along with it, increased treatment options for providers and lower costs for patients.
Authored by Sonia T. Oskouei, PharmD, BCMAS, DPLA, Vice President of Biosimilars at Cardinal Health.