It has often been said that Roche will one day become a victim of its own success where biosimilars are concerned.
Rituxan/MabThera, Herceptin and Avastin – initially approved by regulators in 1997, 1998 and 2004, respectively – generated combined global sales worth $21.5 billion last year; equal to 53 percent of Roche's total pharmaceutical revenues. Unsurprisingly, continued commercial success for these cancer products has positioned them firmly in the crosshairs of biosimilar developers.
The near-term threat to Roche's core oncology franchise is more pronounced in Europe, with Novartis confirming on Monday that its biosimilar version of Rituxan/MabThera – which will be sold as Rixathon – has received European Commission approval.
Rixathon becomes the second biosimilar Rituxan/MabThera product to be approved in Europe, following approval of Celltrion's Truxima in February, and FirstWord's Biosimilar Index illustrates that Roche is set to face intensifying biosimilar competition in the region over the next 12 months. Furthermore, versus the 53 percent of total pharma revenues that Roche generates globally from Rituxan/MabThera, Herceptin and Avastin, these three products accounted for 63 percent of the company's European drug sales in 2016.
In addition to the two now-approved biosimilar versions of Rituxan/MabThera, there are four biosimilar versions of Herceptin awaiting approval in the EU – the first of which could be cleared by regulators by August – and one version of Avastin that could be approved by year-end.
Although it is hard to assess exactly how biosimilar products will perform on a regional basis, and how their availability will impact the performance of Roche's branded products – partly due to country-by-country differences in how utilisation of biosimilars is promoted – analysts at Bernstein anticipate that biosimilars will capture approximately 50 percent of the European rituximab market by 2021. Factors allowing Roche to maintain some brand market share will include retained market exclusivity for subcutaneously administered MabThera/Rituxan and successful switching of some patients to its newer product Gazyva for haematological cancer indications.
With regards to biosimilar versions of Herceptin – where competition looks primed to be most intense over the next few years – key opinion leaders have some reservations about biosimilar use, but are largely accepting that these products will increase treatment access and gain market share at the expense of Roche's brand. Payers will, of course, play a pivotal role in this transition – see Breast Cancer: KOL Insight 
Fewer biosimilar applications overall are pending with the FDA, although the agency has convened an advisory committee meeting for July 13, which will discuss proposed biosimilars to Avastin and Herceptin which will be marketed by Amgen and Mylan, respectively. Approval of both products could occur by year-end, although patent protection will preclude launch of either in the US market until 2019. Roche's exposure to biosimilar erosion has, however, finally begun.
To read more List articles, click here.