So far, Roche has seen little impact from the arrival of biosimilar MabThera in Europe, a company spokeswoman said. The first impact from Herceptin biosimilars is expected by the end of this year.
But experts believe the pressure will grow steadily.
By 2021, European healthcare systems are likely to enjoy annual savings of close to 2 billion euros ($2.4 billion) due to biosimilar competition to Roche's three giant oncology medicines, according to Murray Aitken, head of the QuintilesIMS Institute, an authority on prescription drug sales trends.
That compares to an estimated 300 million euros of savings from Rituxan biosimilars alone in 2017.
The potential of biosimilars is a lure for rival manufacturers, including established generic drug suppliers such as Mylan and Novartis's Sandoz division, as well as South Korean specialists Celltrion and Samsung Bioepis.
It is also a significant opportunity for cash-strapped healthcare providers across Europe.
NHS England head Simon Stevens highlighted the opportunity to save hundreds of millions of pounds by using biosimilars in a speech last week, adding their introduction had the dual advantage of also driving down the cost of the original drugs.
Stevens noted the first biosimilar antibody drug for rheumatoid arthritis and gastrointestinal disorders, infliximab, had driven down cost of treatment by nearly two-thirds to 6.84 pounds ($9.26) a day from 16.80 pounds.
This article was provided by Reuters.