Mabthera (rituximab) has faced the launch of first biosimilars in EU markets between 2016 and 2018. Some outcomes from Emergpharma's "First report on biosimilars in EU markets 2016-2018" are summarized below. Hopefully they will help to understand some of the key topics regarding biosimilar's impact: market penetration, changes in patients under treatment and price impact. More data available by request directly through Linkedin.
Market penetration of biosimilars
The market share that rituximab biosimilars have been able to achieve in their first two years varies from one country to another as showed in the graphic below. Significantly top 5, with the exception of Spain, achieve the highest level of market penetration.
Change to biosimilars in treated patients
"Biosimilars of rituximab are being used both for new patients and for those already treated with Mabthera."
As almost half of patients treated in the biggest markets (France, Italy, Germany) and nearly 80% in UK are on biosimilars, it can be concluded that oncologists are changing patients in Mabthera to other (cheaper) alternatives, despite that efficacy in these patients has not been proven as clinical trials were performed in naive patients. This fact has an important impact in the adoption curve of biosimilars. One of the reasons for this specialist's lack of fear can be that rituximab is a drug for hospital use, a protected environment where patients can be closely monitorized. It remains to be seen if this pragmatism will be the same when it comes to biosimilars of non-hospital products.
Among the Top 5, Spain seems to be an exception, at least for the time being. Last tenders held in January 2019 showed that, although the winning bid for new patients has been a biosimilar (Truxima, Kern Pharma), Mabthera keeps its position as unique choice for patients under treatment, despite being 20% more expensive than Truxima. As the sales data are consistent with this approach, it can be assumed that for now in this market oncologists remain faithful to the protocol of not replacing treatments, although it is questionable whether ultimately pragmatism will prevail, as happens in other large markets. It seems most likely while the clinical results offered by the biosimilars remain equivalent to those of the original drugs.
According to the data, it seems evident that the levels of erosion in price with respect to the original are very different in the case of biosimilars than in the case of generics, at least until now. Very recently Imatinib generic got a price in the first Spanish tender after patent expiration of 2.5% of the price of Glivec, the original drug. However, the first biosimilar of rituximab, Truxima, obtained an initial price equivalent to 81.5% of that of Mabthera and the second, Rixathon just 7% below Truxima. Figures are quite different.
Although when the number of biosimilars increases a higher price erosion can be expected, cost of clinical development and registration of a biosimilar are significantly higher than those of a generic (around 100 to 120 million € as last estimation), which will undoubtedly reduce the number of competitors and make it unlikely to drive prices to levels like those achieved by some generics, in particular in the oncology segment.
Several experts consulted estimate for biosimilars on the hospital environment price erosion close to 20% when there is only one competitor in the market, 25-30% with two, between 40-50% with 3-4 and 70% with more than 5. These are mathematical models based on limited historical data and should be taken carefully.
If finally the trend to change patients under treatment to biosimilars remains and MS of these would reach an average of 60 to 70%, savings can be estimated between 25 and 30% of existing costs on biologics, which is not little in this segment, but possibly, as indicated in a previous post, is not enough to offset the new financial requirements of the new drugs coming to market.