On 2 November, Novartis’ Sandoz division announced that it was no longer pursuing US approval for Rixathon, its biosimilar version of Roche’s Rituxan/MabThera (rituximab); following a request from the FDA for additional information to further support its application.

Rixathon is already approved in the EU, Japan, Switzerland, and Australia, but Sandoz received a complete response letter from the US regulatory body in May 2018. Although the company’s initial plans were to conduct further discussions with the FDA to bring the biosimilar to the US market as soon as possible, Sandoz has now decided to abandon development in this market. The US is lagging behind other markets for biosimilar development, with only 14 approved products to date (versus 61 in the EU). Sandoz’s choice to stop Rixathon development in this market highlights the fact that, even for major players, the US market is not a priority for biosimilars.

Sandoz’s decision was partially due to existing competition from other biosimilar developers like Celltrion for a share of Rituxan’s sales. In a company press release, Stefan Hendricks, Sandoz’s global head of biopharmaceuticals, stated, “…the patient and marketplace needs in the US will be satisfied before Sandoz can generate the data required [to obtain FDA approval of Rixathon].”

Celltrion is likely to gain the coveted first-to-market advantage, as it announced on October 11 that the FDA Oncologic Drugs Advisory Committee unanimously backed its rituximab biosimilar, Truxima. Further delays before a potential approval for Rixathon would mean that Sandoz would have too much catching up to do before stealing any meaningful market share from Truxima. However, Sandoz is keeping its options open by shifting its focus to other markets for opportunities for Rixathon, and looking to develop other biosimilar products in the US.

Although biosimilar development in the US has sped up in recent years, with five products being approved in the past 10 months, significant challenges remain for biosimilar developers in this market. US key opinion leaders (KOLs) interviewed for GlobalData’s Hot Topic Report: Biosimilars in Oncology report stated that they still had doubts surrounding the equivalence of biosimilar products to biologic originator products, and that this would negatively impact biosimilar uptake.

Additionally, current discounts have been deemed insufficient by KOLs, some of whom noted that the cost of switching patients from biologic originator products to biosimilars is greater than the cost that is saved by using biosimilars. Despite the fact that not seeking approval in the US is a lost opportunity in the short term, Sandoz’s strategy to prioritise other more profitable markets for Rixathon will benefit the company in the long term.