Biosimilar mAbs may have tougher time winning US FDA approval says expert
Three products have been filed for review under the US Food and Drug Administration (FDA) biosimilars pathway: Celltrion’s Remsima (tumor necrosis α); and Apotex’s Neupogen (filgrastim); and Sandoz’s version of Zarxio (filgrastim).
Earlier this month the Agency’s oncologic drugs advisory committee (ODAC) recommended that Zarxio, which has been available in Europe as Zarzio since 2009, be approved after what some observers described as an amazingly brief panel discussion.
The speed of the FDA committee’s decision was not a surprise to BioOutsource’s chief scientific officer, Daniel Galbraith, who described Sandoz’ drug “low risk product” in terms of regulatory approval and warned that others may face more difficult reviews.
“Sandoz has stepped through with a low risk product but in the wings there are many other manufacturers with similar products and also the monoclonal drugs already being released as Biosimilars globally.
He added that: “Currently the draft regulations in the US take the analytical studies to a higher level which in turn will lead to more studies and more novel technology applied.”
While this may be a problem for developers it is an opportunity for BioOutsource Galbraith said, adding that the firm is “working with many US clients on monoclonal antibody biosimilars who intend to submit applications to the FDA and would expect the submissions to gain momentum this year.”
What this will mean for Celltrion, the only firm to have filed a monoclonal antibody with the FDA so far, remains to be seen. However, when the firm announced the submission in August last year it said it “anticipates obtaining US FDA approval within one year.”
Legal issues
Regulatory issues are not the only hurdle according to Galbraith, who said the legal challenges firms wanting US approval for biosimilars face will differ from those encountered in the decade since the first copycat biologic was approved in Europe.
“The difficulty in the US still hinges around the regulatory and patent issues and other legal challenges which can delay products in the USA and provide a barrier to entry for those developing biosimilars.”
Celltrion made similar points last April in a lawsuit against Janssen, which makes the originator product Remicade on which its biosimilar candidate is modelled.
In a lawsuit the South Korean firm said Janssen has employed a variety of "manipulative legal" tactics to extend its patents.
In July, the US District Court of Massachusetts rejected Janssen's effort to have the Celltrion lawsuit dismissed.
