Describing the Inevitable
EMA lays ground for bringing biosimilar mAbs to Europe in near term
About a decade ago, conventional wisdom held that mAbs are so complex that it would be extremely difficult, if not impossible, to develop biosimilar versions of them. While some mAb innovators may cling to this line of thinking, the writing on the wall says biosimilar mAbs are coming to the major markets, possibly as soon as 2013.
This is the conclusion stakeholders are drawing from EMA's draft guidelines laying out the non-clinical and clinical requirements for showing that a mAb-containing product is similar to another one already marketed.
The guidelines, issued last month, would give a biosimilar manufacturer the ability to do abbreviated clinical development using smaller trials with equivalence design and surrogate endpoints. Moreover, EMA would allow the follow-on developer to extrapolate its clinical efficacy and safety data to other indications.
Biosimilar developers contacted by BioCentury - and some of the innovators - generally concluded that EMA's approach is scientific. While there are differences of opinion on some details -- like the use of surrogate endpoints and the extrapolation of indications -- most stakeholders agreed the scientific and regulatory landscapes have evolved to the point where biosimilar mAbs are now possible.
Specifically, advances in biomanufacturing and in assays used to characterize mAbs, as well as the experience gained by regulatory agencies in evaluating the effect of manufacturing changes on innovator products, have made biosimilar mAbs a near-term reality.
EMA first put out guidelines on biosimilars in 2005, with six product-specific guidelines following in 2009 and 2010 (see BioCentury, July 18, 2005).
Last month's biosimilar mAb draft guidance is considered a product-specific guidance, just like those for recombinant human insulin and somatropin. In this case, the draft also covers fusion-based proteins based on IgG Fc. There are at least 11 such products with expiring patents and/or exclusivity in the next six years (see "Potential Biosimilar mAbs in Europe," A20).