Following last week’s EU recommendation  to approve Celltrion and Hospira’s biosimilars of Remicade (infliximab), it is high time for an evaluation of which biological products face the most potential competition from biosimilars currently in clinical development.
Using data from FirstWord’s biosimilar and biobetter database, it can be seen that Biogen Idec and Genentech’s Rituxan (rituximab) is the most popular biologic drug being targeted by developers, with 22 biosimilars currently in clinical or preclinical testing globally.
With 2012 sales of just under $6.5 billion, Rituxan is an obvious target for biosimilar developers as its EU patent is due to expire this year, while US exclusivity for the product ends in 2015. Developers of Rituxan biosimilars include industry heavyweights Pfizer and Merck & Co.
Enbrel is the second most popular target, with 17 biosimilars in current preclinical or clinical development. With sales of just under $8 billion, and expected EU patent expiry in 2016 (a submarine patent gives the product patent protection until 2028 in the US), this is another very attractive target for biosimilar developers, which include Novartis' Sandoz unit and Daiichi Sankyo.
Another notable reference product to be targeted is Herceptin (trastuzumab), which has nine biosimilars in clinical or preclinical development. Pfizer is conducting Phase I trials of a Herceptin biosimilar, and with the drug losing patent protection in 2014/2015 in the EU, and in 2019 in the US, it is certainly not too early for companies to consider developing their follow-on versions of the product. Roche has already moved to introduce innovative products with which it can supplant Herceptin, namely Kadcyla (trastuzumab emtansine) and Perjeta (pertuzumab).
It is somewhat surprising that there are so few biosimilars of Humira (adalimumab) in development at present, considering it is the bestselling biologic in the world, with revenues of $9.3 billion in 2012. With EU patent expiry in 2018 preceded by US patent expiry in 2016, biosimilar developers do not have much time to prepare for the earliest possible market entry. In June 2013, Pfizer commenced  a Phase I trial of its Humira biosimilar and aims to recruit 210 subjects in the US and EU. Boehringer Ingelheim is another leading pharmaceutical company developing a biosimilar version of Humira, and in late 2012 it completed its first Phase I trial of the product.
This list demonstrates that the race to market the first biosimilars of many of the most complex biologic drugs is starting to heat up, with several companies vying to launch the first follow-on versions of products in this nascent market.
Contact FIrstWord Dossier  for further information on the report and data file, Charting the Biosimilar and Biobetter Development Pipeline (2013).