Footnotes

• Contributors KBG performed the literature search and drafted and revised the paper. RK contributed to drafting the ‘Biosimilar approval pathways’ section. GRvdB, CYP, ML and VJ performed additional literature searches and revised the draft paper. SPLT, WJS and BGF contributed with thorough revisions to the draft. GRAMD supervised the preparation of the paper and made the final revisions.

• Competing interests GRvdB has received consulting fees from Abbott Laboratories and lecture fees from Abbott Laboratories, Merck Sharp & Dohme and Ferring Pharmaceuticals. He has received research grants from Abbott Laboratories and Ferring Pharmaceuticals. CYP has received unrestricted research grants from Abbott Netherlands, Dr Falk Pharma Benelux, Schering-Plough Netherlands and Tramedico Netherlands and has been on advisory boards for Abbott and Glaxo Smith Kline. ML has served as a speaker for Abbott, Merck Sharp & Dohme and Ferring Pharmaceuticals. SPLT has received consulting fees from Abbott, Asahi-Kasei, Bristol-Myers Squibb, Cosmo Technologies, Coronado Biosciences, Ferring Pharmaceuticals, Genentech, Genzyme Corp, Glaxo Smith Kline, Janssen, Lexicon Pharmaceuticals, Merck Research Laboratories, Millennium Pharmaceuticals, Nisshin Kyorin Pharmaceuticals, Novartis, Novo Nordisk, NPS Pharmaceuticals, PDL Biopharma, Pfizer, Procter and Gamble, Santarus, Schering Plough, Shire Pharmaceuticals, Sigmoid Pharma Ltd, Tillotts Pharma AG, TxCell SA, UCB Pharma and Warner Chilcott UK Ltd, research grants from Abbott, Genentech, Glaxo Smith Kline, Janssen, Novartis, Pfizer, Procter and Gamble, Shire Pharmaceuticals and UCB Pharma, and payments for lectures/speakers bureaux from Abbott, Janssen, Ferring Pharmaceuticals and Warner Chilcott, but holds no stock/stock options. WJS has received consulting fees from Abbott Laboratories, ActoGeniX NV, AGI Therapeutics Inc, Alba Therapeutics Corporation, Albireo, Alfa Wasserman, Amgen, AM-Pharma BV, Anaphore, Astellas Pharma, Athersys, Inc, Atlantic Healthcare Limited, Axcan Pharma (now Aptalis), BioBalance Corporation, Boehringer-Ingelheim Inc, Bristol Meyers Squibb, Celegene, Celek Pharmaceuticals, Cellerix SL, Cerimon Pharmaceuticals, ChemoCentryx, CoMentis, Cosmo Technologies, Coronado Biosciences, Cytokine Pharmasciences, Eagle Pharmaceuticals, Eisai Medical Research Inc, Elan Pharmaceuticals, EnGene, Inc, Eli Lilly, Enteromedics, Exagen Diagnostics, Inc, Ferring Pharmaceuticals, Flexion Therapeutics, Inc, Funxional Therapeutics Limited, Genzyme Corporation, Genentech (now Roche), Gilead Sciences, Given Imaging, Glaxo Smith Kline, Human Genome Sciences, Ironwood Pharmaceuticals (previously Microbia Inc), Janssen (previously Centocor), KaloBios Pharmaceuticals, Inc, Lexicon Pharmaceuticals, Lycera Corporation, Meda Pharmaceuticals (previously Alaven Pharmaceuticals), Merck Research Laboratories, MerckSerono, Millennium Pharmaceuticals (subsequently merged with Takeda), Nisshin Kyorin Pharmaceuticals Co, Ltd, Novo Nordisk A/S, NPS Pharmaceuticals, Optimer Pharmaceuticals, Orexigen Therapeutics, Inc, PDL Biopharma, Pfizer, Procter and Gamble, Prometheus Laboratories, ProtAb Limited, Purgenesis Technologies, Inc, Receptos, Relypsa, Inc, Salient Pharmaceuticals, Salix Pharmaceuticals, Inc, Santarus, Schering Plough Corporation (acquired by Merck), Shire Pharmaceuticals, Sigmoid Pharma Ltd, Sirtris Pharmaceuticals, Inc (a GSK company), SLA Pharma (UK) Ltd, Targacept, Teva Pharmaceuticals, Therakos, Tillotts Pharma AG (acquired by Zeria Pharmaceutical Co, Ltd), TxCell SA, UCB Pharma, Viamet Pharmaceuticals, Vascular Biogenics Ltd (VBL), Warner Chilcott UK Ltd and Wyeth (now Pfizer). He has received lecture fees from Abbott Laboratories, Bristol Meyers Squibb and Janssen (previously Centocor). He has received research support from Abbott Laboratories, Bristol Meyers Squibb, Genentech, Glaxo Smith Kline, Janssen (previously Centocor), Millennium Pharmaceuticals (now Takeda), Novartis, Pfizer, Procter and Gamble Pharmaceuticals, Shire Pharmaceuticals and UCB Pharma. GRAMD has received consultancy fees from Abbott Laboratories, Actogenix, Boerhinger Ingelheim, Centocor, Cosmo Technologies, Engene, Ferring Pharmaceuticals, Glaxo Smith Kline, Jansen Biologics, Millenium Pharmaceuticals, Mitsubishi Pharma, Merck Research Laboratories, Novo Nordisk, PDL Biopharma, Pfizer, Schering Plough, SetPoint, Shire Pharmaceuticals, Sigmoid Pharma Ltd, Takeda, Teva, Tillotts Pharma and UCB Pharma, research grants from Abbott Laboratories, Jansen Biologics, Given Imaging, MSD, DrFalk Pharma, Photopill, speaking honoraria from Abbott Laboratories, Jansen Biologics, Tillotts, Tramedico, Ferring, MSD, UCB, Norgine and Shire, and has stock options from Engene Inc.

• Provenance and peer review Commissioned; externally peer reviewed.