LAUSR

the biggestselling drug list again in 2018, it is hard to see where any challenger might come from to snatch the autoimmune disorder therapy’s crown ahead of its patent expiry in 2023. With the exception of Boehringer Ingelheim, AbbVie’s legal team has successfully settled with companies wanting to launch biosimilar versions of this monoclonal antibody (mAb) targeting tumour necrosis factor (TNF) in the US, while price increases in the region have helped pushed Humira sales up to just under US$20 billion in 2018 (Fig. 1a). AbbVie has reportedly also found a way to compete with the biosimilars that have launched in Europe, winning its first national tender by offering Humira at an 80% discount to its list price. In second position in the list, as in 2017 (Nat. Rev. Drug Discov. 17, 232; 2018), is Celgene’s Revlimid (lenalidomide), with sales of $9.6 billion. The revenue stream for this smallmolecule blood cancer drug, while less than half that for Humira, was probably one of the attractions for the $74 billion move by Bristol MyerSquibb (BMS) to acquire Celgene earlier this year — even if that deal is now facing questions. The continued achievements of Merck & Co.’s PD-1 checkpoint inhibitor Keytruda giant has run to stand still over the last year. Yearon-year growth was flat, which will do little to quieten the voices calling for Pfizer to pull the trigger on a largescale acquisition. Johnson & Johnson edged a little higher in the ranks in 2018 owing to continued growth from psoriasis treatment Stelara (ustekinumab), but this progress is not expected to help to plug the predicted hole in sales from the looming patent expiry of prostate cancer drug Zytiga (abiraterone), which last year contributed $3.5 billion to sales. The group’s continued price cutting to maintain the market share of its TNF inhibitor Remicade (infliximab) will also hit turnover. Notwithstanding Keytruda’s success, Merck & Co. remained in sixth place in the rankings, with GlaxoSmithKline and AbbVie also holding the positions they occupied last year (Nat. Rev. Drug Discov. 17, 232; 2018). Amgen was a new entrant to the top ten. Strong sales growth for products like Repatha (evolocumab) and Prolia (denosumab) and a betterthan-expected performance from its newly launched migraine drug, Aimovig (erenumab), are likely to be offset by heavy sales declines for its bestselling TNF inhibitor Enbrel (etanercept) due to increased competition and biosimilar erosion in Europe. Biosimilar competition is also expected to hit the company’s other bigseller Neulasta (pegfilgrastim) this year, so Amgen’s inclusion in the top ten might be shortlived.