With another quarter of sales comes another warning that the market for Kras-mutant lung cancer might be much smaller than previously thought. Amgen last night reported fourth-quarter Lumakras sales of $71m, missing sellside consensus of $90m-plus, and showing a 5% decline versus the third quarter and 8% versus the second. US revenue has stalled, while that in the rest of the world appears to be evaporating. The group says Lumakras volume rose 12%, but the hit came from lower pricing. Investors in Mirati, whose rival Kras drug Krazati was approved in December, will be watching closely. That Lumakras, expected to sell $1.6bn in 2028 according to Evaluate Pharma sellside consensus, should have plateaued within a year of launch is concerning for Amgen, which is eager to fend off criticism over its lacklustre R&D pipeline. Fears will be amplified by disappointing 2023 guidance and the revelation that Amgen’s $28bn takeover of Horizon, which is designed to fill a revenue hole but has sparked criticism from the Democrat senator Elizabeth Warren, has now been delayed by an FTC request for more information. One pipeline hope is obesity with AMG-133, and yesterday Amgen revealed a new project, AMG-786, in phase 1.