GlaxoSmithKline has agreed to acquire Sierra Oncology for $1.9 billion. Based in California, Sierra is developing momelotinib, a small-molecule drug for myelofibrosis, a fatal cancer of the bone marrow. Sierra plans to file for US Food and Drug Administration approval of the drug in the second quarter. Sierra acquired the compound from Gilead Sciences in 2018 for $3 million up front. GSK says momelotinib will complement its multiple myeloma drug Blenrep (belantamab mafodotin).