Aduro Biotech $ADRO fell sharply amid heavy trading volume in response to its announcement that the FDA has put a partial clinical hold on its LADD (Listeria-based immunotherapy construct) clinical trials. The action, which halts new subjects enrollment , comes after a blood culture sample from an indwelling port of a metastatic pancreatic cancer patient with gastrointestinal symptoms tested positive for Listeria, suspected to be product candidate CRS-207. The patient is doing well after treatment with intravenous antibiotics. Subsequent blood cultures have been Listeria-negative.