LITTLE ROCK, Ark. (AP) — The Food and Drug Administration must halt all primate experimentation at an Arkansas laboratory until allegations of negligence and abuse are properly addressed, U.S. congressmen demanded in a bipartisan call for action.

U.S. Reps. Matt Gaetz, of Florida, and Brendan Boyle, of Pennsylvania, submitted a letter to FDA Commissioner Scott Gottlieb March 21 after they learned of the Aug. 3 death of a 5-year-old rhesus monkey at the National Center for Toxicological Research near Pine Bluff, the Arkansas Democrat-Gazette reported.

"Enough is enough," Gaetz, a Republican, sa...