Roivant Sciences Ltd. has agreed to pay Gyeonggi-do, South Korea-based Intron Biotechnology Inc. up to $667.5 million for global rights to an experimental therapy for treating infectious diseases caused by antibiotic-resistant staphylococci. The deal, focused on Intron's tonabacase (SAL-200), positions the Basel, Switzerland-based company to begin a phase II trial of SAL-200 in 2019, it said.