Abbvie Inc. is stepping away from a 2016 deal with Bioarctic AB to develop alpha-synuclein antibodies for treating Parkinson’s disease, originally valued at up to $775 million. Bioarctic said it plans to stay the course without its big-pocketed partner. Bioarctic’s stock (Stockholm:BIOA-B) fell 14.6% to SEK90 (US$9.40) on April 20.