Art Krieg has been named as CSO of RNA drug developer Sarepta Therapeutics.
Krieg previously served as CEO of gene-activation firm Rana Therapeutics, which he cofounded in 2011. Before that, he led Pfizer's oligonucleotide therapeutics unit.
He remains a Rana senior advisor and scientific advisory board member.
Troubled RNAi drug firm Marina Biotech disclosed this month the resignations of CFO Philip Ranker and executive VP of research and development Richard Ho.
The departures come after Marina shut down essentially all of its operations in mid-2012 due to lack of funding.