David Apelian, chief operating officer and executive medical officer at Eiger BioPharmaceuticals (NASDAQ: [[ticker:EIGR]]) for the past 17 months, is stepping down. The Palo Alto, CA, drug developer said Friday that Apelian accepted an offer to become CEO of an unnamed private biotech company. Apelian, whose last day will be June 14, will remain on the Eiger board of directors. The company added that it plans to announce Apelian’s successor “in the near future.” Eiger’s lead drug candidate, lonafarnib, is in late-stage testing as a treatment for hepatitis delta virus infection.