A year after negotiating to sell MedImmune to the big drugmaker for about $15 billion, David Mott is leaving next week for unspecified reasons, according to a statement. Although Mott vowed to remain after the purchase was completed, this month marks the one-year anniversary since the consummation, so perhaps this is not entirely surprising.

You may recall that Mott was scheduled to receive more than $145 million in cash after the deal was completed - $133.5 million in exchange for the cancellation of already vested stock options and other options that hadn’t yet vested, and the remainder to cover change-of-control payments for bonuses, incentives, tax gross-ups and severance payments. AstraZeneca’s US ceo, Tony Zook, will assume Mott’s job for the time being.