As pipelines thin and regulatory approvals become more difficult, big drugmakers are increasingly shifting R&D around. The lastest change has John Patterson, 61, retiring from AstraZeneca this coming March, and he will be replaced by Anders Ekblom, 54, who actually assume full responsibilities at the end of January.

Patterson was appointed executive director responsible for development in December 2004 and has been in charge of the new drug pipeline during a not-so-great stretch (look here). An industry veteran, who started out with ICI Pharmaceuticals, he was initially brought in as development head in a bid to restore confidence in the pipeline after two big setbacks - FDA rejection of the Exanta anticoagulant Exanta and the failure of the Iressa lung drug in a key trial.

During his time in charge, R&D results have remained mixed, with setbacks for meds that were developed to treat stroke and diabetes. other products including NXY-059 for stroke, heart drug AGI-1067 and Galida for diabetes. At the same time, though, he oversaw alliances with other drugmakers and the acquisition of MedImmune last year, Reuters notes.

And perhaps Patterson will get some credit if sales of Crestor improve after a key study is released this weekend at the American Heart Association meeting. Analysts expect Crestor to show a substantial reduction in the incidence of heart attack, stroke and death in the so-called Jupiter trial, which tested the medicine in patients who would not normally receive so-called statin drugs (back story).

Ekblom joined Astra in 1993 from Sweden’s Karolinska Institutet and is currently vp and head of global clinical development. Under AstraZeneca’s rules, managers are allowed to retire at any time after the age of 60 (see AZ statement).