Shire Pharmaceutical Group plc already has tried once to reduce its reliance on sales of its Adderall for attention deficit hyperactivity disorder with the 1999 acquisition of Roberts Pharmaceutical Corp. But Adderall sales have grown 51 percent since August 1999, compared to a more modest 30 percent growth in sales of other products, maintaining the lopsided distribution of revenues. Now Shire is trying again, acquiring BioChem Pharma Inc. to provide a more balanced revenue stream, along with cash and R&D capabilities to bolster its pipeline.

Shire (LSE:SHP; SHPGY, Andover, U.K.) has made four acquisitions since 1997 that added a series of marketed