Drug developers Adolor (ADLR) Corp. and GlaxoSmithKline PLC said early Monday the Food and Drug Administration has requested more safety data on their postoperative bowel treatment Entereg.

The agency sent the companies an approvable letter on the drug, requesting 12-month safety data that includes analysis of serious cardiovascular events from an ongoing study and a risk management plan. The ongoing study is expected to be complete by the first quarter of 2007, with data available during the second quarter.

Adolor shares plummeted $4.24, or 30.4 percent, to $9.70 in premarket trading on the INET electronic exchange, indicating that stock may open at a new 52-week low. Shares, which closed Friday at $13.94 on the Nasdaq, have ranged between $11.28 and $27.80 over the past year.