Drug distributor Par Pharmaceutical ( PRX) plummeted following an announcement after the market closed Wednesday that the company would restate its financial results back to 2004. The restatement will result in a reduction in revenue of up to $55 million. The stock fell $4.93, or 27%, to $13.32 Thursday. The company attributed the restatement to delays in recognizing customer credits and an understatement of accounts receivable reserves. Since Par has profit-sharing arrangements with a number of partners, in some cases its revenue overstatement has resulted in overpayment. The company says it will attempt to recover a share of profits from products included in the overstated revenue, but says it can't estimate the amount it will be able to recover. MedImmune ( MEDI) received approval from the Food and Drug Administration to use reverse genetics technology to construct new strains of flu vaccines. MedImmune has already begun applying the technology to avian flu research in conjunction with the National Institutes of Health, the company says. Most flu-vaccine makers are already using reverse genetics technology to develop pandemic vaccine candidates because it allows them to avoid working directly with the infectious viruses, the company says. MedImmune, which owns the license to the technology, says it "remains committed to making sure that the technology is accessible to government institutions and industry manufacturers." MedImmune shares rose earlier, but lately were down 3 cents to $46.57. Cancer-drug maker MGI Pharma ( MOGN) signed an agreement with Cilag GmbH, a Johnson & Johnson ( JNJ) company, granting Cilag exclusive development and commercialization rights for the Dacogen injection outside of North America. According to the agreement, Cilag may pay MGI more than $80 million to license the drug, including an upfront payment, potential milestones, and research and development costs. Shares of MGI were 4 cents lower at $21.41. MGI's Dacogen partner Supergen ( SUPG) rose 10.1% to $3.91. Dacogen is an FDA-approved treatment for myelodysplastic syndromes, a type of bone-marrow cancer.