Pfizer may be interested, but UCB also on the prowl... UCB SA (UCBJF.PK), Brussels, Belgium saw U.S. prescriptions for its epilepsy drug Keppra grow by 41% over the past year. The news sent UCB shares up more than seven percent late on Tuesday. An additional factor contributing to this run-up in stock prices are rumors going around that Pfizer Inc. (PFE), the world’s number one pharma might be interested in acquiring UCB’s drug business. UCB’s best known drug, the anti-histamine Zyrtec is sold in the U.S. by Pfizer under license from UCB. Zyrtec is a blockbuster drug with sales of $1.3B last year.