WINSTON-SALEM, N.C.--(BUSINESS WIRE)--Targacept, Inc. (NASDAQ:TRGT), a clinical-stage biopharmaceutical company developing a new class of drugs known as NNR Therapeutics (TM), today announced the designation of a lead compound in its smoking cessation program, triggering a $500,000 milestone payment under its alliance agreement with GlaxoSmithKline (GSK).