Thursday's Early Winners & Losers

Sangamo Biosciences(SGMO Quote) soared after the Richmond, Calif.-based company released data demonstrating that human immune system cells can be made permanently resistant to HIV infection by treatment with its zinc finger DNA-binding protein nucleases. Sangamo's ZFNs are designed to permanently modify the DNA sequence encoding CCR5, a co-receptor that enables HIV to enter and infect cells of the immune system, the company said. The data were presented at a conference in San Francisco. Shares were trading up 62 cents, or 11.52%, to $6.

National Penn Bancshares(NPBC Quote) lost ground after chairman and CEO Wayne R. Weidner announced his plans to retire in December 2007. Glenn E. Moyer, who joined National Penn in 1999 and is currently president of the holding company and president and CEO of National Penn Bank, will succeed Weidner as CEO and chairman. Weidner spent his entire career with the company, starting as a teller in 1962. He has served as chairman, president and CEO since 2002. Shares were trading down 64 cents, or 3.14%, to $19.74.

Smith International(SII Quote) gained on news that the company was replacing Golden West Financial(GDW Quote) in the S&P 500. Golden West is being acquired by Wachovia(WB Quote) in a deal expected to close before the open of trading on Monday. Shares of the Houston-based Smith International were trading up $1.88, or 5.03%, to $39.25 recently.