Alexander Zukiwski, M.D., has been appointed interim chief executive officer of Arno Therapeutics, Inc., effective immediately. Dr. Zukiwski will also continue in his role as vice president and chief medical officer.   Dr. Zukiwski has more than 19 years of experience in pharmaceuticals and biotechnology, including serving as executive vice president, Clinical Research, and chief medical officer at MedImmune, Inc., as well as positions of increasing responsibility with Johnson & Johnson Phar...