Los Angeles-based KYTHERA Biopharmaceuticals, the venture-backed developer of aesthetic medicine products, said today that it has intiated two, PHase II trials of its injectable drugs for reducing under-the-chin fat. KYTHERA is developing drugs used for submental, under-the-chin fat. The company said the two trials will be conducted in approximately 70 centers across the U.S. and Canada, enrolling a total of 1,000 patients. The company said the U.S. trials follow a European Phase II trial of its compounds with Bayer Dermatology.