Cornerstone Pharmaceuticals Inc., of Cranbury, N.J., received a $10 million investment for a minority interest from IDT Corp., of Newark, N.J. Under the investment agreements, IDT has board representation, and IDT and its co-investors have the right to acquire a majority interest in Cornerstone, which develops oncology drugs. The company's lead compound, CPI-613, has generated encouraging preliminary results in early stage trials in patients with advanced pancreatic cancer, acute myeloid leukemia and T-cell lymphoma, IDT said.