COMBINATION AGREEMENT between COVALENT GROUP, INC. (“Covalent”) and Kai Lindevall Jan Lilja Sven-Erik Nilsson Vesa Manninen Seppo Oksanen Heikki Vapaatalo Riitta Korpela Agneta Lindevall NTGLT Pharma BVBA (the “Stockholders”) dated March 2, 2006