Novartis ( NVS ) and GlaxoSmithKline ( GSK ) exchanged more than $20 billion in assets recently to reinforce their profitable divisions and eliminate their weaker businesses as drug manufacturers adjust to competition from generics and spending cuts in healthcare. Transaction Details The transactions, which include Novartis purchasing GSK's cancer treatments and GSK buying Novartis' vaccines division, occurred soon after news that AstraZeneca had declined a bid of over $100 billion from Pfizer. GSK will transfer to Novartis two of its cancer treatments, Mekinist and Tafinlar, which will give Novartis a robust market position for melanoma drugs. Arzerra, for chronic lymphocytic leukemia in thrombocytopenia, and Tykerb, which treats metastasized breast cancer, are included in the transaction.