Johnson & Johnson to buy Momenta Pharma for $6.5 billion

Johnson & Johnson on Wednesday said that it will pay $6.5 billion in cash to buy Momenta Pharmaceuticals, representing a 70% premium to where the Massachusetts drugmaker closed trading yesterday.

Why it matters: Johnson & Johnson is seeking to expand its capacity in drugs to treat autoimmune diseases, including a muscle-weakening condition known as myasthenia gravis.