Driven by strong sales of key products, Pfizer Inc. said Wednesday its fourth quarter profit soared 46%, narrowly beating Wall Street estimates.The world’s largest drug company earned $2.86 billion in the October-December period, up from $1.96 billion a year earlier. Excluding merger-related costs, accounting changes and other items, Pfizer earned $2.94 billion. Revenues for the quarter increased 14% to $9.33 billion from $8.18 billion a year earlier.Pfizer predicted earnings per share did...