The S&P 500 soared more than 32% in 2013, and several big pharma companies, namely Bristol-Myers Squibb (NYSE:BMY), AbbVie (NYSE:ABBV), Roche (NASDAQOTH:RHHBY), Johnson & Johnson (NYSE:JNJ), and AstraZeneca (NYSE:AZN) also performed extraordinarily well. The following slideshow reveals why these companies beat out their big pharma peers and what drove their strong performances in 2013.

Max Macaluso, Ph.D. owns shares of Gilead Sciences. The Motley Fool recommends Gilead Sciences, ImmunoGen, and Johnson & Johnson. The Motley Fool owns shares of Johnson & Johnson. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.