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.

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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.