Immunology and oncology are J&J's key areas. Other large drugmakers with a strong presence in the oncology market include Novartis, AstraZeneca ( AZN - Free Report ), AbbVie ( ABBV - Free Report ), Merck, Bristol-Myers, Roche and Pfizer. In immunology, AbbVie, Amgen, Sanofi, AstraZeneca and Pfizer hold a strong position.