0000950123-06-013485 Sample Contracts

AGREEMENT AND PLAN OF MERGER by and among MERCK & CO., INC., SPINNAKER ACQUISITION CORP. a wholly owned subsidiary of MERCK & CO., INC. and SIRNA THERAPEUTICS, INC. Dated as of October 30, 2006

Merger Agreement • November 3rd, 2006 • Merck & Co Inc • Pharmaceutical preparations • Delaware

• Contract Type
  Merger Agreement
• Filed
  November 3rd, 2006
• Company
  Merck & Co Inc
• Industry
  Pharmaceutical preparations
• Jurisdiction
  Delaware

AGREEMENT AND PLAN OF MERGER (this “Agreement”), dated as of October 30, 2006, by and among MERCK & CO., INC., a New Jersey corporation (“Parent”), SPINNAKER ACQUISITION CORP., a Delaware corporation and a wholly-owned subsidiary of Parent (“Merger Sub”), and SIRNA THERAPEUTICS, INC., a Delaware corporation (the “Company”).

EXHIBIT A FORM OF VOTING AGREEMENT

Voting Agreement • November 3rd, 2006 • Merck & Co Inc • Pharmaceutical preparations • Delaware

• Contract Type
  Voting Agreement
• Filed
  November 3rd, 2006
• Company
  Merck & Co Inc
• Industry
  Pharmaceutical preparations
• Jurisdiction
  Delaware

THIS VOTING AGREEMENT (this “Agreement”) is made and entered into as of October 30, 2006 by and between Merck & Co., Inc., a New Jersey corporation (“Acquiror”), and the undersigned securityholder (“Stockholder”) of Sirna Therapeutics, Inc., a Delaware corporation (“Sirna”).