0001193125-14-401671 Sample Contracts

30,941,102 Shares of Common Stock Warrants to Purchase 22,011,265 Shares of Common Stock and Pre-Funded Warrants to Purchase 13,081,428 Shares of Common Stock MAST THERAPEUTICS, INC. UNDERWRITING AGREEMENT

Underwriting Agreement • November 7th, 2014 • Mast Therapeutics, Inc. • Pharmaceutical preparations • New York

• Contract Type
  Underwriting Agreement
• Filed
  November 7th, 2014
• Company
  Mast Therapeutics, Inc.
• Industry
  Pharmaceutical preparations
• Jurisdiction
  New York

WARRANT AGENT AGREEMENT

Warrant Agent Agreement • November 7th, 2014 • Mast Therapeutics, Inc. • Pharmaceutical preparations • New York

• Contract Type
  Warrant Agent Agreement
• Filed
  November 7th, 2014
• Company
  Mast Therapeutics, Inc.
• Industry
  Pharmaceutical preparations
• Jurisdiction
  New York

This Warrant Agent Agreement (this “Agreement”) is made as of November 6, 2014 between Mast Therapeutics, Inc., a Delaware corporation (“Company”), and American Stock Transfer & Trust Company, LLC, a New York limited liability trust company (“Warrant Agent”).

PRE-FUNDED WARRANT AGENT AGREEMENT

Pre-Funded Warrant Agent Agreement • November 7th, 2014 • Mast Therapeutics, Inc. • Pharmaceutical preparations • New York

• Contract Type
  Pre-Funded Warrant Agent Agreement
• Filed
  November 7th, 2014
• Company
  Mast Therapeutics, Inc.
• Industry
  Pharmaceutical preparations
• Jurisdiction
  New York

This Pre-Funded Warrant Agent Agreement (this “Agreement”) is made as of November 6, 2014 between Mast Therapeutics, Inc., a Delaware corporation (“Company”), and American Stock Transfer & Trust Company, LLC, a New York limited liability trust company (“Warrant Agent”).