Notice of Effectiveness
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
Notice of Effectiveness
Effectiveness Date: May 14, 2014
Accession Number: 0001193125-14-182546
Submission Type: POS AM
CIK: 0001160308
Company Name: Mast Therapeutics, Inc.
File Number: 333-188870