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<TITLE> Mast Therapeutics, Inc. (Form: 8-K) </TITLE>
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		UNITED STATES<BR>
	SECURITIES AND EXCHANGE COMMISSION
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	WASHINGTON, D.C. 20549
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	FORM 8-K
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	CURRENT REPORT
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	Pursuant to Section&nbsp;13 or 15(d) of the Securities Exchange Act of 1934
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	Date of Report (Date of Earliest Event Reported):
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	&nbsp;
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	August 29, 2014
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	Mast Therapeutics, Inc.
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<BR>__________________________________________<BR>
	(Exact name of registrant as specified in its charter)
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	Delaware
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	001-32157
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	84-1318182
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_____________________<BR>
	(State or other jurisdiction
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_____________<BR>
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	of incorporation)
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	File Number)
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	Identification No.)
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	12390 El Camino Real, Suite 150, San Diego, California
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	92130
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_________________________________<BR>
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___________<BR>
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	Registrant&#146;s telephone number, including area code:
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	858-552-0866
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	Not Applicable
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	Former name or former address, if changed since last report
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	&nbsp;
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Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any
of the following provisions:</FONT>
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[&nbsp;&nbsp;]&nbsp;&nbsp;Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)<br>
[&nbsp;&nbsp;]&nbsp;&nbsp;Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)<br>
[&nbsp;&nbsp;]&nbsp;&nbsp;Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))<br>
[&nbsp;&nbsp;]&nbsp;&nbsp;Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))<br>
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	Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.
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On August 29, 2014, Santosh J. Vetticaden, Chief Medical Officer and Senior Vice President of Mast Therapeutics, Inc. (the "Company"), notified the Company of his decision to resign for personal reasons, effective September 12, 2014.  Edwin L. Parsley, D.O., the Chief Medical Officer of Aires Pharmaceuticals, Inc., a wholly-owned subsidiary of the Company, will assume Dr. Vetticaden&#x2019;s former responsibilities as the Company&#x2019;s interim Chief Medical Officer.  Dr. Parsley previously was with Pfizer, where he oversaw clinical trials for Revatio&#174; (sildenafil).  He is a practicing physician and certified by the American Board of Internal Medicine in internal medicine, pulmonary disease, critical care medicine, and sleep medicine.  Dr. Parsley has been actively engaged with the Company since it acquired Aires in February 2014.
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	SIGNATURES
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	Pursuant to the requirements of the Securities Exchange Act of 1934, the
	registrant has duly caused this report to be signed on its behalf by the
	undersigned hereunto duly authorized.
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	Mast Therapeutics, Inc.
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	September 2, 2014
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	By:
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	/s/ Patrick L. Keran
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	Name: Patrick L. Keran
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	Title: President and Chief Operating Officer
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Mast Therapeutics, Inc. (Form: 8-K)
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM 8-K
CURRENT REPORT
Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
Date of Report (Date of Earliest Event Reported):
August 29, 2014
Mast Therapeutics, Inc.
__________________________________________
(Exact name of registrant as specified in its charter)
Delaware
001-32157
84-1318182
_____________________
(State or other jurisdiction
_____________
(Commission
______________
(I.R.S. Employer
of incorporation)
File Number)
Identification No.)
12390 El Camino Real, Suite 150, San Diego, California
92130
_________________________________
(Address of principal executive offices)
___________
(Zip Code)
Registrant's telephone number, including area code:
858-552-0866
Not Applicable
______________________________________________
Former name or former address, if changed since last report
Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any
of the following provisions:
[  ]  Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
[  ]  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
[  ]  Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
[  ]  Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
Top of the Form
Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.
On August 29, 2014, Santosh J. Vetticaden, Chief Medical Officer and Senior Vice President of Mast Therapeutics, Inc. (the "Company"), notified the Company of his decision to resign for personal reasons, effective September 12, 2014.  Edwin L. Parsley, D.O., the Chief Medical Officer of Aires Pharmaceuticals, Inc., a wholly-owned subsidiary of the Company, will assume Dr. Vetticaden's former responsibilities as the Company's interim Chief Medical Officer.  Dr. Parsley previously was with Pfizer, where he oversaw clinical trials for Revatio® (sildenafil).  He is a practicing physician and certified by the American Board of Internal Medicine in internal medicine, pulmonary disease, critical care medicine, and sleep medicine.  Dr. Parsley has been actively engaged with the Company since it acquired Aires in February 2014.
Top of the Form
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the
	registrant has duly caused this report to be signed on its behalf by the
	undersigned hereunto duly authorized.
Mast Therapeutics, Inc.
September 2, 2014
By:
/s/ Patrick L. Keran
Name: Patrick L. Keran
Title: President and Chief Operating Officer