SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* MPM BioVentures IV QP LP (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 04/15/2014	3. Issuer Name and Ticker or Trading Symbol TriVascular Technologies, Inc. [ TRIV ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series A Convertible Preferred Stock	(1)	(1)	Common Stock	798,329	(1)	I	See Footnote(2)
Series B Convertible Preferred Stock	(1)	(1)	Common Stock	230,756	(1)	I	See Footnote(3)
Series C Convertible Preferred Stock	(1)	(1)	Common Stock	114,942	(1)	I	See Footnote(4)
Series D Convertible Preferred Stock	(5)	(5)	Common Stock	379,599	(5)	I	See Footnote(6)
Series E Convertible Preferred Stock	(5)	(5)	Common Stock	253,066	(5)	I	See Footnote(7)
Warrants to Purchase Series D Preferred Stock (Right to Buy)	02/12/2012	02/12/2019	Series D Preferred Stock	1,516,122(8)	$0.3896	I	See Footnote(9)

1. Name and Address of Reporting Person* MPM BioVentures IV QP LP (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MPM BioVentures IV GmbH & Co. Beteiligungs KG (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MPM Asset Management Investors BV4 LLC (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MPM BioVentures IV GP LLC (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MPM BioVentures IV LLC (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* EVNIN LUKE (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Foley Todd (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* KAILIAN VAUGHN M (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. Each share of Series A Preferred Stock, Series B Preferred Stock and Series C Preferred is convertible into 0.0384595 shares of Common Stock without payment of further consideration and will automatically convert into 0.0384595 shares of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

2. The shares are held as follows: 748,227 by MPM BioVentures IV-QP, L.P. ("BV IV QP"), 28,826 by MPM BioVentures IV GmbH & Co. Beteiligungs KG ("BV IV KG") and 21,276 by MPM Asset Management Investors BV4 LLC ("AM BV4"). MPM BioVentures IV GP LLC and MPM BioVentures IV LLC ("BV LLC") are the direct and indirect general partners of BV IV QP and BV IV KG and BV LLC is the manager of AM BV4. Ansbert Gadicke, Luke Evnin, Vaughn M. Kailian, James Paul Scopa and Todd Foley are the members of BV LLC. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its respective pecuniary interest therein.

3. The shares are held as follows: 216,275 by BV IV QP, 8,332 by BV IV KG and 6,149 by AM BV4. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its respective pecuniary interest therein.

4. The shares are held as follows: 107,729 by BV IV QP, 4,150 by BV IV KG and 3,063 by AM BV4. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its respective pecuniary interest therein.

5. Each share of Series D Preferred Stock and Series E Preferred is convertible into 0.0246486 shares of Common Stock without payment of further consideration and will automatically convert into 0.0246486 shares of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

6. The shares are held as follows: 355,777 by BV IV QP, 13,706 by BV IV KG and 10,116 by AM BV4. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its respective pecuniary interest therein.

7. The shares are held as follows: 237,185 by BV IV QP, 9,137 by BV IV KG and 6,744 by AM BV4. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its respective pecuniary interest therein.

8. Upon the closing of the IPO, these warrants will automatically convert into warrants to purchase an aggregate of 37,369 shares of common stock at an exercise price of $15.8061 per share.

9. The warrants are held as follows: 1,420,973 by BV IV QP, 54,743 by BV IV KG and 40,406 by AM BV4. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its respective pecuniary interest therein.

Remarks:

	By Luke Evnin, member of MPM BioVentures IV LLC, the managing member of MPM BioVentures IV GP LLC, the general partner of MPM BioVentures IV-QP, L.P. /s/ Luke Evnin	04/15/2014
	By Luke Evnin, member of MPM BioVentures IV LLC, the managing member of MPM BioVentures IV GP LLC, the managing limited partner of MPM BioVentures IV GmbH & Co. /s/ Luke Evnin	04/15/2014
	By Luke Evnin, member of MPM BioVentures IV LLC, the manager of MPM Asset Management Investors BV4 LLC /s/ Luke Evnin	04/15/2014
	By Luke Evnin, member of MPM BioVentures IV LLC, the managing member of MPM BioVentures IV GP LLC /s/ Luke Evnin	04/15/2014
	By Luke Evnin, member of MPM BioVentures IV LLC /s/ Luke Evnin	04/15/2014
	/s/ Luke Evnin	04/15/2014
	/s/ Todd Foley	04/15/2014
	/s/ Vaughn M. Kailian	04/15/2014
	** Signature of Reporting Person	Date
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