Tobira Therapeutics SC 13G/A Tobira Therapeutics, Inc.

UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549

SCHEDULE 13G/A(Rule 13d-102)

Information To Be Included In Statements Filed PursuantTo § 240.13d-1(b), (c), and (d) and Amendments Thereto FiledPursuant To § 240.13d-2

Under the Securities Exchange Act of 1934
(Amendment No. 1)^*
Tobira Therapeutics, Inc.(Name of Issuer)

Common Stock, $0.001 par value per share(Title of Class of Securities)

88883P101(CUSIP Number)

December 31, 2015(Date of Event Which Requires Filing of This Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

☐	Rule 13d-1(b)
☐	Rule 13d-1(c)
☒	Rule 13d-1(d)

^* The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 88883P101 SCHEDULE 13G   Page 2 of 9 Pages  

1	NAMES OF REPORTING PERSONS Quaker BioVentures, L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a)  ☐ (b)  ☐
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER* 0
		6	SHARED VOTING POWER 82,463
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 82,463
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 82,463
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) ☐
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9** 0.4%
12	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) PN

* Based on 18,809,993 shares of the Issuer's common stock issued and outstanding as of November 6, 2015, as disclosed in the Issuer's Quarterly Report on Form 10-Q for the quarter ended September 30, 2015.

CUSIP No. 88883P101 SCHEDULE 13G   Page 3 of 9 Pages  

1	NAMES OF REPORTING PERSONS Quaker BioVentures Capital, L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a)  ☐ (b)  ☐
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER* 0
		6	SHARED VOTING POWER 82,463
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 82,463
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 82,463
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) ☐
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9** 0.4%
12	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) PN

* Based on 18,809,993 shares of the Issuer's common stock issued and outstanding as of November 6, 2015, as disclosed in the Issuer's Quarterly Report on Form 10-Q for the quarter ended September 30, 2015.

CUSIP No. 88883P101 SCHEDULE 13G   Page 4 of 9 Pages  

1	NAMES OF REPORTING PERSONS Quaker BioVentures Capital, LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a)  ☐ (b)  ☐
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER*
		6	SHARED VOTING POWER 82,463
		7	SOLE DISPOSITIVE POWER
		8	SHARED DISPOSITIVE POWER 82,463
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 82,463
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) ☐
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9** 0.4%
12	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) PN

* Based on 18,809,993 shares of the Issuer's common stock issued and outstanding as of November 6, 2015, as disclosed in the Issuer's Quarterly Report on Form 10-Q for the quarter ended September 30, 2015.

CUSIP No. 88883P101 SCHEDULE 13G   Page 5 of 9 Pages  

Item 1(a)	Name of Issuer: Tobira Therapeutics, Inc.
Item 1(b)	Address of Issuer's Principal Executive Offices: 701 Gateway Blvd., Suite 300South San Francisco, CA 94080
Item 2(a)	Name of Person Filing: Quaker BioVentures, L.P. Quaker BioVentures Capital, L.P. Quaker BioVentures Capital, LLC
Item 2(b)	Address of Principal Business Office or, if none, Residence: The address of the principal business office of each of the Reporting Persons is 2929 Arch Street, Cira Centre, Philadelphia, PA 19104-2868.
Item 2(c)	Citizenship: Quaker BioVentures, L.P. – Delaware Quaker BioVentures Capital, L.P. – Delaware Quaker BioVentures Capital, LLC – Delaware
Item 2(d)	Title of Class of Securities: Common Stock, $0.001 par value per share
Item 2(e)	CUSIP Number: 88883P101
Item 3	Not applicable.

CUSIP No. 88883P101 SCHEDULE 13G   Page 6 of 9 Pages  

Item 4 Ownership.***   Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.   (a)    Amount beneficially owned:   Quaker BioVentures, L.P. –  82,463 Quaker BioVentures Capital, L.P. – 82,463 Quaker BioVentures Capital, LLC –82,463  (b)Percent of class:   Quaker BioVentures, L.P. – 0.4% Quaker BioVentures Capital, L.P. – 0.4% Quaker BioVentures Capital, LLC – 0.4%   (c)Number of shares as to which the person has:   (i)Sole power to vote or to direct the vote   Quaker BioVentures, L.P. – 0 Quaker BioVentures Capital, L.P. – 0 Quaker BioVentures Capital, LLC – 0   (ii)Shared power to vote or to direct the vote   Quaker BioVentures, L.P. –  82,463 Quaker BioVentures Capital, L.P. – 82,463 Quaker BioVentures Capital, LLC – 82,463    (iii)Sole power to dispose or to direct the disposition of   Quaker BioVentures, L.P. – 0 Quaker BioVentures Capital, L.P. – 0 Quaker BioVentures Capital, LLC – 0   (iv)Shared power to dispose or to direct the disposition of   Quaker BioVentures, L.P. –  82,463 Quaker BioVentures Capital, L.P. – 82,463 Quaker BioVentures Capital, LLC – 82,463  

________________________

*** Consists of (i) 82,463 shares deemed to be beneficially owned by Quaker BioVentures, L.P.; Quaker BioVentures Capital, L.P. is the general partner of Quaker BioVentures, L.P.;  Quaker BioVentures Capital, LLC is the general partner of Quaker BioVentures Capital, L.P.

CUSIP No. 88883P101 SCHEDULE 13G   Page 7 of 9 Pages  

Item 5	Ownership of Five Percent or Less of a Class. If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than 5 percent of the class of securities, check the following ☒.
Item 6	Ownership of More than Five Percent on Behalf of Another Person. Not applicable.
Item 7	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person. Not applicable.
Item 8	Identification and Classification of Members of the Group. Each of the Reporting Persons may be deemed to be a member of a group with respect to the issuer or securities of the issuer for the purpose of Section 13(d) or 13(g) of the Securities Exchange Act of 1934, as amended.
Item 9	Notice of Dissolution of Group. Not applicable.
Item 10	Certification. By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

CUSIP No. 88883P101 SCHEDULE 13G   Page 8 of 9 Pages  

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: February 12, 2016	QUAKER BIOVENTURES, L.P. By: Quaker BioVentures Capital, L.P., its general partner By: Quaker BioVentures Capital, LLC, its general partner /s/ Richard S. Kollender Name: Richard S. Kollender Title: Executive Manager
	QUAKER BIOVENTURES CAPITAL, L.P. By: Quaker BioVentures Capital, LLC, its general partner /s/ Richard S. Kollender Name: Richard S. Kollender Title: Executive Manager
	QUAKER BIOVENTURES CAPITAL, LLC /s/ Richard S. Kollender Name: Richard S. Kollender Title: Executive Manager

CUSIP No. 88883P101 SCHEDULE 13G   Page 9 of 9 Pages  

Exhibit 1

JOINT FILING AGREEMENT

Joint Filing Agreement, dated as of February 12, 2016, is by and among Quaker BioVentures, L.P., Quaker BioVentures Capital, L.P. and Quaker BioVentures Capital, LLC (the "Quaker Filers").

Each of the Quaker Filers may be required to file with the United States Securities and Exchange Commission a statement on Schedule 13G/A with respect to shares of Common Stock, par value $0.001 per share, of Tobira Therapeutics, Inc. beneficially owned by it from time to time.  Pursuant to and in accordance with Rule 13(d)(1)(k) promulgated under the Securities Exchange Act of 1934, as amended, each of the Quaker Filers hereby agree to be responsible for the timely filing of the Schedule 13G/A and any amendments thereto on behalf of the Quaker Filers, and for the completeness and accuracy of the information concerning itself contained therein.  Each of the Quaker Filers hereby further agree to file this Joint Filing Agreement as an exhibit to the statement and each such amendment, as required by such rule.

This Joint Filing Agreement may be terminated by any of the Quaker Filers upon one week's prior written notice or such lesser period of notice as the Quaker Filers may mutually agree.

Executed and delivered as of the date first above written.

QUAKER BIOVENTURES, L.P.

By: Quaker BioVentures Capital, L.P., its general partner

By: Quaker BioVentures Capital, LLC, its general partner

/s/ Richard S. Kollender

Name: Richard S. Kollender

Title: Executive Manager

QUAKER BIOVENTURES CAPITAL, L.P.

By: Quaker BioVentures Capital, LLC, its general partner

/s/ Richard S. Kollender

Name: Richard S. Kollender

Title: Executive Manager

QUAKER BIOVENTURES CAPITAL, LLC

/s/ Richard S. Kollender

Name: Richard S. Kollender

Title: Executive Manager