SC 13D/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1)*

Anthera Pharmaceuticals, Inc.

(Name of Issuer)

Common Stock, Par Value $0.001 Per Share

(Title of Class of Securities)

03674U 201

(CUSIP Number)

OrbiMed Advisors LLC

OrbiMed Capital GP IV LLC

Samuel D. Isaly

601 Lexington Avenue, 54th Floor

 New York, NY  10022

Telephone:  (212) 739-6400

(Name, Address and Telephone Number of Person Authorized

to Receive Notices and Communications)

May 14, 2014

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g) check the following box o.

Note:  Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits.  See §§ 240.13d-7(b) for other parties to whom copies are to be sent.

* 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).

(Continued on following pages)

SCHEDULE 13D

CUSIP No.  03674U 201 Page 2 of 9 Pages

1	NAME OF REPORTING PERSONS OrbiMed Advisors LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) o (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions) N/A
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			o
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 1,099,417
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,099,417
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,099,417
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions)			o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.22%*
14	TYPE OF REPORTING PERSON (See Instructions) IA

* This percentage is calculated based upon 20,887,586 Shares of the Issuer’s common stock outstanding, as set forth in the Issuer’s Form 10-Q, filed with the Securities and Exchange Commission (the “SEC”) on May 14, 2014.

SCHEDULE 13D

CUSIP No.  03674U 201 Page 3 of 9 Pages

1	NAME OF REPORTING PERSONS OrbiMed Capital GP IV LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) o (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions) N/A
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			o
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 1,099,417
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,099,417
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,099,417
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions)			o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.22%*
14	TYPE OF REPORTING PERSON (See Instructions) OO

* This percentage is calculated based upon 20,887,586 Shares of the Issuer’s common stock outstanding, as set forth in the Issuer’s Form 10-Q filed with the SEC on May 14, 2014.

SCHEDULE 13D

CUSIP No.  03674U 102 Page 4 of 9 Pages

1	NAME OF REPORTING PERSONS Samuel D. Isaly
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) o (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions) N/A
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			o
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 1,099,417
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,099,417
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,099,417
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions)			o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.22%*
14	TYPE OF REPORTING PERSON (See Instructions) IN

* This percentage is calculated based upon 20,887,586 Shares of the Issuer’s common stock outstanding, as set forth in the Issuer’s Form 10-Q filed with the SEC on May 14, 2014.

Item 1. Security and Issuer.

This Schedule 13D (the “Statement”) relates to the common stock, par value $0.001 per share (“Shares”), of Anthera Pharmaceuticals, Inc., a corporation organized under the laws of the state of Delaware (the “Issuer”), with its principal executive offices located at 25801 Industrial Boulevard, Suite B, Hayward, California 94545.  Information given in response to each item shall be deemed incorporated by reference in all other items, as applicable.

On May 14, 2014, the Issuer filed a Form 10-Q disclosing that its total number of outstanding Shares had increased to 20,887,586 as of May 1, 2014.  Based on this updated information, the percentage of outstanding Shares of which the Reporting Persons (as defined below) may be deemed to be the beneficial owners has been reduced by more than one percent since the Reporting Persons filed the original Schedule 13D that is being amended hereby.

Item 2. Identity and Background.

(a)          This Statement is being filed by OrbiMed Advisors LLC (“OrbiMed Advisors”), a limited liability company organized under the laws of Delaware, OrbiMed Capital GP IV LLC (“GP IV”), a limited liability company organized under the laws of Delaware, and Samuel D. Isaly (“Isaly”), an individual (collectively, the “Reporting Persons”).

(b) – (c) OrbiMed Advisors, a registered investment adviser under the Investment Advisers Act of 1940, as amended, is the sole managing member of GP IV.  GP IV is the sole general partner of OrbiMed Private Investments IV, LP (“OPI IV”), which holds Shares, as more particularly described in Item 6 below.  OrbiMed Advisors has its principal offices at 601 Lexington Avenue, 54th Floor, New York, NY  10022.

GP IV has its principal offices at 601 Lexington Avenue, 54th Floor, New York, NY  10022.

Isaly, a natural person, owns a controlling interest in OrbiMed Advisors.

The directors and executive officers of OrbiMed Advisors and GP IV are set forth on Schedules I and II, attached hereto.  Schedules I and II set forth the following information with respect to each such person:

(i)           name;

(ii)          business address (or residence address where indicated);

(iii)         present principal occupation or employment and the name, principal business and address of any corporation or other organization in which such employment is conducted;

(iv)         citizenship.

(d) – (e)  During the last five years, neither the Reporting Persons nor any Person named in Schedules I or II have been (i) convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors) or (ii) a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(f)  Isaly is a citizen of the United States.

Item 3. Source and Amount of Funds or Other Considerations.

Not applicable.  As described more fully in Item 1 above, the events giving rise to the obligation of the Reporting Person to file this Statement did not involve any transactions effected by one or more Reporting Persons with respect to the Shares.

Item 4. Purpose of Transaction.

Not applicable.  As described more fully in Item 1 above, the events giving rise to the obligation of the Reporting Person to file this Statement did not involve any transactions effected by one or more Reporting Persons with respect to the Shares.

Item 5. Interest in Securities of the Issuer.

(a) – (b) As of this date of this filing, OrbiMed Advisors, GP IV and Isaly may be deemed directly or indirectly, including by reason of their mutual affiliation, to be the beneficial owners of 1,099,417 Shares.  Based upon information contained in the most recent available filing by the Issuer with the SEC, such Shares constitute approximately 5.22% of the issued and outstanding Shares, as calculated pursuant toRule 13d-3(d)(1)(i).  As a result of the agreements and relationships described in Item 2 above and Item 6 below, OrbiMed Advisors, GP IV and Isaly share power to direct the vote and to direct the disposition of the Shares described in this Item 5.

(c)      The Reporting Persons have not engaged in any transaction in the Shares in the past 60 days.

(d)      Not applicable.

(e)      Not applicable.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer.

In addition to the relationships between the Reporting Persons described in Items 2 and 5, GP IV is the sole general partner of OPI IV, pursuant to the terms of the limited partnership agreement of OPI IV, and OrbiMed Advisors is the sole managing member of GP IV, pursuant to the terms of the limited liability company agreement of GP IV.  Pursuant to these agreements and relationships, OrbiMed Advisors and GP IV have discretionary investment management authority with respect to the assets of OPI IV.  Such authority includes the power to vote and otherwise dispose of securities purchased by OPI IV.  The number of outstanding Shares of the Issuer attributable to OPI IV consists of 932,750 Shares and a warrant to purchase 166,667 Shares (the “Warrant”).  OrbiMed Advisors, pursuant to its authority as the managing member of GP IV may be considered to hold indirectly 932,750  Shares and a Warrant to purchase 166,667 Shares and GP IV, pursuant to its authority as the general partner of OPI IV, may be considered to hold indirectly 932,750 Shares and a Warrant to purchase 166,667 Shares.

On May 16, 2013, Peter Thompson, currently an employee of OrbiMed Advisors, tendered his resignation from the board of directors of the Issuer, effective on the same date, and since that date the Reporting Persons have had no representation on the Issuer’s board of directors.

Other than the agreements and the relationships mentioned above, to the best knowledge of the Reporting Persons, there are no contracts, arrangements, understandings or relationships (legal or otherwise) among the persons named in Item 2 and between such persons and any persons with respect to any securities of the Issuer, including, but not limited to, transfer or voting of any of the Shares, finder’s fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or loss, or the giving of withholding of proxies.

Item 7. Materials to be Filed as Exhibits.

1. Joint Filing Agreement among OrbiMed Advisors, GP IV and Isaly.

SIGNATURES

After reasonable inquiry and to the best of each of the undersigned’s knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

Dated:  May 19, 2014

OrbiMed Advisors LLC
By:	/s/ Samuel D. Isaly
	Name:	Samuel D. Isaly
	Title:	Managing Member

OrbiMed Capital GP IV LLC
By:	OrbiMed Advisors LLC, its Managing Member
By:	/s/ Samuel D. Isaly
	Name:	Samuel D. Isaly
	Title:	Managing Member

By:	/s/ Samuel D. Isaly
	Name:	Samuel D. Isaly

Schedule I

The name and present principal occupation of each of the executive officers and directors of OrbiMed Advisors LLC are set forth below.  Unless otherwise noted, each of these persons are United States citizens and have as their business address 601 Lexington Avenue, 54th Floor, New York, NY  10022.

Name	Position with Reporting Person	Principal Occupation
Samuel D. Isaly	Managing Member	Managing Member OrbiMed Advisors LLC
Carl L. Gordon	Member	Member OrbiMed Advisors LLC
Sven H. Borho German and Swedish Citizen	Member	Member OrbiMed Advisors LLC
Jonathan T. Silverstein	Member	Member OrbiMed Advisors LLC
W. Carter Neild	Member	Member OrbiMed Advisors LLC
Geoffrey C. Hsu	Member	Member OrbiMed Advisors LLC
Evan D. Sotiriou	Chief Financial Officer	Chief Financial Officer OrbiMed Advisors LLC

Schedule II

The business and operations of OrbiMed Capital GP IV LLC are managed by the executive officers and directors of its managing member, OrbiMed Advisors LLC, set forth on Schedule I attached hereto.

EXHIBIT INDEX

Exhibit	Description	Page No.
A.	Joint Filing Agreement among OrbiMed Advisors LLC, OrbiMed Capital GP IV LLC and Samuel D. Isaly	A-1

EX-99.A

Exhibit A

JOINT FILING AGREEMENT

The undersigned hereby agree that the Statement on this Schedule 13D, dated May 19, 2014 (the “Schedule 13D”), with respect to the common stock, $0.001 par value per share, of Anthera Pharmaceuticals, Inc. is filed on behalf of each of us pursuant to and in accordance with the provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, and that this Agreement shall be included as an Exhibit to this Schedule 13D.  Each of the undersigned agrees to be responsible for the timely filing of the Schedule 13D, and for the completeness and accuracy of the information concerning itself contained therein.  This Agreement may be executed in any number of counterparts, all of which taken together shall constitute one and the same instrument.

IN WITNESS WHEREOF, the undersigned have executed this Agreement as of the 19th day of May, 2014.

OrbiMed Advisors LLC
By:	/s/ Samuel D. Isaly
	Name:	Samuel D. Isaly
	Title:	Managing Member

OrbiMed Capital GP IV LLC
By:	OrbiMed Advisors LLC, its Managing Member
By:	/s/ Samuel D. Isaly
	Name:	Samuel D. Isaly
	Title:	Managing Member

By:	/s/ Samuel D. Isaly
	Name:	Samuel D. Isaly