SC 13D

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 13D

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No.     )*

Eiger BioPharmaceuticals, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

28249U 10 5

(CUSIP Number)

INTERWEST PARTNERS

2710 SAND HILL ROAD, SUITE 200

MENLO PARK, CALIFORNIA 94025

TELEPHONE: (650) 854-8585

(Name, Address and Telephone Number of PersonAuthorized to Receive Notices and Communications)

March 23, 2016

(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 of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.  ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 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).

CUSIP No. 28249U 10 5 13D

1.	Name of Reporting Persons InterWest Partners X, L.P.
2.	Check the Appropriate Box if a Member of a Group (see instructions) (a)  ¨        (b)  x(1)
3.	SEC USE ONLY
4.	Source of Funds (see instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Item 2(d) or 2(e) ¨
6.	Citizenship or Place of Organization California, United States of America
Number of Shares Beneficially Owned by Each Reporting Person With		7.	Sole Voting Power 1,599,593 shares of Common Stock (2)
		8.	Shared Voting Power 0
		9.	Sole Dispositive Power 1,599,593 shares of Common Stock (2)
		10.	Shared Dispositive Power 0
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,599,593 shares of Common Stock (2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (see instructions) ¨
13.	Percent of Class Represented by Amount in Row 11 23.0% (3)
14.	Type of Reporting Person (see instructions) PN

(1) This Schedule 13D is filed by InterWest Partners X, L.P. (“InterWest X”), InterWest Management Partners X, LLC (“IMP X,” together with InterWest X, the “InterWest Entities”), Philip T. Gianos (“Gianos”), W. Stephen Holmes III (“Holmes”), Gilbert H. Kliman (“Kliman”), Arnold L. Oronsky (“Oronsky”), Bruce A. Cleveland (“Cleveland”), Khaled A. Nasr (“Nasr”) and Keval Desai (“Desai”). Together with the InterWest Entities, Gianos, Holmes, Kliman, Oronsky, Cleveland, Nasr and Desai are herein collectively referred to as the “Reporting Persons”). The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2) The shares are owned by InterWest X. IMP X serves as the general partner of InterWest X. Gianos, Holmes, Kliman, Oronsky and Cleveland are Managing Directors of IMP X, and Nasr and Desai are Venture Members of IMP X and share voting and dispositive power over the shares held by InterWest X, and may be deemed to own beneficially the shares held by InterWest X.

(3) This percentage set forth on the cover sheets is calculated based on 6,942,061 shares of the Issuer’s Common Stock outstanding.

2.

CUSIP No. 28249U 10 5 13D

1.	Name of Reporting Persons InterWest Management Partners X, LLC
2.	Check the Appropriate Box if a Member of a Group (see instructions) (a)  ¨        (b)  x(1)
3.	SEC USE ONLY
4.	Source of Funds (see instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Item 2(d) or 2(e) ¨
6.	Citizenship or Place of Organization California, United States of America
Number of Shares Beneficially Owned by Each Reporting Person With		7.	Sole Voting Power 1,599,593 shares of Common Stock (2)
		8.	Shared Voting Power 0
		9.	Sole Dispositive Power 1,599,593 shares of Common Stock (2)
		10.	Shared Dispositive Power 0
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,599,593 shares of Common Stock (2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (see instructions) ¨
13.	Percent of Class Represented by Amount in Row 11 23.0% (3)
14.	Type of Reporting Person (see instructions) OO

(1) This Schedule 13D is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2) The shares are owned by InterWest X. IMP X serves as the general partner of InterWest X. Gianos, Holmes, Kliman, Oronsky and Cleveland are Managing Directors of IMP X, and Nasr and Desai are Venture Members of IMP X and share voting and dispositive power over the shares held by InterWest X, and may be deemed to own beneficially the shares held by InterWest X.

(3) This percentage set forth on the cover sheets is calculated based on 6,942,061 shares of the Issuer’s Common Stock outstanding.

3.

CUSIP No. 28249U 10 5 13D

1.	Name of Reporting Persons Bruce A. Cleveland
2.	Check the Appropriate Box if a Member of a Group (see instructions) (a)  ¨        (b)  x(1)
3.	SEC USE ONLY
4.	Source of Funds (see instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Item 2(d) or 2(e) ¨
6.	Citizenship or Place of Organization United States of America
Number of Shares Beneficially Owned by Each Reporting Person With		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,599,593 shares of Common Stock (2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,599,593 shares of Common Stock (2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,599,593 shares of Common Stock (2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (see instructions) ¨
13.	Percent of Class Represented by Amount in Row 11 23.0% (3)
14.	Type of Reporting Person (see instructions) IN

(1) This Schedule 13D is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2) The shares are owned by InterWest X. IMP X serves as the general partner of InterWest X. Gianos, Holmes, Kliman, Oronsky and Cleveland are Managing Directors of IMP X, and Nasr and Desai are Venture Members of IMP X and share voting and dispositive power over the shares held by InterWest X, and may be deemed to own beneficially the shares held by InterWest X.

(3) This percentage set forth on the cover sheets is calculated based on 6,942,061 shares of the Issuer’s Common Stock outstanding.

4.

CUSIP No. 28249U 10 5 13D

1.	Name of Reporting Persons Philip T. Gianos
2.	Check the Appropriate Box if a Member of a Group (see instructions) (a)  ¨        (b)  x(1)
3.	SEC USE ONLY
4.	Source of Funds (see instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Item 2(d) or 2(e) ¨
6.	Citizenship or Place of Organization United States of America
Number of Shares Beneficially Owned by Each Reporting Person With		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,599,593 shares of Common Stock (2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,599,593 shares of Common Stock (2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,599,593 shares of Common Stock (2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (see instructions) ¨
13.	Percent of Class Represented by Amount in Row 11 23.0% (3)
14.	Type of Reporting Person (see instructions) IN

(1) This Schedule 13D is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2) The shares are owned by InterWest X. IMP X serves as the general partner of InterWest X. Gianos, Holmes, Kliman, Oronsky and Cleveland are Managing Directors of IMP X, and Nasr and Desai are Venture Members of IMP X and share voting and dispositive power over the shares held by InterWest X, and may be deemed to own beneficially the shares held by InterWest X.

(3) This percentage set forth on the cover sheets is calculated based on 6,942,061 shares of the Issuer’s Common Stock outstanding.

5.

CUSIP No. 28249U 10 5 13D

1.	Name of Reporting Persons W. Stephen Holmes III
2.	Check the Appropriate Box if a Member of a Group (see instructions) (a)  ¨        (b)  x(1)
3.	SEC USE ONLY
4.	Source of Funds (see instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Item 2(d) or 2(e) ¨
6.	Citizenship or Place of Organization United States of America
Number of Shares Beneficially Owned by Each Reporting Person With		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,599,593 shares of Common Stock (2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,599,593 shares of Common Stock (2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,599,593 shares of Common Stock (2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (see instructions) ¨
13.	Percent of Class Represented by Amount in Row 11 23.0% (3)
14.	Type of Reporting Person (see instructions) IN

(1) This Schedule 13D is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2) The shares are owned by InterWest X. IMP X serves as the general partner of InterWest X. Gianos, Holmes, Kliman, Oronsky and Cleveland are Managing Directors of IMP X, and Nasr and Desai are Venture Members of IMP X and share voting and dispositive power over the shares held by InterWest X, and may be deemed to own beneficially the shares held by InterWest X.

(3) This percentage set forth on the cover sheets is calculated based on 6,942,061 shares of the Issuer’s Common Stock outstanding.

6.

CUSIP No. 28249U 10 5 13D

1.	Name of Reporting Persons Gilbert H. Kliman
2.	Check the Appropriate Box if a Member of a Group (see instructions) (a)  ¨        (b)  x(1)
3.	SEC USE ONLY
4.	Source of Funds (see instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Item 2(d) or 2(e) ¨
6.	Citizenship or Place of Organization United States of America
Number of Shares Beneficially Owned by Each Reporting Person With		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,599,593 shares of Common Stock (2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,599,593 shares of Common Stock (2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,599,593 shares of Common Stock (2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (see instructions) ¨
13.	Percent of Class Represented by Amount in Row 11 23.0% (3)
14.	Type of Reporting Person (see instructions) IN

(1) This Schedule 13D is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2) The shares are owned by InterWest X. IMP X serves as the general partner of InterWest X. Gianos, Holmes, Kliman, Oronsky and Cleveland are Managing Directors of IMP X, and Nasr and Desai are Venture Members of IMP X and share voting and dispositive power over the shares held by InterWest X, and may be deemed to own beneficially the shares held by InterWest X.

(3) This percentage set forth on the cover sheets is calculated based on 6,942,061 shares of the Issuer’s Common Stock outstanding.

7.

CUSIP No. 28249U 10 5 13D

1.	Name of Reporting Persons Khaled A. Nasr
2.	Check the Appropriate Box if a Member of a Group (see instructions) (a)  ¨        (b)  x(1)
3.	SEC USE ONLY
4.	Source of Funds (see instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Item 2(d) or 2(e) ¨
6.	Citizenship or Place of Organization United States of America
Number of Shares Beneficially Owned by Each Reporting Person With		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,599,593 shares of Common Stock (2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,599,593 shares of Common Stock (2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,599,593 shares of Common Stock (2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (see instructions) ¨
13.	Percent of Class Represented by Amount in Row 11 23.0% (3)
14.	Type of Reporting Person (see instructions) IN

(1) This Schedule 13D is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2) The shares are owned by InterWest X. IMP X serves as the general partner of InterWest X. Gianos, Holmes, Kliman, Oronsky and Cleveland are Managing Directors of IMP X, and Nasr and Desai are Venture Members of IMP X and share voting and dispositive power over the shares held by InterWest X, and may be deemed to own beneficially the shares held by InterWest X.

(3) This percentage set forth on the cover sheets is calculated based on 6,942,061 shares of the Issuer’s Common Stock outstanding.

8.

CUSIP No. 28249U 10 5 13D

1.	Name of Reporting Persons Arnold L. Oronsky
2.	Check the Appropriate Box if a Member of a Group (see instructions) (a)  ¨        (b)  x(1)
3.	SEC USE ONLY
4.	Source of Funds (see instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Item 2(d) or 2(e) ¨
6.	Citizenship or Place of Organization United States of America
Number of Shares Beneficially Owned by Each Reporting Person With		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,599,593 shares of Common Stock (2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,599,593 shares of Common Stock (2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,599,593 shares of Common Stock (2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (see instructions) ¨
13.	Percent of Class Represented by Amount in Row 11 23.0% (3)
14.	Type of Reporting Person (see instructions) IN

(1) This Schedule 13D is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2) The shares are owned by InterWest X. IMP X serves as the general partner of InterWest X. Gianos, Holmes, Kliman, Oronsky and Cleveland are Managing Directors of IMP X, and Nasr and Desai are Venture Members of IMP X and share voting and dispositive power over the shares held by InterWest X, and may be deemed to own beneficially the shares held by InterWest X.

(3) This percentage set forth on the cover sheets is calculated based on 6,942,061 shares of the Issuer’s Common Stock outstanding.

9.

CUSIP No. 28249U 10 5 13D

1.	Name of Reporting Persons Keval Desai
2.	Check the Appropriate Box if a Member of a Group (see instructions) (a)  ¨        (b)  x(1)
3.	SEC USE ONLY
4.	Source of Funds (see instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Item 2(d) or 2(e) ¨
6.	Citizenship or Place of Organization United States of America
Number of Shares Beneficially Owned by Each Reporting Person With		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,599,593 shares of Common Stock (2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,599,593 shares of Common Stock (2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,599,593 shares of Common Stock (2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (see instructions) ¨
13.	Percent of Class Represented by Amount in Row 11 23.0% (3)
14.	Type of Reporting Person (see instructions) IN

(1) This Schedule 13D is filed by the Reporting Persons. The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2) The shares are owned by InterWest X. IMP X serves as the general partner of InterWest X. Gianos, Holmes, Kliman, Oronsky and Cleveland are Managing Directors of IMP X, and Nasr and Desai are Venture Members of IMP X and share voting and dispositive power over the shares held by InterWest X, and may be deemed to own beneficially the shares held by InterWest X.

(3) This percentage set forth on the cover sheets is calculated based on 6,942,061 shares of the Issuer’s Common Stock outstanding.

10.

Explanatory Note

The following constitutes the Schedule 13D filed by the undersigned (the “Schedule 13D”). This Schedule 13D is being filed by the Reporting Persons (as defined below) to report the acquisition of shares of Common Stock (as defined below) of the Issuer (as defined below) on April 14, 2015 as described in Item 3 below.

Item 1. Security and Issuer

a) This statement on Schedule 13D relates to the common stock, par value $0.0001 per share (“Common Stock”) of Eiger BioPharmaceuticals, Inc., a Delaware corporation (the “Issuer”).

b) The principal executive offices of the Issuer are located at 350 Cambridge Ave., Suite 350, Palo Alto, CA 94306.

Item 2. Identity and Background

a) The persons and entities filing this statement are InterWest Partners X, L.P. (“InterWest X”), InterWest Management Partners X, LLC (“IMP X,” together with InterWest X, the “InterWest Entities”), Philip T. Gianos (“Gianos”), W. Stephen Holmes III (“Holmes”), Gilbert H. Kliman (“Kliman”), Arnold L. Oronsky (“Oronsky”), Bruce A. Cleveland (“Cleveland”), Khaled A. Nasr (“Nasr”) and Keval Desai (“Desai”). Together with the InterWest Entities, Gianos, Holmes, Kliman, Oronsky, Cleveland, Nasr and Desai are herein collectively referred to as the “Reporting Persons”).

b) The address of the principal place of business of each of the Reporting Persons is 2710 Sand Hill Road, Suite 200, Menlo Park, California 94025.

c) The principal business of each of the Reporting Persons is the venture capital investment business.

d) During the last five years, none of the Reporting Persons nor the Listed Persons (as defined below) has been convicted in any criminal proceeding (excluding traffic violations or similar misdemeanors).

e) During the last five years, none of the Reporting Persons nor the Listed Persons has been 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) The Listed Persons are United States citizens; InterWest X is a California limited partnership and IMP X is a California limited liability company.

In accordance with the provisions of General Instruction C to Schedule 13D, information concerning the managers and each other person controlling IMP X (the “Listed Persons”) required by Item 2 of Schedule 13D is listed on Schedule 1 hereto and is incorporated by reference herein.

Item 3. Source and Amount of Funds or Other Consideration

On March 22, 2016, the Issuer merged into Celladon Corporation and Celladon Corporation changed its name to Eiger BioPharmaceuticals, Inc. (the “Merger”). InterWest X was an investor in Eiger BioPharmaceuticals, Inc. and effective at the closing, all of those interests converted into equity interests of the Issuer

The funds used by InterWest X to acquire the securities described herein were obtained from capital contributions by their partners and from direct capital commitments by the InterWest Entities.

Item 4. Purpose of Transaction

InterWest X was a stockholder of Eiger BioPharmaceuticals, Inc. when it was a private company and received securities in the Issuer upon the closing of the Merger.

Subject to applicable legal requirements, one or more of the Reporting Persons may purchase additional securities of the Issuer from time to time in open market or private transactions, depending on their evaluation of the Issuer’s business, prospects and financial condition, the market for the Issuer’s securities, other developments concerning the Issuer, the reaction of the Issuer to the Reporting Persons’ ownership of the Issuer’s securities, other opportunities available to the Reporting Persons, and general economic, money market and stock market conditions. In addition, depending upon the factors referred to above, the Reporting Persons may dispose of all or a portion of their securities of the Issuer at any time. Each of the Reporting Persons reserves the right to increase or decrease its holdings on such terms and at such times as each may decide.

11.

Other than as described above in this Item 4, none of the Reporting Persons have any plan or proposal relating to or that would result in: (a) the acquisition by any person of additional securities of the Issuer or the disposition of securities of the Issuer; (b) an extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Issuer or any of its subsidiaries; (c) a sale or transfer of a material amount of assets of the Issuer or any of its subsidiaries; (d) any change in the present Board of Directors or management of the Issuer, including any plans or proposals to change the number or terms of directors or to fill any existing vacancies on the Board of Directors of the Issuer; (e) any material change in the present capitalization or dividend policy of the Issuer; (f) any other material change in the Issuer’s business or corporate structure; (g) any changes in the Issuer’s charter, by-laws or instruments corresponding thereto or other actions which may impede the acquisition of control of the Issuer by any person; (h) a class of securities of the Issuer being delisted from a national securities exchange or ceasing to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association; (i) a class of equity securities of the Issuer becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Act; or (j) any action similar to those enumerated above.

Nina Kjellson, a former Managing Director of InterWest X, serves on the Issuer’s Board of Directors.

Item 5. Interest in Securities of the Issuer

The following information with respect to the ownership of the Common Stock of the Issuer by the Reporting Persons filing this Statement on Schedule 13D is provided as of the date of this filing:

Reporting Persons	Shares Held Directly (1)		Sole Voting Power (1)		Shared Voting Power (1)		Sole Dispositive Power (1)		Shared Dispositive Power (1)		Beneficial Ownership (1)		Percentage of Class (1, 3)
InterWest X		1,599,593		1,599,593		0		1,599,593		0		1,599,593		23.0	%
IMP X (2)		0		1,599,593		0		1,599,593		0		1,599,593		23.0	%
Cleveland (2)		0		0		1,599,593		0		1,599,593		1,599,593		23.0	%
Gianos (2)		0		0		1,599,593		0		1,599,593		1,599,593		23.0	%
Holmes (2)		0		0		1,599,593		0		1,599,593		1,599,593		23.0	%
Kliman (2)		0		0		1,599,593		0		1,599,593		1,599,593		23.0	%
Nasr (2)		0		0		1,599,593		0		1,599,593		1,599,593		23.0	%
Oronsky (2)		0		0		1,599,593		0		1,599,593		1,599,593		23.0	%
Desai (2)		0		0		1,599,593		0		1,599,593		1,599,593		23.0	%

(1) Represents the number of shares of Common Stock currently underlying all Securities held by the Reporting Persons.

(2) The shares are owned by InterWest X. IMP X serves as the general partner of InterWest X and has sole power to direct the voting and disposition of shares held by InterWest X. Gianos, Holmes, Kliman, Oronsky and Cleveland are Managing Directors of IMP X, and Nasr and Desai are Venture Members of IMP X and share voting and dispositive power over the shares held by InterWest X, and may be deemed to own beneficially the shares held by InterWest X. Gianos, Holmes, Kliman, Oronsky, Cleveland, Ehrlich, Nasr and Desai own no securities of the Issuer directly as of the date of this filing.

(3) This percentage set forth on the cover sheets is calculated based on 6,942,061 shares of the Issuer’s Common Stock outstanding.

The information provided in Item 3 is hereby incorporated by reference.

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

Item 7. Material to Be Filed as Exhibits

A. Agreement regarding filing of joint Schedule 13D

12.

SIGNATURES

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: April 1, 2016

INTERWEST PARTNERS X, L.P.
By:	InterWest Management Partners X, LLC
Its:	General Partner
By:	/s/ Arnold L. Oronsky
	W. STEPHEN HOLMES III
	Managing Director
INTERWEST MANAGEMENT PARTNERS X, LLC
By:	/s/ Arnold L. Oronsky
	W. STEPHEN HOLMES III
	Managing Director

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for Bruce A. Cleveland

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for Philip T. Gianos

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for W. Stephen Holmes III

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for Gilbert H. Kliman

/s/ Arnold L. Oronsky

Arnold L. Oronsky

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for Khaled A. Nasr

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for Keval Desai

The original statement shall be signed by each person on whose behalf the statement is filed or his authorized representative. If the statement is signed on behalf of a person by his authorized representative (other than an executive officer or general partner of the filing person), evidence of the representative’s authority to sign on behalf of such person shall be filed with the statement: provided, however, that a power of attorney for this purpose which is already on file with the Commission may be incorporated by reference. The name and any title of each person who signs the statement shall be typed or printed beneath his signature.

Attention: Intentional misstatements or omissions of fact

constitute Federal criminal violations (See 18 U.S.C. 1001)

13.

SCHEDULE I

Managers:

Bruce A. Cleveland

c/o InterWest Partners

2710 Sand Hill Road, Suite 200

Menlo Park, California 94025

Principal Occupation: Managing Director of IMP X, which serves as the general partner of InterWest X

Citizenship: United States of America

Philip T. Gianos

c/o InterWest Partners

2710 Sand Hill Road, Suite 200

Menlo Park, California 94025

Principal Occupation: Managing Director of IMP X, which serves as the general partner of InterWest X

Citizenship: United States of America

W. Stephen Holmes III

c/o InterWest Partners

2710 Sand Hill Road, Suite 200

Menlo Park, California 94025

Principal Occupation: Managing Director of IMP X, which serves as the general partner of InterWest X

Citizenship: United States of America

Gilbert H. Kliman

c/o InterWest Partners

2710 Sand Hill Road, Suite 200

Menlo Park, California 94025

Principal Occupation: Managing Director of IMP X, which serves as the general partner of InterWest X

Citizenship: United States of America

Arnold L. Oronsky

c/o InterWest Partners

2710 Sand Hill Road, Suite 200

Menlo Park, California 94025

Principal Occupation: Managing Director of IMP X, which serves as the general partner of InterWest X

Citizenship: United States of America

Venture Members:

Khaled A. Nasr

c/o InterWest Partners

2710 Sand Hill Road, Suite 200

Menlo Park, California 94025

Principal Occupation: Venture Member of IMP X, which serves as the general partner of InterWest X

Citizenship: United States of America

Keval Desai

c/o InterWest Partners

2710 Sand Hill Road, Suite 200

Menlo Park, California 94025

Principal Occupation: Venture Member of IMP X, which serves as the general partner of InterWest X

Citizenship: United States of America

14.

EXHIBIT INDEX

A. Agreement regarding filing of joint Schedule 13D

15.

EX-99.A

Exhibit A

JOINT FILING STATEMENT

I, the undersigned, hereby express my agreement that the attached Schedule 13D (and any amendments thereto) relating to the Common Stock of Eiger BioPharmaceuticals, Inc. is filed on behalf of each of the undersigned.

Date:	April 1, 2016
INTERWEST PARTNERS X, L.P.
By:	InterWest Management Partners X, LLC
Its:	General Partner
By:	/s/ Arnold L. Oronsky
	W. STEPHEN HOLMES III
	Managing Director
INTERWEST MANAGEMENT PARTNERS X, LLC
By:	/s/ Arnold L. Oronsky
	W. STEPHEN HOLMES III
	Managing Director

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for Bruce A. Cleveland

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for Philip T. Gianos

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for W. Stephen Holmes III

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for Gilbert H. Kliman

/s/ Arnold L. Oronsky

Arnold L. Oronsky

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for Khaled A. Nasr

/s/ Karen A. Wilson

Karen A. Wilson, Attorney-in-Fact for Keval Desai

16.