clarus-catabasis13d

CUSIP NO. 14875P107

13D

Page 2 of 17 Pages

1	NAMES OF REPORTING PERSONS. I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY). Clarus Lifesciences II, L.P.
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) WC
5	CHECK 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 shares
		8	SHARED VOTING POWER 2,752,488 shares
		9	SOLE DISPOSITIVE POWER 0 shares
		10	SHARED DISPOSITIVE POWER 2,752,488 shares
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,752,488 shares
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 17.99%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) PN

CUSIP NO. 14875P107

13D

Page 3 of 17 Pages

1	NAMES OF REPORTING PERSONS. I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY). Clarus Ventures II GP, L.P.
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) AF
5	CHECK 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 shares
		8	SHARED VOTING POWER 2,752,488 shares
		9	SOLE DISPOSITIVE POWER 0 shares
		10	SHARED DISPOSITIVE POWER 2,752,488 shares
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,752,488 shares
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 17.99%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) PN

CUSIP NO. 14875P107

13D

Page 4 of 17 Pages

1	NAMES OF REPORTING PERSONS. I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY). Clarus Ventures II, 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) AF
5	CHECK 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 shares
		8	SHARED VOTING POWER 2,752,488 shares
		9	SOLE DISPOSITIVE POWER 0 shares
		10	SHARED DISPOSITIVE POWER 2,752,488 shares
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,752,488 shares
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 17.99%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) OO

CUSIP NO. 14875P107

13D

Page 5 of 17 Pages

1	NAMES OF REPORTING PERSONS. I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY). Robert Liptak
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) AF
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States citizen
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0 shares
		8	SHARED VOTING POWER 2,752,488 shares
		9	SOLE DISPOSITIVE POWER 0 shares
		10	SHARED DISPOSITIVE POWER 2,752,488 shares
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,752,488 shares
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 17.99%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) IN

CUSIP NO. 14875P107

13D

Page 6 of 17 Pages

1	NAMES OF REPORTING PERSONS. I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY). Nicholas Simon
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) AF
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States citizen
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0 shares
		8	SHARED VOTING POWER 2,752,488 shares
		9	SOLE DISPOSITIVE POWER 0 shares
		10	SHARED DISPOSITIVE POWER 2,752,488 shares
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,752,488 shares
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 17.99%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) IN

CUSIP NO. 14875P107

13D

Page 7 of 17 Pages

1	NAMES OF REPORTING PERSONS. I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY). Nicholas Galakatos
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) AF
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States citizen
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0 shares
		8	SHARED VOTING POWER 2,752,488 shares
		9	SOLE DISPOSITIVE POWER 0 shares
		10	SHARED DISPOSITIVE POWER 2,752,488 shares
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,752,488 shares
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 17.99%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) IN

CUSIP NO. 14875P107

13D

Page 8 of 17 Pages

1	NAMES OF REPORTING PERSONS. I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY). Dennis Henner
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) AF
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States citizen
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0 shares
		8	SHARED VOTING POWER 2,752,488 shares
		9	SOLE DISPOSITIVE POWER 0 shares
		10	SHARED DISPOSITIVE POWER 2,752,488 shares
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,752,488 shares
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 17.99%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) IN

CUSIP NO. 14875P107

13D

Page 9 of 17 Pages

1	NAMES OF REPORTING PERSONS. I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY). Kurt Wheeler
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) AF
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States citizen
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0 shares
		8	SHARED VOTING POWER 2,752,488 shares
		9	SOLE DISPOSITIVE POWER 0 shares
		10	SHARED DISPOSITIVE POWER 2,752,488 shares
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,752,488 shares
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 17.99%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) IN

CUSIP NO. 14875P107

13D

Page 10 of 17 Pages

1	NAMES OF REPORTING PERSONS. I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY). Michael Steinmetz
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) AF
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION Federal Republic of Germany citizen
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0 shares
		8	SHARED VOTING POWER 2,752,488 shares
		9	SOLE DISPOSITIVE POWER 0 shares
		10	SHARED DISPOSITIVE POWER 2,752,488 shares
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,752,488 shares
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 17.99%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) IN

CUSIP NO. 14875P107

13D

Page 11 of 17 Pages

Schedule 13D

Item 1. Security and Issuer.

This statement relates to the Common Stock, par value $0.001 per share (the “Common Stock”), of Catabasis Pharmaceuticals, Inc. (the “Issuer”). The address of the principal executive offices of the Issuer is One Kendall Square, Building 1400E, Suite B14202, Cambridge, MA 02139.

Item 2. Identity and Background.

This statement is being filed by:

(a) Clarus Lifesciences II, L.P. (the “Fund”);

(b) Clarus Ventures II GP, L.P. (“Clarus GP”), which is the sole general partner of the Fund; and Clarus Ventures II, LLC (“Clarus GPLLC” and, together with Clarus GP, the “Control Entities”), which is the sole general partner of Clarus GP; and

(c) Robert Liptak, Nicholas Simon, Nicholas Galakatos, Dennis Henner, Kurt Wheeler and Michael Steinmetz (together, the “Managing Directors”). The Managing Directors are the directors of Clarus GPLLC.

The persons named in this Item 2 are referred to individually herein as a “Reporting Person” and collectively as the “Reporting Persons.” The Reporting Persons have entered into a Joint Filing Agreement, dated as of the date hereof, a copy of which is filed with this Schedule 13D as Exhibit 99.1 (which is incorporated herein by reference), pursuant to which the Reporting Persons have agreed to file this statement jointly in accordance with the provisions of Rule 13d-1(k) under the Act.

The address of the principal business office of the Reporting Persons is Clarus Ventures, 101 Main Street, Suite 1210, Cambridge, MA 02142.

The principal business of the Fund is to invest in and assist early-stage and/or growth-oriented businesses in healthcare and life sciences. The principal business of Clarus GP is to act as the sole general partner of the Fund. The principal business of Clarus GPLLC is to act as the sole general partner of Clarus GP. The principal business of each of the Managing Directors is to manage the Control Entities, the Fund and affiliated entities with similar businesses.

During the five years prior to the date hereof, none of the Reporting Persons has been convicted in a criminal proceeding or has been a party to a civil proceeding ending in 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.

The Fund and Clarus GP are limited partnerships organized under the laws of the State of Delaware. Clarus GPLLC is a limited liability company organized under the laws of the State of Delaware. Each of the Messrs. Liptak, Simon, Galakatos, Henner and Wheeler is a United States citizen. Mr. Steinmetz is a Federal Republic of Germany citizen.

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

The 2,752,488 shares of Common Stock owned directly by the Fund were acquired on June 30, 2015, in connection with the closing of the Issuer’s initial public offering (the “IPO”) pursuant to a registration statement on Form S-1 filed under the Securities Act of 1933, as amended (the “Registration Statement”), whereupon (i) all Series A Preferred Stock held by the Fund converted into 1,618,676 shares of Common Stock and (ii) all Series B Preferred Stock held by the Fund converted into 757,117 shares of Common Stock. In addition, in connection with the IPO, the Fund purchased 376,695 shares of Common Stock at the initial public offering price of $12.00 per share in the IPO. The Fund’s preferred shares were acquired prior to the filing of the Registration Statement using working capital proceeds. The Fund now holds a total of 2,752,488 shares of the Issuer’s Common Stock (the “Clarus Shares”).

CUSIP NO. 14875P107

13D

Page 12 of 17 Pages

The working capital of the Fund was the source of the funds for the purchase of the Clarus Shares. No part of the purchase price of the Clarus Shares was represented by funds or other consideration borrowed or otherwise obtained for the purpose of acquiring, holding, trading or voting the Clarus Shares.

Item 4. Purpose of Transaction.

The Fund acquired the Clarus Shares for investment purposes only. Depending on market conditions, its continuing evaluation of the business and prospects of the Issuer and other factors, the Fund and other Reporting Persons may dispose of or acquire additional shares of the Issuer.

None of the Reporting Persons have any present plans or proposals that relate to or would result in any change in the business, policies, management, structure or capitalization of the Issuer. The Reporting Persons reserve the right to acquire, or dispose of, additional securities of the Issuer in the ordinary course of their business, to the extent deemed advisable in light of their general investment and trading policies, market conditions or other factors. The Reporting Persons may engage in discussions from time to time with other stockholders of the Issuer regarding the acquisition by the Reporting Persons or others of shares of the Issuer’s Common Stock held by such stockholders.

The Reporting Persons may seek information from management and the Issuer’s Board of Directors, and may engage in further discussions with management, the Issuer’s Board of Directors, other stockholders of the Issuer and other relevant parties, concerning the business, operations, governance, management, strategy, capitalization and/or future plans of the Issuer, or in proposing one or more of the other actions described in subparagraphs (a) through (j) of this Item 4.

Except as set forth above, none of the Reporting Persons has any present plans which relate to or 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 term of directors or to fill any existing vacancies on the board;

(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)

Changes in the Issuer’s charter, bylaws or instruments corresponding thereto or other actions which may impede the acquisition of control of the Issuer by any person;

(h)

Causing a class of securities of the Issuer to be delisted from a national securities exchange or to cease 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 any of those enumerated above.

CUSIP NO. 14875P107

13D

Page 13 of 17 Pages

Item 5. Interest in Securities of the Issuer.

The Fund is the record owner of the Clarus Shares. As the sole general partner of the Fund, Clarus GP may be deemed to own beneficially the Clarus Shares. As the sole general partner of Clarus GP, Clarus GPLLC may be deemed to own beneficially the Clarus Shares. As members of Clarus GPLLC, each of the Managing Directors may be deemed to own beneficially the Clarus Shares.

Each Reporting Person disclaims beneficial ownership of the Clarus Shares other than those shares which such person owns of record.

The percentage of outstanding Common Stock of the Issuer which may be deemed to be beneficially owned by each Reporting Person is set forth on Line 13 of such Reporting Person’s cover sheet and was calculated based on the 15,297,794 shares of Common Stock reported to be outstanding as of November 1, 2015 on the Issuer’s Form 10-Q filed with the Securities Exchange Commission on November 12, 2015. The percentage of outstanding Common Stock of the Issuer which was deemed to be beneficially owned by each Reporting Person, as of the date of the event that triggered this filing was 18.92% based upon 14,547,796 shares of Common Stock outstanding as indicated in the Issuer’s Final Prospectus filed June 25, 2015.

(b)

Regarding the number of shares as to which such person has:

(i)

sole power to vote or to direct the vote: See line 7 of cover sheets

(ii)

shared power to vote or to direct the vote: See line 8 of cover sheets

(iii)

sole power to dispose or to direct the disposition: See line 9 of cover sheets.

(iv)

shared power to dispose or to direct the disposition: See line 10 of cover sheets

(c)

Except as set forth in Item 3 above, none of the Reporting Persons has effected any transaction in the Common Stock during the last 60 days.

(d)

No other person is known to have the right to receive or the power to direct the receipt of dividends from, or any proceeds from the sale of, securities beneficially owned by any of the Reporting Persons.

(e)

Not applicable.

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

Pursuant to Rule 13d-1(k) promulgated under the Securities Exchange Act of 1934, as amended, the Reporting Persons have entered into an agreement with respect to the joint filing of this statement, and any amendment or amendments thereto.

In connection with the IPO, the Fund and certain other persons entered into lock-up agreements (each a “Lock-up Agreement”), pursuant to which such persons agreed, subject to certain exceptions, not to directly or indirectly sell, transfer or otherwise convey any of the Issuer’s securities held by them for a period of 180-days following the date of the IPO.

CUSIP NO. 14875P107

13D

Page 14 of 17 Pages

The Reporting Persons and certain other persons are parties to an amended and restated investor rights agreement with the Issuer (the “Investor Rights Agreement”), which provides for certain registration rights. Subject to certain limitations, the Reporting Persons and other signatory stockholders have the right to request the Issuer to prepare, file and maintain up to two registration statements on Form S-1 (or Form S-3 if the Issuer is eligible and certain other conditions are met) covering the sale of such shares of Common Stock. Additionally, the Reporting Persons and other signatory stockholders have unlimited “piggyback” registration rights to include these shares of Common Stock in future registration statements that the Issuer may initiate, subject to certain conditions and limitations (including customary cut-back rights). Under the Investor Rights Agreement, the Issuer will pay all expenses relating to such registrations, including the reasonable fees of one special counsel for the participating holders.

Item 7. Material to be Filed as Exhibits.

Exhibit 99.1 – Agreement regarding filing of joint Schedule 13D.

Exhibit 99.2 – Power of Attorney regarding filings under the Act.

CUSIP NO. 14875P107

13D

Page 15 of 17 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 19, 2016

CLARUS LIFESCIENCES II, L.P.

By: Clarus Ventures II GP, L.P., its general partner

By: Clarus Ventures II, LLC, its general partner

By: /s/ Robert Liptak

Manager

CLARUS VENTURES II GP, L.P.

By: Clarus Ventures II, LLC, its general partner

By: /s/ Robert Liptak

Manager

CLARUS VENTURES II, LLC

By: /s/ Robert Liptak

Manager

Nicholas Galakatos

Dennis Henner

/s/ Robert Liptak

Robert Liptak

Nicholas Simon

Michael Steinmetz

Kurt Wheeler

*By: /s/ Robert Liptak

Robert Liptak, as Attorney-in-Fact

This Schedule 13D was executed by Robert Liptak on behalf of the individuals listed above pursuant to a Power of Attorney a copy of which is attached as Exhibit 99.2.

CUSIP NO. 14875P107

13D

Page 16 of 17 Pages

EXHIBIT 99.1

AGREEMENT

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the undersigned hereby agree that only one statement containing the information required by Schedule 13D need be filed with respect to the ownership by each of the undersigned of shares of Common Stock of Catabasis Pharmaceuticals, Inc.

Date: February 19, 2016

CLARUS LIFESCIENCES II, L.P.

By: Clarus Ventures II GP, L.P., its general partner

By: Clarus Ventures II, LLC, its general partner

By: /s/ Robert Liptak

Manager

CLARUS VENTURES II GP, L.P.

By: Clarus Ventures II, LLC, its general partner

By: /s/ Robert Liptak

Manager

CLARUS VENTURES II, LLC

By: /s/ Robert Liptak

Manager

Nicholas Galakatos

Dennis Henner

/s/ Robert Liptak

Robert Liptak

Nicholas Simon

Michael Steinmetz

Kurt Wheeler

*By: /s/ Robert Liptak

Robert Liptak, as Attorney-in-Fact

This Agreement was executed by Robert Liptak on behalf of the individuals listed above pursuant to a Power of Attorney a copy of which is attached as Exhibit 99.2.