UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1 )*

Inozyme Pharma, Inc.

(Name of Issuer)

Common Stock, par value $0.0001 per share

(Title of Class of Securities)

45790W 108

(CUSIP Number)

Peter Haahr

Novo Holdings A/S

Tuborg Havnevej 19

Hellerup, Denmark DK-2900

+45 3527 6592

Copy to:

B. Shayne Kennedy, Esq.

Latham & Watkins LLP

650 Town Center Drive, 20^th Floor

Costa Mesa, CA 92626

Telephone: (714) 540-1235

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

September 30, 2020

(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 which is subject of this Schedule 13D, and is filing this statement because of Rule 13d-1(e), 13d-1(f) or 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 Rule 13d-7(b) for other parties to whom copies are to be sent.

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 (the “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).

2

This amendment (“Amendment No. 1”), amends the Schedule 13D originally filed with the Securities and Exchange Commission (“SEC”) on July 29, 2020 (the “Schedule”), to report and reflect that Martin Edwards, a board member of the Issuer, no longer serves as an employee of, and is no longer affiliated with, Novo Holdings A/S. All capitalized terms contained herein but not otherwise defined shall have the meanings ascribed to such terms in the Schedule.

Item 2 is amended and replaced in its entirety as follows:

The name of each director and executive officer of both Novo Holdings A/S and the Foundation is set forth on Schedule I to this Schedule 13D.

The residence or business address of each director and executive officer of both Novo Holdings A/S and the Foundation is set forth on Schedule I to this Schedule 13D.

The Foundation is a Danish self-governing and profit-making foundation, whose objectives are to provide a stable basis for commercial and research activities undertaken by the group of Novo companies and to support scientific, humanitarian and social purposes through grants.

Item 4 is amended and replaced in its entirety as follows:

The acquisitions of Issuer securities made by Novo Holdings A/S, as described in this Schedule 13D, were for investment purposes. Novo Holdings A/S intends to review its investments in the Issuer on a continuing basis and any actions Novo Holdings A/S might undertake will be dependent upon its review of numerous factors from time to time, including, but not limited to: an ongoing evaluation of the Issuer’s business, financial condition, operations and prospects; price levels of the Issuer’s securities; general market, industry and economic conditions; the relative attractiveness of alternative business and investment opportunities; and other future developments. Novo Holdings A/S may, at any time and from time to time, acquire additional securities of the Issuer, or retain or sell all or a portion of the securities of the Issuer then held, in the open market or in privately negotiated transactions. Other than as described herein, Novo Holdings A/S currently does not have any plans or proposals that relate to, or would result in, any of the matters listed in Items 4(a)–(j) of Schedule 13D, although, depending on the factors discussed herein, Novo Holdings A/S may review or reconsider or change its purpose or formulate different plans, strategies, or proposals with respect thereto at any time.

3

Item 5 is amended and replaced in its entirety as follows:

(a)    Novo Holdings A/S beneficially owns 2,569,379 shares of Common Stock (the “Novo Shares”) representing approximately 11.0% of the Issuer’s outstanding shares of Common Stock, based upon 23,364,851 shares of the Issuer’s Common Stock outstanding as of August 31, 2020, as reported in the Issuer’s 10-Q filed with the SEC on September 3, 2020.

(b)    Novo Holdings A/S is a Danish limited liability company wholly owned by the Novo Nordisk Foundation. Novo Holdings A/S, through its Board of Directors (the “Novo Board”), has the sole power to vote and dispose of the Novo Shares. The Novo Board may exercise voting and dispositive control over the Novo Shares with approval by a majority of the Novo Board. As such, no individual member of the Novo Board is deemed to hold any beneficial ownership or reportable pecuniary interest in the Novo Shares. Except as described above regarding the Novo Board, neither the Foundation nor any person listed on Schedule I has the power to direct the vote as to, or the disposition of, the Novo Shares.

(c)    Except as described herein, Novo Holdings A/S has not effected any transactions in the Issuer’s Common Stock within the past 60 days and neither the Foundation nor any person listed on Schedule I has effected any transactions in the Issuer’s Common Stock within the past 60 days.

(d)    Novo Holdings A/S does not know of any other person having the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Novo Shares.

(e)    Not applicable.

4

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.

Schedule I

Information regarding each director and executive officer of both Novo Holdings A/S and the Novo Nordisk Foundation is set forth below.