	UNITED STATES
	SECURITIES AND EXCHANGE COMMISSION
	Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934
(Amendment No. 1)*

Homology Medicines, Inc.

(Name of Issuer)

Common Stock, par value $0.0001 per share

(Title of Class of Securities)

438083107

(CUSIP Number)

December 31, 2019

(Date of Event Which Requires Filing of this Statement)

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

o	Rule 13d-1(b)
o	Rule 13d-1(c)
x	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. 438083107						13G

	1.	Names of Reporting Persons I.R.S. Identification Nos. of Above Persons (Entities Only) Novartis Institutes for BioMedical Research, Inc.

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		o

	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 1,979,226

			7.		Sole Dispositive Power 0

			8.		Shared Dispositive Power 1,979,226

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,979,226

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 4.5% (1)

	12.	Type of Reporting Person (See Instructions) CO

(1) This percentage is calculated based upon 44,034,647 shares of common stock of Homology Medicines, Inc. (the “Issuer”) outstanding as of November 5, 2019, as reported in the Issuer’s quarterly report on Form 10-Q filed with the Securities and Exchange Commission (the “SEC”) on November 12, 2019.

CUSIP No. 438083107						13G

	1.	Names of Reporting Persons I.R.S. Identification Nos. of Above Persons (Entities Only) Novartis AG

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		o

	3.	SEC Use Only

	4.	Citizenship or Place of Organization Switzerland

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 0

			6.		Shared Voting Power 1,979,226

			7.		Sole Dispositive Power 0

			8.		Shared Dispositive Power 1,979,226

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,979,226

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 4.5% (1)

	12.	Type of Reporting Person (See Instructions) CO

(1) This percentage is calculated based upon 44,034,647 shares of common stock of the Issuer outstanding as of November 5, 2019, as reported in the Issuer’s quarterly report on Form 10-Q filed with the SEC on November 12, 2019.

CUSIP No. 438083107

13G

Item 1.
	(a)	Name of Issuer Homology Medicines, Inc. (the “Issuer”)
	(b)	Address of Issuer’s Principal Executive Offices 1 Patriots Park, Bedford, MA 01730

Item 2.
	(a)	Name of Person Filing This statement is filed on behalf of the following persons with respect to shares of Common Stock of the Issuer: (i) Novartis Institutes for BioMedical Research, Inc. (“NIBRI”), a Delaware corporation, with respect to shares held by it; and (ii) Novartis AG, a Switzerland corporation, as the publicly owned parent of NIBRI, with respect to the shares held by NIBRI. The foregoing persons are hereinafter referred to collectively as the “Reporting Persons.”
	(b)	Address of the Principal Office or, if none, Residence The address of the principal business office of NIBRI is 250 Massachusetts Avenue, Cambridge, MA 02139. The address of the principal business office of Novartis AG is Lichtstrasse 35, 4056 Basel, Switzerland.
	(c)	Citizenship NIBRI is a corporation organized under the laws of Delaware and is an indirect wholly-owned subsidiary of Novartis AG. Novartis AG is a corporation organized under the laws of Switzerland and is the publicly owned parent of NIBRI.
	(d)	Title of Class of Securities Common Stock, par value $0.0001 per share (“Common Stock”).
	(e)	CUSIP Number 438083107

Item 3.	If this statement is filed pursuant to §§240.13d-1(b), or 240.13d-2(b) or (c), check whether the person filing is a:
Not applicable.

CUSIP No. 438083107

13G

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: NIBRI is the record owner of 1,979,226 shares of Common Stock of the Issuer. As the indirect parent of NIBRI, Novartis AG may be deemed to beneficially own these securities.
	(b)	Percent of class: 4.5%, based upon 44,034,647 shares of the Issuer’s common stock outstanding as of November 5, 2019, as reported in the Issuer’s quarterly report on Form 10-Q filed with the Securities and Exchange Commission on November 12, 2019.
	(c)	Number of shares as to which the person has:
		(i)	Sole power to vote or to direct the vote: Not applicable
		(ii)	Shared power to vote or to direct the vote: 1,979,226
		(iii)	Sole power to dispose or to direct the disposition of: Not applicable
		(iv)	Shared power to dispose or to direct the disposition of: 1,979,226

Item 5.	Ownership of 5 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 x.

Item 6.	Ownership of More than 5 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.
Not applicable.

Item 9.	Notice of Dissolution of a Group.
Not applicable.

CUSIP No. 438083107

13G

Item 10.	Certification.
Not applicable.

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.

Dated: March 10, 2020

	NOVARTIS INSTITUTES FOR BIOMEDICAL RESEARCH, INC.

	By:	/s/ Scott A. Brown
		Scott A. Brown, VP, General Counsel

	NOVARTIS AG

	By:	/s/ Christian Rehm
		Christian Rehm, Authorized Signatory

	By:	/s/ Daniel Weiss
		Daniel Weiss, Authorized Signatory

EXHIBIT INDEX

SCHEDULE 13G

Exhibit Number		Exhibit Description
99.1		Joint Filing Agreement

Exhibit 99.1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, each of the persons named below agrees to the joint filing of a Statement on Schedule 13G (including amendments thereto) with respect to the shares of Common Stock of Homology Medicines, Inc., a Delaware corporation, and further agree that this Joint Filing Agreement shall be included as an exhibit to such joint filings.

This Joint Filing Agreement may be executed in one or more counterparts, each of which shall be deemed to be an original instrument, but all of such counterparts together shall constitute one agreement.

In evidence thereof, the undersigned, being duly authorized, hereby execute this Joint Filing Agreement as of March 10, 2020.

		NOVARTIS INSTITUTES FOR BIOMEDICAL RESEARCH, INC.

		By:	/s/ Scott A. Brown
			Scott A. Brown, VP, General Counsel

		NOVARTIS AG

		By:	/s/ Christian Rehm
			Christian Rehm, Authorized Signatory

		By:	/s/ Daniel Weiss
			Daniel Weiss, Authorized Signatory