RNA Avidity Biosciences Inc

FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).         
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES                                                                                   
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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940                       

1. Name and Address of Reporting Person * RTW INVESTMENTS, LP	2. Issuer Name and Ticker or Trading Symbol Avidity Biosciences, Inc. [ RNA ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                    __X__ 10% Owner _____ Officer (give title below)    _____ Other (specify below)
(Last)          (First)          (Middle) 40 10TH AVENUE, 7TH FLOOR	3. Date of Earliest Transaction (MM/DD/YYYY) 8/4/2021
(Street) NEW YORK, NY 10014 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _ X _ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	8/4/2021		P		800000	A	$18	4795000	I	By RTW (1)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series C Preferred Stock	(2)	6/11/2020		C			3995000	(2)	(2)	Common Stock	3995000	(2)	0	I	By RTW (3)

Explanation of Responses:
(1)	The above-referenced shares (the "Shares") of Avidity Biosciences, Inc. (the "Issuer") reported herein are held in the form of common stock (the "Common Stock"). The Shares are held by RTW Master Fund, Ltd. and one or more funds (together the "Funds"), managed by RTW Investments, LP (the "Adviser"). The Adviser, in its capacity as the investment manager of the Funds, has the power to vote and the power to direct the disposition of all such Shares held by the Funds. Accordingly, for the purposes of Reg. Section 240.13d-3, the Adviser may be deemed to beneficially own an aggregate of 4,795,000 Shares, or 10.5% of the Issuer's 45,600,288 Shares deemed issued and outstanding as of August 4, 2021, as disclosed in the Issuer's Prospectus Supplement to its Prospectus dated July 2, 2021, as such supplement was filed with the Securities and Exchange Commission on August 3, 2021.
(2)	The shares of Series C Preferred Stock are convertible, at any time, at the holder's election, at a ratio of one-for-2.1095 shares of the Issuer's common stock. In addition, effective immediately prior to the closing of the Issuer's initial public offering of its common stock, each share of Series C Preferred Stock will automatically convert at a ratio of one-for-2.1095 shares of the Issuer's common stock. The Series C Preferred Stock has no expiration date.
(3)	Roderick Wong, M.D., is the Managing Partner and Chief Investment Officer of the Adviser. This report shall not be deemed an admission that the Adviser, the Funds or any other person is the beneficial owner of the securities reported herein for purposes of Section 13 of the Securities Exchange Act of 1934, as amended, or for any other purpose. Each of the Reporting Persons herein disclaims beneficial ownership of the Shares reported herein except to the extent of the reporting person's pecuniary interest therein.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
RTW INVESTMENTS, LP 40 10TH AVENUE 7TH FLOOR NEW YORK, NY 10014		X
WONG RODERICK 40 10TH AVENUE 7TH FLOOR NEW YORK, NY 10014			MP and CIO

Signatures
RTW Investments, LP By: /s/ Roderick Wong		8/6/2021
**Signature of Reporting Person		Date
Roderick Wong By: /s/ Roderick Wong		8/6/2021
**Signature of Reporting Person		Date