# EDGAR Filing Document

**Accession Number:** 0001000264
**File Stem:** 0001193125-23-032530
**Filing Date:** 2023-2
**Character Count:** 9351
**Document Hash:** 48059d24d40806d2515d8a8844eabc83
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-23-032530.hdr.sgml**: 20230210

**ACCESSION NUMBER**: 0001193125-23-032530

**CONFORMED SUBMISSION TYPE**: SC 13G

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20230210

**DATE AS OF CHANGE**: 20230210

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Cabaletta Bio, Inc.
- **CENTRAL INDEX KEY:** 0001759138
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **IRS NUMBER:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SC 13G
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-91178
- **FILM NUMBER:** 23611730

**BUSINESS ADDRESS:**
- **STREET 1:** 2929 ARCH STREET
- **STREET 2:** SUITE 600
- **CITY:** PHILADELPHIA
- **STATE:** PA
- **ZIP:** 19104
- **BUSINESS PHONE:** (267) 759-3100

**MAIL ADDRESS:**
- **STREET 1:** 2929 ARCH STREET
- **STREET 2:** SUITE 600
- **CITY:** PHILADELPHIA
- **STATE:** PA
- **ZIP:** 19104
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ALGER ASSOCIATES INC
- **CENTRAL INDEX KEY:** 0001000264
- **IRS NUMBER:** 000000000

**FILING VALUES:**
- **FORM TYPE:** SC 13G

**BUSINESS ADDRESS:**
- **STREET 1:** 100 PEARL STREET
- **STREET 2:** 27TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10004
- **BUSINESS PHONE:** 2128068806

**MAIL ADDRESS:**
- **STREET 1:** 100 PEARL STREET
- **STREET 2:** 27TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10004

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**UNITED STATES** 

**SECURITIES AND EXCHANGE COMMISSION** 

**Washington, D.C. 20549** 

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**SCHEDULE 13G** 

**Under the Securities Exchange Act of 1934** 

**(Amendment No.)\*** 

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## CABALETTA BIO, INC.
**(Name of Issuer)** 

**Common Stock** 

**(Title of Class of Securities)** 

**12674W109** 

**(CUSIP Number)** 

**January 31, 2023** 

**(Date of Event Which Requires Filing of this Statement)** 

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

☒ Rule 13d-1(b)

☐ Rule 13d-1(c)

☐ 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 the disclosures provided in a prior cover page.

The information required in 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).

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CUSIP No. 12674W109

1. Names of Reporting Persons Alger Associates, Inc. 13-3017981

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

3. SEC Use Only

4. Citizenship or Place of Organization New York

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| | | |
|:---|:---|:---|
| &nbsp;&nbsp;&nbsp; Number of<br> Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person<br> With | &nbsp;&nbsp;&nbsp;&nbsp;5. | Sole Voting Power<br>3,478,427 |
| &nbsp;&nbsp;&nbsp; Number of<br> Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person<br> With | &nbsp;&nbsp;&nbsp;&nbsp;6. | Shared Voting Power<br>0 |
| &nbsp;&nbsp;&nbsp; Number of<br> Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person<br> With | &nbsp;&nbsp;&nbsp;&nbsp;7. | Sole Dispositive Power<br>3,478,427 |
| &nbsp;&nbsp;&nbsp; Number of<br> Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person<br> With | &nbsp;&nbsp;&nbsp;&nbsp;8. | Shared Dispositive Power<br>0 |

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9. Aggregate Amount Beneficially Owned by Each Reporting Person 3,478,427

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

11. Percent of Class Represented by Amount in Row (9) 11.9%

12. Type of
Reporting Person (See Instructions) HC

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| | | |
|:---|:---|:---|
| **Item 1.** |  |  |
|  | (a) | Name of Issuer<br> Cabaletta Bio, Inc. |
|  | (b) | Address of Issuer's Principal Executive Offices<br> 2929 Arch Street, Suite 600<br> Philadelphia, PA 19104 |
| **Item 2.** |  |  |
|  | (a) | Name of Person Filing<br> Alger Associates, Inc. |
|  | (b) | Address of Principal Business Office or, if none, Residence<br> 100 Pearl Street, 27th Floor, New York, NY 10004 |
|  | (c) | Citizenship<br> New York |
|  | (d) | Title of Class of Securities<br> Common Stock |
|  | (e) | CUSIP Number<br> 12674W109 |
| **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:** | **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:** |
|  | (a) | ☐ Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o); |
|  | (b) | ☐ Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c); |
|  | (c) | ☐ Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c); |
|  | (d) | ☐ Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8); |
|  | (e) | ☐ An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E); |
|  | (f) | ☐ An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F); |
|  | (g) | ☒ A parent holding company or control person in accordance with §240.13d-1(b)(1)(ii)(G); |
|  | (h) | ☐ A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813); |
|  | (i) | ☐ A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3); |
|  | (j) | ☐ A non-U.S. institution in accordance with § 240.13d–1(b)(1)(ii)(J); |
|  | (k) | ☐ Group, in accordance with § 240.13d–1(b)(1)(ii)(K). If filing as a non-U.S. institution in accordance with§ 240.13d–1(b)(1)(ii)(J), please specify the type of institution:<u> </u> |

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**Item 4.** **Ownership** <br>

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| | |
|:---|:---|
| Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1. | 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:<br> 3,478,427 |
| (b)  | Percent of class: |
|  | 11.9% |
| (c)  | Number of shares as to which the person has:<br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i) | Sole power to vote or to direct the vote |
|  | 3478427 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii) | Shared power to vote or to direct the vote |
|  | 0 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(iii) | Sole power to dispose or to direct the disposition of |
|  | 3478427 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(iv) | Shared power to dispose or to direct the disposition of |
|  | 0 |

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**Item 5.** **Ownership of Five Percent or Less of a Class** <br>

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 five percent of the class of securities, check the following ☐.

**Item 6.** **Ownership of More than Five Percent on Behalf of Another Person** <br>

The securities reported herein are beneficially owned by one or more open-end investment companies or other managed accounts that are investment management clients of Fred Alger Management, LLC ("FAM"), a registered investment adviser. FAM is a 100% owned subsidiary of Alger Group Holdings, LLC ("AGH"), a holding company. AGH is a 100% owned subsidiary of Alger Associates, Inc., a holding company.

**Item 7.** **Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person** <br>

See Exhibit A

**Item 8.** **Identification and Classification of Members of the Group** <br>

**Item 9.** **Notice of Dissolution of Group** <br>

**Item 10.** **Certification** <br>

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

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**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.

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| | |
|:---|:---|
| By: | Alger Associates, Inc. |
| By: | /s/ Hal Liebes |
| Name: | Hal Liebes |
| Title: | Secretary |
| Date: | February 10, 2023 |

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**Exhibit A** 

<u>Subsidiary</u> 

Alger Group Holdings, LLC\* — HC

Fred Alger Management, LLC\* — IA

\* Entity beneficially owns 5% or greater of the outstanding shares of the security class being reported on this Schedule 13G.