# EDGAR Filing Document

**Accession Number:** 0001759138
**File Stem:** 0000000000-23-002866
**Filing Date:** 2023-3
**Character Count:** 3408
**Document Hash:** e2fe6ffb861fd0a10ffa1731ed5f88e5
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000000000-23-002866.hdr.sgml**: 20230524

**ACCESSION NUMBER**: 0000000000-23-002866

**CONFORMED SUBMISSION TYPE**: UPLOAD

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20230322

**FILED FOR**: 

**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:** UPLOAD

**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
**PUBLIC REFERENCE ACCESSION NUMBER**: 0001193125-23-072030

## Text-Extract

```

United States securities and exchange commission logo

                          March 22, 2023

       Steven Nichtberger
       President and Chief Executive Officer
       Cabaletta Bio, Inc.
       2929 Arch Street, Suite 600
       Philadelphia, Pennsylvania 19104

                                                        Re: Cabaletta Bio, Inc.
                                                            Registration
Statement on Form S-3
                                                            Filed March 16,
2023
                                                            File No. 333-270599

       Dear Steven Nichtberger:

              This is to advise you that we have not reviewed and will not
review your registration
       statement.

               Please refer to Rules 460 and 461 regarding requests for
acceleration. We remind you
       that the company and its management are responsible for the accuracy and
adequacy of their
       disclosures, notwithstanding any review, comments, action or absence of
action by the staff.

                                                        Please contact Alan
Campbell at 202-551-4224 with any questions.

                          Sincerely,

                          Division of Corporation Finance

                          Office of Life Sciences
       cc:                                              Gabriela
Morales-Rivera, Esq.

```

### Attached PDF Documents

**Attachment 1:** `filename1`

![img-0.jpeg](img-0.jpeg)

DIVISION OF
CORPORATION FINANCE

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

March 22, 2023

Steven Nichtberger
President and Chief Executive Officer
Cabaletta Bio, Inc.
2929 Arch Street, Suite 600
Philadelphia, Pennsylvania 19104

**Re: Cabaletta Bio, Inc.**
**Registration Statement on Form S-3**
**Filed March 16, 2023**
**File No. 333-270599**

Dear Steven Nichtberger:

This is to advise you that we have not reviewed and will not review your registration statement.

Please refer to Rules 460 and 461 regarding requests for acceleration. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff.

Please contact Alan Campbell at 202-551-4224 with any questions.

Sincerely,

Division of Corporation Finance
Office of Life Sciences

cc: Gabriela Morales-Rivera, Esq.