# EDGAR Filing Document

**Accession Number:** 0001707502
**File Stem:** 0001193125-23-074426
**Filing Date:** 2023-3
**Character Count:** 11544
**Document Hash:** d8b0964fdca55dbf56a2a32f661cb77d
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-23-074426.hdr.sgml**: 20230320

**ACCESSION NUMBER**: 0001193125-23-074426

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 14

**CONFORMED PERIOD OF REPORT**: 20230319

**ITEM INFORMATION**: Regulation FD Disclosure

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20230320

**DATE AS OF CHANGE**: 20230320

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Solid Biosciences Inc.
- **CENTRAL INDEX KEY:** 0001707502
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **IRS NUMBER:** 900943402
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-38360
- **FILM NUMBER:** 23744945

**BUSINESS ADDRESS:**
- **STREET 1:** 500 RUTHERFORD AVENUE
- **STREET 2:** 3RD FLOOR
- **CITY:** CHARLESTOWN
- **STATE:** MA
- **ZIP:** 02129
- **BUSINESS PHONE:** 617-337-4680

**MAIL ADDRESS:**
- **STREET 1:** 500 RUTHERFORD AVENUE
- **STREET 2:** 3RD FLOOR
- **CITY:** CHARLESTOWN
- **STATE:** MA
- **ZIP:** 02129

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Solid Biosciences, LLC
- **DATE OF NAME CHANGE:** 20170524

?xml version="1.0" encoding="utf-8" ? 8-K

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### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### WASHINGTON, D.C. 20549

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### FORM 8-K

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#### CURRENT REPORT

#### Pursuant to Section 13 or 15(d)

#### of the Securities Exchange Act of 1934

#### Date of Report (Date of earliest event reported): March 19, 2023

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## Solid Biosciences Inc.

#### (Exact Name of Registrant as Specified in its Charter)

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| | | |
|:---|:---|:---|
| **Delaware** | **001-38360** | **90-0943402** |
| **(State or Other Jurisdiction**<br> **of Incorporation)** | **(Commission**<br> **File Number)** | **(IRS Employer**<br> **Identification No.)** |

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#### 500 Rutherford Avenue, Third Floor

#### Charlestown, Massachusetts 02129

#### (Address of Principal Executive Offices) (Zip Code)

#### Registrant's telephone number, including area code: (617) 337-4680

#### (Former Name or Former Address, if Changed Since Last Report)

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Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (*see* General Instruction A.2. below):

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

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| | | |
|:---|:---|:---|
| **Title of each class** | **Trading**<br> **Symbol** | **Name of each exchange**<br> **on which registered** |
| Common Stock $0.001 par value per share | SLDB | The Nasdaq Global Select Market |

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Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☒

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| | |
|:---|:---|
| **Item 7.01.** | **Regulation FD Disclosure.**  |

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On March 19, 2023, Solid Biosciences Inc. (the "Company") presented one-year post-treatment data relating to safety, efficacy and microdystrophin expression in muscle biopsies for patients enrolled in the Company's IGNITE DMD Phase I/II dose-ascending clinical trial evaluating SGT-001 in a poster presentation at the Muscular Dystrophy Association Clinical and Scientific Conference. Other than the required ongoing observation of patients in IGNITE DMD and the completion of already in process preclinical experiments, the SGT-001 program has concluded.

A copy of the Company's poster presentation is attached as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

The information provided under Item 7.01 of this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

By providing the information in Item 7.01 of this Current Report on Form 8-K (including Exhibit 99.1), the Company is not making an admission as to the materiality of any information herein. The information contained in this Current Report on Form 8-K is intended to be considered in the context of more complete information included in the Company's filings with the SEC and other public announcements that the Company has made and may make from time to time by press release or otherwise. The Company undertakes no duty or obligation to update or revise the information contained in this Current Report on Form 8-K, although it may do so from time to time as its management believes is appropriate. Any such updating may be made through the filing of other reports or documents with the SEC, through press releases or through other public disclosures.

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| | |
|:---|:---|
| **Item 9.01.** | **Financial Statements and Exhibits.**  |

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(d) Exhibits

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| | |
|:---|:---|
| **Exhibit**<br> **Number** | **Description** |
| 99.1 | [Solid Biosciences Inc. Poster Presentation March 19, 2023](d487716dex991.htm) |
| 104 | Cover Page Interactive Data File (formatted as Inline XBRL) |

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#### SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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| | | |
|:---|:---|:---|
|  | SOLID BIOSCIENCES INC. | SOLID BIOSCIENCES INC. |
| Date: March 20, 2023 | By: | /s/ Alexander Cumbo |
|  | Name: | Alexander Cumbo |
|  | Title: | Chief Executive Officer |

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## Exhibit 99.1

**Exhibit 99.1**![LOGO](g487716g11a66.jpg)

Exhibit 99.1 SOLID BIO SCIENCES IGNITE DMD Phase I/II Study of SGT-001 Microdystrophin Gene Therapy for Duchenne Muscular Dystrophy Roxana Donisa Dreghici1, J. Patrick Gonzalez1, Kristy J. Brown1, Carl A. Morris1, Perry Shieh2, Barry Byrne3 1 Solid Biosciences, Charlestown, MA; 2University of California at Los Angeles, Los Angeles, CA; 3University of Florida, Gainesville, FL Duchenne Muscular Dystrophy Duchenne muscular dystrophy (DMD) is a fatal neuromuscular disease caused by mutations in the DMD gene that lead to the absence of functional dystrophin protein SGT-001 Capsid Promoter Transgene Skeletal and cardiac muscle tropism High skeletal and cardiac muscle expression Retains critical elements of full-length dystrophin including the nNOS binding domain AAV9 CK8 nNOS Microdystrophin nNOS Binding Domain Action Binding Domain Dystroglycan Binding Domain NH3 Hinge 1 R1 R16 R17 R23 R24 Hinge 4 COOH nNOS: neuronal nitric oxide synthase SGT-001 is an AAV microdystrophin gene transfer therapy evaluated for the safety, tolerability and efficacy in adolescents and children with DMD. SGT-001 was designed to deliver a unique, rationally designed dystrophin surrogate to replace absent protein in skeletal and cardiac muscles throughout the body Methods IGNITE DMD Phase I/II clinical trial to assess the safety and efficacy of SGT-001 (NCT03368742) Cohorts n=3 control subjects analyzed n=3 subjects at 5E13 vg/kg (Patients 1-3) n=6 subjects at 2E14 vg/kg (Patients 4-9) Safety Assessments Incidence of adverse events Biopsy Assessments Microdystrophin expression in muscle biopsies (2E14 vg/kg cohort) Clinical Assessments NSAA, 6MWT, FVC % Predicted, FEV1 % Predicted, PODCI Results presented as mean ± standard deviation for all control and treated subjects unless otherwise noted Enrollment in the study is complete and long term follow up to 5 years post-dosing continues Results: Biopsy Analysis Microdystrophin Expression and Protein Function in 3-Month and 12-Month Muscle Biopsies† Microdystrophin â-Sarcoglycan nNOS Activity Biopsy from Pt. 5 at 18 months 3 months 12 months 18 months 24 months Biopsy Results (2E14 vg/kg Cohort) (Mean % - (Mean % - (Pt. 5) † (Pt. 4) † Pts. 4-9) Pts. 6-9) % Normal Dystrophin (Western Blot) 6.6% 7.0% 69.8% BLQ\* % Positive Fibers (Immunofluorescence) Manual Assessment 31% 22% 85% 10% Automated Assessment 40% 30% 84% 32% \*BLQ: Below the 5% limit of quantification by Western blot BLQ values assigned 0.5\*LLOQ for Mean calculations (=2.5%) †12-month biopsies for Pts. 4 and 5 collected at 24 months and 18 months, respectively, due to COVID-19. Results: 1-Year Assessments Cumulative Summary Tabulations of Safety Findings Serious Adverse All SGT-001 Related to Events (SAEs) (n=9) SGT-001 Thrombocytopenia 1/9 Yes Hepatotoxicity 1/9 Yes Systemic Inflammatory 2/9 Yes Response Syndrome Giardiasis 1/9 No Most Common Treatment-Emergent All SGT-001 Adverse Events (TEAEs) (n=9) Nausea 9/9 Vomiting 9/9 Pyrexia 8/9 Thrombocytopenia 7/9 Headache 4/9 Viral Upper Respiratory Tract Infection 4/9 Motor Function Evaluated by 6-Minute Walk Test (6MWT) and North Star Ambulatory Assessment (NSAA) 6MWT - 1-Year NSAA - 1-Year Change from Baseline (meters) Change from Baseline (units) Control SGT-001 SGT-001 5E13 vg/kg 2E14 vg/kg Control SGT-001 SGT-001 5E13 vg/kg 2E14 vg/kg 8 6 4 2 0 -2 -4 -6 -8 -10 100 75 50 25 0 -25 -50 Pulmonary Function Tests Performed by Spirometry to Evaluate Forced Vital Capacity (FVC) and Forced Expiratory Volume in 1 Second (FEV1) FVC % Predicted - 1-Year FEV1 % Predicted - 1-Year Change from Baseline (%p) Change from Baseline (%p) Control SGT-001 SGT-001 5E13 vg/kg 2E14 vg/kg Control SGT-001 SGT-001 5E13 vg/kg 2E14 vg/kg 40 30 20 10 0 -10 -20 40 20 0 -20 Patient Reported Outcome Measures Evaluated by the Pediatric Outcomes Data Collection Instrument (PODCI) PODCI - Global Function - 1-Year Control SGT-001 SGT-001 5E13 vg/kg 2E14 vg/kg PODCI - Transfer / Basic Mobility - 1-Year Control SGT-001 SGT-001 5E13 vg/kg 2E14 vg/kg PODCI - Sports / Physical Functioning - 1-Year Control SGT-001 SGT-001 5E13 vg/kg 2E14 vg/kg 30 20 10 0 -10 -20 -30 Change from Baseline (Points) Change from Baseline (Points) Change from Baseline (Points) 20 10 0 -10 -20 40 20 0 -20 Conclusions All subjects in IGNITE DMD have reached the 1-year study time point Results show positive changes from baseline to 1-year for motor function, pulmonary function, and patient reported outcome measures Subjects continue to be monitored for safety and have not shown any new treatment-associated AEs after the first 90 days post-dosing Development of SGT-001 has concluded, with the next-generation SGT-003 program using an updated construct with novel muscle-tropic capsid currently in IND-enabling studies Additional updates on the IGNITE DMD study are expected to be provided following completion of the 5-year follow up timepoint for all subjects