Solid Biosciences Files Prospectus Supplement for Up to $200M Share Offering

What Happened

• On August 6, 2026, Solid Biosciences Inc. announced it filed a prospectus supplement under its universal shelf registration (Form S-3, declared effective May 27, 2025) to offer and sell up to $200.0 million of its common stock pursuant to an Amended and Restated Sales Agreement with Jefferies LLC (dated March 13, 2024).
• The company previously filed a prior prospectus supplement to sell up to $85.0 million and, as of the new prospectus supplement date, had issued and sold shares for aggregate gross proceeds of approximately $85.0 million under that prior supplement. Upon filing the new prospectus supplement, Solid will not make offers or sales under the prior prospectus supplement. Wilmer Cutler Pickering Hale and Dorr LLP delivered a legal opinion related to the offering (filed as Exhibit 5.1).

Key Details

• Offering size: up to $200.0 million of common stock.
• Filing date: August 6, 2026; underlying S-3 registration declared effective May 27, 2025.
• Sales agent: Jefferies LLC under an Amended and Restated Sales Agreement dated March 13, 2024.
• Prior activity: ~ $85.0 million of aggregate gross proceeds previously sold under the prior prospectus supplement; prior supplement will no longer be used.

Why It Matters

• This filing gives Solid Biosciences the ability to raise up to $200M through at-the-market sales, providing capital flexibility for operations or development programs.
• Future sales of shares under this prospectus could dilute existing shareholders and increase the number of shares outstanding, which investors should consider.
• The 8-K is a registration/availability filing — it is not itself an offer to sell securities, and any actual sales will be made only by means of the prospectus supplement.