🧾 What This Document Is

This is a PRE 14A filing, a "Preliminary Proxy Statement." Think of it as a preview of the agenda and information packet for Solid Biosciences' upcoming annual shareholder meeting. The company is giving shareholders the details they need to vote on important issues. It's "preliminary" because it's filed with the SEC for review before the final version is sent out.

Why it matters: As a shareholder, this document tells you what decisions are being put to a vote, who is running the company, how executives are paid, and asks for your approval on key plans. It's your chance to have a say.

📅 The Meeting & Voting Details

Solid Biosciences is holding its 2026 Annual Meeting of Stockholders virtually on Wednesday, June 10, 2026, at 8:00 a.m. Eastern Time.

• Who can vote? You must have been a shareholder by the close of business on the Record Date of April 16, 2026.
• How to vote? You can vote online (before or during the meeting), by phone, or by mail. The meeting itself will be hosted online at http://www.virtualshareholdermeeting.com/SLDB2026.
• Quorum Needed: For the meeting to be valid, shareholders holding a majority of the company's outstanding stock must be present (either online or by proxy).

Why it matters: The virtual format means you can participate from anywhere. However, you need your 16-digit control number (found on your proxy card) to log in and vote. Your vote counts, so use it.

🗳️ What Shareholders Are Voting On

The board of directors recommends voting "FOR" all five proposals. Here they are:

1. Proposal 1: Elect Three Directors

   • Vote to elect Clare Kahn, Adam Stone, and Lynne Sullivan as Class II directors.
   • They will serve a 3-year term until 2029 if elected.

2. Proposal 2: Ratify Ilan Ganot's Director Appointment (Advisory)

   • This is an advisory (non-binding) vote to approve the board's decision to move Ilan Ganot, a company founder, from Class III to Class I director. This means his term now runs until 2028.

3. Proposal 3: Ratify the Auditor

   • Approve the appointment of PricewaterhouseCoopers LLP (PwC) as the company's independent accounting firm for 2026.

4. Proposal 4: Increase Authorized Shares (Key Proposal)

   • Approve an amendment to the company's charter to double the number of authorized common shares from 240,000,000 to 480,000,000.

5. Proposal 5: Advisory Vote on Executive Compensation ("Say-on-Pay")

   • A non-binding vote to approve the compensation paid to the company's top executives.

Why it matters: Proposals 1, 2, and 5 are considered "non-discretionary." If your broker doesn't receive your voting instructions, they cannot vote on your behalf for these items, which could result in a "broker non-vote." Proposals 3 and 4 are typically discretionary, meaning your broker might be able to vote on them if you don't instruct them.

🏢 What The Company Does

👉 In simple terms, Solid Biosciences is a biotechnology company focused on developing treatments for Duchenne muscular dystrophy (DMD), a rare genetic muscle-wasting disease. They are working on gene therapies and other approaches. The creation of a dedicated "Clinical Committee" on their board highlights the importance of clinical development and regulatory strategy to their business.

Why it matters: As a clinical-stage biotech, the company is likely pre-revenue and consuming cash to fund research and trials. Major decisions like increasing authorized shares (Proposal 4) are often done to raise capital for these expensive activities.

🚀 Key Move: Doubling the Authorized Shares

The most significant proposal is Proposal 4: Increasing the authorized common stock from 240 million to 480 million shares. This is a 100% increase.

Why this matters: Companies typically increase authorized shares for flexibility. This could be to:

• Raise capital through future stock offerings.
• Have shares available for acquisitions or partnerships.
• Implement stock splits or reward employees. For shareholders: It can lead to dilution (your ownership percentage shrinks if new shares are issued). The board is seeking this approval now to have the flexibility for future strategic moves without needing another shareholder vote later.

👥 Board & Governance

Solid Biosciences has a classified, three-tiered board of directors, with one class up for election each year. This structure can make hostile takeovers more difficult.

• Current Structure (9 members):
  • Class I (Term ends 2028): Alexander Cumbo (CEO), Ilan Ganot (Co-Founder), Sukumar Nagendran.
  • Class II (Up for election in 2026): Clare Kahn, Adam Stone, Lynne Sullivan.
  • Class III (Term ends 2027): Martin Freed, Georgia Keresty, Ian Smith (Executive Chairman).
• Independence: All directors except the CEO, Alexander Cumbo, are considered independent.
• Key Committees: The board has four standing committees: Audit, Compensation, Nominating & Governance, and a Clinical Committee (unique to their focus).
• Leadership: The roles of Chairman (Ian Smith) and CEO (Alexander Cumbo) are separate.

Why it matters: A strong, independent board provides oversight. The specialized Clinical Committee is crucial for a biotech like Solid, ensuring expert guidance on their most critical work.

💼 Executive Compensation Snapshot

The filing details the compensation for the company's top executives. This information is provided ahead of Proposal 5, the advisory "say-on-pay" vote.

• The Compensation Committee, advised by an independent consultant (Radford), oversees executive pay.
• The committee uses data from biotech/pharma industry peers to set compensation.
• The filing includes detailed tables showing salary, bonuses, stock awards, and option awards for each named executive officer for 2025.

Why it matters: This section allows shareholders to evaluate if the leadership's pay is reasonable and aligned with company performance, especially for a company that is not yet profitable. Your vote on Proposal 5 sends a signal to the board about shareholder sentiment.

🧠 The Analogy

This proxy statement is like the agenda and background packet for a major homeowners' association (HOA) meeting. It lists the big decisions to be made (e.g., elect board members, hire a new landscaping company, vote on a special assessment to build a new pool), provides bios of the board candidates, shows how much the HOA manager is paid, and explains why they might need to amend the rules to allow for more special assessments in the future.

🧩 Final Takeaway

Solid Biosciences is asking shareholders to approve its board slate, ratify key appointments, and, most importantly, double its authorized shares—a move likely aimed at securing financial flexibility for future fundraising to support its Duchenne muscular dystrophy drug development pipeline. Your vote, especially on the share increase, directly influences the company's strategic and financial options.