🧾 What This Document Is

This is a DEF 14A, or "Definitive Proxy Statement." Think of it as the official invitation and agenda for Sutro Biopharma's annual shareholder meeting. It's not a report on quarterly earnings; instead, it's where the company asks its owners (the shareholders) to vote on key governance and compensation issues.

Why it exists: Public companies are required by the SEC to give shareholders this detailed information before a vote, ensuring transparency.

What to expect: The main event is the 2026 Annual Meeting of Shareholders, to be held virtually on June 5, 2026, at 8:00 AM Pacific Time. The core of the document explains three proposals for your vote.

👉 Key Takeaway: This document is your guide to understanding what you're voting on and why each item is important for the company's direction.

🏢 What The Company Does

In simple terms, Sutro Biopharma is a biotechnology company focused on developing new cancer-fighting drugs.

They use a unique "cell-free" protein synthesis platform (basically, making complex proteins without living cells) to create targeted therapies called antibody-drug conjugates (ADCs). These are designed to act like guided missiles to deliver potent drugs directly to cancer cells, potentially reducing side effects.

Their work is early-stage and research-intensive, typical for a biotech firm. The success of their pipeline is crucial for their future value.

🔮 The Meeting & Voting Logistics

This is the "how, when, and where" of shareholder participation.

• Virtual Meeting: The meeting will be online only at www.virtualshareholdermeeting.com/STRO2026. This increases access and lowers costs.
• Record Date: Only shareholders who own stock by the close of business on April 7, 2026, are entitled to vote.
• How to Vote: You can vote online before the meeting (by 11:59 PM ET on June 4, 2026), by phone, by mail, or live during the virtual meeting. You'll need your control number (found on your proxy card) to access the meeting.
• Your Share = Your Voice: Each share of common stock owned gives you one vote. As of the record date, there are 16,567,887 shares outstanding.

👉 Key Takeaway: Your vote matters. If you don't vote, your shares won't be counted on the proposals, which could allow a small group to decide the outcomes.

🗳️ The Three Proposals to Vote On

The Board of Directors is recommending shareholders vote FOR all three proposals.

1. 👥 Electing Directors

You are voting to elect three Class II directors to the board. They will serve a three-year term.

• Nominees: Jane Chung (the CEO), Connie Matsui (the Board Chair), and James Panek.
• Why it matters: The board provides strategic oversight of the company and management. These individuals are ultimately responsible for the company's performance and governance.

2. 💼 Ratifying the Auditor

You are voting to approve the selection of Ernst & Young LLP as the company's independent accounting firm for 2026.

• Why it matters: This is a standard shareholder check on the company's financial watchdog. It ensures the people auditing Sutro's financial statements are trusted and independent.

3. 💸 Advisory Vote on Executive Pay ("Say-on-Pay")

You are voting on a non-binding, advisory approval of the compensation paid to the company's top executives.

• Why it matters: This gives shareholders a direct voice on whether the pay packages (salaries, bonuses, stock awards) for the leadership team are reasonable and align with company performance. While the vote isn't legally binding, the board has committed to taking the results seriously.

🏛️ Board & Governance Structure

Good companies have strong oversight. Here’s how Sutro’s board is structured.

• Leadership Split: The roles of CEO (Jane Chung) and Board Chair (Connie Matsui) are held by two different people. This is considered good governance as it creates a balance of power—the CEO runs daily operations while the Chair leads an independent board that oversees management.
• Board Independence: The board has 9 directors total. 8 are considered independent under Nasdaq rules, meaning they have no material relationship with the company that could impair their judgment.
• Key Committees: The board has four main committees, each with independent directors:
  • Audit Committee: Oversees financial reporting and auditors. (Financial experts: Sukhi Jagpal, Heidi Hunter).
  • Compensation Committee: Sets pay for executives and directors. (Uses consultant FW Cook).
  • Nominating & Governance Committee: Finds director candidates and oversees governance policies.
  • Science & Technology Committee: Reviews R&D and platform strategy—critical for a biotech.

⚖️ Big Picture: Strengths & Risks

Based on the governance and information presented:

👍 Strengths (Signals Positive Governance):

• Strong Independent Oversight: A majority-independent board with separate Chair/CEO roles and multiple specialized committees.
• Transparent Processes: Uses an independent compensation consultant, has formal committee charters, and provides stockholder nomination procedures.
• Cybersecurity Focus: The board has a dedicated process for overseeing cybersecurity risk, which is increasingly important.

⚠️ Risks & Considerations:

• Bioscience Risk: As a development-stage biotech, the company's success hinges entirely on clinical trial results and regulatory approvals for its drug candidates. This is inherently high-risk.
• Dependence on Key Personnel: Like many biotechs, Sutro's success is likely tied to its key scientists and executives (like CEO Jane Chung).
• Cash Runway: As a research-focused company not yet selling products, it must carefully manage its cash to fund operations and trials until a drug is commercialized.

📊 Financial Context Note

While this proxy isn't a financial report, it contains important context:

• The company executed a 1-for-10 reverse stock split in December 2025. All share numbers in this document reflect that split. This is often done to increase the stock price per share.
• The Executive Compensation section details how leaders are paid, showing a mix of salary, bonuses, and equity awards (stock options/RSUs) meant to tie their rewards to long-term shareholder success.

🧠 The Analogy

Voting on these proposals is like being a teammate evaluating the team's coach, strategy, and playbook. You're not setting the day-to-day plays (that's management's job), but you are:

1. Electing your team captains (Directors) who hire and oversee the coach.
2. Ratifying the official scorekeeper (Auditor) to make sure the stats are accurate.
3. Giving feedback on the captain's and star players' contracts (Executive Pay) to ensure they're incentivized to win the championship (company success).

🧩 Final Takeaway

This proxy statement is your tool to exercise ownership rights in Sutro Biopharma. The core decision is whether to endorse the company's current leadership slate, its financial watchdog, and its executive pay philosophy. The board's recommendations are all "FOR," signaling confidence in the current path, but your vote is your voice in holding them accountable.