Form 4: Xilio Therapeutics CFO Reports Stock Transactions

Xilio Therapeutics' Chief Financial Officer, Christopher James Frankenfield, reported the exercise of restricted stock units, a 'sell to cover' transaction for tax obligations, and the grant of new stock options.

Summary

• Chief Financial Officer Christopher James Frankenfield reported several transactions involving Xilio Therapeutics, Inc. common stock and derivative securities.
• Acquired 19,375 shares of Common Stock on January 1, 2026, resulting from the conversion of Restricted Stock Units (RSUs).
• Disposed of 7,030 shares of Common Stock on January 2, 2026, at a price of $0.6432 per share.
• The disposal was a 'sell to cover' transaction executed automatically under a Rule 10b5-1 trading plan adopted on April 8, 2024, solely to satisfy tax withholding obligations related to RSU vesting.
• Acquired 668,789 stock options on December 31, 2025, with an exercise price of $0.841.
• These options were granted under the Xilio Therapeutics, Inc. 2025 Stock Incentive Plan, which was approved by stockholders on November 21, 2025.
• A portion of these options (Tranche 3 Options) met performance criteria on December 31, 2025, linked to the exercise or cancellation of Series B Warrants due to the receipt of Non-Dilutive Capital.
• The stock options will vest in three equal annual installments over a three-year period beginning on December 31, 2025, subject to continued service.
• Following these reported transactions, the CFO beneficially owns 24,766 shares of Common Stock directly, 668,789 stock options directly, and 38,750 Restricted Stock Units directly.

Sentiment

Score: 6

Explanation: The filing details routine executive compensation events, including RSU vesting, a tax-related stock sale, and a new option grant. These are generally neutral to slightly positive as they reflect ongoing compensation and incentive alignment, but do not indicate significant new operational or financial developments.

Positives

• The Chief Financial Officer received a significant grant of 668,789 stock options, aligning executive incentives with company performance.
• The vesting of Restricted Stock Units (RSUs) indicates the achievement of compensation milestones for the executive.

Negatives

• The 'sell to cover' transaction resulted in a reduction of the CFO's direct common stock holdings by 7,030 shares, although this was for tax obligations and not a discretionary sale.

Future Outlook

The newly granted stock options will vest in three equal annual installments over a three-year period beginning December 31, 2025, contingent on the CFO's continued service. Remaining Restricted Stock Units will continue to vest in annual installments.

Management Comments

• The 'sell to cover' transaction was executed automatically under a Rule 10b5-1 trading plan adopted on April 8, 2024, specifically to cover tax withholding obligations from RSU vesting.

Industry Context

NA

Corporate Governance

Stakeholder Impact

• Shareholders: The executive compensation structure, including equity grants, aims to align the Chief Financial Officer's interests with long-term shareholder value creation.
• Employees: The adoption of the 2025 Stock Incentive Plan provides a framework for future equity grants, potentially benefiting other employees and enhancing retention.

Next Steps

• Future vesting of 668,789 stock options in three equal annual installments over a three-year period beginning December 31, 2025.
• Continued vesting of the remaining 38,750 Restricted Stock Units in annual installments.

Key Dates

Recommendation

The filing details routine insider transactions related to executive compensation, including RSU vesting, a 'sell to cover' for tax purposes, and a new stock option grant. These events are expected and do not provide new fundamental information that would alter an investment thesis for Xilio Therapeutics. Therefore, a 'hold' recommendation is appropriate as the filing does not present a compelling reason to buy or sell based solely on these disclosures.

Keywords

Xilio Therapeutics, XLO, Form 4, Insider Transaction, Stock Options, Restricted Stock Units, RSU, Sell to Cover, Executive Compensation, Christopher James Frankenfield, 10b5-1 Plan