XBIT · XBiotech Inc.

On March 17, 2025 (the Grant Date) John Simard was granted nonstatutory stock options under the Company's 2015 Equity Incentive Plan to purchase shares of the Company's Common Stock at an exercise price equal to the closing price of the Company's common stock, as reported by the Nasdaq Stock Market, on the Grant Date. The options vested immediately on the Grant Date.

On January 31, 2025, the Convertible Loan Agreement (the "Loan") dated as of January 3, 2024 between XBiotech Inc. and John Simard, the Company's Founder, President, Chief Executive Officer, and Chairman, was terminated upon full repayment of the Loan by the Company. As a result, all conversion rights to XBiotech stock associated with the Loan were extinguished.

On January 3, 2024, XBiotech Inc. ("XBiotech" or the "Company") entered into a Convertible Loan Agreement (the "Loan") with John Simard, the Company's Founder, President, Chief Executive Officer and Chairman. The Loan provides $10 million in immediate funding for the construction of a new, state-of-the-art research and development facility at 5217 Winnebago Lane in Austin, Texas. The Loan is secured by the real estate and cash holdings of the Company, with interest to accrue at a simple rate equal to eight percent per year and interest-only payments to be made at six - month intervals after the Loan is funded. At Mr. Simard's election, the balance may be converted to XBiotech stock at any time the Loan balance is outstanding at a fixed conversion price equal to the average Nasdaq Official Closing Price of the common stock (as reflected on Nasdaq.com) for the five trading days immediately preceding the signing of this Agreement, which is $4.048 per share. Continued in Remarks.

As of the filing date of this Form 4, Mr. Simard could obtain up to 2,470,355 XBiotech common or preferred shares by converting the full $10,000,000 Loan balance at the conversion price of $4.048 per share. The total number of shares exercisable under the Loan could fluctuate based on Mr. Simard' cumulative stock ownership and the total number of XBiotech shares outstanding.

This figure is derived by adding the 2,470,355 shares that Mr. Simard could obtain by converting the Loan balance as of the filing date of this Form 4 to the 1,370,381 stock options Mr. Simard holds as previously disclosed in XBiotech's April 28, 2023 Schedule 14A. As stated in footnote 2 above, the total number of shares exercisable under the Loan could fluctuate based on Mr. Simard' cumulative stock ownership and the total number of XBiotech shares outstanding.

On February 10, 2023 (the Grant Date) the reporting person was granted stock options (the Options) under the Company's 2015 Equity Incentive Plan to purchase shares of the Company's Common Stock (the Shares) at an exercise price equal to the closing sales price of the Shares on the Grant Date as quoted by the Nasdaq Stock Market. The Options vest in four equal portions in two years commencing as of August 10, 2023, with an expiry of ten years from the Grant Date.

Represents a "net exercise" of outstanding stock options. The reporting person received 36,507 shares of common stock on net exercise of option to purchase 250,000 shares of common stock. The Company withheld 213,493 shares of common stock underlying the option for payment of the exercise price using the closing stock price on December 16, 2021 of $11.71, pursuant to the terms of the 2005 Equity Incentive Plan.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions. The reporting person undertakes to provide to XBIT, any security holder of XBIT, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.