AKBA · Akebia Therapeutics, Inc.

This sale represents an automatic "sell to cover" transaction to cover tax withholding obligations in connection with the vesting of restricted stock units granted on June 28, 2024. The sale was effected pursuant to durable automatic sell-to-cover instructions adopted by the reporting person on September 8, 2025.

The restricted stock units (the "RSUs") were granted by the Issuer pursuant to its 2023 Stock Incentive Plan (the "2023 Plan"), as provided by the Issuer's Fifth Amended and Restated Non-Employee Director Compensation Program (the "Program"). The RSUs will vest in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The option to purchase shares of the Issuer's common stock (the "Stock Option") was granted by the Issuer pursuant to the 2023 Plan, as provided by the Program. The Stock Option will vest and become exercisable in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The option to purchase shares of the Issuer's common stock (the "Stock Option") was granted by the Issuer pursuant to the 2023 Plan, as provided by the Program. The Stock Option will vest and become exercisable in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The restricted stock units (the "RSUs") were granted by the Issuer pursuant to its 2023 Stock Incentive Plan (the "2023 Plan"), as provided by the Issuer's Fifth Amended and Restated Non-Employee Director Compensation Program (the "Program"). The RSUs will vest in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The restricted stock units (the "RSUs") were granted by the Issuer pursuant to its 2023 Stock Incentive Plan (the "2023 Plan"), as provided by the Issuer's Fifth Amended and Restated Non-Employee Director Compensation Program (the "Program"). The RSUs will vest in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The option to purchase shares of the Issuer's common stock (the "Stock Option") was granted by the Issuer pursuant to the 2023 Plan, as provided by the Program. The Stock Option will vest and become exercisable in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The option to purchase shares of the Issuer's common stock (the "Stock Option") was granted by the Issuer pursuant to the 2023 Plan, as provided by the Program. The Stock Option will vest and become exercisable in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The restricted stock units (the "RSUs") were granted by the Issuer pursuant to its 2023 Stock Incentive Plan (the "2023 Plan"), as provided by the Issuer's Fifth Amended and Restated Non-Employee Director Compensation Program (the "Program"). The RSUs will vest in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The restricted stock units (the "RSUs") were granted by the Issuer pursuant to its 2023 Stock Incentive Plan (the "2023 Plan"), as provided by the Issuer's Fifth Amended and Restated Non-Employee Director Compensation Program (the "Program"). The RSUs will vest in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The option to purchase shares of the Issuer's common stock (the "Stock Option") was granted by the Issuer pursuant to the 2023 Plan, as provided by the Program. The Stock Option will vest and become exercisable in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The restricted stock units (the "RSUs") were granted by the Issuer pursuant to its 2023 Stock Incentive Plan (the "2023 Plan"), as provided by the Issuer's Fifth Amended and Restated Non-Employee Director Compensation Program (the "Program"). The RSUs will vest in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The option to purchase shares of the Issuer's common stock (the "Stock Option") was granted by the Issuer pursuant to the 2023 Plan, as provided by the Program. The Stock Option will vest and become exercisable in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continuous service to the Issuer through such vesting date.

The option to purchase shares of the Issuer's common stock (the "Stock Option") was granted by the Issuer pursuant to the 2023 Plan, as provided by the Fifth Amended and Restated Non-Employee Director Compensation Program. The Stock Option will vest over three years: 33 1/3 % of the options will vest on the first anniversary of the grant date and the remaining 66 2/3 % will vest ratably on the first day of each calendar quarter thereafter, subject to the Reporting Person's continued service to the Issuer.

The reporting person's purchase of Akebia Therapeutics, Inc. ("Akebia") common stock reported herein was matchable under Section 16(b) of the Securities Exchange Act of 1934, to the extent of 69,270 shares, with the reporting person's sale of 341,305 shares of Akebia common stock at a price of $1.39 per share on February 2, 2026 pursuant to an automatic sell-to-cover instruction solely to cover applicable withholding taxes in connection with the vesting of the reporting person's RSUs granted on January 31, 2023, 2024 and 2025. The reporting person has paid Akebia, upon settlement of the sale, $9,664.60 representing the full amount of the profit realized in connection with the short-swing transaction.

The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $1.23 to $1.28, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote of this Form 4.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 8, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2024.

As reported in February 2025, the Reporting Person was granted performance-based restricted stock units ("PSUs") pursuant to the Issuer's 2023 Stock Incentive Plan, as amended. Each PSU right represents a contingent right to receive one share of the Issuer's common stock. One-half of the total number of shares of common stock underlying the PSUs vests on the later of (i) the first anniversary of the grant date and (ii) the date that the Compensation Committee certifies that the average closing price of the Issuer's common stock equals or exceeds $3.50 over a 30-day trading period (the "Stock Price Hurdle 1 Performance Condition"), subject to the reporting persons continuous employment through the applicable vesting date. In July2025, the Compensation Committee certified that the Stock Price Hurdle 1 Performance Condition was met during the performance period and therefore one-half of the PSUs vested on January 31, 2026.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 17, 2023.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2024.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2025.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 8, 2025.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 17, 2023.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2023.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 8, 2025.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 8, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2025.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 9, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2025.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 9, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2024.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 8, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2024.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 17, 2023.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2023.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 8, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2025.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 8, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-half of the reporting person's performance stock units granted on January 31, 2025.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 8, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2025.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 8, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2023.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 8, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on January 31, 2024.

The restricted stock units were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. One third of the restricted stock units will vest on each of the first, second and third anniversaries of the grant date, subject to the reporting person's continued service with the Issuer on each vesting date.

The restricted stock units were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. One third of the restricted stock units will vest on each of the first, second and third anniversaries of the grant date, subject to the reporting person's continued service with the Issuer on each vesting date.

Includes 1,500 shares of the Issuer's common stock purchased on June 30, 2025 and 1,500 shares of the Issuer's common stock purchased on December 31, 2025, each under the Issuer's Amended and Restated 2014 Employee Stock Purchase Plan.

The restricted stock units were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. One third of the restricted stock units will vest on each of the first, second and third anniversaries of the grant date, subject to the reporting person's continued service with the Issuer on each vesting date.

Includes 1,500 shares of the Issuer's common stock purchased on June 30, 2025 and 1,500 shares of the Issuer's common stock purchased on December 31, 2025, each under the Issuer's Amended and Restated 2014 Employee Stock Purchase Plan.

The restricted stock units were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. One third of the restricted stock units will vest on each of the first, second and third anniversaries of the grant date, subject to the reporting person's continued service with the Issuer on each vesting date.

The options were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. The options will vest over four years: 25% of the options will vest on the first anniversary of the grant date with the remaining 75% vesting in equal quarterly installments thereafter, subject to the reporting person's continued service with the Issuer on each vesting date.

The options were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. The options will vest over four years: 25% of the options will vest on the first anniversary of the grant date with the remaining 75% vesting in equal quarterly installments thereafter, subject to the reporting person's continued service with the Issuer on each vesting date.

The options were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. The options will vest over four years: 25% of the options will vest on the first anniversary of the grant date with the remaining 75% vesting in equal quarterly installments thereafter, subject to the reporting person's continued service with the Issuer on each vesting date.

The options were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. The options will vest over four years: 25% of the options will vest on the first anniversary of the grant date with the remaining 75% vesting in equal quarterly installments thereafter, subject to the reporting person's continued service with the Issuer on each vesting date.

The options were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. The options will vest over four years: 25% of the options will vest on the first anniversary of the grant date with the remaining 75% vesting in equal quarterly installments thereafter, subject to the reporting person's continued service with the Issuer on each vesting date.

The restricted stock units were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. One third of the restricted stock units will vest on each of the first, second and third anniversaries of the grant date, subject to the reporting person's continued service with the Issuer on each vesting date.

The options were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. The options will vest over four years: 25% of the options will vest on the first anniversary of the grant date with the remaining 75% vesting in equal quarterly installments thereafter, subject to the reporting person's continued service with the Issuer on each vesting date.

The restricted stock units were granted by the Issuer pursuant to its 2023 Stock Incentive Plan, as amended. One third of the restricted stock units will vest on each of the first, second and third anniversaries of the grant date, subject to the reporting person's continued service with the Issuer on each vesting date.

Includes 159,928 shares previously held by John Butler 2019 GRAT, and 1,500 shares of the Issuer's common stock purchased on June 30, 2025 and 1,500 shares of the Issuer's common stock purchased on December 31, 2025, each under the Issuer's Amended and Restated 2014 Employee Stock Purchase Plan.

This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 21, 2024.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of one-third of the reporting person's restricted stock units granted on June 28, 2024.

The restricted stock units (the "RSUs") were granted by the Issuer pursuant to its 2023 Stock Incentive Plan (the "2023 Plan"), as provided by the Issuer's Fourth Amended and Restated Non-Employee Director Compensation Program (the "Program"). The RSUs will vest in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continued service to the Issuer.

The option to purchase shares of the Issuer's common stock (the "Stock Option") was granted by the Issuer pursuant to the 2023 Plan, as provided by the Program. The Stock Option will vest and become exercisable in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continued service to the Issuer.

The restricted stock units (the "RSUs") were granted by the Issuer pursuant to its 2023 Stock Incentive Plan (the "2023 Plan"), as provided by the Issuer's Fourth Amended and Restated Non-Employee Director Compensation Program (the "Program"). The RSUs will vest in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continued service to the Issuer.

The option to purchase shares of the Issuer's common stock (the "Stock Option") was granted by the Issuer pursuant to the 2023 Plan, as provided by the Program. The Stock Option will vest and become exercisable in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continued service to the Issuer.

The option to purchase shares of the Issuer's common stock (the "Stock Option") was granted by the Issuer pursuant to the 2023 Plan, as provided by the Program. The Stock Option will vest and become exercisable in full (100%) on the first anniversary of the grant date (or, if earlier, immediately prior to the first annual meeting of the Company's stockholders occurring after the date of grant), subject to the Reporting Person's continued service to the Issuer.