Exhibit 24

         LIMITED POWER OF ATTORNEY FOR SECTION 16 REPORTING OBLIGATIONS

                                POWER OF ATTORNEY

                Know all by these present, that the undersigned hereby
constitutes and appoints each of Jason A. Amello, John P. Butler and Nicole R.
Hadas, signing singly, as the undersigned's true and lawful attorney-in-fact to:

        (1)     execute for and on behalf of the undersigned, in the
                undersigned's capacity as an officer and/or director or
                shareholder of Akebia Therapeutics, Inc. (the "Company"), Forms
                3, 4 and 5 in accordance with Section 16(a) of the Securities
                Exchange Act of 1934, as amended (the "Act"), and the rules
                thereunder;

        (2)     do and perform any and all acts for and on behalf of the
                undersigned which may be necessary or desirable to complete and
                execute any such Form 3, 4 or 5 and timely file such form with
                the United States Securities and Exchange Commission and any
                stock exchange or similar authority; and

        (3)     take any other action of any type whatsoever in connection with
                the foregoing which, in the opinion of such attorney-in-fact,
                may be of benefit to, in the best interest of, or legally
                required by, the undersigned, it being understood that the
                documents executed by such attorney-in-fact on behalf of the
                undersigned pursuant to this Power of Attorney shall be in such
                form and shall contain such terms and conditions as such
                attorney-in-fact may approve in such attorney-in-fact's
                discretion.

                The undersigned hereby grants to each attorney-in-fact full
power and authority to do and perform any and every act and thing whatsoever
requisite, necessary or proper to be done in the exercise of any of the rights
and powers herein granted, as fully to all intents and purposes as the
undersigned might or could do if personally present, with full power of
substitution or revocation, hereby ratifying and confirming all the acts such
attorney-in-fact shall lawfully do or cause to be done by virtue of this power
of attorney and the rights and powers herein granted. The undersigned
acknowledges that each of the foregoing attorneys-in-fact, in serving in such
capacity at the request of the undersigned, is not assuming any of the
undersigned's responsibilities to comply with Section 16 of the Act.

                This Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file Forms 3, 4 and 5 with
respect to the undersigned's holdings of and transactions in securities issued
by the Company, unless earlier revoked by the undersigned in a signed writing
delivered to each of the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of March 11, 2014.

                                By:           /s/ Robert Shalwitz, M.D.
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                                Print Name:   Robert Shalwitz, M.D.
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