Power of Attorney

   The undersigned, hereby constitutes and appoints Francis Sarena and David
Smith, for so long as each such person is an officer of Five Prime Therapeutics,
Inc., a Delaware corporation ("FivePrime"), Julie Shah, for so long as she is an
employee of FivePrime, and Laura Berezin, for so long as she is a partner of a
law firm representing FivePrime, the undersigned's true and lawful
attorney-in-fact, with full power of substitution and resubstitution, each with
the power to act alone for the undersigned and in the undersigned's name, place
and stead, to:

   1.	Complete and execute Forms 3, 4 and 5 under the Securities Exchange Act of
1934, as amended (the "Exchange Act"), and other forms and all amendments
thereto on the undersigned's behalf as such attorney-in-fact shall in his or her
discretion determine to be required or advisable pursuant to Section 16 of the
Exchange Act and the rules and regulations promulgated thereunder, or any
successor laws and regulations, as a consequence of the undersigned's beneficial
ownership of securities of FivePrime or changes in such beneficial ownership;
and

   2.	Do all acts necessary in order to file such forms and amendments with the
Securities and Exchange Commission, any securities exchange or national
association, FivePrime and such other persons or agencies as the
attorney-in-fact shall deem appropriate.

   The undersigned hereby ratifies and confirms all that said attorneys-in-fact
and agents shall do or cause to be done by virtue hereof. The undersigned
acknowledges that the foregoing attorneys-in-fact, in serving in such capacity
at the request of the undersigned, are not assuming, nor is FivePrime assuming,
any of the undersigned's responsibilities to comply with or liability under
Section 16 of the Exchange Act or any rules and regulations promulgated
thereunder or any successor laws and regulations.

   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 beneficial ownership of securities of FivePrime or changes in such
beneficial ownership, unless earlier revoked by the undersigned in a signed
writing delivered to FivePrime and to the foregoing attorneys-in-fact.

   The undersigned has executed this Power of Attorney as of April 13, 2020.


                                       /s/ Thomas Civik
                                       Thomas Civik