POWER OF ATTORNEY
AUTHORIZATION

I hereby authorize Joseph W. Turgeon, Kurt A. Gustafson and Thomas Riga,
acting singly, to sign and file on my behalf any and all forms required
by the Securities and Exchange Commission pursuant to Section 16 of the
Securities Exchange Act of 1934 (the "Exchange Act") relating to the
reporting of beneficial ownership of equity securities of Spectrum
Pharmaceuticals, Inc., a Delaware corporation (the "Company"), and
of changes in such beneficial ownership, together with any and all
amendments thereto.  This authorization shall be effective on and
after the date set forth below and shall continue in effect until
I am no longer required to file such forms, unless earlier revoked
by me in writing.

I acknowledge that the persons authorized hereunder are not assuming,
nor is the Company assuming, any of my responsibilities to comply
with Section 16 of the Exchange Act.

Dated as of this 1st day of June, 2018.

    /s/ Keith M. McGahan
     Keith M. McGahan