Exhibit 10.1
 
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June 30, 2015

Dear Mr. Rubin:

In consideration of the release of $3.5 million to MabVax Therapeutics Holdings,
Inc. (the “Company”) on June 30, 2015, in accordance with the terms of an Escrow
Deposit Agreement dated as of April 14, 2015, as amended June 22, 2015, by and
between Signature Bank, as Escrow Agent, OPKO Health, Inc., (“OPKO”) and the
Company (this “Agreement”), the Company hereby agrees that from the date hereof,
through and including June 30, 2016, OPKO shall have the right, but not an
obligation, to nominate and appoint up to two additional members to the
Company’s board of directors designated in writing by OPKO; or the Company may
nominate and OPKO shall approve in writing the person(s) so nominated by this
Agreement.  The identity of the person(s) so nominated by this Agreement shall
be approved by OPKO, subject to execution of the board candidate’s consent to
serve and candidate’s otherwise satisfying the reasonable requirements as
evaluated by the Company’s Nominating and Governance Committee and any national
securities exchange on which the shares of common stock of the Company are then
listed or intended to be listed.
 
Very truly yours,

MabVax Therapeutics Holdings, Inc.
By: /s/ J. David Hansen
Name: J. David Hansen
Title: President and CEO
 
 
 
OPKO Health, Inc.
By: /s/Steven Rubin
Name: Steven Rubin
Title: Executive VP