Exhibit 10.1

AMENDMENT TO

SEPARATION, TRANSITION, AND RELEASE OF CLAIMS AGREEMENT

This Amendment (“Amendment”) is made by and between Oliver S. Fetzer, Ph.D
(“Fetzer”) and Cerulean Pharma Inc. (“Cerulean” or the “Company”) (together, the
“Parties”). Any capitalized term used but not otherwise defined herein shall
have the meaning assigned to it in the Agreement (as defined below).

WHEREAS, Fetzer and the Company entered into that certain Separation, Transition
and Release of Claims Agreement as of October 29, 2014 (“Agreement”); and

WHEREAS, the Parties wish to amend the Agreement to extend the Consulting Period
(as defined below).

NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which is hereby acknowledged, the Parties hereby agree as follows:

1. Section 2 of the Agreement is deleted in its entirety and replaced with the
following:

“2. Post-Employment Consulting and Assistance. In order to assist the Company in
making a smooth transition to new leadership, the Employee agrees that, until
September 30, 2015 (the “Consulting Period”), he shall make himself reasonably
available by telephone or e-mail from time to time, upon reasonable notice and
on an as-needed basis, to consult with the Company and to provide any reasonable
information and/or guidance that the Company may request concerning his former
duties and responsibilities and/or his knowledge of the Company’s business and
operations (the “Post-Employment Assistance”). The Employee acknowledges and
agrees that the consideration set forth in this Agreement is being provided, in
part, as consideration for this Post-Employment Assistance, and that he will not
be entitled to receive any additional compensation or benefits for such
assistance.

2. Except as set forth herein, no term or condition of the Agreement shall be
affected by this Amendment. This Amendment may be executed in any number of
counterparts, each of which when so executed and delivered shall be taken to be
an original, but all of which together shall constitute one and the same
document. Facsimile and PDF signatures shall be deemed to be of equal force and
effect as originals.

3. This Amendment shall be governed by the laws of the Commonwealth of
Massachusetts without regard to conflict of laws provisions. The Parties hereby
irrevocably submit to and acknowledge and recognize the jurisdiction of the
courts of the Commonwealth of Massachusetts, or, if appropriate, a federal court
located in the Commonwealth of Massachusetts (which courts, for purposes of this
Amendment, are the only courts of competent jurisdiction), over any suit, action
or other proceeding arising out of, under or in connection with this Amendment
or the subject matter hereof.

[Signature page follows]

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IN WITNESS WHEREOF, the Parties, intending to be legally bound, have executed
this Amendment on the date(s) indicated below.

 

CERULEAN PHARMA INC.       By:  

/s/ Christopher D. T. Guiffre

    March 2, 2015   Christopher D. T. Guiffre       Chief Operating Officer    
  I HEREBY AGREE TO THE TERMS AND CONDITIONS SET FORTH ABOVE.

/s/ Oliver S. Fetzer, Ph.D

      March 3, 2015    

Oliver S. Fetzer, Ph.D