October 19, 2016 Mr. Matthew Plunkett CT1 BioPharma, Inc. 3103 Western Avenue Suite #600 Seattle, WA 98121 Re: Side Letter #2 on Term Sheet Timing Issues Dear Mr. Plunkett:

October 19, 2016

Xx. Xxxxxxx Xxxxxxxx
CT1 BioPharma, Inc.
0000 Xxxxxxx Xxxxxx
Xxxxx #000
Xxxxxxx, XX 00000

Re: Side Letter #2 on Term Sheet Timing Issues

Dear Xx. Xxxxxxxx:

Pursuant to Section 16.7 of the Development, Commercialization and License Agreement, dated November 14, 2013, as previously amended by that certain letter agreement re Side Letter on Term Sheet Timing Issues, dated September 19, 2016, between CTI BioPharma Corp. and Baxalta US Inc., as well as all other previous amendments (the “DCLA”), this letter, for good and valuable consideration, further amends that agreement.

The parties hereby agree that, notwithstanding anything to the contrary in the DCLA, if, as of 5:00pm Eastern Time on October 21, 2016, the parties have not reached a final signed agreement reflecting the terms contained within the nonbinding Term Sheet agreed to between the parties as of September 19, 2016, then (a) for purposes of computing any applicable termination period(s) and deadlines under Section 15.2 of the DCLA, September 13, 2016 shall be deemed the effective date of the notice of termination of the DCLA by Xxxxxxx (but for the avoidance of doubt shall not be the effective date of the termination of the DCLA) and (b) the termination notice of September 13, 2016 shall be revived.

IN WITNESS WHEREOF, the Parties have executed this Side Letter.

CTI BIOPHARMA CORP.

By: /s/ Xxxxxxx Xxxxxxxx        

Name: Xxxxxxx Xxxxxxxx        

Title: EVP, Chief Business Officer        

BAXALTA US INC. (on behalf of itself and its affiliates)

By: /s/ Xxxxxxx X. Xxxxxx        

Name: Xxxxxxx X. Xxxxxx        

Title: Head Counsel US Oncology & BioSimilars