Juno Therapeutics S-1 IPO registration

Exhibit 10.12B

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions.

Amendment No. 1

to the

Exclusive License Agreement

This Amendment No. 1, dated as of August 4, 2014, is entered into between Seattle Children’s Hospital d/b/a Seattle Children’s Research Institute, a Washington non-profit corporation (“Licensor”) and Juno Therapeutics, Inc., a Delaware corporation (“Licensee”)

• Licensor and Licensee previously entered into an Exclusive License Agreement, dated as of February 13, 2014 (“Original Agreement”).

• Licensor and Licensee want to amend the Original Agreement to add patent application(s) to the Licensed Patents, all as set forth below.

Accordingly, the parties agree as follows:

1.Exhibit A. Exhibit A is hereby amended to add the following patent application(s):

[***]	[***]	[***]
[***]	[***]	[***]
[***]	[***]	[***]

2.Exhibit A Restated. Exhibit A, in full, now reads as follows:

[***]	[***]	[***]
[***]	[***]	[***]
[***]	[***]	[***]
[***]	[***]	[***]
[***]	[***]	[***]
[***]	[***]	[***]

3.Full Force and Effect. Except as modified by this Amendment No. 1, all other terms of the Original Agreement will remain in full force and effect.

Seattle Children’s Hospital d/b/a Seattle Children’s Research Institute and Juno Therapeutics, Inc., Exclusive License Agreement, Amendment 1, Page 2 of 2

JUNO THERAPEUTICS, INC.		SEATTLE CHILDREN’S HOSPITAL D/B/A SEATTLE CHILDREN’S RESEARCH INSTITUTE
By:	/s/ H. Bishop	By:	/s/ James B. Hendricks, PhD
Name:	H. Bishop	Name:	James B. Hendricks, PhD
Title:	C.E.O.	Title:	President, Seattle Children’s Research Institute

2