	US 12,441,781 B2
	Interleukin 15 fusion proteins, and compositions and therapeutic methods thereof
Yang-Xin Fu, Dallas, TX (US); Hua Peng, Beijing (CN); and Jingya Guo, Beijing (CN)
Assigned to IMMUNE TARGETING INC., Dallas, TX (US)
Appl. No. 17/051,160
Filed by IMMUNE TARGETING INC., Dallas, TX (US)
PCT Filed May 3, 2019, PCT No. PCT/US2019/030594 § 371(c)(1), (2) Date Oct. 27, 2020, PCT Pub. No. WO2019/213517, PCT Pub. Date Nov. 7, 2019.
Claims priority of application No. 201810420739.6 (CN), filed on May 4, 2018.
Prior Publication US 2024/0218047 A1, Jul. 4, 2024
Int. Cl. C07K 14/715 (2006.01); A61K 38/00 (2006.01); A61P 35/00 (2006.01); C07K 14/54 (2006.01); C12N 15/62 (2006.01)

CPC C07K 14/7155 (2013.01) [A61P 35/00 (2018.01); C07K 14/5443 (2013.01); C12N 15/62 (2013.01); A61K 38/00 (2013.01); C07K 2319/30 (2013.01)]

21 Claims

1. A fusion protein, comprising:

a first structural unit: a subunit, or a fragment thereof, of interleukin 15 receptor (IL15R);

a second structural unit: an active interleukin 15 (IL15);

a third structural unit: an antibody Fc fragment, located at the C-terminus of the fusion protein;

two first linker segments covalently linking the first, second and third structural units, wherein the second structural unit is located between the first structural unit and the third structural unit;

a fourth structural unit located at the N-terminus of the first structural unit: an extracellular domain of the IL 15 receptor subunit (RB);

a linker segment L2 covalently linking the fourth structural unit to the first structural unit,

wherein the first structural unit is covalently linked to the C-terminus of the fourth structural unit, and

wherein the linker segment L2 is capable of being recognized and hydrolyzed by a proteolytic enzyme specifically expressed in a tumor microenvironment.