US 12,459,980 B2
IL-21 prodrugs and methods of use thereof
Yuefeng Lu, Newbury Park, CA (US); and Chunxiao Yu, Santa Barbara, CA (US)
Assigned to ASKGENE PHARMA, INC., Camarillo, CA (US)
Appl. No. 17/262,940
Filed by ASKGENE PHARMA, INC., Camarillo, CA (US)
PCT Filed Jul. 25, 2019, PCT No. PCT/US2019/043360
§ 371(c)(1), (2) Date Jan. 25, 2021,
PCT Pub. No. WO2020/023702, PCT Pub. Date Jan. 30, 2020.
Claims priority of provisional application 62/703,383, filed on Jul. 25, 2018.
Prior Publication US 2021/0163562 A1, Jun. 3, 2021
Int. Cl. C07K 14/54 (2006.01); A61K 38/00 (2006.01); A61P 35/00 (2006.01); C07K 14/715 (2006.01); C07K 16/28 (2006.01)
CPC C07K 14/54 (2013.01) [A61P 35/00 (2018.01); C07K 14/7155 (2013.01); C07K 16/2818 (2013.01); A61K 38/00 (2013.01); C07K 2319/30 (2013.01)] 25 Claims
OG exemplary drawing
 
1. A prodrug comprising a human IL-21 agonist polypeptide, a masking moiety, and a carrier moiety, wherein the human IL-21 agonist polypeptide comprises SEQ ID NO: 1, or comprise an amino acid sequence identical to SEQ ID NO: 1 but for one or more mutations selected from D18A/K, Q19K, and E109R (numbering according to SEQ ID NO: 1), the masking moiety comprises consists of an extracellular domain (ECD) of a human IL-21 receptor α or γ subunit,
the human IL-21 agonist polypeptide is fused to the carrier moiety, and
the masking moiety is fused to the human IL-21 agonist polypeptide or to the carrier moiety through a cleavable peptide linker.