Activatable cytokine constructs and combination methods

A method of treating a subject having a cancer comprising administering a combination of an activatable cytokine construct (ACC) and a PD-1/PD-L1 pathway inhibitor to the subject, wherein the ACC comprises a first monomer construct and a second monomer construct, wherein:

• (a) the first monomer construct is a polypeptide comprising a first peptide mask (PM1), a first mature cytokine protein (CP1), a first and a third cleavable moieties (CM1 and CM3), and a first dimerization domain (DD1);
• (b) the second monomer construct is a polypeptide comprising a second peptide mask (PM2), a second mature cytokine protein (CP2), a second and a fourth cleavable moieties (CM2 and CM4), and a second dimerization domain (DD2);
• (c) the first monomer construct comprises, in an N- to C-terminal direction, the PM1, the CM3, the CP1, the CM1, and the DD1;
• (d) the second monomer construct comprises, in an N- to C-terminal direction, the PM2, the CM4, the CP2, the CM2, and the DD2;
• and
• (e) each of the CP1 and the CP2 is an interferon alpha and the ACC is characterized by having a by at least a 1000-fold reduction in interferon alpha activity as compared to wildtype interferon alpha or a corresponding pegylated interferon;
• (f) the DD1 and the DD2 are covalently linked to each other via disulfide bonds;
• (g) each of the CP1 and the CP2 is an interferon alpha-2b and wherein the ACC exhibits lower toxicity in vivo compared to either wildtype interferon alpha-2b or PEGylated interferon alpha-2b;
• (h) the first monomer construct comprises a linking region comprising no more than 12 amino acids between a C-terminus of the CP1 and the amino acid residue that is N-terminally adjacent to a proximal point of interaction between the DD1 and the DD2;
• (i) the second monomer construct comprises a linking region comprising no more than 12 amino acids between a C-terminus of the CP2 and the amino acid residue that is N-terminally adjacent to the proximal point of interaction between the DD1 and the DD2;
• (j) each of the PM1 and the PM2 is not a receptor for the CP1 and the CP2;
• and
• (k) each of the PM1 and the PM2 is not a fragment of a receptor for the CP1 and the CP2.

A method of treating a subject having a cancer comprising sequentially administering an activatable cytokine construct (ACC) and a PD-1/PD-L1 pathway inhibitor to the subject, wherein the ACC comprises a first monomer construct comprising an amino acid sequence that is at least 95% identical to SEQ ID NO:

• 290 and a second monomer construct comprising an amino acid sequence that is at least 95% identical to SEQ ID NO:
• 290,
• wherein the first monomer construct and the second monomer construct are covalently bound to each other via two or more disulfide bonds,
• wherein the ACC is characterized by having a by at least a 1000-fold reduction in interferon alpha activity as compared to wildtype interferon alpha or a corresponding pegylated interferon,
• wherein the ACC exhibits lower toxicity in vivo compared to either wildtype interferon alpha-2b or PEGylated interferon alpha-2b, and
• wherein the PD-1/PD-L1 pathway inhibitor is selected from the group consisting of nivolumab, pembrolizumab, tislelizumab, spartalizumab, camrelizumab, cetrelimab, cemiplimab, Balstilimab, Dostarlimab, Prolgolimab, Sasanlimab, zimberelimab, Atezolizumab, Avelumab, Durvalumab, adebrelimab, Lodapolimab, Envafolimab, Cosibelimab, budigalimab, ezabenlimab, finotonlimab, geptanolimab, lodapolimab, penpulimab, pimivalimab, pucotenlimab, serplulimab, Sintilimab, toripalimab, zeluvalimab, iparomlimab, nofazinlimab, rulonilimab, garivulimab, manelimab, opucolimab, pacmilimab (CX-072), sudubrilimab, sugemalimab, socazolimab, and tagitanlimab.