Multi-domain molecules

A multi-domain molecule comprising:

• (i) a first binding domain that binds to PD-1, (ii) a second binding domain that binds to CD1a, wherein:
• (a) the first binding domain comprises a CDR1, a CDR2 and a CDR3 comprising the following sequences:
• CDR1—GFTFSSYA (SEQ ID NO:
• 1), with zero, one, two or three mutations therein,
• CDR2—IASDGAST (SEQ ID NO:
• 2), with zero, one, two or three mutations therein, and
• CDR3—CARGGYLTYDRY (SEQ ID NO:
• 3), with zero, one, two or three mutations therein;
• (b) the second binding domain comprises a CDR1, a CDR2 and a CDR3 comprising the following sequences:
• CDR1—GRTFNPGDLMG (SEQ ID NO:
• 4), GRAFRPHNVMA (SEQ ID NO:
• 5), or GRTFSPSDLMG (SEQ ID NO:
• 6), with zero, one, two or three mutations therein,
• CDR2—AIKWGPTYYADSVKG (SEQ ID NO:
• 7), AARWSGIYYAESVKG (8), or AIKWGPTYYSDSVKG (SEQ ID NO:
• 9), with zero, one, two or three mutations therein, and
• CDR3—GSGTFSSNYRDFEY (SEQ ID NO:
• 10), STAQDMTLALMSDYDY (SEQ ID NO:
• 11), or GSSTFSANYRDYEY (SEQ ID NO:
• 12), with zero, one, two or three mutations therein,
• wherein the C-terminus of the first binding domain is linked to the N-terminus of the second binding domain.

A single domain antibody that binds to CD1a, comprising a CDR1, CDR2 and CDR3, comprising the following amino acid sequences:

• CDR1—GRTFNPGDLMG (SEQ ID NO:
• 4), GRAFRPHNVMA (SEQ ID NO:
• 5), or GRTFSPSDLMG (SEQ ID NO:
• 6), with zero, one, two or three mutations therein,
• CDR2—AIKWGPTYYADSVKG (SEQ ID NO:
• 7), AARWSGIYYAESVKG (8), or AIKWGPTYYSDSVKG (SEQ ID NO:
• 9), with zero, one, two or three mutations therein,
• CDR3—GSGTFSSNYRDFEY (SEQ ID NO:
• 10), STAQDMTLALMSDYDY (SEQ ID NO:
• 11), or GSSTFSANYRDYEY (SEQ ID NO:
• 12), with zero, one, two or three mutations therein.

A multi-domain molecule comprising:

• (i) a PD-1 agonist VHH, (ii) a humanized CD1a-binding VHH, and (iii) a half-life extending domain, wherein:
• (a) the PD-1 agonist VHH comprises a CDR1, a CDR2 and a CDR3 comprising the following sequences:
• CDR1—GFTFSSYA (SEQ ID NO:
• 1), with zero or one mutation therein,
• CDR2—IASDGAST (SEQ ID NO:
• 2), with zero or one mutation therein, and
• CDR3—CARGGYLTYDRYGQ (SEQ ID NO:
• 3), with zero or one mutations therein;
• (b) the humanized CD1a-binding VHH comprises a CDR1, a CDR2 and a CDR3 comprising the following sequences:
• CDR1—GRTFNPGDLMG (SEQ ID NO:
• 4), with zero or one mutation therein,
• CDR2—AIKWGPTYYADSVKG (SEQ ID NO:
• 7), with zero or one mutation therein, and
• CDR3—GSGTFSSNYRDFEY (SEQ ID NO:
• 10), with zero or one mutation therein;
• and
• (c) the half-life extending domain comprises a first IgG Fc chain (FC1) and a second IgG Fc chain (FC2), wherein the FC1 chain and FC2 chain dimerise to form an Fc domain;
• wherein the C-terminus of the PD-1 agonist VHH is linked to the N-terminus of the humanized CD1a-binding VHH by a linker comprising the following sequence:
• GGGGS (SEQ ID NO:
• 44), with zero, one, two or three mutations therein;
• and
• wherein the C-terminus of the humanized CD1a-binding VHH is linked to the N-terminus of FC1 via an IgG hinge sequence, and/or wherein the Fc domain comprises an IgG hinge sequence at the N-terminus of FC2.

A multi-domain molecule comprising:

• (i) a PD-1 agonist VHH, (ii) a humanized CD1a-binding VHH, and (iii) a half-life extending domain, wherein:
• (a) the PD-1 agonist VHH comprises a CDR1, a CDR2 and a CDR3 comprising the following sequences:
• CDR1—GFTFSSYA (SEQ ID NO:
• 1), with zero, one, two or three mutations therein,
• CDR2—IASDGAST (SEQ ID NO:
• 2), with zero, one, two or three mutations therein, and
• CDR3—CARGGYLTYDRYGQ (SEQ ID NO:
• 3), with zero, one, two or three mutations therein;
• (b) the humanized CD1a-binding VHH comprises a CDR1, a CDR2 and a CDR3 comprising the following sequences:
• CDR1—GRAFRPHNVMA (SEQ ID NO:
• 5), with zero, one, two or three mutations therein,
• CDR2—AARWSGIYYAESVKG (8), with zero, one, two or three mutations therein, and
• CDR3—STAQDMTLALMSDYDY (SEQ ID NO:
• 11), with zero, one, two or three mutations therein;
• and
• (c) the half-life extending domain comprises a first IgG Fc chain (FC1) and a second IgG Fc chain (FC2), wherein the FC1 chain and FC2 chain dimerise to form an Fc domain;
• wherein the C-terminus of the PD-1 agonist VHH is linked to the N-terminus of the humanized CD1a-binding VHH by a linker comprising the following sequence:
• GGGGS (SEQ ID NO:
• 44), with zero, one, two or three mutations therein;
• and
• wherein the C-terminus of the humanized CD1a-binding VHH is linked to the N-terminus of FC1 via an IgG hinge sequence, and/or wherein the Fc domain comprises an IgG hinge sequence at the N-terminus of FC2.

A multi-domain molecule comprising:

• (i) a PD-1 agonist VHH, (ii) a humanized CD1a-binding VHH, and (iii) a half-life extending domain, wherein:
• (a) the PD-1 agonist VHH comprises a CDR1, a CDR2 and a CDR3 comprising the following sequences:
• CDR1—GFTFSSYA (SEQ ID NO:
• 1), with zero, one, two or three mutations therein,
• CDR2—IASDGAST (SEQ ID NO:
• 2), with zero, one, two or three mutations therein, and
• CDR3—CARGGYLTYDRYGQ (SEQ ID NO:
• 3), with zero, one, two or three mutations therein;
• (b) the humanized CD1a-binding VHH comprises a CDR1, a CDR2 and a CDR3 comprising the following sequences:
• CDR1—GRTFSPSDLMG (SEQ ID NO:
• 6), with zero, one, two or three mutations therein,
• CDR2—AIKWGPTYYSDSVKG (SEQ ID NO:
• 9), with zero, one, two or three mutations therein, and
• CDR3—GSSTFSANYRDYEY (SEQ ID NO:
• 12) with zero, one, two or three mutations therein;
• and
• (c) the half-life extending domain comprises a first IgG Fc chain (FC1) and a second IgG Fc chain (FC2), wherein the FC1 chain and FC2 chain dimerise to form an Fc domain;
• wherein the C-terminus of the PD-1 agonist VHH is linked to the N-terminus of the humanized CD1a-binding VHH by a linker comprising the following sequence:
• GGGGS (SEQ ID NO:
• 44), with zero, one, two or three mutations therein;
• and
• wherein the C-terminus of the humanized CD1a-binding VHH is linked to the N-terminus of FC1 via an IgG hinge sequence, and/or wherein the Fc domain comprises an IgG hinge sequence at the N-terminus of FC2.

A method of treating an autoimmune disease in a subject, the method comprising:

• (i) determining a baseline level of soluble PD-1 (sPD-1) in a biological sample obtained from the subject (TO),
• (ii) administering to the subject a first dosage amount of a multi-domain molecule binding to PD-1 and CD1a, and
• (iii) determining a level of sPD-1 after (ii) in a biological sample obtained from the subject (T1),
• wherein if T1 is greater than or equal to T0, then a second dosage amount of the multi-domain molecule is administered, wherein the second dosage amount is the same or less than the first dosage amount, or
• wherein if the T1 is less than TO, then the second dosage amount of the multi-domain molecule is greater than the first dosage amount and/or further comprises a second autoimmune disease treatment.