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NANOBODIES AGAINST SEVERE ACCUTE RESPIRATORY SYNDROME CORONAVIRUS 2
EP22382224A
EP2023055830W
WO2023170111A1
WO2023170111A1
The invention relates to a nanobody directed against the receptor binding domain (RBD) of spike protein from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), to a fusion protein comprising said nanobody, and to a heavy chain antibody comprising two heavy chains, wherein each heavy chain comprises said fusion protein. The invention also relates to a bivalent construction comprising two nanobodies, wherein said two nanobodies are linked by a peptide bond. The invention also relates to a nucleic acid encoding the said nanobody, fusion protein or bivalent construction, to a vector comprising said nucleic acid, to a host cell comprising said nucleic acid or said vector, and to a pharmaceutical composition comprising said nanobody, fusion protein, heavy chain antibody or bivalent construction. The invention also relates to the medical uses of said nanobody, fusion protein, heavy chain antibody, bivalent construction or pharmaceutical composition for use in the treatment and/or prevention of an infection caused by SARS-CoV-2, and to a method for diagnosing an infection SARS-CoV-2 in a subject comprising contacting a sample from the subject with said nanobody, fusion protein, heavy chain antibody or bivalent construction.
Accordingly, in a first aspect, the invention relates to a nanobody directed against the receptor binding domain (RBD) of spike protein from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), wherein the nanobody comprises a variable domain comprising a CDR1 comprising the amino acid sequence shown in SEQ ID NO: 10, a CDR2 comprising the amino acid sequence shown in SEQ ID NO: 11 and a CDR3 comprising the amino acid sequence shown in SEQ ID NO: 12, or functionally equivalent variants of said CDRs, wherein the functionally equivalent variants have at least 70% sequence identity to the amino acid sequences of SEQ ID NO: 10, 11 or 12 and maintain their capacity to bind to their cognate antigen when being part of the nanobody. In a second aspect, the invention relates to a fusion protein comprising the nanobody of the first aspect and the Fc region of a heavy chain. In a third aspect, the invention relates to a heavy chain antibody comprising two heavy chains, wherein each heavy chain comprises the fusion protein according to the second aspect, wherein both heavy chains are identical. In a fourth aspect, the invention relates to a fusion protein comprising two nanobodies, wherein (i) the first nanobody is the nanobody according to the first aspect and (ii) the second nanobody comprises a variable domain selected from the group consisting of: (a) a variable domain comprising a CDR1 comprising the amino acid sequence shown in SEQ ID NO: 1, a CDR2 comprising the amino acid sequence shown in SEQ ID NO: 2 and a CDR3 comprising the amino acid sequence shown in SEQ ID NO: 3, or functionally equivalent variants of said CDRs, or (b) a CDR1 comprising the amino acid sequence shown in SEQ ID NO: 4, a CDR2 comprising the amino acid sequence shown in SEQ ID NO: 5 and a CDR3 comprising the amino acid sequence shown in SEQ ID NO: 6, or functionally equivalent variants of said CDRs, or (c) a CDR1 comprising the amino acid sequence shown in SEQ ID NO: 7, a CDR2 comprising the amino acid sequence shown in SEQ ID NO: 8 and a CDR3 comprising the amino acid sequence shown in SEQ ID NO: 9, or functionally equivalent variants of said CDRs, or (d) a CDR1 comprising the amino acid sequence shown in SEQ ID NO: 13, a CDR2 comprising the amino acid sequence shown in SEQ ID NO: 14 and a CDR3 comprising the amino acid sequence shown in SEQ ID NO: 15, or functionally equivalent variants of said CDRs, or (e) a CDR1 comprising the amino acid sequence shown in SEQ ID NO: 16, a CDR2 comprising the amino acid sequence shown in SEQ ID NO: 17 and a CDR3 comprising the amino acid sequence shown in SEQ ID NO: 18, or functionally equivalent variants of said CDRs, or a CDR1 comprising the amino acid sequence shown in SEQ ID NO: 19, a CDR2 comprising the amino acid sequence shown in SEQ ID NO: 20 and a CDR3 comprising the amino acid sequence shown in SEQ ID NO: 21 , or functionally equivalent variants of said CDRs, wherein the functionally equivalent variants have at least 70% sequence identity to the amino acid sequences of SEQ ID NO: 1-9 or SEQ ID NO: 13-21 and maintain their capacity to bind to their cognate antigen when being part of the nanobody.