Compositions and methods for the treatment of disorders related to syntaxin-binding protein 1 deficiency.

Claims

CLAIMS 1. An adeno-associated virus (AAV) particle, characterized in that it comprises: a) an AAV capsid variant comprising an amino acid sequence having the following formula: [N1]-[N2]-[N3], wherein: (i) optionally [N1] comprises X1, X2 and X3, wherein at least one of X1, X2 or X3 is G; (ii) [N2] comprises the amino acid sequence of SPH; and (iii) [N3] comprises X4, X5 and X6, wherein at least one of X4, X5 or X6 is a basic amino acid; and b) a viral genome comprising a syntaxin-binding protein 1 (STXBP1) coding sequence.

2. AAV particle, according to claim 1, characterized in that the amino acid sequence [N1]-[N2]-[N3] is in hypervariable loop IV of the AAV capsid variant.

3. AAV particle, according to claim 1 or 2, characterized in that an AAV capsid variant is an AAV9 capsid variant.

4. AAV particle, according to any one of claims 1 to 3, characterized in that [N1] comprises X1, X2 and X3, wherein at least one of X1, X2 or X3 is G.

5. AAV particle, according to any one of claims 1 to 4, characterized in that [N2]-[N3] comprises the amino acid sequence of SPHSKA (SEQ ID NO: 941).

6. Adeno-associated virus particle (AAV), characterized in that it comprises a viral genome comprising a syntaxin-binding protein 1 (STXBP1) coding sequence Petition 870250089501, 10 / 01 / 2025, p. 728 / 770 2 / 23 and an AAV9 capsid variant comprising the SPHSKA amino acid sequence (SEQ ID NO: 941).

7. AAV particle, according to claim 6, characterized in that the amino acid sequence of SPHSKA (SEQ ID NO: 941) is in hypervariable loop IV of the AAV9 capsid variant.

8. AAV particle, according to claim 6 or 7, characterized in that the amino acid sequence of SPHSKA (SEQ ID NO: 941) is present immediately after an amino acid position that corresponds to position 455 of SEQ ID NO: 4 or SEQ ID NO:

36.

9. AAV particle, according to any one of claims 6 to 8, characterized in that an AAV9 capsid variant further comprises one, two or all of: an N at an amino acid position corresponding to position 452, an E at an amino acid position corresponding to position 451 and / or a V at an amino acid position corresponding to position 453 of SEQ ID NO:

4.

10. AAV particle, according to any one of claims 6 to 9, characterized in that a capsid variant of AAV9 comprises the amino acid sequence KTENVSGSPHSKAQNQQT (SEQ ID NO: 3272).

11. AAV particle, according to any one of claims 6 to 10, characterized in that an AAV9 capsid variant comprises: (i) a VP1 protein comprising an amino acid sequence having at least 90% identity with SEQ ID NO: 4; (ii) a VP2 protein comprising an amino acid sequence having at least 90% identity with positions 138 to 742 of SEQ ID NO: 4; and / or (iii) a VP3 protein comprising an amino acid sequence having at least 90% identity with positions 203 to 742 of SEQ ID NO:

4.

12. AAV particle, according to any one of claims 6 to 11, characterized in that an AAV9 capsid variant comprises: (i) a VP1 protein comprising an amino acid sequence having at least 95% identity with SEQ ID NO: 4; (ii) a VP2 protein comprising an amino acid sequence having at least 95% identity with positions 138 to 742 of SEQ ID NO: 4; and / or (iii) a VP3 protein comprising an amino acid sequence having at least 95% identity with positions 203 to 742 of SEQ ID NO:

4.

13. AAV particle, according to any one of claims 6 to 12, characterized in that an AAV9 capsid variant comprises: (i) a VP1 protein comprising an amino acid sequence having at least 99% identity with SEQ ID NO: 4; (ii) a VP2 protein comprising an amino acid sequence having at least 99% identity with positions 138 to 742 of SEQ ID NO: 4; and / or (iii) a VP3 protein comprising an amino acid sequence having at least 99% identity with positions 203 to 742 of SEQ ID NO:

4.

14. AAV particle, according to any one of claims 6 to 13, characterized in that a variant of Petition 870250089501, dated 10 / 01 / 2025, p. 730 / 770 4 / 23 AAV9 capsid comprises: (i) a VP1 protein comprising the amino acid sequence from SEQ ID NO: 4; (ii) a VP2 protein comprising the amino acid sequence from positions 138 to 742 of SEQ ID NO: 4; and / or (iii) a VP3 protein comprising the amino acid sequence from positions 203 to 742 of SEQ ID NO:

4.

15. AAV particle, according to any one of claims 6 to 13, characterized in that a capsid variant of AAV9 comprises: (i) the amino acid sequence of SPHSKA (SEQ ID NO: 941), wherein the amino acid sequence is present immediately after an amino acid position corresponding to position 455 of SEQ ID NO: 4; (ii) an E at an amino acid position corresponding to position 451 and a V at an amino acid position corresponding to position 453 of SEQ ID NO: 4; and (iii) no other modification relative to wild-type AAV9.

16. AAV particle, according to any one of claims 6 to 8, characterized in that an AAV9 capsid variant further comprises one, two or all of: an E at an amino acid position corresponding to position 451, an R at an amino acid position corresponding to position 452 and / or a V at an amino acid position corresponding to position 453 of SEQ ID NO:

36.

17. AAV particle, according to any one of claims 6 to 8 and 16, characterized in that a capsid variant of AAV9 comprises the amino acid sequence KTERVSGSPHSKAQNQQT (SEQ ID NO: 3589). Petition 870250089501, dated 10 / 01 / 2025, p. 731 / 770 5 / 23 18. AAV particle, according to any one of claims 6 to 8, 16, and 17, characterized in that an AAV9 capsid variant comprises: (i) a VP1 protein comprising an amino acid sequence having at least 90% identity with SEQ ID NO: 36; (ii) a VP2 protein comprising an amino acid sequence having at least 90% identity with positions 138 to 742 of SEQ ID NO: 36; and / or (iii) a VP3 protein comprising an amino acid sequence having at least 90% identity with positions 203 to 742 of SEQ ID NO:

36.

19. AAV particle, according to any one of claims 6 to 8 and 16 to 18, characterized in that an AAV9 capsid variant comprises: (i) a VP1 protein comprising an amino acid sequence having at least 95% identity with SEQ ID NO: 36; (ii) a VP2 protein comprising an amino acid sequence having at least 95% identity with positions 138 to 742 of SEQ ID NO: 36; and / or (iii) a VP3 protein comprising an amino acid sequence having at least 95% identity with positions 203 to 742 of SEQ ID NO:

36.

20. AAV particle, according to any one of claims 6 to 8 and 16 to 19, characterized in that an AAV9 capsid variant comprises: (i) a VP1 protein comprising an amino acid sequence having at least 99% identity with SEQ ID NO: 36; Petition 870250089501, dated 10 / 01 / 2025, p. 732 / 770 6 / 23 (ii) a VP2 protein comprising an amino acid sequence having at least 99% identity with positions 138 to 742 of SEQ ID NO: 36; and / or (iii) a VP3 protein comprising an amino acid sequence having at least 99% identity with positions 203 to 742 of SEQ ID NO:

36.

21. AAV particle, according to any one of claims 6 to 8 and 16 to 20, characterized in that an AAV9 capsid variant comprises: (i) a VP1 protein comprising the amino acid sequence from SEQ ID NO: 36; (ii) a VP2 protein comprising the amino acid sequence from positions 138 to 742 of SEQ ID NO: 36; and / or (iii) a VP3 protein comprising the amino acid sequence from positions 203 to 742 of SEQ ID NO:

36.

22. AAV particle, according to any one of claims 6 to 8 and 16 to 20, characterized in that a capsid variant of AAV9 comprises: (i) the amino acid sequence SPHSKA (SEQ ID NO: 941), wherein the amino acid sequence is present immediately after an amino acid position corresponding to position 455 of SEQ ID NO: 36; (ii) an E at an amino acid position corresponding to position 451, an R at an amino acid position corresponding to position 452, and a V at an amino acid position corresponding to position 453 of SEQ ID NO: 36; and (iii) none of the other modifications relating to wild-type AAV9.

23. AAV particle, according to any one of claims 1 to 4, characterized in that [N1]-[N2]-[N3] is present immediately after a position corresponding to the position of amino acid 452 of SEQ ID NO: 982; and wherein an AAV capsid variant comprises an amino acid sequence that is at least 90% identical, for example, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identical, to the amino acid sequence of SEQ ID NO: 982, for example, for positions 203 to 742 of SEQ ID NO:

982.

24. AAV particle, according to claim 23, characterized in that [N1] comprises GHD.

25. AAV particle, according to claim 23 or 24, characterized in that [N1] comprises amino acid G at a position corresponding to position 453, amino acid H at position 454, and amino acid D at position 455 of SEQ ID NO: 138 or SEQ ID NO:

982.

26. AAV particle, according to any one of claims 23 to 25, characterized in that [N3] comprises KSG.

27. AAV particle, according to any one of claims 23 to 26, characterized in that an AAV capsid variant comprises: (i) a VP1 protein comprising the amino acid sequence of SEQ ID NO: 982 or an amino acid sequence having at least 90% identity with SEQ ID NO: 982; (ii) a VP2 protein comprising the amino acid sequence from positions 138 to 742 of SEQ ID NO: 982 or an amino acid sequence having at least 90% identity with positions 138 to 742 of SEQ ID NO: 982; or (iii) a VP3 protein comprising the sequence of Petition 870250089501, dated 10 / 01 / 2025, p. 734 / 770 8 / 23 amino acid from positions 203 to 742 of SEQ ID NO: 982 or an amino acid sequence having at least 90% identity with positions 203 to 742 of SEQ ID NO:

982.

28. AAV particle, according to any one of claims 23 to 27, characterized in that an AAV capsid variant comprises: (i) a VP1 protein comprising the amino acid sequence from SEQ ID NO: 982 or an amino acid sequence having at least 95% identity with SEQ ID NO: 982; (ii) a VP2 protein comprising the amino acid sequence from positions 138 to 742 of SEQ ID NO: 982 or an amino acid sequence having at least 95% identity with positions 138 to 742 of SEQ ID NO: 982; or (iii) a VP3 protein comprising the amino acid sequence from positions 203 to 742 of SEQ ID NO: 982 or an amino acid sequence having at least 95% identity with positions 203 to 742 of SEQ ID NO:

982.

29. AAV particle, according to any one of claims 23 to 28, characterized in that an AAV capsid variant comprises: (i) a VP1 protein comprising the amino acid sequence of SEQ ID NO: 982 or an amino acid sequence having at least 99% identity with SEQ ID NO: 982; (ii) a VP2 protein comprising the amino acid sequence of positions 138 to 742 of SEQ ID NO: 982 or an amino acid sequence having at least 99% identity with positions 138 to 742 of SEQ ID NO: 982; or (iii) a VP3 protein comprising the amino acid sequence from positions 203 to 742 of SEQ ID NO: 982 or an amino acid sequence having at least 99% identity with Petition 870250089501, dated 10 / 01 / 2025, page 735 / 770 9 / 23 positions 203 to 742 of SEQ ID NO:

982.

30. AAV particle, according to any one of claims 23 to 29, characterized in that an AAV capsid variant comprises: (i) a VP1 protein comprising the amino acid sequence from SEQ ID NO: 982; (ii) a VP2 protein comprising the amino acid sequence from positions 138 to 742 of SEQ ID NO: 982; or (iii) a VP3 protein comprising the amino acid sequence from positions 203 to 742 of SEQ ID NO:

982.

31. AAV particle, according to any one of claims 1 to 30, characterized in that the viral genome encodes a wild-type STXBP1 protein.

32. AAV particle, according to any one of claims 1 to 31, characterized in that the viral genome encodes a human STXBP1 protein.

33. AAV particle, according to claim 31 or 32, characterized in that the STXBP1 protein comprises the amino acid sequence of SEQ ID NO: 6413.

34. AAV particle, according to any one of claims 1 to 33, characterized in that the coding sequence of STXBP1 comprises a nucleotide sequence that is at least 90% identical (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identical) with SEQ ID NO: 6414.

35. AAV particle according to claim 34, characterized in that the coding sequence of STXBP1 comprises a nucleotide sequence that is at least 95% identical to SEQ ID NO: 6414. Petition 870250089501, dated 10 / 01 / 2025, pp. 736 / 770 10 / 23 36. AAV particle, according to claim 35, characterized in that the coding sequence of STXBP1 comprises a nucleotide sequence that is at least 99% identical to SEQ ID NO: 6414.

37. AAV particle, according to claim 36, characterized in that the coding sequence of STXBP1 comprises the nucleotide sequence of SEQ ID NO: 6414.

38. AAV particle, according to claim 36, characterized in that the coding sequence of STXBP1 consists of the nucleotide sequence with SEQ ID NO: 6414.

39. AAV particle, according to any one of claims 1 to 38, characterized in that the viral genome comprises a promoter operatively linked to the STXBP1 coding sequence.

40. AAV particle, according to claim 39, characterized in that the promoter is the α subunit of human elongation factor 1 (EF1a), immediate early enhancer and / or promoter of cytomegalovirus (CMV), chicken β-actin (CBA), CAG, CAG derivative, β-glucuronidase (GUSB) or ubiquitin C (UBC), neuron-specific enolase (NSE), platelet-derived growth factor (PDGF), platelet-derived growth factor B chain (PDGF-β), intercellular adhesion molecule 2 (ICAM-2), synapsin (Syn), synapsin 1 (Syn1), methyl-CpG binding protein 2 (MeCP2), Ca2+ / calmodulin-dependent protein kinase II (CaMKII), metabotropic glutamate receptor 2 (mGluR2), light or heavy neurofilament (NFL). (NFH), nβ2 minigene of β-globin, preproenkephalin (PPE), enkephalin (Enk) and excitatory amino acid transporter 2 (EAAT2), glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), a cardiovascular promoter (e.g., αMHC,cTnT and CMV-MLC2k), a hepatic promoter (e.g., hAAT, TBG), a skeletal muscle promoter (e.g., desmin, MCK, C512) or a fragment, for example, a truncation or a functional variant thereof.

41. AAV particle, according to any one of claims 1 to 40, characterized in that the viral genome still comprises an inverted terminal repeat (ITR) sequence.

42. AAV particle, according to claim 41, characterized in that the viral genome comprises an ITR sequence positioned 5' relative to the STXBP1 coding sequence.

43. AAV particle, according to claim 41 or 42, characterized in that the viral genome comprises an ITR sequence positioned 3' relative to the STXBP1 coding sequence.

44. AAV particle, according to any one of claims 41 to 43, characterized in that the viral genome comprises an ITR sequence positioned 5' relative to the STXBP1 coding sequence, and an ITR sequence positioned 3' relative to the STXBP1 coding sequence.

45. Adeno-associated virus (AAV) particle, characterized in that it comprises a viral genome comprising a syntaxin-binding protein 1 (STXBP1) coding sequence and an AAV capsid variant comprising: (i) a VP1 protein comprising the amino acid sequence from SEQ ID NO: 4; (ii) a VP2 protein comprising the amino acid sequence from positions 138 to 742 of SEQ ID NO: 4; and / or (iii) a VP3 protein comprising the amino acid sequence from positions 203 to 742 of SEQ ID NO:

4.

46. ​​Adeno-associated virus (AAV) particle, characterized Petition 870250089501, dated 10 / 01 / 2025, page 738 / 770 12 / 23 by the fact that it comprises a viral genome comprising a syntaxin-binding protein 1 (STXBP1) coding sequence and an AAV capsid variant comprising: (i) a VP1 protein comprising the amino acid sequence from SEQ ID NO: 36; (ii) a VP2 protein comprising the amino acid sequence from positions 138 to 742 of SEQ ID NO: 36; and / or (iii) a VP3 protein comprising the amino acid sequence from positions 203 to 742 of SEQ ID NO:

36.

47. Cell, characterized in that it comprises the AAV particle, as defined in any one of claims 1 to 46, optionally wherein the cell is a mammalian cell (e.g., an HEK293 cell), an insect cell (e.g., an Sf9 cell) or a bacterial cell.

48. A method for preparing the AAV particle, as defined in any one of claims 1 to 46, the method characterized in that it comprises: (i) providing a cell comprising a viral genome comprising a sequence encoding STXBP1 and a nucleic acid encoding an AAV capsid variant; and (ii) incubating the cell under suitable conditions to encapsulate the viral genome in an AAV capsid variant; thereby preparing the AAV particle.

49. Method according to claim 48, characterized in that: (a) the viral genome comprises the nucleotide sequence of SEQ ID NO: 6414 or a nucleotide sequence that is at least 90% identical (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identical) to it; and (b) an AAV capsid variant comprises: (i) a VP1 protein comprising the amino acid sequence of SEQ ID NO: 4 or an amino acid sequence having at least 90% identity (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity) with SEQ ID NO: 4;(ii) a VP2 protein comprising the amino acid sequence from positions 138 to 742 of SEQ ID NO: 4 or an amino acid sequence having at least 90% identity (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity) with positions 138 to 742 of SEQ ID NO: 4; or (iii) a VP3 protein comprising the amino acid sequence from positions 203 to 742 of SEQ ID NO: 4 or an amino acid sequence having at least 90% identity (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity) with positions 203 to 742 of SEQ ID NO: 4.; 50. Method according to claim 49, characterized in that an AAV capsid variant comprises the amino acid sequence from SEQ ID NO: 4, the amino acid sequence from positions 138 to 742 of SEQ ID NO: 4 and / or the amino acid sequence from positions 203 to 742 of SEQ ID NO:

4.

51. Method according to claim 48, characterized in that: (a) the viral genome comprises the nucleotide sequence of SEQ ID NO: 6414 or a nucleotide sequence that is at least 90% identical (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identical) to it; and (b) an AAV capsid variant comprises: (i) a VP1 protein comprising the amino acid sequence of SEQ ID NO: 36 or an amino acid sequence having at least 90% identity (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity) with SEQ ID NO: 36;(ii) a VP2 protein comprising the amino acid sequence from positions 138 to 742 of SEQ ID NO: 36 or an amino acid sequence having at least 90% identity (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity) with positions 138 to 742 of SEQ ID NO: 36; or (iii) a VP3 protein comprising the amino acid sequence from positions 203 to 742 of SEQ ID NO: 36 or an amino acid sequence having at least 90% identity (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity) with positions 203 to 742 of SEQ ID NO: 36.; 52. Method according to claim 51, characterized in that an AAV capsid variant comprises the amino acid sequence of SEQ ID NO: 36, the amino acid sequence from positions 138 to 742 of SEQ ID NO: 36 and / or the amino acid sequence from positions 203 to 742 of SEQ ID NO:

36.

53. Method according to claim 48, characterized in that: (a) the viral genome comprises a nucleotide sequence of SEQ ID NO: 6414 or a nucleotide sequence that is at least 90% identical (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identical) to the same; and (b) an AAV capsid variant comprises: (i) a VP1 protein comprising the amino acid sequence of SEQ ID NO: 982 or an amino acid sequence having at least 90% identity (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity) with SEQ ID NO: 982;(ii) a VP2 protein comprising the amino acid sequence from positions 138 to 742 of SEQ ID NO: 982 or an amino acid sequence having at least 90% identity (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity) with positions 138 to 742 of SEQ ID NO: 982; or (iii) a VP3 protein comprising the amino acid sequence from positions 203 to 742 of SEQ ID NO: 982 or an amino acid sequence having at least 90% identity (for example, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity) with positions 203 to 742 of SEQ ID NO:

982. Petition 870250089501, dated 10 / 01 / 2025, p. 742 / 770 16 / 23; 54. Method according to claim 53, characterized in that an AAV capsid variant comprises the amino acid sequence from SEQ ID NO: 982, the amino acid sequence from positions 138 to 742 of SEQ ID NO: 982 and / or the amino acid sequence from positions 203 to 742 of SEQ ID NO:

982.

55. Method, according to any one of claims 48 to 54, characterized in that it further comprises, before step (i), the introduction of a first nucleic acid molecule comprising the viral genome into the cell.

56. Method according to any one of claims 48 to 55, characterized in that the cell comprises a second nucleic acid molecule encoding an AAV capsid variant, optionally wherein the method further comprises, prior to step (i), introduction of the second nucleic acid molecule into the cell.

57. A method according to any one of claims 48 to 56, characterized in that the cell comprises a mammalian cell (for example, an HEK293 cell), an insect cell (for example, an Sf9 cell), or a bacterial cell.

58. Pharmaceutical composition, characterized in that it comprises the AAV particle, as defined in any one of claims 1 to 46, and a pharmaceutically acceptable excipient.

59. Pharmaceutical composition, characterized in that it comprises the AAV particle as defined in any one of claims 5 to 22, and a pharmaceutically acceptable excipient.

60. Pharmaceutical composition, characterized in that it comprises the AAV particle, as defined in any one of claims 9 to 15 and 45, and a pharmaceutically acceptable excipient. Petition 870250089501, dated 10 / 01 / 2025, page 743 / 770 17 / 23 61. Pharmaceutical composition, characterized in that it comprises the AAV particle, as defined in any one of claims 16 to 22 and 46, and a pharmaceutically acceptable excipient.

62. A method for delivering an AAV particle encoding an STXBP1 protein to an individual, characterized in that it comprises administering to the individual an effective amount of the pharmaceutical composition as defined in any one of claims 58 to 61 or the AAV particle as defined in any one of claims 1 to 46.

63. Method, according to claim 62, characterized in that the individual has, has been diagnosed with, or is at risk of having a disorder related to STXBP1, optionally wherein the STXBP1-related disorder is a neurodegenerative or neuromuscular disorder related to STXBP1.

64. A method according to claim 62 or 63, characterized in that the individual has, has been diagnosed with, or is at risk of having STXBP1 encephalopathy, epileptic encephalopathy, Ohtahara syndrome, developmental encephalopathy, West syndrome, early myoclonic epileptic encephalopathy, Lennox-Gaustaut syndrome, autism (e.g., autism with STXBP1 mutations and, optionally, other mutations), Dravet syndrome (not caused by mutations in SCN1A), or Rett syndrome phenotype (not caused by MECP2 or CDKL5 mutation).

65. Method for treating an individual who has or has been diagnosed with a disorder related to STXBP1, characterized in that it comprises administering to the individual an effective amount of the pharmaceutical composition as defined in any one of claims 58 to 61 or of the AAV particle as defined in any one of claims 1 to 46.

66. Method for treating an individual who has or has been diagnosed with a disorder related to STXBP1, characterized in that it comprises administering to the individual an effective amount of the pharmaceutical composition as defined in claim 59 or of the AAV particle as defined in any of claims 5 to 22.

67. Method for treating an individual who has or has been diagnosed with a disorder related to STXBP1, characterized in that it comprises administering to the individual an effective amount of the pharmaceutical composition as defined in claim 60 or of the AAV particle as defined in any one of claims 9 to 15 and 45.

68. Method for treating an individual who has or has been diagnosed with a disorder related to STXBP1, characterized in that it comprises administering to the individual an effective amount of the pharmaceutical composition as defined in claim 61 or of the AAV particle as defined in any one of claims 16 to 22 and 46.

69. Method, according to any one of claims 65 to 68, characterized in that the STXBP1-related disorder is a neurodegenerative or neuromuscular disorder related to STXBP1.

70. Method, according to claim 69, characterized in that the neurodegenerative or neuromuscular disorder related to STXBP1 is STXBP1 encephalopathy, epileptic encephalopathy, Ohtahara syndrome, developmental encephalopathy, West syndrome, early myoclonic epileptic encephalopathy, Lennox-Gaustaut syndrome, autism (e.g., autism with mutations in STXBP1 and, optionally, other mutations), Dravet syndrome (not caused by mutations in SCN1A) or Rett syndrome phenotype (not caused by mutation of MECP2 or CDKL5).

71. Method for treating an individual with STXBP1 encephalopathy or diagnosed with STXBP1 encephalopathy, characterized in that it comprises administering to the individual an effective amount of the pharmaceutical composition as defined in any one of claims 58 to 61 or of the AAV particle as defined in any one of claims 1 to 46.

72. Method for treating an individual with STXBP1 encephalopathy or diagnosed with STXBP1 encephalopathy, characterized in that it comprises administering to the individual an effective amount of the pharmaceutical composition as defined in claim 59 or of the AAV particle as defined in any of claims 5 to 22.

73. Method for treating an individual with STXBP1 encephalopathy or diagnosed with STXBP1 encephalopathy, characterized in that it comprises administering to the individual an effective amount of the pharmaceutical composition as defined in claim 60 or of the AAV particle as defined in any one of claims 9 to 15 and 45.

74. Method for treating an individual with STXBP1 encephalopathy or diagnosed with STXBP1 encephalopathy, characterized in that it comprises administering to the individual an effective amount of the pharmaceutical composition as defined in claim 61 or of the AAV particle as defined in any one of claims 16 to 22 and 46.

75. A method, according to any one of claims 62 to 74, characterized in that the individual has one or more mutations in the STXBP1 gene.

76. Method, according to any of the claims Petition 870250089501, dated 10 / 01 / 2025, pp. 746 / 770 20 / 23 62 to 75, characterized by the fact that the individual has a reduced level of STXBP1 activity compared to a reference level in an individual who does not have an STXBP1-related disorder.

77. A method, according to any one of claims 65 to 76, characterized in that the treatment results in the prevention of the progression of the disorder in the individual.

78. A method, according to any one of claims 65 to 77, characterized in that the treatment results in the improvement of at least one symptom of the disorder and / or a change in one or more biomarkers of the disorder.

79. Method according to claim 78, characterized in that one or more biomarkers comprise an STXBP1 activity or a neurofilament light chain.

80. Method according to claim 78, characterized in that at least one symptom comprises epilepsy, autistic features, ataxia, generalized tremors, dystonia, or a combination thereof.

81. A method, according to any one of claims 62 to 80, characterized in that the individual is a human.

82. A method according to any one of claims 62 to 81, characterized in that the AAV particle is delivered to a cell, tissue or region of the CNS, for example, a region of the brain or spinal cord, for example, the parenchyma, cortex, substantia nigra, cerebellum, caudate nucleus, striatum, corpus callosum, cerebellum, putamen, caudate nucleus of the brainstem, thalamus, superior colliculus, spinal cord or a combination thereof, and / or to neurons, for example, GABAergic neurons, glutamatergic neurons or a combination thereof.

83. Method, according to any of the claims Petition 870250089501, dated 10 / 01 / 2025, pp. 747 / 770 21 / 23 62 to 82, characterized in that it further comprises evaluating, for example, measuring, the expression level of STXBP1, for example, STXBP1 gene expression, STXBP1 mRNA expression and / or STXBP1 protein expression, in the individual, for example, in a cell, tissue or fluid of the individual.

84. Method, according to claim 83, characterized in that the expression level of the STXBP1 protein is measured by an ELISA, a Western blot, or an immunohistochemistry assay.

85. Method according to claim 83 or 84, characterized in that the assessment of the STXBP1 expression level is performed before and after administration of the AAV particle, optionally where the STXBP1 expression level before treatment is compared to the STXBP1 expression level after administration.

86. Method, according to any one of claims 83 to 85, characterized in that it comprises evaluating the expression level of STXBP1 in a cell or tissue of the central nervous system (e.g., parenchyma).

87. A method according to any one of claims 83 to 86, characterized in that the expression level of the STXBP1 protein in the individual subsequent to administration is increased relative to the expression level of the STXBP1 protein in the individual prior to administration.

88. Method, according to any one of claims 62 to 87, characterized in that it further comprises assessing, for example, measuring, the level of STXBP1 activity in the individual, for example, in a cell or tissue of the individual.

89. Method, according to any one of claims 62 to 88, characterized in that administration results in an increase in: (i) STXBP1 activity in a cell, tissue (e.g., a CNS cell or tissue, e.g., the cortex, striatum, thalamus, cerebellum and / or brainstem) and / or fluid (e.g., CSF and / or serum) of the individual, relative to the STXBP1 activity in the individual before administration; (ii) viral genomes (VGs) at the cellular level in a CNS tissue (e.g., cortex, striatum, thalamus, cerebellum, brainstem and / or spinal cord) of the individual, relative to the individual's VGs at the cellular level in a peripheral tissue; and / or (iii) STXBP1 mRNA expression in a cell or tissue (e.g., a CNS cell or tissue, e.g., the cortex, thalamus, and / or brainstem) of the individual, compared with STXBP1 mRNA expression in the individual prior to administration.

90. A method according to any one of claims 65 to 89, characterized in that it further comprises administering to the individual an additional agent suitable for the treatment or prevention of a disorder related to STXBP1; optionally wherein the additional agent comprises one or more antiepileptic drugs (e.g., levetiracetam, phenobarbital, clobazam, topiramate), adrenocorticotropic hormone, or a combination thereof.

91. Method, according to any one of claims 65 to 90, characterized in that it further comprises the administration of an immunosuppressant to the individual.

92. Method according to claim 91, characterized in that the immunosuppressant comprises a corticosteroid (e.g., prednisone, prednisolone, methylprednisolone and / or dexamethasone), rapamycin, mycophenolate mofetil, tacrolimus, rituximab and / or eculizumab hydroxychloroquine.

93. Pharmaceutical composition, according to any one of claims 58 to 61 or the AAV particle, according to any one of claims 1 to 46, characterized in that it is for use in the treatment of a disorder related to STXBP1; optionally wherein the disorder related to STXBP1 is STXBP1 encephalopathy, epileptic encephalopathy, Ohtahara syndrome, developmental encephalopathy, West syndrome, early myoclonic epileptic encephalopathy, Lennox-Gaustaut syndrome, autism (e.g., autism with mutations in STXBP1 and, optionally, other mutations), Dravet syndrome (not caused by mutations in SCN1A) or Rett syndrome phenotype (not caused by mutation of MECP2 or CDKL5).

94. Use of the pharmaceutical composition, as defined in any one of claims 58 to 61, or of the AAV particle, as defined in any one of claims 1 to 46, characterized in that it is for the manufacture of a medicament for the treatment of a disorder related to STXBP1; optionally wherein the disorder related to STXBP1 is STXBP1 encephalopathy, epileptic encephalopathy, Ohtahara syndrome, developmental encephalopathy, West syndrome, early myoclonic epileptic encephalopathy, Lennox-Gaustaut syndrome, autism (e.g., autism with mutations in STXBP1 and, optionally, other mutations), Dravet syndrome (not caused by mutations in SCN1A) or Rett syndrome phenotype (not caused by mutation of MECP2 or CDKL5).

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