EP-4414002-B1 - RAC2 G12V MUTANT FOR USE IN ABLATING HEMATOPOIESIS AND IN THE TREATMENT OF HEMATOPOIETIC MALIGNANCIES

Inventors

• LAGRESLE-PEYROU, Chantal
• OLICHON, Aurélien
• SADEK-ROCK, Hanem
• ANDRE, ISABELLE
• CAVAZZANA, MARINA

Dates

Publication Date

20260513

Application Date

20200717

Claims (9)

1. A polynucleotide encoding for a polypeptide comprising the amino acid sequence as set forth in SEQ ID NO:1 wherein the amino residue (G) at position 12 is substituted by a valine residue (V) for use in a method of full ablating hematopoiesis in a patient in need thereof.
2. The polynucleotide encoding for a polypeptide comprising the amino acid sequence as set forth in SEQ ID NO: 1 wherein the amino residue (G) at position 12 is substituted by a valine residue (V) for use according to claim 1 for preparing the patient to bone marrow transplantation.
3. The polynucleotide encoding for a polypeptide comprising the amino acid sequence as set forth in SEQ ID NO: 1 wherein the amino residue (G) at position 12 is substituted by a valine residue (V) is for use according to claim 2 wherein the bone marrow transplantation is hematopoietic stem cell transplantation.
4. The polynucleotide encoding for a polypeptide comprising the amino acid sequence as set forth in SEQ ID NO: 1 wherein the amino residue (G) at position 12 is substituted by a valine residue (V) for use according to any one of claims 1 to 3 wherein the polynucleotide is a messenger RNA (mRNA).
5. The polynucleotide encoding for a polypeptide comprising the amino acid sequence as set forth in SEQ ID NO: 1 wherein the amino residue (G) at position 12 is substituted by a valine residue (V) for use according to any one of claims 1 to 3 wherein the polynucleotide is inserted in a vector.
6. The polynucleotide encoding for a polypeptide comprising the amino acid sequence as set forth in SEQ ID NO:1 wherein the amino residue (G) at position 12 substituted by a valine residue (V) for use according to any one of claims 1 to 5 wherein the polynucleotide is conjugated to at least one other molecule selected from the group consisting of polynucleotides, polypeptides, lipids, lectins, carbohydrates, vitamins, cofactors, and drugs.
7. The polynucleotide encoding for a polypeptide comprising the amino acid sequence as set forth in SEQ ID NO: 1 wherein the amino residue (G) at position 12 is substituted by a valine residue (V) for use according to claim 6 wherein the polypeptide is conjugated to a molecule having a specific affinity for hematopoietic cells, such as antibodies or peptides having a binding affinity for a protein expressed at the surface of a hematopoietic stem cell.
8. The polynucleotide encoding for a polypeptide comprising the amino acid sequence as set forth in SEQ ID NO: 1 wherein the amino residue (G) at position 12 is substituted by a valine residue (V) for use according to any one of claims 1 to 7 wherein the polynucleotide is formulated with lipidoids.
9. The polynucleotide encoding for a polypeptide comprising the amino acid sequence as set forth in SEQ ID NO: 1 wherein the amino residue (G) at position 12 substituted by a valine residue (V) for use according to any one of claims 1 to 7 wherein the polynucleotide is formulated using one or more liposomes, lipoplexes, or lipid nanoparticles.

Description

FIELD: The present disclosure is in the field of haematology. BACKGROUND: Hematopoietic stem cell transplantation (HSCT) is a potentially curative therapeutic approach for a variety of malignant and non-malignant hematopoietic diseases. When HSCT is performed in patients with malignant disorders, preparative or conditioning regimens are administered as part of the procedure to achieve 3 goals: make space in the bone-marrow (myeloablation), provide sufficient immunoablation to prevent graft rejection and reduce the tumor burden. The intensity of conditioning regimens can vary substantially, and when selecting the optimal conditioning regimen for any given patient, disease-related factors such as diagnosis and remission status, as well as patient-related factors including age, donor availability, and presence of comorbid conditions, need to be considered. Although full consensus has not been reached within the HCT community, conditioning regimens have been classified as high-dose (myeloablative), reduced-intensity, and non-myeloablative. For instance myeloablative, or "high-dose" regimens, consisting of alkylating agents (single or multiple) with or without total body irradiation, are expected to ablate hematopoiesis, not allowing autologous hematologic recovery. The administration of conditioning regimens is associated with immediate and delayed toxicities. For instance, nausea, vomiting, transient acute parotiditis, xerostomia, mucositis, and diarrhea are commonly observed acute complications. Interstitial pneumonitis, idiopathic pulmonary fibrosis, and reduced lung pulmonary function can also be observed. The occurrence of sinusoidal obstruction syndrome (also known as veno-occlusive disease of the liver) is more common in chemotherapy-based regimens. Long-term side effects include infertility, cataract formation, hypothyroidism and thyroiditis, and secondary malignancies. Accordingly, there is a need for new method that will allow full ablation of hematopoiesis with a minimal occurrence of short and long term severe adverse side effects. RAC2 belongs to the Rac subfamily of the Rho family of small GTPases. In the inactive GDP-bound state, RAC2 is located in the cytosol. Upon stimulation and activation by guanine nucleotide exchange factors, the active RAC2-GTP-bound form is translocated to the plasma membrane. There, RAC2 triggers various signalling pathways until the GTP is hydrolysed or the GTPase is degraded by the cell 7-9. Unlike the other members of the Rac subfamily (RAC1 and RAC3), expression of RAC2 is restricted to the hematopoietic lineage 10,11. WO 2016/164502 is an example of several alternative strategies for myeloablation and/or controlling the proliferation of hematopoietic cells, in the context of a bone marrow transplantation. In particular, the document uses a toxin specifically directed to hematopoietic cells via specific cell surface determinants. SUMMARY OF THE INVENTION: The present invention is defined by the claims. In particular, the present invention relates to a polynucleotide encoding for a polypeptide comprising the amino acid sequence as set forth in SEQ ID NO:1 wherein the amino residue (G) at position 12 is substituted by a valine residue (V) for use in a method of full ablating hematopoiesis in a patient in need thereof. The following detailed description, figures and example do not fall under the scope of the present invention and are present for understanding and illustration purposes only. Furthermore, any reference in the description to methods of treatment refer to the compounds, pharmaceutical compositions and medicaments of the present invention for use in a method of treatment of the human body by therapy. DETAILED DESCRIPTION: The inventors have identified an autosomal dominant (AD) missense mutation in the RAC2 gene (coding for Ras-related C3 botulinum toxin substrate 2 (RAC2)) in three Severe combined immunodeficiencies (SCID) patients whose clinical presentation overlaps with the RD SCID form but who lack AK2 mutations and deafness. Using biochemical and in vitro differentiation assays, the inventors demonstrated that the RAC2 mutation was closely related to an impairment in cell differentiation capacity and defects in cellular and mitochondrial networks. Taken as a whole, the data demonstrate that a dominant gain-of-function (GOF) mutation in the RAC2 protein's GDP/GTP binding site inhibits HSPC differentiation and leads to a severe AD form of SCID with a clinical presentation of RD. Accordingly, the results prompt to consider that introduction of the identified RAC2 mutein in the hematopoietic lineage would be suitable for inducing full ablation of hematopoiesis. The first object of the present invention relates to a method of full ablating hematopoiesis in a patient in need thereof comprising administering to the patient a therapeutically effective amount of a polynucleotide encoding for a polypeptide comprising the amino acid sequence as set forth in SEQ I