Enzyme Therapy for Targeted Treatment of Cystine-Related Disorders

Introduction

Metabolic disorders, particularly those involving the accumulation of amino acids like cystine and cysteine, pose significant treatment challenges. Patients suffering from conditions such as cystinosis face a lifetime of managing symptoms, often with limited therapeutic options. Traditional treatments focus on symptom management rather than addressing the root cause of the problem. Our patented engineered primate cystine/cysteine degrading enzymes offer a groundbreaking approach to these disorders, providing a targeted therapy designed to break down excess cystine and cysteine, reducing the risk of long-term complications and improving patient outcomes.

The Ongoing Need for Advanced Therapeutics

Current therapies for metabolic disorders related to amino acid buildup, such as cystinosis, are often inadequate in fully preventing the progression of the disease. Most treatments aim to reduce the symptoms of these conditions but don’t offer a permanent solution to the underlying metabolic imbalance. For patients, this can mean long-term reliance on medications that may not fully prevent organ damage or other complications resulting from cystine/cysteine buildup.

The limitations of existing treatments highlight the urgent need for more effective, targeted therapies that go beyond symptom management. This is particularly important for rare genetic disorders, where options are often limited, and therapies that directly address the biochemical root cause of the disease are few and far between.

A New Path Forward with Enzyme Therapy

Our engineered primate cystine/cysteine degrading enzymes offer a novel solution to this longstanding problem. These enzymes have been specifically designed to target and degrade excess cystine and cysteine in the body, preventing their harmful accumulation in tissues and organs. By breaking down these amino acids, the therapy reduces the toxic effects associated with their buildup, which can lead to organ damage, particularly in the kidneys and eyes.

This technology opens up new treatment possibilities for patients with cystinosis and related disorders. In addition to addressing the root cause of these diseases, enzyme therapy offers the potential for fewer side effects, greater efficacy, and improved quality of life for patients. The therapy could also be adapted for other conditions where cystine/cysteine accumulation plays a role, broadening its applicability in the treatment landscape.

Key Advantages

Targeted Therapy: Specifically degrades cystine and cysteine, addressing the root cause of metabolic disorders.
Reduced Complications: Lowers the risk of organ damage by preventing amino acid buildup.
Broad Application Potential: Can be adapted to treat multiple cystine/cysteine-related disorders.
Enhanced Patient Outcomes: Offers a more effective, long-term solution compared to traditional symptom management.

Innovating the Future of Metabolic Disease Treatment

Licensing this enzyme therapy technology provides biotechnology and pharmaceutical companies with the opportunity to lead in developing targeted treatments for metabolic and genetic disorders. This breakthrough offers hope for improving patient care and developing new therapeutics that address the root causes of these complex conditions.

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Abstract
Claims

Methods and compositions related to the engineering of a protein with L-cyst(e)ine degrading enzyme activity are described. For example, disclosed are modified cystathionine-γ-lyases comprising one or more amino acid substitutions and capable of degrading L-cyst(e)ine. Furthermore, compositions and methods are provided for the treatment of cancer and cystinuria using the disclosed modified enzymes or nucleic acids encoding said enzymes.

What is claimed is:

1. An isolated, modified primate cystathionine-γ-lyase (CGL) enzyme having the following substitutions relative to a native human CGL amino acid sequence (SEQ ID NO: 1), wherein the modified enzyme has both cystinase and cysteinase activity, and wherein said primate is selected from the group consisting of Homo sapiens, Pongo abelii, Pan troglodytes, Pan paniscus, and Macaca fascicularis; said substitutions comprising: a glutamic acid at position 55, a threonine at position 59, and a valine at position 339.

2. The isolated, modified CGL enzyme of claim 1, further comprising an aspartic acid at position 336.

3. The isolated, modified CGL enzyme of claim 1, wherein the isolated, modified CGL enzyme is a modified Pongo abelii CGL enzyme, wherein said substitutions comprise H55E, V59T, and E339V.

4. The isolated, modified CGL enzyme of claim 3, further comprising a T336D substitution.

5. The isolated, modified CGL enzyme of claim 1, wherein the isolated, modified CGL enzyme is a modified Homo sapiens CGL enzyme, a modified Macaca fascicularis CGL enzyme, a modified Pan troglodytes CGL enzyme, or a modified Pan paniscus CGL enzyme, wherein said substitutions comprise H55E, E59T, and E339V.

6. The isolated, modified CGL enzyme of claim 5, further comprising a T336D substitution.

7. The isolated, modified CGL enzyme of claim 1, further comprising a heterologous peptide segment or a polysaccharide.

8. The isolated, modified CGL enzyme of claim 7, wherein the heterologous peptide segment is an XTEN peptide, an IgG Fc, an albumin, or an albumin binding peptide.

9. The isolated, modified CGL enzyme of claim 7, wherein the polysaccharide comprises polysialic acid polymers.

10. The isolated, modified CGL enzyme of claim 1, wherein the enzyme is coupled to a polyethylene glycol (PEG).

11. The isolated, modified CGL enzyme of claim 10, wherein the enzyme is coupled to the PEG via one or more lysine residues.

12. A therapeutic formulation comprising an enzyme of claim 1, in a pharmaceutically acceptable carrier.

13. A method of treating a tumor cell or subject having a tumor cell comprising administering to the tumor cell or the subject a therapeutically effective amount of the formulation of claim 12.

14. The method of claim 13, wherein the subject is maintained on a L-cystine and/or L-cysteine restricted diet.

15. The method of claim 13, wherein the subject is maintained on a normal diet.

16. The method of claim 13, wherein the tumor cell has been identified as having a decreased expression level of a cystathionine-β-synthase or cystathionine-γ-lyase gene product relative to a non-tumor cell.

17. The method of claim 13, wherein the tumor cell has been identified as having an increased expression level of a xCT(−) cystine/glutamate antiporter gene product relative to a non-tumor cell.

18. The method of claim 13, wherein the tumor cell is a prostate cancer cells, a small cell lung cancer cell, or a hematological malignancy cell.

19. The method of claim 18, wherein the hematologic malignancy cell is a chronic myelogenous leukemia cell, chronic lymphocytic leukemia cell, acute myelogenous leukemia cell, acute lymphocytic leukemia cell, acute monocytic leukemia cell, diffuse large B-cell lymphoma, myelodysplastic syndrome, chronic myelomonocytic leukemia, primary myelofibrosis, Hodgkin’s lymphoma cell, non-Hodgkin’s lymphoma cell, or multiple myeloma cell.

20. The method of claim 13, wherein the subject is a human patient.

21. The method of claim 13, wherein the formulation is administered intravenously, intraarterially, intraperitoneally, intralesionally, intramuscularly, intravesicularlly, by injection, by infusion, by continuous infusion, by localized perfusion bathing target cells directly, or via a catheter.

22. The method of claim 13, wherein the formulation is administered to a nutrient medium of the tumor cell.

23. The method of claim 22, wherein the nutrient medium is blood, lymphatic fluid, or spinal fluid.

24. The method of claim 13, further comprising administering at least a second anticancer therapy to the subject.

25. The method of claim 24, wherein the second anticancer therapy is a surgical therapy, chemotherapy, radiation therapy, cryotherapy, hormone therapy, immunotherapy or cytokine therapy.

26. The method of claim 24, wherein the secondary anticancer therapy is fludarabine.

27. A method of treating a subject having or at risk of developing cystinuria comprising administering to the subject a therapeutically effective amount of a formulation of claim 12.

28. The method of claim 27, wherein the subject is maintained on a L-cystine and/or L-cysteine restricted diet.

29. The method of claim 27, wherein the subject is maintained on a methionine-restricted diet.

30. The method of claim 27, wherein the subject is maintained on a normal diet.

31. The method of claim 27, wherein the subject is a human patient.

32. The method of claim 27, wherein the formulation is administered intravenously, intraarterially, intraperitoneally, intramuscularly, intravascularly, subcutaneously, by injection, by infusion, by continuous infusion, by localized perfusion bathing target cells directly, or via a catheter.

33. The method of claim 27, wherein the subject has previously been treated for cystinuria and the enzyme is administered to prevent the recurrence of cystinuria.

34. The method of claim 27, further comprising administering at least a second cystinuria therapy to the subject.

35. The method of claim 34, wherein the second cystinuria therapy is a surgical therapy or a shock wave therapy.

36. An isolated, modified human cystathionine-γ-lyase (CGL) enzyme having the following substitutions relative to a native human CGL amino acid sequence (SEQ ID NO: 1), wherein the modified enzyme has both cystinase and cysteinase activity, said substitutions comprising: a glutamic acid at position 55, a threonine at position 59, and a valine at position 339.

Title

Engineered primate cystine/cysteine degrading enzymes for therapeutic uses

Inventor(s)

George Georgiou, Everett Stone, Shira Cramer

Assignee(s)

University of Texas System

Patent #

10865407

Patent Date

December 15, 2020