Compositions and methods for treating cancer with arginine depletion and immuno oncology agents

1. A method of inhibiting tumor growth in a subject, comprising administering to said subject a pharmaceutical composition comprising a therapeutically effective amount of a human Arginase I enzyme comprising a cobalt cofactor and a therapeutically effective amount of an immuno-oncology agent, wherein the immuno-oncology agent is selected from the group consisting of: pembrolizumab, ipilimumab, atezolizumab and nivolumab.

2. The method of claim 1 , wherein the subject has a tumor that comprises arginine auxotrophic tumor cells.

3. The method of claim 1 , wherein the human Arginase I enzyme is stabilized by association with a stabilizing agent.

4. The method of claim 3 , wherein the stabilizing agent is selected from the group consisting of: polyethylene glycol, a synthetic protein polymer, an Fc fusion, and albumin.

5. The method of claim 1 , wherein the human Arginase I enzyme is pegylated.

6. The method of claim 1 , wherein the subject has a tumor that exhibits a reduced or inhibited expression of argininosuccinate synthetase, ornithine transcarbamylase, argininosuccinate lyase, or a combination thereof.

7. The method of claim 1 , wherein the subject is an animal subject.

8. The method of claim 1 , wherein the subject s a human cancer patient.

9. The method of claim 1 , wherein the agent is ipilimumab.

10. The method of claim 1 , wherein the subject has a tumor selected from the group consisting: a hepatocellular carcinoma, a renal cell carcinoma, a breast cancer, a melanoma, a prostate cancer, a pancreatic cancer, a bladder cancer, a colon carcinoma, a colorectal cancer, a triple negative breast cancer, a Hodgkin's lymphoma, a gastric cancer, a glioblastoma, a Merkel cell carcinoma, a lung carcinoma, a small cell lung cancer, and a non-small cell lung cancer.

11. The method of claim 1 , wherein the immuno-oncology agent and the human Arginase I enzyme are administered concurrently.

12. The method of claim 1 , wherein the immuno-oncology agent and the human Arginase I enzyme are administered sequentially.

13. The method of claim 1 , wherein the human Arginase I enzyme displays a k cat /K M for the hydrolysis of arginine between 400 mM −1 s −1 and 4,000 mM −1 s −1 at pH 7.4 and 37° C.

14. The method of claim 1 , wherein the human Arginase enzyme comprises a ratio of cobalt to arginase of from 2 to 3 μg Co/mg arginase.

15. The method of claim 1 , wherein the human Arginase I enzyme is produced by contacting an arginase apoenzyme with cobalt or a cobalt ion at a temperature of from 30° C. to 55° C. for a period of from 15 minutes to 60 minutes.

16. A method of treating cancer in a cancer patient comprising administering to said patient a therapeutically effective amount of a pharmaceutical composition comprising a pegylated human Arginase I enzyme comprising a cobalt cofactor and an immune system modulating therapy, wherein the immune system modulating therapy is an immuno-oncology agent selected from the group consisting of: pembrolizumab, ipilimumab, atezolizumab, and nivolumab.

17. The method of claim 16 , wherein the pharmaceutical composition comprising the pegylated human Arginase I enzyme comprising the cobalt cofactor and the pharmaceutical composition comprising the immuno-oncology agent are administered concurrently.

18. The method of claim 16 , wherein the pharmaceutical composition comprising the human Arginase I enzyme comprising the cobalt cofactor and the pharmaceutical composition comprising the immuno-oncology agent are administered sequentially.

19. The method of claim 16 , wherein the therapeutically effective amount of the pegylated human Arginase I enzyme comprising the cobalt cofactor is from about 0.01 mg/kg to about 7.5 mg/kg.

20. The method of claim 16 , wherein the therapeutically effective amount of the pegylated human Arginase I enzyme comprising the cobalt cofactor is from about 0.05 mg/kg to about 5 mg/kg.

21. The method of claim 16 , wherein the therapeutically, effective amount of the pegylated human Arginase I enzyme comprising cobalt cofactor is from about 0.1 mg/kg to about 5 mg/kg.

22. The method of claim 16 , wherein the cancer patient is treated for a hepatocellular carcinoma, a renal cell carcinoma, a breast cancer, a melanoma, a prostate cancer, a pancreatic cancer, a bladder cancer, a colon carcinoma, a colorectal cancer, a triple a negative breast cancer, a Hodgkin's lymphoma, a gastric cancer, a glioblastoma, a Merkel cell carcinoma, a lung carcinoma, a small cell lung cancer, or a non-small cell lung cancer.

23. The method of claim 16 , wherein the pharmaceutical composition comprising the pegylated human Arginase I enzyme comprising the cobalt cofactor is administered parenterally.

24. The method of claim 16 , wherein the pharmaceutical composition comprising the pegylated human Arginase I enzyme comprising the cobalt cofactor is administered topically, intravenously, intradermally, intraarterially, intraperitoneally, intralesionally, intracranially, intraarticularly, intraprostaticaly, intrapleurally, intratracheally, intraocularly, intranasally, intravitreally, intravaginally, intrarectally, intramuscularly, subcutaneously, subconjunctival, intravesicularlly, mucosally, intrapericardially, intraumbilically, orally, by inhalation, by injection, by infusion, by continuous infusion, by localized perfusion bathing target cells directly, via a catheter, or via a lavage.

25. The method of claim 16 , wherein the pharmaceutical composition is administered intravenously.

26. The method of claim 16 , wherein the treatment results in from 50% to 99% reduction in serum arginine in the cancer patient.

27. The method of claim 16 , wherein the treatment results in from 90% to 99% reduction of serum arginine in the cancer patient.

28. The method of claim 16 , Wherein the treatment results in reduction of serum arginine in the cancer patient to an undetectable level.