Formulations of 5-fluorocytosine and uses thereof

1. An oral pharmaceutical composition comprising 5-fluorocytosine (FC), wherein the pharmaceutical composition is a monolithic solid tablet form comprising at least one hydrophilic matrix forming polymer of about 5 weight percent to about 40 weight percent, at least one diluent of about 10 weight percent to about 40 weight percent and at least one binder of about 0.5 weight percent to about 30 weight percent and wherein the pharmaceutical composition is restricted to the upper gastrointestinal tract and releases 5-FC into the upper gastrointestinal tract of a subject over a sustained period of time, wherein the composition has an in vitro 5-FC dissolution rate of less than 33% at 0.5 hours in pH 1.2.

2. The pharmaceutical composition of claim 1 , further comprising at least two hydrophilic matrix forming polymer.

3. The pharmaceutical composition of claim 1 , wherein the hydrophilic matrix forming polymer is one or more of carbomer, polyvinyl acetate and povidone based polymer, hydroxypropyl cellulose (HPC), hydroxymethyl cellulose (HPMC), and polyethylene oxide (PolyOx).

4. The pharmaceutical composition of claim 3 , wherein the hydrophilic matrix forming polymers make up about 10 weight percent to about 40 weight percent of the composition.

5. The pharmaceutical composition of claim 1 , wherein 5-FC is present in an amount of about 100 mg to about 2000 mg.

6. The pharmaceutical composition of claim 1 , wherein the composition exhibits a 5-FC in vitro dissolution rate of greater than about 80% within about 4 to about 12 hours as measured by the USP Type II dissolution apparatus (paddle method) at 75 rpm in 900 ml water at 37° C. using 5-FC USP method with UV detection at about 275-285 nm.

7. The pharmaceutical composition of claim 1 , wherein after a single dose oral administration to a fed subject the composition exhibits: (i) a t median of about 3 hrs or greater; (ii) a t max of about 3 hrs or greater; and (iii) a t 1/2 of between about 3-8 hrs.

8. The pharmaceutical composition of claim 1 , wherein 5-FC is present in the pharmaceutical composition in an amount of about 500 mg, after single oral administration of the 500 mg pharmaceutical composition to a fed subject, the composition exhibits one or more of the following: (i) a 5-FC C max of between about 2.0 μg/ml and about 10.0 μg/ml; (ii) a t max of about 3 hrs or greater; (iii) an AUC ∞ of about 20-80 μg*hr/ml; and (iv) a t 1/2 of between about 3-8 hrs.

9. The pharmaceutical composition of claim 5 , wherein the AUC in a fed human subject after a single administration of a 2 gram composition provides an AUC of 15-40 μg·hr/mL over a 24 hour period.

10. The pharmaceutical composition of claim 5 , wherein the AUC in a fed human subject administered 2 gram 5-FC provides an AUC of 100-150 μg·hr/mL over a 24 hour period.

11. The pharmaceutical composition of claim 5 , wherein following administration of 2 grams 5-FC to a fed human subject the 5-FC concentration in the serum during a 24 hour period is above 10 μg/ml for about 5-15 hours.

12. The pharmaceutical composition of claim 5 , wherein following daily administration for about 7 days or about 5 half-lives or more with 1-250 mg/Kg/day in divided doses to a fed human subject the mean serum concentration of 5-FC during a 24 hour period is about 1-200 μg/ml.

13. The pharmaceutical composition of claim 12 , wherein following a repeated dose for 6 weeks with 1-250 mg/Kg/day in divided doses to a fed human subject the mean serum concentration of 5-FC during a 24 hour period is about 1-200 μg/ml.

14. The pharmaceutical composition of claim 12 , wherein following daily administration for 7 days or about 5 half-lives or more with 1-250 mg/Kg/day in divided doses to a fed human subject the mean serum concentration of 5-FC during a 24 hour period is about 30-80 μg/ml.

15. The pharmaceutical composition of claim 8 , wherein the composition is administered 1-4 times per day.

16. A pharmaceutical composition according to claim 1 , where the total AUC in a fed human is about 75-125% of a current immediate release formulation of 5-FC.

17. A method of treating a fungal infection by administering a pharmaceutical composition of claim 1 .

18. A method of treating cancer in a mammal by administering a pharmaceutical composition of claim 1 in conjunction with a polypeptide comprising cytosine deaminase activity to treat cancer in a mammal.

19. A method of treating cancer in a mammal by administering a pharmaceutical composition of claim 1 in conjunction with a polynucleotide encoding a cytosine deaminase to treat cancer in a mammal.

20. A method of treating cancer in a mammal having previously received cytosine deaminase gene therapy comprising administering to the mammal a pharmaceutically effective amount of a composition of claim 1 .

21. A method of claim 19 , wherein the polynucleotide encoding a cytosine deaminase is delivered with a viral vector.

22. A method of claim 19 , wherein the polynucleotide encoding a cytosine deaminase is delivered with a non-viral vector.

23. The method of claim 21 , wherein the viral vector is retroviral vector or an adenoviral vector.

24. The method of claim 23 , wherein the retroviral vector is a non-replication competent retroviral vector, a replication competent retroviral vector or a recombinant replication retroviral vector.

25. The method of claim 24 , wherein the replication competent retroviral vector comprises an oncoretroviral vector.

26. The method of claim 25 , wherein the replication competent retroviral vector comprises an internal ribosomal entry site (IRES) 5′ to the polynucleotide encoding a cytosine deaminase.

27. The method of claim 26 , wherein the polynucleotide encoding a cytosine deaminase is 3′ to a ENV polynucleotide.

28. The method of claim 17 , wherein the fungal infection is an infection by a fungus selected from the group consisting of Candida spp., Cryptococcus spp., Sporothrix spp., Aspergillus spp., Cladosporium spp., Exophila spp. and Phialophora spp.

29. The method of claim 17 , further comprising administration of a fungus-treating effective amount of amphotericin B, fluconazole, leukovorin or itraconazole.

30. The method of claim 17 , wherein the fungal disease is a foot fungal disease.

31. A method of treating a cancer comprising administering to a subject in need thereof a sufficient amount of an expression vector comprising a cytosine deaminase which is capable of converting 5-fluorocytosine to 5-fluorouracil in cells of the cancer and a cancer-treating effective amount of a composition of claim 1 .

32. The method of claim 31 , wherein the cancer comprises a solid tumor.

33. The method of claim 31 , wherein the composition is administered one, two or three times per day.

34. The method of claim 31 , wherein the expression vector is a retroviral vector or an adenoviral vector.

35. The method of claim 34 , wherein the retroviral vector is a replication competent retroviral vector, a replication defective retroviral vector or a recombinant replication competent retroviral vector.

36. The method of claim 31 , wherein the method further comprises administering leukovorin.

37. A method of treating a subject with a cancer, comprising:

identifying a tumor size;

determining the number of therapeutic units of a replication competent retroviral vector comprising a cassette having an IRES linked to a polynucleotide encoding a cytosine deaminase;

calculating a dose of a 5-FC formulation based upon the tumor size and therapeutic units;

administering the replication competent retroviral vector to the subject;

administering the dose of a 5-FC formulation.

38. The method of claim 37 , wherein the dose comprises about 1-250 mg/kg administered 1 to 4 times per day.

39. The method of claim 38 , further comprising determining a subject's renal function.

40. The method of claim 38 , further comprising determining a subject's creatinine clearance.

41. An oral extended release formulation comprising 5-Fluorocytosine (5-FC), wherein said formulation is a monolithic solid tablet form comprising at least one hydrophilic matrix forming polymer of about 5 weight percent to about 40 weight percent, at least one diluent of about 10 weight percent to about 40 weight percent, and at least one binder of about 0.5 weight percent to about 30 weight percent and wherein the formulation provides enhanced bioavailability with food and wherein upon administration the ratio of the AUC in the fed state over the AUC in the fasted state has a value selected from the group consisting of: (i) about 1.5 to about 3.0; (ii) about 1.8 to about 2.5; and (iii) about 1.9 to about 2.3.

42. The oral extended release formulation of claim 41 , wherein the hydrophilic matrix forming polymer is one or more of carbomer, polyvinyl acetate and povidone based polymer, hydroxypropyl cellulose (HPC), hydroxymethyl cellulose (HPMC), and polyethylene oxide (PolyOx).

43. The oral extended release formulation of claim 42 , wherein the hydrophilic matrix forming polymers make up about 10 weight percent to about 40 weight percent of the composition.

44. The oral extended release formulation of claim 43 , wherein 5-FC is present in an amount of about 100 mg to about 2000 mg.

45. The oral extended release formulation of claim 41 , wherein the composition exhibits 5-FC in vitro dissolution rate of greater than about 80% within about 4 to about 12 hours as measured by the USP Type II dissolution apparatus (paddle method) at 75 rpm in 900 ml water at 37° C. using 5-FC USP method with UV detection at about 275-285 nm.

46. An oral extended release formulation comprising 5-Fluorocystosine in a monolithic solid tablet form comprising at least one hydrophilic matrix forming polymer of about 5 weight percent to about 40 weight percent, at least one diluent of about 10 weight percent to about 40 weight percent, and at least one binder of about 0.5 weight percent to about 30 weight percent and wherein upon administration the ratio of C max fed/C max fasted has a value selected from the group consisting of (i) about 1.5 to about 3.0 and (ii) about 1.8 to about 2.4.

47. The oral extended release formulation of claim 46 , wherein the hydrophilic matrix forming polymer is one or more of carbomer, polyvinyl acetate and povidone based polymer, hydroxypropyl cellulose (HPC), hydroxymethyl cellulose (HPMC), and polyethylene oxide (PolyOx).

48. The oral extended release formulation of claim 47 , wherein the hydrophilic matrix forming polymers make up about 10 weight percent to about 40 weight percent of the composition.

49. The oral extended release formulation of claim 48 , wherein 5-FC is present in an amount of about 100 mg to about 2000 mg.

50. The oral extended release formulation of claim 46 , wherein the composition exhibits 5-FC in vitro dissolution rate of greater than about 80% within about 4 to about 12 hours as measured by the USP Type II dissolution apparatus (paddle method) at 75 rpm in 900 ml water at 37° C. using 5-FC USP method with UV detection at about 275-285 nm.

51. An oral extended release formulation comprising 5-Fluorocytosine in a monolithic solid tablet form comprising at least one hydrophilic matrix forming polymer of about 5 weight percent to about 40 weight percent, at least one diluent of about 10 weight percent to about 40 weight percent, and at least one binder of about 0.5 weight percent to about 30 weight percent and wherein said formulation provides enhanced bioavailability with food and wherein upon administration the AUC 0-inf in the fed state is greater than about 70% of the AUC in the fasted state of flucytosine immediate release.

52. The formulation of claim 51 , wherein said AUC in the fed state is less than about 125% of the AUC in the fasted state of flucytosine immediate release.

53. The formulation of claim 51 , wherein said AUC in the fed state is about 80-100% of the AUC in the fasted state for flucytosine immediate release.

54. The formulation of claim 51 , wherein said AUC in the fed state is about 83-95% of the AUC in the fasted state for flucytosine immediate release.

55. The oral extended release formulation of claim 51 , wherein the hydrophilic matrix forming polymer is one or more of carbomer, polyvinyl acetate and povidone based polymer, hydroxypropyl cellulose (HPC), hydroxymethyl cellulose (HPMC), and polyethylene oxide (PolyOx).

56. The oral extended release formulation of claim 55 , wherein the hydrophilic matrix forming polymers make up about 10 weight percent to about 40 weight percent of the composition.

57. The oral extended release formulation of claim 56 , wherein 5-FC is present in an amount of about 100 mg to about 2000 mg.

58. The oral extended release formulation of claim 51 , wherein the composition exhibits 5-FC in vitro dissolution rate of greater than about 80% within about 4 to about 12 hours as measured by the USP Type II dissolution apparatus (paddle method) at 75 rpm in 900 ml water at 37° C. using 5-FC USP method with UV detection at about 275-285 nm.

59. An oral extended release formulation comprising 5-Fluorocytosine in a monolithic solid tablet form comprising at least one hydrophilic matrix forming polymer of about 5 weight percent to about 40 weight percent, at least one diluent of about 10 weight percent to about 40 weight percent, and at least one binder of about 0.5 weight percent to about 30 weight percent and wherein upon administration the C max in the fed state is less than about 90% of the C max in the fasted state of flucytosine immediate release.

60. The formulation of claim 59 , wherein said C max in the fed state is greater than about 30% of the C max in the fasted state of flucytosine immediate release.

61. The formulation of claim 59 , wherein said C max in the fed state is about 50-85% of the C max in the fasted state for flucytosine immediate release.

62. The oral extended release formulation of claim 59 , wherein the hydrophilic matrix forming polymer is one or more of carbomer, polyvinyl acetate and povidone based polymer, hydroxypropyl cellulose (HPC), hydroxymethyl cellulose (HPMC), and polyethylene oxide (PolyOx).

63. The oral extended release formulation of claim 62 , wherein the hydrophilic matrix forming polymers make up about 10 weight percent to about 40 weight percent of the composition.

64. The oral extended release formulation of claim 59 , wherein 5-FC is present in an amount of about 100 mg to about 2000 mg.

65. The oral extended release formulation of claim 59 , wherein the composition exhibits 5-FC in vitro dissolution rate of greater than about 80% within about 4 to about 12 hours as measured by the USP Type II dissolution apparatus (paddle method) at 75 rpm in 900 ml water at 37° C. using 5-FC USP method with UV detection at about 275-285 nm.

66. An oral pharmaceutical monolithic tablet comprising 5-fluorocytosine (5-FC) and:

(i) about 5% to about 15% of a binding agent;

(ii) about 10% to about 30% of a diluent;

(iii) about 10% to about 20% of at least one hydrophilic polymer; and

(iv) about 1% to about 3% of a coating, wherein the composition has an in vitro 5-FC dissolution rate of less than 33% at 0.5 hours in pH 1.2.

67. The oral pharmaceutical composition of claim 66 , wherein the 5-FC comprises about 500 mg/tablet.

68. The oral pharmaceutical composition of claim 66 comprising

about 500 mg of 5-fluorocytosine;

about 60 mg of hydroxypropyl cellulose;

about 100 mg of dicalcium phosphate;

about 110 mg of carbomer; and

about 180 mg of microcrystalline cellulose.