Compounds and methods for the treatment of COVID-19

1. Crystalline (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate hydrate having one or more characteristics selected from the group consisting of a powder X-ray diffraction pattern, a 13 C solid state NMR spectrum and a Raman spectrum;

wherein the powder X-ray diffraction pattern characteristic is selected from

a) a powder X-ray diffraction pattern comprising peaks at 4.1±0.2 and 7.2±0.2 degrees 2-Theta;

b) a powder X-ray diffraction pattern comprising peaks at 4.1±0.2, 7.2±0.2 and 10.4±0.2 degrees 2-Theta; and

c) a powder X-ray diffraction pattern comprising peaks at 4.1±0.2, 7.2±0.2, 10.4±0.2 and 14.5±0.2 degrees 2-Theta;

wherein the 13 C solid state NMR spectrum characteristic is selected from

a) 13 C solid state NMR spectrum comprising peaks at 21.7, 153.8 and 172.2 ppm; each peak±0.2 ppm;

b) a 13 C solid state NMR spectrum comprising peaks at 21.7, 153.8, 172.2 and 118.6 ppm; each peak±0.2 ppm; and

c) a 13 C solid state NMR spectrum comprising peaks at 21.7, 153.8, 172.2, 118.6 and 57.8 ppm; each peak±0.2 ppm; and

wherein the Raman spectrum characteristic is selected from

a) a Raman spectrum comprising Raman peaks at 1271, 1421 and 1217 cm −1 , each peak±2 cm −1 ,

b) a Raman spectrum comprising Raman peaks at 1271, 1421, 1217 and 1640 cm −1 ; each peak±2 cm −1 and

c) a Raman spectrum comprising Raman peaks at 1271, 1421, 1217, 1640 and 3074 cm −1 ; each peak±2 cm −1 .

2. The compound (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate, methyl ethyl ketone solvate.

3. The compound of claim 2 which is a crystalline (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate, methyl ethyl ketone solvate.

4. The compound of claim 3 which is crystalline (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate, methyl ethyl ketone solvate having one or more characteristics selected from the group consisting of a powder X-ray diffraction pattern, a 13 C NMR spectrum and a Raman spectrum;

wherein the powder X-ray diffraction pattern characteristic is selected from

a) a powder X-ray diffraction pattern comprising peaks at 7.7±0.2, 8.1±0.2 and 23.1±0.2 degrees 2-Theta;

b) a powder X-ray diffraction pattern comprising peaks at 7.7±0.2, 8.1±0.2, 23.1±0.2 and 17.0±0.2 degrees 2-Theta; and

c) a powder X-ray diffraction pattern comprising peaks at 7.7±0.2, 8.1±0.2, 23.1±0.2, 17.0±0.2 and 25.8±0.2 degrees 2-Theta;

wherein the 13 C solid state NMR spectrum characteristic is selected from

a) a 13 C solid state NMR spectrum comprising peaks at 7.2, 206.4 and 215.8 ppm; each ±0.2 ppm;

b) a 13 C solid state NMR spectrum comprising peaks at 7.2, 206.4, 215.8 and 42.2 ppm; each ±0.2 ppm; and

c) a 13 C solid state NMR spectrum comprising peaks at 7.2, 206.4, 215.8, 42.2 and 101.2 ppm; each ±0.2 ppm; and

wherein the Raman spectrum characteristic is selected from

a) a Raman spectrum comprising peaks at 1511, 1644 and 3081 cm −1 , each ±2 cm −1 ,

b) a Raman spectrum comprising peaks at 1511, 1644, 3081 and 1265 cm −1 ; each ±2 cm −1 ; and

c) a Raman spectrum comprising peaks at 1511, 1644, 3081,1265 and 446 cm −1 ; each ±2 cm −1 .

5. The compound (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate, dimethylsulfoxide solvate.

6. The compound of claim 5 which is crystalline (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate, dimethylsulfoxide solvate.

7. The compound of claim 6 which is crystalline (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate, dimethylsulfoxide solvate having one or more characteristics selected from the group consisting of a powder X-ray diffraction pattern, a 13 C solid state NMR spectrum and a Raman spectrum;

wherein the powder X-ray diffraction pattern characteristic is selected from

a) a powder X-ray diffraction pattern comprising peaks at 7.4±0.2, 14.8±0.2 and 26.2±0.2 degrees 2-Theta;

b) a powder X-ray diffraction pattern comprising peaks at 7.4±0.2, 14.8±0.2, 26.2±0.2 and 10.8±0.2 degrees 2-Theta; and

c) a powder X-ray diffraction pattern comprising peaks at 7.4±0.2, 14.8±0.2, 26.2±0.2, 10.8±0.2 and 22.3±0.2 degrees 2-Theta;

wherein the 13 C solid state NMR spectrum characteristic is selected from

a) a 13 C solid state NMR spectrum comprising peaks at 173.4±0.2, 210.7±0.2 and 26.2±0.2 ppm;

b) a 13 C solid state NMR spectrum comprising peaks at 173.4±0.2, 210.7±0.2, 26.2±0.2 and 22.8±0.2 ppm; and

c) a 13 C solid state NMR spectrum comprising peaks at 173.4±0.2, 210.7±0.2, 26.2±0.2, 22.8±0.2 and 25.5±0.2 ppm; and

wherein the Raman spectrum characteristic is a Raman spectrum comprising peaks at 1717±2 and 675±2 cm −1 .

8. The compound (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate, dimethylsulfoxide solvate hydrate.

9. The compound of claim 8 which is crystalline (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate, dimethylsulfoxide solvate hydrate.

10. The compound of claim 6 which is crystalline (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate, dimethylsulfoxide solvate hydrate having a powder X-ray diffraction pattern characteristic;

wherein the X-ray powder diffraction pattern characteristic is selected from

a) a powder X-ray diffraction pattern comprising peaks at 14.5±0.2, 25.6±0.2 and 26.6±0.2 degrees 2-Theta;

b) a powder X-ray diffraction pattern comprising peaks at 14.5±0.2, 25.6±0.2, 26.6±0.2 and 21.9±0.2 degrees 2-Theta; and

c) a powder X-ray diffraction pattern comprising peaks at 14.5±0.2, 25.6±0.2, 26.6±0.2, 21.9±0.2, 17.8±0.2 degrees 2-Theta.

11. A pharmaceutical composition comprising a therapeutically effective amount of (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate, or a pharmaceutically acceptable salt, solvate or hydrate thereof, a pharmaceutically acceptable carrier and a buffering agent wherein:

a) the pharmaceutically acceptable salt is selected from the group consisting of benzathine, calcium, choline, diethylamine, diolamine, magnesium, meglumine, lysine, piperazine, potassium, tris(hydroxymethyl)aminomethane and sodium;

b) the molar ratio of the salt counterion to the (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate in the pharmaceutically acceptable salt is approximately 0.5:1 to approximately 3:1; and

c) the buffering agent is selected from the group consisting of phosphoric acid, citric acid, maleic acid, tartaric acid, lactic acid and acetic acid.

12. The pharmaceutical composition of claim 11 wherein:

a) the pharmaceutically acceptable salt is sodium;

b) the molar ratio of the sodium counterion to the (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate in the pharmaceutically acceptable salt is approximately 0.5:1 to approximately 2:1;

c) the buffering agent is citric acid; and

d) the molar ratio of (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-L-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl dihydrogen phosphate to citric acid is approximately 2:1 to approximately 10:1.

13. The pharmaceutical composition of claim 11 wherein the composition is in the form of a powder or lyophile wherein the solution pH of the reconstituted formulation is in the range of 2 to 6.

14. The pharmaceutical composition of claim 13 wherein the solution pH of the reconstituted formulation is in the range of 3 to 5.

15. The pharmaceutical composition of claim 14 wherein the pharmaceutical composition further comprises one or more stabilizing agents.

16. The pharmaceutical composition of claim 15 wherein the one or more stabilizing agents are selected from the group consisting of polyethylene glycol 300, polyethylene glycol 400 and polyethylene glycol 3350.

17. The pharmaceutical composition of claim 14 wherein the pharmaceutical composition further comprises one or more solubilizing agents.

18. The pharmaceutical composition of claim 17 wherein the solubilizing agent is selected from the group consisting of polysorbate 20, polyethoxylated castor oil, polyethylene glycol (15)-hydroxystearate, hydroxypropyl-beta-cyclodextrin, sulfobutylether-beta cyclodextrin, gamma cyclodextrin, and polysorbate 80.

19. The pharmaceutical composition of claim 18 wherein the solubilizing agent is polysorbate 80 and the buffering agent is citric acid.