IP Library Granted Patent US 10,118,897
Granted Patent B2
US 10,118,897 · App. 15/462,688 · Granted Nov 6, 2018

Crystalline forms of a prolyl hydroxylase inhibitor

Inventors: Claudia Witschi (San Francisco, CA); Jung Min Park (San Francisco, CA); Michael D. Thompson (Redwood City, CA); Michael John Martinelli (San Francisco, CA); David A. Yeowell (Chapel Hill, NC); Michael P. Arend (Foster City, CA)
Assignee: FibroGen, Inc.
C07D217/26A61K31/47C07B2200/13
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Quick Facts
Patent No.
US 10,118,897
App. No.
15/462,688
Granted
Nov 6, 2018
Kind
B2
Abstract

The present disclosure relates to crystalline solid forms of [(4-hydroxy-1-methyl-7-phenoxy-isoquinoline-3-carbonyl)-amino]-acetic acid, the process of preparing the forms, and pharmaceutical compositions and methods of use thereof.

Claims (18)

1. A process for preparing crystalline [(4-hydroxy-1-methyl-7-phenoxy-isoquinoline-3-carbonyl)-amino]-acetic acid (Compound A), comprising contacting Compound A, or a salt thereof, with acetic acid for a time sufficient to provide a crystalline Compound A wherein at least about 95% of the crystalline Compound A is Form A.

2. The process of claim 1 , wherein the process further comprises, following said contacting step, isolating the crystalline Compound A Form A.

3. The process of claim 2 , wherein the isolating comprises the steps of filtering, washing and drying the crystalline Compound A Form A.

4. The process of claim 1 , wherein the contacting comprises adding the acetic acid to Compound A at a temperature of from about 10° C. to about 90° C.

5. The process of claim 4 , wherein the acetic acid is added to the Compound A as an aqueous solution, slowly with stirring.

6. The process of claim 1 , wherein prior to contacting Compound A with the acetic acid, an aqueous solution of sodium hydroxide is added slowly to a stirred suspension of Compound A in water at temperature of from about 10° C. to about 90° C.

7. The process of claim 1 , wherein the Compound A Form A is characterized by a differential scanning calorimetry (DSC) curve that comprises an endotherm at about 223° C.

8. The process of claim 7 , wherein the DSC curve is substantially as shown in FIG. 2 .

9. The process of claim 1 , wherein the Compound A Form A is characterized by an X-ray powder diffractogram comprising a peak at 8.5 ° 2θ±0.2 ° 2θ.

10. The process of claim 1 , wherein the Compound A Form A is characterized by an X-ray powder diffractogram comprising a peak at 16.2 ° 2θ±0.2 ° 2θ.

11. The process of claim 1 , wherein the Compound A Form A is characterized by an X-ray powder diffractogram comprising a peak at 27.4 ° 2θ±0.2 ° 2θ.

12. The process of claim 1 , wherein the Compound A Form A is characterized by an X-ray powder diffractogram comprising peaks at 8.5, 16.2, and 27.4 ° 2θ±0.2° 2θ.

13. The process of claim 12 , wherein the X-ray powder diffractogram further comprises peaks at 12.8, 21.6, and 22.9 ° 2θ±0.2 ° 2θ.

14. The process of claim 1 , wherein the Compound A Form A is characterized by an X-ray powder diffractogram substantially as shown in FIG. 1 .

15. The process of claim 1 , wherein at least about 99% of the crystalline Compound A produced by the process is Compound A Form A.

16. The process of claim 1 , wherein at least about 99.5% of the crystalline Compound A produced by the process is Compound A Form A.

17. The process of claim 1 , wherein at least about 99.9% of the crystalline Compound A produced by the process is Compound A Form A.

18. The process of claim 1 , wherein at least about 99.99% of the crystalline Compound A produced by the process is Compound A Form A.

Assignments (4)
CHANGE OF NAME Recorded Feb 18, 2026
From: FIBROGEN, INC.
To: KYNTRA BIO, INC.
Reel/Frame 074923/0352 →
RELEASE OF SECURITY INTEREST Recorded Sep 3, 2025
From: WILMINGTON TRUST, NATIONAL ASSOCIATION, AS AGENT
To: FIBROGEN, INC.
Reel/Frame 072785/0760 →
SECURITY INTEREST Recorded May 1, 2023
From: FIBROGEN, INC.
To: WILMINGTON TRUST, NATIONAL ASSOCIATION
Reel/Frame 063504/0221 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 6, 2017
From: WITSCHI, CLAUDIA; PARK, JUNG MIN; THOMPSON, MICHAEL D.; MARTINELLI, MICHAEL JOHN; YEOWELL, DAVID A.; AREND, MICHAEL P.
To: FIBROGEN, INC.
Reel/Frame 042927/0185 →
Continuity (6)
Continuation 14805345 · Jul 21, 2015
Continuation 13942443 · Jul 15, 2013
Provisional Application 61832566 · Jun 7, 2013
Provisional Application 61768297 · Feb 22, 2013
Provisional Application 61672191 · Jul 16, 2012
Related Publication 20170190667A1 · Jul 6, 2017