Granted Patent B2

US 12,365,865 · App. 17/050,608 · Granted Jul 22, 2025

Inventors: Claire G. Zhang (Rockville, MD); Shaojie Weng (Rockville, MD); Ya-Chen Chang (Rockville, MD); Franz M. Gerner (Rockville, MD)

Assignee: REGENXBIO INC.

C12M47/02B01D39/18B01D39/2068C12N15/86B01D2239/065C12N2750/14143C12N2750/14151

Abstract

Claims (19)

1. A method for the clarification of a feed containing recombinant adeno-associated virus (rAAV) particles and an impurity comprising: (a) providing a feed comprising a suspension cell culture; (b) pretreating the feed by adding salt to a final concentration between about 0.2 M and about 0.6 M; (c) applying the pretreated feed to a filter train comprising a primary depth filter connected to a secondary depth filter, wherein the outflow of the primary depth filter is connected to the inflow of the secondary depth filter; (d) applying a buffer comprising 200 mM salt to the filter train after step (c); and (e) recovering a filtrate comprising the rAAV particles, wherein (i) the impurity comprises cells or cellular debris, (i) the method separates the rAAV particles from the impurity without the use of centrifugation or tangential flow microfiltration prior to (a), (iii) the feed volume is between about 100 liters and about 3000 liters, and (iv) steps (c) and (d) are performed at a flux between about 175 L/m 2 /hr (LMH) and about 225 LMH.

2. The method of claim 1 , wherein the filter train further comprises a tertiary filter connected to the secondary depth filter, wherein the outflow of the secondary depth filter is connected to the inflow of the tertiary filter.

3. The method of claim 1 , wherein the primary depth filter comprises a porous depth filter media comprising at least 2 graded layers of non-woven fibers having a total thickness of about 0.3 cm to about 3 cm, and wherein each of the at least 2 graded layers of non-woven fibers have a nominal pore size rating more than about 40 μm.

4. The method of claim 1 , wherein the secondary depth filter comprises a media comprising a composite of cellulose and diatomaceous earth.

5. The method of claim 2 , wherein the tertiary filter comprises a sterilizing grade filter media.

6. The method of claim 1 , wherein the ratio of primary filter area to secondary filter area is between about 1:3 and about 3:1.

7. The method of claim 2 , wherein the ratio of primary filter area to tertiary filter area is between about 1:3 and about 3:1.

8. The method of claim 2 , wherein the ratio of primary filter area to secondary filter area to tertiary filter area ratio is within the range of about 0.3-3 to about 0.3-3 to about 0.2-5.

9. The method of claim 1 , wherein the suspension culture is comprises a culture of Human Embryonic Kidney 293 HEK293 cells.

10. The method of claim 1 , wherein the culture has a total cell density of between about 1×10 6 cells/ml and about 30×10 6 cells/ml.

11. The method of claim 1 , wherein the salt in step (b) is NaCl.

12. The method of claim 1 , wherein the rAAV particles comprise an AAV capsid protein from an AAV selected from AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV-11, AAV-12, AAV-13, AAV-14, AAV-15 and AAV-16, AAV.rh8, AAV.rh10, AAV.rh20, AAV.rh39, AAV.Rh74, AAV.RHM4-1, AAV.hu37, AAV.Anc80, AAV.Anc80L65, AAV.7m8, AAV.PHP.B, AAV2.5, AAV2tYF, AAV3B, AAV.LK03, AAV.HSC1, AAV.HSC2, AAV.HSC3, AAV.HSC4, AAV.HSC5, AAV.HSC6, AAV.HSC7, AAV.HSC8, AAV.HSC9, AAV.HSC10, AAV.HSC11, AAV.HSC12, AAV.HSC13, AAV.HSC14, AAV.HSC15, and AAV.HSC16.

13. The method of claim 12 , wherein the AAV capsid serotype is AAV-8 or AAV-9.

14. The method of claim 1 , wherein the feed volume is between about 500 liters and about 3000 liters.

15. A method for producing a composition comprising isolated recombinant adeno-associated virus (rAAV) particles from a feed comprising an impurity, comprising

(a) clarifying the feed according to the method of claim 1 , and

(b) isolating the rAAV particles from the filtrate by one or more of tangential flow filtration, affinity chromatography, size exclusion chromatography, ion exchange chromatography, and hydrophobic interaction chromatography.

16. The method of claim 15 , wherein the isolating the rAAV particles comprises a first tangential flow filtration, affinity chromatography, anion exchange chromatography, and a second tangential flow filtration.

17. The method of claim 1 , wherein the feed is not pretreated with a chemical flocculent.

Assignments (1)

Continuity (3)

References Cited (21)