Recombinant human acid alpha-glucosidase
Provided are a recombinant acid α-glucosidase and pharmaceutical composition comprising a recombinant acid α-glucosidase, wherein the recombinant acid α-glucosidase is expressed in Chinese hamster ovary (CHO) cells and comprises an increased content of N-glycan units bearing one or two mannose-6-phosphate residues when compared to a content of N-glycan units bearing one or two mannose-6-phosphate residues of alglucosidase alfa. Also provided herein are methods of producing, purifying, and formulating the recombinant acid α-glucosidase or pharmaceutical composition for administration to a subject and methods of treating a disease or disorder such as Pompe disease using the recombinant acid α-glucosidase or pharmaceutical composition.
1. A method of reducing urine hexose tetrasaccharide in an ERT-switch patient having Pompe disease in need thereof, the method comprising:
intravenously administering to the patient a population of recombinant human acid a-glucosidase (rhGAA) molecules from Chinese hamster ovary (CHO) cells at a dose of 20 mg/kg; and
concurrently or sequentially orally administering miglustat or a pharmaceutically acceptable salt thereof at a dose of 260 mg,
wherein the rhGAA molecules comprise seven potential N-glycosylation sites;
wherein the rhGAA molecules on average comprise 3-4 mannose-6-phosphate (M6P) residues; and
wherein the rhGAA molecules on average comprise at least 0.5 mol bis-mannose-6-phosphate (bis-M6P) per mol of rhGAA at the first potential N-glycosylation site as determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS),
and wherein, compared to baseline, the patient's levels of urine hexose tetrasaccharide after six months of treatment are reduced by at least 35%.
2. The method of claim 1 , wherein the population of rhGAA molecules is administered bimonthly, monthly, bi-weekly, weekly, twice weekly, or daily.
3. The method of claim 1 , wherein the miglustat or pharmaceutically acceptable salt thereof is administered prior to administration of the rhGAA.
4. The method of claim 1 , wherein the rhGAA molecules comprise an amino acid sequence having at least 95% sequence identity to SEQ ID NO: 1 or SEQ ID NO: 5.
5. The method of claim 1 , wherein at least 30% of the rhGAA molecules comprise one or more N-glycan units bearing one mannose-6-phosphate residue (mono-M6P) or bis-M6P, as determined using LC-MS/MS.
6. The method of claim 1 , wherein the rhGAA molecules comprise on average from 0.5 mol to 7.0 mol of mono-M6P or bis-M6P per mol of rhGAA, as determined using LC-MS/MS.
7. The method of claim 1 , wherein the rhGAA molecules comprise on average at least 2.5 mol M6P per mol of rhGAA and at least 4 mol sialic acid per mol of rhGAA, as determined using LC-MS/MS.
8. The method of claim 1 , wherein, per mol of rhGAA, the rhGAA molecules comprise on average:
(a) 0.4 to 0.6 mol mono-M6P at the second potential N-glycosylation site;
(b) 0.4 to 0.6 mol bis-M6P at the fourth potential N-glycosylation site; and
(c) 0.3 to 0.4 mol mono-M6P at the fourth potential N-glycosylation site;
wherein (a)-(c) are determined using LC-MS/MS.
9. The method of claim 8 , wherein, per mol of rhGAA, the rhGAA molecules comprise on average:
(a) 0.9 to 1.2 mol sialic acid at the third potential N-glycosylation site;
(b) 0.8 to 0.9 mol sialic acid at the fifth potential N-glycosylation site; and
(c) 1.5 to 4.2 mol sialic acid at the sixth potential N-glycosylation site;
wherein (a)-(c) are determined using LC-MS/MS, and
wherein, per mol of rhGAA, the rhGAA molecules further comprise 4 mol to 7.3 mol sialic acid.
10. The method of claim 1 , wherein the population of rhGAA molecules is formulated in a pharmaceutical composition.
11. The method of claim 10 , wherein the pharmaceutical composition further comprises at least one buffer selected from the group consisting of a citrate, a phosphate, and a combination thereof, and at least one excipient selected from the group consisting of mannitol, polysorbate 80, and a combination thereof; wherein the pharmaceutical composition has a pH of 5.0 to 7.0.
12. The method of claim 11 , wherein, in the pharmaceutical composition, the population of rhGAA molecules is present at a concentration of 5-50 mg/mL, the at least one buffer is a sodium citrate buffer present at a concentration of 10-100 mM, the at least one excipient is mannitol present at a concentration of 10-50 mg/mL and polysorbate 80 present at a concentration of 0.1-1 mg/mL, and the pharmaceutical composition further comprises water and optionally comprises an acidifying agent and/or alkalizing agent; wherein the pharmaceutical composition has a pH of 6.0.
13. The method of claim 1 , wherein, compared to baseline, the patient's pulmonary function, as measured by an upright forced vital capacity (FVC) test, is improved after six months of treatment.
14. The method of claim 1 , wherein, after six months of treatment, the patient is ambulatory and, compared to baseline, the patient's creatine kinase levels are reduced by at least 15%; or the patient is nonambulatory and, compared to baseline, the patient's creatine kinase levels are reduced by at least 20%.
15. A method of improving pulmonary function in an ERT-switch patient having Pompe disease in need thereof, the patient having an upright forced vital capacity (FVC) of 30-80% of predicted normal value, the method comprising:
intravenously administering to the patient a population of recombinant human acid α-glucosidase (rhGAA) molecules from Chinese hamster ovary (CHO) cells at a dose of 20 mg/kg; and
concurrently or sequentially orally administering miglustat or a pharmaceutically acceptable salt thereof at a dose of 260 mg,
wherein the rhGAA molecules comprise seven potential N-glycosylation sites;
wherein the rhGAA molecules on average comprise 3-4 mannose-6-phosphate (M6P) residues; and
wherein the rhGAA molecules on average comprise at least 0.5 mol bis-mannose-6-phosphate (bis-M6P) per mol of rhGAA at the first potential N-glycosylation site as determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS).
16. The method of claim 15 , wherein the improvement of pulmonary function is measured by an upright forced vital capacity (FVC) test after six months of treatment and the patient exhibits an improvement in FVC of at least 4%.
17. A method of reducing creatine kinase levels in an ERT-switch patient having Pompe disease in need thereof, the method comprising:
intravenously administering to the patient a population of recombinant human acid a-glucosidase (rhGAA) molecules from Chinese hamster ovary (CHO) cells at a dose of 20 mg/kg; and
concurrently or sequentially orally administering miglustat or a pharmaceutically acceptable salt thereof at a dose of 260 mg,
wherein the rhGAA molecules comprise seven potential N-glycosylation sites;
wherein the rhGAA molecules on average comprise 3-4 mannose-6-phosphate (M6P) residues; and
wherein the rhGAA molecules on average comprise at least 0.5 mol bis-mannose-6-phosphate (bis-M6P) per mol of rhGAA at the first potential N-glycosylation site as determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and wherein after six months of treatment, if the patient is ambulatory, compared to baseline, the patient's creatine kinase levels are reduced by at least 15%; or if the patient is nonambulatory, compared to baseline, the patient's creatine kinase levels are reduced by at least 20%.
18. The method of claim 1 , wherein the patient has an upright forced vital capacity (FVC) of 30-80% of predicted normal value.
19. The method of claim 17 , wherein the patient has an upright forced vital capacity (FVC) of 30-80% of predicted normal value.