Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

12.2           Pharmacodynamics

The exposure-response relationship and time course of pharmacodynamic response for the safety and effectiveness of margetuximab-cmkb have not been fully characterized.

Pharmacokinetic Properties

12.3           Pharmacokinetics

Following the approved recommended dosage, the steady-state geometric mean (%CV) Cmax of margetuximab-cmkb is 466 (20%) µg/mL and AUC0-21d is 4120 (21%) µg.day/mL in patients with HER2-positive relapsed or refractory advanced breast cancer. Margetuximab-cmkb undergoes both linear and nonlinear elimination. After a single dose, margetuximab-cmkb Cmax and AUC0-21d increase in an approximately dose proportional manner from 10 to 18 mg/kg (0.67 to 1.2 times the approved recommended dose). At the approved recommended dosage, time to steady-state was 2 months, and accumulation ratio was 1.65 based on AUC0-21d. No clinically significant differences in margetuximab-cmkb exposure were observed when infusion time was reduced from 120 minutes to 30 minutes.

Distribution

Margetuximab-cmkb geometric mean (%CV) steady-state volume of distribution is 5.47 L (22%).

Elimination

The geometric mean (%CV) terminal half-life of margetuximab-cmkb is 19.2 days (28%) and clearance is 0.22 L/day (24%). Four months after margetuximab-cmkb discontinuation, concentrations decrease to approximately 3% of the steady-state trough serum concentration.

Metabolism

Margetuximab-cmkb is expected to be metabolized into small peptides by catabolic pathways.
Specific Populations
No clinically significant differences in margetuximab-cmkb PK were observed based on age (29 to 83 years), sex, race (Caucasian, Black, Asian), mild to moderate (CLcr 30 to 89 mL/min estimated using the Cockcroft-Gault equation) renal impairment, mild hepatic impairment (total bilirubin ≤ ULN and AST > ULN, or total bilirubin 1 to 1.5 ULN and any AST), HER2 expression level (0 to 3 by IHC), tumor burden (2 – 317 mm), ECOG score (0 to 2), albumin (24 to 50 g/L), FCGR3A (CD16A), FCGR2A (CD32A) and FCGR2B (CD32B) genotype, number of metastatic sites (≤ 2 or > 2), number of prior therapy lines (≤ 2 or > 2) or concurrent chemotherapies (capecitabine, gemcitabine, eribulin and vinorelbine).

The effect of severe renal impairment (CLcr 15 to 29 mL/min), end-stage renal disease with or without hemodialysis, and moderate (total bilirubin > 1.5 to ≤ 3 ULN and any AST) or severe hepatic impairment (total bilirubin >3 ULN and any AST) on margetuximab-cmkb PK is unknown.