[Population pharmacokinetics of two recombinant human coagulation factor â § preparations in patients with hemophilia A].

Objective: To compare the differences in population pharmacokinetic (PK) parameters between two recombinant coagulation factor Ⅷ (FⅧ) preparations, Kogenate FS and Advate, in patients with hemophilia A, and to provide the theoretical basis of precise individualized treatment for those patients. Methods: Patients with moderate or severe hemophilia A who had at least one injection of Kogenate FS or Advate at 41 international hemophilia centers were enrolled as subjects from the WAPPS-Hemo project since January 2015 to December 2017. The half-lives of the two drugs and the time of FⅧ activity reaching 2% (TAT 2%) were calculated, and the differences of PK between the two drugs among different age and dose subgroups were further analyzed. Results: ①The mean age of patients in the Kogenate FS (n=117) and Advate groups (n=120) were (27.6±17.7) and (23.4±16.2) years old, respectively. All patients in the two groups were males. ②The administration doses in the Kogenate FS and Advate groups were (31.5±13.1) IU/kg and (38.17±14.83) IU/kg, respectively; the half-lives of the two drugs were (12.3±3.5) h and (10.8±2.9) h, respectively; and the TAT 2% were (65.2±21.7) h and (57.0±17.9) h, respectively. ③In the Kogenate FS group, the drug half-lives in patients aged ≥12 and <12 years old were (12.7±3.7) h and (11.1±2.5) h, respectively; the TAT 2% were (68.6±22.9) h and (55.8±14.6) h, respectively. In the Advate group, the drug half-lives in patients aged ≥12 and <12 years old were (11.4±3.1) h and (9.4±1.8) h, respectively; and the TAT 2% were (61.1±18.0) h and (45.2±11.3) h, respectively. ④In the Kogenate FS group, the drug half-lives in <20 IU/kg, (20-29) IU/kg, (30-39) IU/kg and ≥40 IU/kg groups were (13.3±4.0) h, (12.3±3.6) h, (12.2±3.5) h and (11.6±2.6) h, respectively; and the TAT 2% were (61.5±21.4) h, (63.9±22.4) h, (67.0±24.3) h and (68.0±19.5) h, respectively. In the Advate group, the drug half-lives in <20 IU/kg, (20-29) IU/kg, (30-39) IU/kg and <40 IU/kg groups were (11.5±3.8) h, (11.4±3.7) h, (11.0±2.9) h and (10.4±2.3) h, respectively; and the TAT 2% were (50.8±19.2) h, (56.7±21.0) h, (58.2±18.8) h and (58.1±15.8) h, respectively. Conclusion: The PK parameters of Kogenate FS are superior to those of Advate among different age and dose subgroups.

Comment on "Finding finite-time invariant manifolds in two-dimensional velocity fields" [Chaos 10, 99 (2000)].

This note serves as a commentary of the paper of Haller [Chaos 10, 99 (2000)] on techniques for detecting invariant manifolds. Here we show that the criterion of Haller can be improved in two ways. First, by using the strain basis reference frame, a more efficient version of theorem 1 of Haller (2000) allows to better detect the manifolds. Second, we emphasize the need to nondimensionalize the estimate of hyperbolic persistence. These statements are illustrated by the example of the Kida ellipse. (c) 2001 American Institute of Physics.