Pharmacokinetics of Sifuvirtide in Treatment-Naive and Treatment-Experienced HIV-Infected Patients

The pharmacokinetics assessment in two clinical studies of sifuvirtide (a novel HIV fusion inhibitor) was first reported in Chinese HIV patients. Nineteen treatment-naive HIV patients were treated with s.c.(subcutaneous injection) sifuvirtide [10 or 20 mg q.d.(quaque die)] for 28 days in study 1, and eight treatment-experienced HIV patients were treated with s.c. sifuvirtide (20 mg q.d.) in combination with HAART drugs (lamivudine, didanosine, and Kaletra) for 168 days in study 2. In study 1, T-1/2 was 17.8 +/- 3.7 h for 10 mg group and 39.0 +/- 3.5 h for 20 mg group; the mean C-max of last dose was 498 +/- 54 ng/mL for 10 mg group and 897 +/- 136 ng/mL for 20 mg group. In study 2, T-1/2 was 6.71 +/- 2.17 h in treatment-experienced patients. C-max was 765 +/- 288 ng/mL after last 168th dosage. Sifuvirtide showed improved clinical pharmacokinetics characteristics compared with Enfuvirtide, and showed very different pharmacokinetic characteristics between treatment-naive and treatment-experienced patients. (c) 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:4038-4047, 2014