PI-047 - COMPARISON OF PATIENT-CENTRIC MICROSAMPLING VS. TRADITIONAL BLOOD SAMPLING FOR PHARMACOKINETIC ANALYSIS OF ABROCITINIB.

M. Shahin¹, S. Tripathy¹, J. Winton¹, X. Wan¹, D. Stanciu², V. Le¹, O. Kavetska¹, B. Malhotra³; ¹Pfizer Global Research and Development, Groton, CT, USA, ²Pfizer Global Research and Development, Groton, CT, United Kingdom, ³Pfizer, New York, NY, USA.

Background: Patient-centric microsampling has the potential to transform clinical trials as it allows for remote sampling, with minute sample volume, and potentially lesser invasive collection method in comparison to conventional collection methods for systemic blood levels. Herein, we aimed to compare the pharmacokinetics of abrocitinib (ABRO) samples collected using Tasso vs. conventional venous sampling.

Methods: In this open-label, randomized, single dose, crossover, 3-treatment, 6 sequence, 3-period study, 19 healthy participants were randomized to receive one of the following: ABRO 200 mg tablet (TRT A), ABRO 200 mg suspension (TRT B), or famotidine (40 mg tablet) + ABRO 200 mg tablet (TRT C). Serum micro samples, obtained using Tasso-SST and Tasso+, as well as venous plasma samples for all subjects in all periods were collected at three selected time points (1, 8, 12 hrs). PK parameters were calculated using Pfizer-validated Software (oNCA, ver. 2.6.21). Natural log-transformed AUClast, and Cmax of abrocitinib were analyzed using a mixed-effects model with sequence, period, and treatment as fixed effects and subject within sequence as a random effect.

Results: Mean abrocitinib concentration-time profiles were similar between Tasso serum and venous plasma for each of the treatments (TRT A, B and C). For TRT A, B, and C, the 90% confidence intervals for the geometric mean ratios for AUClast and Cmax of Tasso Serum (Test) vs. venous plasma (Reference) were wholly contained within the bioequivalence (BE) acceptance range (80 - 125%).

Conclusion: Abrocitinib AUClast, and Cmax ratios (Tasso serum vs. venous plasma) met the BE criteria for each treatment. These results confirm the feasibility of using Tasso as a reliable patient-centric collection device for PK analysis of abrocitinib.