Pharmacokinetics, pharmacodynamics, and safety of single-dose subcutaneous sarilumab with or without methotrexate in Japanese patients with rheumatoid arthritis: Two single-dose studies

Objectives To assess the safety and pharmacokinetics (PK) of single-dose subcutaneous (SC) sarilumab or tocilizumab SC +/- methotrexate (MTX) and to assess the pharmacodynamics (PD) of sarilumab SC or tocilizumab SC monotherapy in Japanese rheumatoid arthritis (RA) patients. Methods TDU13402 was a randomized, double-blind, placebo-controlled, single-ascending dose Phase 1 study (NCT01850680). Twenty-four patients (6 per treatment group) received sarilumab 50, 100, or 200 mg plus MTX or placebo (2 per cohort) on Day (D) 1; PK and safety were assessed through D57. PDY14191 was a randomized, open-label, single-dose study (NCT02404558). Thirty patients (15 per arm) received sarilumab 150 mg or tocilizumab 162 mg on D1; PK, PD, and safety were assessed through D43. Results TDU13402: mean serum sarilumab exposure increased in a greater than dose proportional manner from 50 to 200 mg dose with no clinically meaningful increase in treatment-emergent adverse events (TEAEs). PDY14191: PK profiles of single-dose sarilumab 150 mg or tocilizumab 162 mg were similar; some numerical differences in PD profiles and TEAEs were observed. Neutrophil count decrease/neutropenia was the most frequently reported TEAE with sarilumab treatment in both studies. Conclusions PK, PD, and safety profiles of single-dose sarilumab SC with/without MTX were consistent with results anticipated in Japanese patients with RA.