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Abstract Background and Objective Tinengotinib, a novel multi-target small molecule kinase inhibitor, is currently undergoing phase II clinical trial in the USA and China. The purpose of this open-label study was to investigate the absorption, metabolism, and excretion of [14C]tinengotinib following a single oral dose in healthy subjects. Methods Six healthy male subjects received a single oral dose of [14C]tinengotinib capsules at 10 mg/100 µCi, and blood, urine, and feces samples were collected. Phenotyping experiments were further conducted to confirm the enzymes involved in its metabolism. Results Tinengotinib was rapidly absorbed in plasma with a time to peak drug concentration (T max) of 1.0–4.0 h post-dose and a long terminal half-life (t ½) of 23.7 h. Blood-to-plasma radioactivity concentration ratios across timepoints ranged from 0.780 to 0.827, which indicated minimal association of radioactivity with blood cells. The mean cumulative excreted radioactivity was 99.57% of the dose, including 92.46% (68.65% as unchanged) in feces and 7.11% (0.28% as unchanged) in urine. In addition to unchanged tinengotinib, a total of 11 radioactive metabolites were identified in plasma, urine, and feces. The most abundant circulating radioactivity was the parent drug in plasma, which comprised 88.23% of the total radioactivity area under the concentration–time curve (AUC). Metabolite M410-3 was a major circulating metabolite, accounting for 5.38% of the parent drug exposure and 4.75% of the total drug-related exposure, respectively. All excreted metabolites accounted for less than 5.10% and 1.82% of the dose in feces and urine, respectively. In addition, no unique metabolites were observed in humans. Tinengotinib was metabolized mainly via CYP3A4. Conclusions Overall, tinengotinib demonstrated a complete mass balance with limited renal excretion, no disproportionate blood metabolism, and slow elimination, primarily through the fecal route. The results of this study provide evidence to support the rational use of tinengotinib as a pharmacotherapeutic agent. Registration ChinadrugTrials.org.cn identifier: CTR20212852.

Abstract Introduction The B cell survival factor B lymphocyte stimulator (BLyS) is elevated in patients with systemic lupus erythematosus (SLE) and associated with disease activity. Belimumab, a monoclonal antibody specific for soluble BLyS, is approved for the treatment of adults with active, autoantibody-positive SLE receiving standard therapy. Ethnicity is one of the factors that can potentially affect the pharmacokinetics (PK) of therapeutic monoclonal antibodies, and therefore their efficacy and safety. Methods This phase 1, open-label study (200909) evaluated the pharmacokinetics (PK, primary objective), pharmacodynamics (PD), and safety (secondary objectives) of belimumab in Chinese patients with SLE (N = 20). Blood samples were taken up to 84 days after a single intravenous (IV) dose of belimumab 10 mg/kg. Results Peak serum concentrations of belimumab (C max) were obtained within the 1-h infusion. Geometric mean C max, area under the concentration–time curve (time 0 to last quantifiable concentration), terminal half-life, systemic clearance, and volume of distribution were 221 μg/mL, 2395 day·μg/mL, 14.6 days, 4.06 mL/day/kg, and 85.7 mL/kg, respectively. Decreases in CD20+, CD20+/CD27− naïve, CD20+/CD69+ active, CD20+/CD138+ plasmacytoid, CD19+/CD27BRIGHT/CD38BRIGHT SLE subset, and CD20−/CD138+ plasma B Cells post-dose were accompanied by an increase in CD20+/CD27+ memory B cells. Four cases of upper respiratory tract infection (three mild, one moderate) and one case of mild pharyngitis were possibly drug-related; all resolved during the study. Conclusion PK of a single belimumab 10 mg/kg IV dose in Chinese patients with SLE were similar to those observed previously in Japanese and American (white and African-American) patients with SLE. PD results were consistent with belimumab inhibiting BLyS, and belimumab was well tolerated. These data support the use of belimumab in Chinese patients with SLE. Trial Registration ClinicalTrials.gov identifier, NCT02880852.