Abstract
Introduction: RC98 is the monoclonal antibody against Programmed Cell Death Ligand 1 (PD-L1). Relevant reports have confirmed that the influence of PD-L1 expressed by tumor cells on antitumor CD8+ T cell responses is well characterized, but the impact of PD-L1 expressed by immune cells has not been well defined.
Objective: This study aimed to design a Pharmacokinetics/Pharmacology (PK/PD) study of RC98 in normal cynomolgus monkeys to research the effect on the immune system.
Methods: RC98 and vehicle were administered to cynomolgus monkeys at 15 mg/kg via intravenous infusion once a week for 4 weeks to evaluate the relationship between PK and PD. The pharmacodynamic activity was measured by the PD-L1 receptor occupancy (RO) in CD3+ T cells, A T-cell-dependent antibody response (TDAR), and the concentration of soluble PD-L1.
Results: The pharmacokinetic result showed that the exposure from the last administration was lower than that of the first administration, probably due to immunogenicity production. There was a strong correlation between systemic exposure and RO in CD3+ T cells but decreased RO levels after the last dose, which indirectly reflected the activation of T cells. The keyhole limpet hemocyanin (KLH)-induced TDAR in the RC98 group was higher than in the vehicle group. The concentration of soluble PD-L1 had increased feedback with RC98, and the concentration of soluble PD-L1 was maintained at a higher level after multiple doses than before dosing.
Conclusion: These data indicate that the immune system was clearly activated. In addition, the non-clinical data could provide a basis for its efficacy evaluation in clinical trials.
Keywords: RC98, pharmacokinetic, receptor occupancy, T cell-dependent antibody response, soluble PD-L1, cynomolgus monkeys.
[http://dx.doi.org/10.1016/j.immuni.2013.07.012] [PMID: 23890059]
[http://dx.doi.org/10.2174/0929867324666170804143706] [PMID: 28782469]
[http://dx.doi.org/10.1016/j.immuni.2018.03.014] [PMID: 29562194]
[http://dx.doi.org/10.3389/fimmu.2020.586907] [PMID: 33329566]
[http://dx.doi.org/10.1016/j.ejca.2020.01.003] [PMID: 32037060]
[http://dx.doi.org/10.3389/fimmu.2017.00961] [PMID: 28848559]
[http://dx.doi.org/10.1136/jclinpath-2017-204853] [PMID: 29097600]
[http://dx.doi.org/10.1146/annurev.immunol.26.021607.090331] [PMID: 18173375]
[http://dx.doi.org/10.1038/nm730] [PMID: 12091876]
[http://dx.doi.org/10.4049/jimmunol.169.10.5538] [PMID: 12421930]
[http://dx.doi.org/10.1080/15476910500362838] [PMID: 18958673]
[http://dx.doi.org/10.1056/NEJMoa1200690] [PMID: 22658127]
[http://dx.doi.org/10.1056/NEJMoa1200694] [PMID: 22658128]
[http://dx.doi.org/10.1016/j.xphs.2018.12.014] [PMID: 30599169]
[http://dx.doi.org/10.1186/s13045-019-0779-5] [PMID: 31488176]
[http://dx.doi.org/10.1080/1547691X.2019.1635234] [PMID: 31290717]
[http://dx.doi.org/10.1016/j.yrtph.2014.02.008] [PMID: 24566336]
[http://dx.doi.org/10.1016/j.jaci.2011.08.008] [PMID: 21908031]
[http://dx.doi.org/10.1016/j.ymeth.2006.07.020] [PMID: 17161298]
[http://dx.doi.org/10.1016/S1074-7613(00)00030-3] [PMID: 11021528]
[http://dx.doi.org/10.4049/jimmunol.164.10.5015] [PMID: 10799854]
[http://dx.doi.org/10.1038/s41577-019-0264-y] [PMID: 31965064]