Metabolism and Interspecies Variation of IMMH-010, a Programmed Cell Death Ligand 1 Inhibitor Prodrug

IMMH-010 is an ester prodrug of YPD-29B, a potent programmed cell death ligand 1 (PD-L1) inhibitor. The metabolism of IMMH-010 was investigated and compared in various species. Four metabolites of IMMH-010 were identified, and the major metabolite was the parent compound, YPD-29B, which was mainly catalyzed by carboxylesterase 1 (CES1). We observed IMMH-010 metabolism in the plasma of various species. IMMH-010 was rapidly metabolized to YPD-29B in rat and mouse plasma, whereas it remained stable in human and monkey plasma. In the liver S9 fractions of human, monkey, dog, and rat, IMMH-010 was quickly transformed to YPD-29B with no obvious differences among species. In addition, the transformation ratio of IMMH-010 to YPD-29B was low in rat and human intestines, which indicated that the intestine was not an important site for IMMH-010 hydrolysis. Moreover, we demonstrated the remarkable antitumor efficacy of IMMH-010 in B16F10 melanoma and MC38 colon carcinoma xenograft mouse models. We also compared the pharmacokinetic profiles of IMMH-010 in rodents and primates. After oral administration of IMMH-010, the general exposure of active metabolite YPD-29B was slightly lower in primates than in rodents, suggesting that data should be extrapolated cautiously from rodents to humans.

Identification and Analysis of Components in Yizhi Granule and Cynomolgus Monkey Plasma after Oral Administration by UPLC/ESI-Q-TOF MS and Their Protective Effects on PC12 Cells

Yizhi Granule (YZG) is a health food containing six traditional Chinese medicines (TCMs). It improves memory barriers in rat experiments. Here, we describe the first fast and sensitive ultraperformance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC/ESI-Q-TOF MS) method for analyzing YZG in plasma. We used this technique for studies in cynomolgus monkey plasma. By comparing retention time, MS, and MS/MS data of reference compounds, 70 compounds were detected in YZG. Of these, 63 were identified including 60 saponins, 2 flavones, and 1 methyl ester. There were 33 saponins, 1 flavone, and 1 methyl ester in the plasma. Next, to study the therapeutic properties of YZG, the neuroprotective effect of some of the absorbed components was evaluated using PC12 cell damage caused by the Aβ25–35 model. The results showed that 9 compounds protect PC12 cells from Aβ25–35 with cell viability (%) of 111.00 ± 8.12 (G-Rb1), 102.20 ± 4.22 (G-Rb2), 100.34 ± 6.47 (G-Rd), 102.83 ± 2.10 (G-Re), 101.68 ± 7.64 (NG-Fa), 101.19 ± 7.83 (NG-R1), 102.53 ± 0.55 (NG-R2), 106.88 ± 4.95 (gypenoside A), and 103.95 ± 4.11 (gypenoside XLIX), respectively, versus the control group (87.51 ± 6.59). These results can reveal the real pharmacodynamic basis of YZG and provide a theoretical basis for subsequent studies. It can also provide some references for the research of Alzheimer’s disease.

Specific Substitutions in Region V2 of gp120 env confer SHIV Neutralisation Resistance

A tier 2 SHIV-MK38 strain was obtained after two in vivo passages of tier 1 SHIV-MK1. SHIV-MK38#818, cloned from the MK38 strain, was neutralisation-resistant, like the parental MK38 strain, to SHIV-infected monkey plasma (MP), HIV-1-infected human pooled plasma (HPP), and KD247 monoclonal antibody (mAb) (anti-V3 gp120 env). We investigated the mechanisms underlying the resistance of #818, specifically the amino acid substitutions that confer resistance to MK1. We introduced amino acid substitutions in the MK1 envelope by in vitro mutagenesis and then compared the neutralisation resistance to MP, HPP, and KD247 mAb with #818 in a neutralisation assay using TZM-bl cells. We selected 11 substitutions in the V1, V2, C2, V4, C4, and V5 regions based on the alignment of env of MK1 and #818. The neutralisation resistance of the mutant MK1s with 7 of 11 substitutions in the V1, C2, C4, and V5 regions did not change significantly. These substitutions did not alter any negative charges or N-glycans. The substitutions N169D and K187E, which added negative charges, and S190N in the V2 region of gp120 and A389T in V4, which created sites for N-glycan, conferred high neutralisation resistance. The combinations N169D+K187E, N169D+S190N, and N169D+A389T resulted in MK1 neutralisation resistance close to that of #818. The combinations without 169D were neutralisation-sensitive. Therefore, N169D is the most important substitution for neutralisation resistance. This study demonstrated that although the V3 region sequences of #818 and MK1 are the same, V3 binding antibodies cannot neutralise #818 pseudovirus. Instead, mutations in the V2 and V4 regions inhibit the neutralisation of anti-V3 antibodies. We hypothesised that 169D and 190N altered the MK1 Env conformation so that the V3 region is buried. Therefore, the V2 region may block KD247 from binding to the tip of the V3 region.