Biomarker analysis of the phase II JO25567 study comparing erlotinib with or without bevacizumab in first-line advanced EGFR+non-small-cell lung cancer.

Background: Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs), such as erlotinib, are standard-of-care for patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC), but most patients progress within 1 year. Previously, we demonstrated that erlotinib plus bevacizumab (EB) improved progression-free survival (PFS) in patients with EGFR-positive non-squamous NSCLC in the randomized JO25567 study. To understand this effect, we conducted comprehensive exploratory biomarker analyses. Methods: Using blood and tissue specimens from patients enrolled in the JO25567 study, angiogenesis-related serum factors, plasma vascular endothelial growth factor-A (pVEGFA), angiogenesis-related gene polymorphisms, and messenger RNAs (mRNAs) in tumor tissue were analyzed. Interactions between potential predictors and treatment effect on PFS were analyzed in a Cox model. Continuous variable predictors were evaluated by multivariate fractional polynomial interaction methodology and subpopulation treatment effect pattern plotting (STEPP). Results: Overall, 152 patients treated with EB or erlotinib alone (E) were included in the analysis. Among 26 factors analyzed in 134 baseline serum samples, high follistatin and low leptin were identified as potential biomarkers for worse and better outcomes with EB, with interaction P values of 0.0168 and 0.0049, respectively. Serum concentrations of 12 angiogenic factors were significantly higher in patients with high follistatin. Low pVEGFA levels related to better outcomes with EB, interaction P=0.033. VEGF-A165a was the only predictive tissue mRNA, showing a similar trend to pVEGFA. No valid results were obtained in 13 polymorphisms of eight genes. Conclusions: EB treatment showed better treatment outcomes in patients with low pVEGFA and serum leptin, and limited efficacy in patients with high serum follistatin.

Ethnic sensitivity assessment of the antibody-drug conjugate trastuzumab emtansine (T-DM1) in patients with HER2-positive locally advanced or metastatic breast cancer.

PURPOSE: Trastuzumab emtansine (T-DM1) is indicated for previously treated HER2-positive metastatic breast cancer. Ethnic sensitivity assessment of T-DM1 was conducted using data from eight clinical studies to ensure that the clinically recommended dose is appropriate across ethnicities. METHODS: Four approaches were used: (1) non-compartmental analysis (NCA) comparing pharmacokinetic parameters of T-DM1 and relevant analytes across ethnic groups, (2) population pharmacokinetic (popPK) analysis assessing the impact of ethnicity on pharmacokinetics, (3) comparison of T-DM1 pharmacokinetics in Japanese patients versus the global population, and (4) exposure-response analyses assessing the impact of ethnicity on safety and efficacy. RESULTS: NCA pharmacokinetic parameters (T-DM1, total trastuzumab, DM1) were comparable across ethnic groups; mean cycle 1 T-DM1 AUCinf was 475, 442, and 518 day µg/mL for white (n = 461), Asian (n = 68), and others (n = 57), respectively. PopPK analysis showed that ethnicity (white, Asian, and others) was not a significant covariate for T-DM1 pharmacokinetics (n = 671). Additionally, visual predictive check plots indicated that observed pharmacokinetic profiles in Japanese patients (n = 42) were within the prediction interval generated from the final PopPK model. Exposure-response analyses showed that ethnicity was not a significant covariate impacting efficacy or hepatotoxicity risk, but there was a trend of greater thrombocytopenia risk among Asians versus non-Asians, which could not be explained by similar exposure between the ethnic groups. Most Asians with thrombocytopenia were able to continue T-DM1 using dose-adjustment rules recommended for the global population. CONCLUSIONS: These results suggest that T-DM1 pharmacokinetics are comparable across ethnic groups and that use of the current dosing regimen is appropriate across ethnicities.

Antigen-dependent internalization is related to rapid elimination from plasma of humanized anti-HM1.24 monoclonal antibody.

Anti-HM1.24 monoclonal antibody (AHM) is a humanized anti-HM1.24 monoclonal antibody that binds to the HM1.24 antigen, a protein that is highly expressed in multiple myeloma cells. The pharmacokinetics of AHM was determined in experiments in which AHM was administered intravenously to cynomolgus monkeys. The area under the plasma concentration-time curve increased by more than the dose ratio between 2 and 20 mg/kg, and nonlinear pharmacokinetics was observed. The elimination half-life of AHM from the plasma was 7.56 h at 2 mg/kg and 28.6 h at 20 mg/kg, which was shorter than that observed for other therapeutic humanized monoclonal antibodies, such as trastuzumab and bevacizumab. Although antibodies to AHM were detected in all monkeys on or after 10 days of administration, there was a temporal disassociation between the rapid elimination of AHM and the appearance of anti-AHM antibodies. HM1.24 antigen-dependent internalization and intracellular metabolism of AHM were investigated in peripheral blood mononuclear, KPMM2, and U937 cells. In all cases, AHM was rapidly internalized from the cell surface; this internalization was significantly prevented by phenylarsine oxide in KPMM2 cells, an inhibitor of receptor-mediated endocytosis, and the internalized AHM was subsequently degraded within the cells. Furthermore, immunofluorescence microscopy revealed that the internalized AHM is delivered to and degraded in late endosomes/lysosomes. Taken together, our results suggest that the rapid elimination of AHM from plasma in monkey is due to HM1.24 antigen-dependent internalization followed by delivery to the lysosomes.

The safety, tolerability, pharmacokinetics, and pharmacodynamics of single oral doses of CH4987655 in healthy volunteers: target suppression using a biomarker.

PURPOSE: CH4987655 (RO4987655) is an orally active and highly selective small-molecule MEK inhibitor. It potently inhibits mitogen-activated protein kinase signaling pathway activation and tumor cell growth, with an in vitro IC(50) of 5.2 nmol/L for inhibition of MEK1/2. Single-agent oral administration of CH4987655 resulted in complete tumor regressions in xenograft models. EXPERIMENTAL DESIGN: All 40 subjects received a single oral dose followed by 72 hrs of pharmacokinetic, pharmacodynamic, and safety/tolerability assessments. The pharmacodynamics were measured by changes in phosphorylated extracellular signal-regulated kinase (pERK) levels in a surrogate tissue peripheral blood mononuclear cells ex vivo stimulated by PMA. RESULTS: Doses of 0.5, 1, 2, 3, and 4 mg were safe and well tolerated. No clinically significant safety event was observed. A total of 26 adverse events (n = 15) were reported: 21 mild, 5 moderate, and none severe. Moderate adverse events were experienced by one subject at 1 mg (autonomic nervous system imbalance) and three subjects at 4 mg (diarrhea, abdominal pain, autonomic nervous system and acne). CH4987655 was rapidly absorbed with a t(max) of approximately 1 h. Exposures were dose proportional from 0.5 to 4 mg. The disposition was biphasic with a terminal t(1/2) of approximately 25 hr. Intersubject variability was low, 9% to 23% for C(max) and 14% to 25% for area-under-the-curve (AUC). pERK inhibition was exposure dependent and was greater than 80% inhibition at higher doses. The pharmacokinetic-pharmacodynamic relationship was characterized by an inhibitory E(max) model (E(max) approximately 100%; IC(50) 40.6 ng/mL) using nonlinear mixed-effect modeling. CONCLUSIONS: A significant extent of pERK inhibition was achieved for a single dose that was considered to be safe and well tolerated in healthy volunteers.