NCT01110291: induction of CYP3A activity and lowered exposure to docetaxel in patients with primary breast cancer

Factors affecting the efficacy and safety of docetaxel combined with platinum in the treatment of advanced non-small cell lung cancer

BACKGROUND

This study aimed to quantitatively evaluate factors influencing the efficacy and safety of the docetaxel-platinum regimen to provide reliable information for optimizing chemotherapy regimens.

RESEARCH DESIGN AND METHODS

A parametric survival function model was used to describe the time course of overall survival (OS) of patients with advanced non-small cell lung cancer (NSCLC) receiving a docetaxel-platinum regimen. A random-effects model in a single-arm meta-analysis was used to analyze the objective response rate and grade 3-4 adverse event rates based on various docetaxel-platinum regimens.

RESULTS

The model revealed that the risk of death in East Asians was approximately 1.5-fold higher than that in non-East Asians, with a median OS of 13.7 (95% confidence interval [CI]: 12.8-14.7) months and 9.3 (95% CI: 7.7-11.1) months, respectively. No significant impact of different administration regimens on OS was found. However, when drug exposure increased, the incidence of grade 3-4 anemia or neutropenia significantly increased.

CONCLUSIONS

The docetaxel-platinum regimen has different efficacies in the treatment of advanced NSCLC between East Asian and non-East Asian populations. A better benefit-risk ratio can be obtained with a lower exposure regimen of docetaxel combined with platinum.

Potential Dexamethasone-Direct Oral Anticoagulant Drug Interaction: Is This a Concern in COVID?

OBJECTIVE

To evaluate the literature on a potential dexamethasone-direct oral anticoagulant (DOAC) drug interaction and provide management considerations with COVID hypercoagulability.

DATA SOURCES

A search of EMBASE, PubMed, and Google Scholar (January 1990 to May 2021), limited to the English language, using applicable search terms resulted in 137 articles, with 21 relevant articles included. Regulatory agency and clinical guidance documents were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

Included articles describe in vitro or in vivo animal or human data for dexamethasone induction of cytochrome P450 (CYP) 3A4 or P-glycoprotein (P-gp).

DATA SYNTHESIS

Dexamethasone has the potential to interact with the DOACs via CYP3A4 and/or P-gp induction. Only apixaban and rivaroxaban have CYP3A4 metabolism. Dexamethasone can increase CYP3A4 activity by up to 70% and reduce the area under the concentration-time curve (AUC) of CYP3A4 substrates by >40%, which is consistent with criteria for a weak CYP inducer. In rodents, dexamethasone P-gp induction is associated with AUC reductions of 20% to 50%. Human data are lacking.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Severe COVID-19 infection is associated with hypercoagulability. Although heparins are the preferred anticoagulants for hospitalized COVID-19 patients, DOACs are being utilized. Dexamethasone is recommended for hospitalized COVID-19 patients requiring supplemental oxygen. The concurrent use of dexamethasone and apixaban or rivaroxaban in such patients carries the potential for reduced anticoagulant effect during a state of heightened thrombotic risk.

CONCLUSIONS

Concurrent use of dexamethasone and apixaban or rivaroxaban in hospitalized COVID-19 patients with laboratory evidence of COVID coagulopathy should be avoided until higher-quality data are available.

Role of TDM-based dose adjustments for taxane anticancer drugs

The classical taxanes (paclitaxel, docetaxel), the newer taxane cabazitaxel and the nanoparticle-bound nab-paclitaxel are among the most widely used anticancer drugs. Still, the optimal use and the value of pharmacological personalization of the taxanes is still controversial. We give an overview on the pharmacological properties of the taxanes, including metabolism, pharmacokinetics-pharmacodynamic relations and aspects in the clinical use of taxanes. The latter includes the ongoing debate on the most effective and safe regimen, the recommended initial dose, and pharmacological dosing individualization. The taxanes are among the most widely used anticancer drugs in patients with solid malignancies. Despite their longtime use in clinical routine, the optimal dosing strategy (weekly versus 3-weekly) or optimal average dose (cabazitaxel, nab-paclitaxel) has not been fully resolved, as it may differ according to tumour entity and line of treatment. The value of pharmacological individualization of the taxanes (TDM, TCI) has been partly explored for 3-weekly paclitaxel and docetaxel, but remains mostly unexplored for cabazitaxel and nab-paclitaxel at present.

Use of Taxanes in Metastatic HER2-negative Breast Cancer - a Status Report

The most important goal of treatment of patients with metastatic breast cancer is maintenance or even improvement of quality of life. In this setting, chemotherapy should be used with as much restraint as possible. If palliative chemotherapy is indicated, the taxane drug class is an established treatment option. The updated guidelines of the Gynaecological Oncology Working Group (AGO), Breast Committee, of the German Society for Gynaecology and Obstetrics (DGGG) and the German Cancer Society e. V. (DKG) provide recommendations with the greatest possible evidence on which of the licensed taxanes can be used in which treatment situation in the metastatic setting.

Effects of prednisone on docetaxel pharmacokinetics in men with metastatic prostate cancer: A randomized drug-drug interaction study

AIMS

Docetaxel has been approved for the treatment of metastatic prostate cancer in combination with prednisone. Since prednisone is known to induce the cytochrome P450 iso-enzyme CYP3A4, which is the main metabolizing enzyme of docetaxel in the liver, a potential drug-drug interaction may occur. In this prospective randomized pharmacokinetic cross-over study we investigated docetaxel exposure with concomitant prednisone, compared to docetaxel monotherapy in men with metastatic prostate cancer.

METHODS

Patients scheduled to receive at least 6 cycles of docetaxel (75 mg/m² ) and who gave written informed consent were randomized to receive either the 1^st 3 cycles, or the last 3 consecutive cycles with prednisone (twice daily 5 mg). Pharmacokinetic blood sampling was performed during cycle 3 and cycle 6. Primary endpoint was difference in docetaxel exposure, calculated as area under the curve (AUC_0-inf ) and analysed by means of a linear mixed model. Given the cross-over design the study was powered on 18 patients to answer the primary, pharmacokinetic, endpoint.

RESULTS

Eighteen evaluable patients were included in the trial. Docetaxel concentration with concomitant prednisone (AUC_0-inf 2784 ng*h/mL, 95% confidence interval 2436-3183 ng*h/mL) was similar to the concentration of docetaxel monotherapy (AUC_0-inf 2647 ng*h/mL, 95% confidence interval 2377-2949 ng*h/mL). Exploratory analysis showed no toxicity differences between docetaxel monotherapy and docetaxel cycles with prednisone.

CONCLUSION

No significant difference in docetaxel concentrations was observed. In addition, we found similar toxicity profiles in absence and presence of prednisone. Therefore, from a pharmacokinetic point of view, docetaxel may be administrated with or without prednisone.

Phase I study of the gamma secretase inhibitor PF-03084014 in combination with docetaxel in patients with advanced triple-negative breast cancer

Background

The NOTCH signaling pathway may be involved in the survival of stem cell-like tumor-initiating cells and contribute to tumor growth. In this phase Ib, open-label, multicenter study (NCT01876251), we evaluated PF-03084014, a selective gamma-secretase inhibitor in patients with advanced triple-negative breast cancer.

Methods

The dose-finding part was based on a 2×3 matrix design using the modified toxicity probability interval method. Oral PF-03084014 was administered twice daily continuously in combination with intravenous docetaxel given on day 1 of each 21-day cycle. Primary endpoint was first-cycle dose-limiting toxicity (DLT) for the dose-finding part and 6-month progression-free survival (PFS) for the expansion cohort treated at the maximum tolerated dose (MTD). Secondary endpoints included safety, objective response, and pharmacokinetics of the combination.

Results and Conclusions

The MTD was estimated to be PF-03084014 100 mg twice daily / docetaxel 75 mg/m2. At this dose level, combination treatment was generally well tolerated (one DLT, grade 3 diarrhea, among eight DLT-evaluable patients). The most common all-grade, treatment-related adverse events reported in all patients (N = 29) were neutropenia (90%), fatigue (79%), nausea (72%), leukopenia (69%), diarrhea (59%), alopecia (55%), anemia (55%), and vomiting (48%). No effect was observed on the pharmacokinetics of docetaxel when administered in combination with PF-03084014. Four (16%) of 25 response-evaluable patients achieved a confirmed partial response; nine (36%) patients had stable disease, including five patients with unconfirmed partial response. In the expansion cohort, median PFS was 4.1 (95% CI 1.3-8.1) months (6-month PFS rate 17.1% [95% CI 0.8-52.6%]).

Pharmacogenetics, enzyme probes and therapeutic drug monitoring as potential tools for individualizing taxane therapy

The taxanes are a class of chemotherapeutic agents that are widely used in the treatment of various solid tumors. Although taxanes are highly effective in cancer treatment, their use is associated with serious complications attributable to large interindividual variability in pharmacokinetics and a narrow therapeutic window. Unpredictable toxicity occurrence necessitates close patient monitoring while on therapy and adverse effects frequently require decreasing, delaying or even discontinuing taxane treatment. Currently, taxane dosing is based primarily on body surface area, ignoring other factors that are known to dictate variability in pharmacokinetics or outcome. This article discusses three potential strategies for individualizing taxane treatment based on patient information that can be collected before or during care. The clinical implementation of pharmacogenetics, enzyme probes or therapeutic drug monitoring could enable clinicians to personalize taxane treatment to enhance efficacy and/or limit toxicity.

A physiologically based pharmacokinetic (PBPK) approach to evaluate pharmacokinetics in patients with cancer

Potential differences in pharmacokinetics (PK) between healthy subjects and patients with cancer were investigated using a physiologically based pharmacokinetic approach integrating demographic and physiological data from patients with cancer. Demographic data such as age, sex and body weight, and clinical laboratory measurements such as albumin, alpha-1 acid glycoprotein (AAG) and hematocrit were collected in ~2500 patients with cancer. A custom oncology population profile was built using the observed relationships among demographic variables and laboratory measurements in Simcyp® software, a population based ADME simulator. Patients with cancer were older compared with the age distribution in a built-in healthy volunteer profile in Simcyp. Hematocrit and albumin levels were lower and AAG levels were higher in patients with cancer. The custom population profile was used to investigate the disease effect on the pharmacokinetics of two probe substrates, saquinavir and midazolam. Higher saquinavir exposure was predicted in patients relative to healthy subjects, which was explained by the altered drug binding due to elevated AAG levels in patients with cancer. Consistent with historical clinical data, similar midazolam exposure was predicted in patients and healthy subjects, supporting the hypothesis that the CYP3A activity is not altered in patients with cancer. These results suggest that the custom oncology population profile is a promising tool for the prediction of PK in patients with cancer. Further evaluation and extension of this population profile with more compounds and more data will be needed.