Characterizing interspecies differences in gastric fluid properties to improve understanding of in vivo oral drug formulation performance

An in-depth understanding of the properties of gastric fluid(s) prior to an in vivo pharmacokinetic investigation can vastly improve predictions of in vivo performance. Previously, properties of animal and human gastric fluids have been characterized with varying methods. Unfortunately, characterization has often not been thorough, and some properties, such as density and viscosity, have not been reported. Here, human, porcine and canine gastric fluids were harvested and characterized for pH, viscosity, surface tension, density, and osmolarity. We found that the variability of pH and surface tension between dogs was significantly higher than the variability between pigs, and, furthermore, gastric fluids collected from the same canine species (beagles) housed in two different countries (Denmark and China) had surprisingly different pH values. Next, an in vitro dissolution study in diluted gastric fluids from each species was performed using minitablets containing ibuprofen. Human gastric fluids and porcine gastric fluids showed similar dissolution profiles and corroborated well with biorelevant human Fasted State Simulated Gastric Fluid (FaSSGF). In contrast, differences in canine gastric fluids caused highly variable dissolution results. We systematically compared our findings to those in the literature and based on this evaluation, propose obtaining aspirates from the animals used for in vivo studies to ensure knowledge on the fluid properties affecting the performance of the formulated drug in question.

Improved Formula for Predicting Hemodialyzability of Intravenous and Oral Drugs

BACKGROUND

The rate of drug removal by hemodialysis needs to be considered when designing drug dosage regimens for patients on hemodialysis. We previously developed a simplified equation to predict the removal rates of intravenously administered drugs by hemodialysis. Here, we addressed shortcomings of this equation and developed a more accurate equation that can also predict the removal rates of orally administered drugs.

METHODS

A total of 70 drugs with known pharmacokinetic and physical parameters and drug removal rates that were measured during hemodialysis in clinical cases were randomly assigned at a 4:1 ratio to a training data group or a test data group. A prediction equation was developed by performing stepwise multiple regression analyses using the training data (i.e., the removal rate by hemodialysis) as the objective variable and pharmacokinetic parameters as the explanatory variables. The equation was validated using the test data.

RESULTS

Multiple regression analyses revealed that molecular weight (MW), protein binding rate, and fraction excreted unchanged in urine relative to the volume of distribution (Vd) were independently correlated with the drug clearance rate (adjusted coefficient of determination, 0.83; p = 2.2e-16). The following equation was obtained: drug removal rate by hemodialysis (%) = -17.32 × [log (MW)] - 0.39 × [protein binding rate (%)] + 0.06 × [fraction excreted unchanged in urine (%)/Vd (L/kg)] + 83.34. Validation of the equation using the test data showed a very high correlation between predicted and measured reduction rate (R = 0.93, p = 1.87e-6). Mean error was -3.34 (95% confidence interval: -10.03, 3.35), mean absolute error was 9.59, and root mean square error was 16.48.

CONCLUSION

The modified equation derived in this study using pharmacokinetic and physical parameters as variables precisely predicted the removal rates of both intravenous and oral drugs by hemodialysis.

Real-world experience of palbociclib and ribociclib: novel oral therapy in metastatic breast cancer

Background Palbociclib and ribociclib are novel oral agents in hormone receptor-positive metastatic breast cancer. Neutropenia is a common adverse event associated with these treatments and its clinical management often requires regimen changes, such as cycle delays and dose adjustments. Objective To provide a real-world experience of the effectiveness and toxicities associated with these drugs and to evaluate the impact of regimen changes in disease progression. Setting This study was performed at Hospital Universitario La Paz, in Spain. Methods Observational, retrospective study which included hormone receptor-positive metastatic breast cancer patients who initiated treatment with palbociclib or ribociclib between March 1st, 2018 and March 1st, 2019. Main outcome measure The primary effectiveness variable was progression-free survival. Safety evaluation was performed to determine neutropenia-incidence and severity, as well as its clinical management, including dose adjustments and treatment interruptions. Correlations between these regimen changes and effectiveness were also evaluated. Results Sixty-one patients were included, 33 treated with palbociclib and 28 with ribociclib. Palbociclib was mainly used as second line of treatment in the metastatic setting (81.8%) and ribociclib as first line (67.9%). The median progression-free survival was 12.76 months (95% CI 7.5 to not estimable) in palbociclib and not reached in ribociclib. After 12 months, the progression-free survival rate was 51.5% (95% CI 34-69) in palbociclib and 78.6% (95% CI 63-94.1) in ribociclib. Neutropenia was the most common adverse event with an incidence rate of 87.9% in palbociclib and 82.1% in ribociclib. Cycle delays were needed in more than half of the patients treated with palbociclib and ribociclib (63.6% and 64.3%). Dose adjustments were seen in 42.4% and 53.6% of the patients receiving palbociclib and ribociclib, respectively. Regimen changes did not involve statistically significant differences in 12-month PFS rates in the cohort investigated. Conclusion Palbociclib and ribociclib outcomes are comparable to those reached in the phase III trials, PALOMA-3 and MONALEESA-2, respectively, and cannot be compared as they were used in different treatment settings. The toxicity profile is favourable, being neutropenia the most common adverse event, easily managed with regimen changes. Further studies are needed to confirm the observed tendency of no detrimental impact on effectiveness of these regimen changes.

Oral etoposide in heavily pre-treated metastatic breast cancer: results from the ESME cohort and comparison with other chemotherapy regimens

INTRODUCTION

HER2-negative metastatic breast cancer (MBC) is a common setting in which chemotherapy could be effective even in later lines of treatment. Oral etoposide has demonstrated clinical activity in this setting in small-scale studies, but its efficacy has not been compared to that of other chemotherapy regimens.

METHODS

We used the ESME database (Epidemiological Strategy and Medical Economics), a real-life national French multicentre cohort of MBC patients initiating therapy between 1 January 2008 to 31 December 2014. HER2-negative MBC patients who received oral etoposide as > 3rd chemotherapy line and for more than 14 days were included. Primary objective was progression-free survival (PFS); secondary objectives were overall survival (OS), and propensity-score matched Cox models including comparison with other therapies in the same setting.

RESULTS

Three hundred forty-five out of 16,702 patients received oral etoposide and 222 were eligible. Median PFS was 3.2 months [95% CI 2.8-4] and median OS 7.3 months [95% CI 5.7-10.3]. Median PFS did not significantly differ according to the therapeutic line. The only prognostic factor for both PFS and OS was the MBC phenotype (hormone receptor-positive versus triple-negative, HR = 0.71 [95% CI 0.52-0.97], p = 0.028 for PFS and HR = 0.65 [0.46-0.92], p = 0.014 for OS). After matching for the propensity score, no differential effect on PFS or OS was observed between oral etoposide and other chemotherapy regimens administered in the same setting (HR = 0.94 [95% CI 0.77-1.15], p = 0.55 for PFS and HR = 1.10 [95% CI 0.88-1.37], p = 0.40 for OS).

CONCLUSION

Oral etoposide retains some efficacy in selected heavily pre-treated patients with HER2-negative MBC, with the advantages of oral administration.

Non-conventional dosing of oral anticancer agents in oncology and malignant haematology: a systematic review protocol

BACKGROUND

Recent advances in cancer therapeutics have resulted in significantly improved overall survival and progression-free survival for patients. Targeted oral systemic anticancer therapies (SACT) offer a range of treatment approaches that differ from traditional cytotoxic chemotherapy: non-cytotoxic oral SACT target malignant disease continuously, have less broad and more favourable safety profiles, which can improve patients' quality of life (QoL). Toxicities associated with daily oral SACT administration can, however, result in non-adherence and a reduced QoL. Non-conventional dosing of oral SACT, where unlicensed doses/schedules of drugs are prescribed, is one approach increasingly adopted by clinicians to reduce toxicities and subsequent non-adherence and to improve QoL. Guidance governing this practice is, however, limited. This systematic review aims to identify evidence about prescribing practices of, and outcomes from, non-conventional dosing of oral SACT in oncology and malignant haematology.

METHODS

A search using the following electronic databases will be conducted: Ovid MEDLINE, Ovid EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Cochrane Registry of Controlled Trials. Studies will be selected based on predefined inclusion/exclusion criteria. Critical appraisal will be conducted to identify potential biases, strengths and limitations of included studies. Extracted data will be tabulated to sort and summarise key findings. An initial literature search indicated that studies reporting non-standard dosing of oral SACT intervention studies are diverse and heterogeneous in study design. Extracted data will, therefore, be tabulated, and together with a narrative synthesis of integrated key findings, will be presented and discussed in reference to the strengths and weaknesses of the evidence base. If sufficient stratified data is available (e.g. age group, tumour type, disease stage) or intervention (drug, dosing schedule), sub-group analysis will be conducted to inform prescribing practice.

DISCUSSION

This review will identify relevant literature on the topic to inform prescribers working in oncology and malignant haematology. It will also analyse any evidence of the following outcomes: toxicity, treatment adherence and/or QoL outcomes for patients receiving non-standard doses of oral SACT. Limitations in the evidence base may arise from variability in both the type and quality of studies reviewed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017076195 .

Oral proteasome inhibitor with strong preclinical efficacy in myeloma models

BACKGROUND

The proteasome is a validated anti-cancer target and various small-molecule inhibitors are currently in clinical development or on the market. However, adverse events and resistance associated with those proteasome inhibitors indicate the need for a new generation of drugs. Therefore, we focused on developing an oral proteasome inhibitor with improved efficacy and safety profiles.

METHOD

The in vitro inhibition of the 20S proteasome catalytic activities was determined in human multiple myeloma (MM) cellular lysates with fluorogenic peptide substrates specific for each catalytic subunit. Cell cytotoxicity was assessed with the ATP bioluminescence assay using human cell samples from tumor cell lines, MM patients or normal healthy donors. In mice bearing human MM xenografts, a single dose of LC53-0110 was administered orally, and concentration-time profiles of LC53-0110 and the 20S proteasome catalytic activities in plasma, blood, and tumor were determined. The efficacy of repeat-dose compound with regard to tumor growth inhibition in vivo was also evaluated in the same MM xenograft models.

RESULTS

LC53-0110 is far more specific for the chymotrypsin-like proteolytic (β5) site of the 20S proteasome as compared to bortezomib, carfilzomib, or ixazomib. LC53-0110 treatment showed accumulation of ubiquitinated proteins, inhibited cell viability with a low nM range potency in various tumor cell lines, and showed potent activity on CD138(+) cells isolated from MM patients who are resistant/refractory to current FDA-approved drug treatment. When a single dose was administered orally to tumor-bearing mice, LC53-0110 showed both greater maximum and sustained tumor proteasome inhibition as compared with ixazomib in MM xenograft models. The robust pharmacodynamic responses in tumor correlated with tumor growth regression. In addition, LC53-0151, an analog of LC53-0110, in combination with pomalidomide, a third-generation immunomodulatory drug, showed synergistic inhibition of tumor growth both in vitro and in the xenograft mouse model.

CONCLUSIONS

In view of the in vitro, in vivo, and ex vivo profiles, further investigation of additional LC compounds in preclinical studies is warranted for the nomination of a clinical development candidate.

Combination therapy with daclatasvir and asunaprevir for dialysis patients infected with hepatitis C virus

The standard antiviral therapy for dialysis patients infected with hepatitis C virus (HCV) is (pegylated) interferon monotherapy, but its efficacy is insufficient. Oral direct-acting antiviral agents (DAAs) have recently been developed for chronic hepatitis C patients. However, some DAAs have contraindications for chronic renal failure (CRF). Daclatasvir and asunaprevir are metabolized largely in the liver and are not contraindicated in CRF. Combination therapy with daclatasvir and asunaprevir was used for 4 dialysis patients infected with genotype 1b HCV. One patient had viral breakthrough, and the 3 others had sustained virological response 12. One patient was admitted for heart failure and percutaneous coronary intervention due to concomitant ischemic disease. Heart failure was unlikely to be caused by the combination therapy, as it was probably due to water overload. The patient continued to receive the combination therapy after the remission of the heart failure. The combination therapy was well tolerated in the other patients.

Oral treatment with a novel small molecule alpha 4 integrin antagonist, AJM300, prevents the development of experimental colitis in mice

BACKGROUND AND AIMS

Inhibition of lymphocyte trafficking by treatment with an anti-α4 integrin antibody has been clinically validated as a therapeutic approach for inflammatory bowel disease (IBD), and the orally effective 'anti-α4 integrin therapy' may be more convenient in clinical practice. The aim of this study was to investigate the pharmacological profile and anti-inflammatory effect of a novel, orally active small molecule α4 integrin antagonist, AJM300.

METHODS

The binding specificity/potency of HCA2969 (the active metabolite of AJM300) were investigated in vitro. The pharmacodynamics for α4 integrin antagonism of AJM300 was investigated in mice. The anti-inflammatory effect of AJM300 fed in a diet and the anti-α4 integrin monoclonal antibody was evaluated in a mouse colitis model induced by transfer of IL-10 deficient T cells.

RESULTS

HCA2969 selectively inhibited the in vitro binding of α4 integrin (α4β7/α4β1) to the cell adhesion molecules. Oral treatment with AJM300 dose-dependently inhibited lymphocyte homing to Peyer's patches and increased the peripheral lymphocyte count in the same dose range. AJM300 dose-dependently prevented the development of experimental colitis in mice. A significant inhibition of colon weight increase was accompanied by inhibition of T-cell infiltration into the lamina propria of colon. The maximum efficacy of AJM300 (1% diet) was comparable to that achieved by the saturated α4 integrin blockade with antibody.

CONCLUSIONS

Oral treatment with the selective small molecule α4 integrin antagonist (AJM300) prevented the development of colitis and its efficacy was comparable to that of the anti-α4 integrin antibody.