To Take or Not to Take With Meals? Unraveling Issues Related to Food Effects Labeling for Oral Antineoplastic Drugs

Physiologically Based Pharmacokinetic Absorption Model for Pexidartinib to Evaluate the Impact of Meal Contents and Intake Timing on Drug Exposure

Pexidartinib is a systemic treatment for patients with tenosynovial giant cell tumor not amenable to surgery. Oral absorption of pexidartinib is affected by food; administration with a high-fat meal (HFM) or low-fat meal (LFM) increases absorption by approximately 100% and approximately 60%, respectively, compared with the fasted state. Pexidartinib is currently dosed 250 mg orally twice daily with an LFM (approximately 11-14 g of total fat). We developed a physiologically based pharmacokinetic model to determine the impact on drug exposure of dose timing with respect to meals, meal type, and caloric content. A 15%-16% increase in plasma exposure was predicted when consuming an HFM 1 hour after dosing with an LFM, but almost no effect on pharmacokinetics was predicted when an HFM was consumed 3 hours or more before or after pexidartinib dosing with an LFM. Exposure was not significantly affected when pexidartinib was taken with a 500-kcal LFM over the range of fat (approximately 11-14 g of total fat; 20%-25% calories from fat) for an LFM. These findings on timing of pexidartinib dose with respect to meals should be considered by patients and physicians to reduce the potential for side effects.

Dosing Recommendation Based on the Effects of Different Meal Types on Pexidartinib Pharmacokinetics in Healthy Subjects: Implementation of Model-informed Drug Development Strategy

Pexidartinib, an oral small molecule inhibitor of the colony-stimulating factor 1 receptor, is approved for treatment of adults with symptomatic tenosynovial giant cell tumor associated with severe morbidity or functional limitations and not amenable to improvement with surgery. The original dosing regimen is 400 mg of pexidartinib (2 × 200-mg capsules) twice daily, administered on an empty stomach at least 1 hour before or 2 hours after a meal or snack. Because pexidartinib is likely to be taken over an extended period of time, the ability to take pexidartinib with a meal would simplify timing of administration and potentially improve compliance. Since administering 400 mg of pexidartinib with a low-fat meal increases exposure by ≈60% relative to the fasted state, administering 250 mg of pexidartinib with a low-fat meal (low-fat meal dosing regimen) was predicted to achieve an exposure similar to 400 mg administered during a fasted state (original dosing regimen). Based on clinical trial simulations with two one-sided t-tests and bootstrapping (ie, resampling) analyses, a bioequivalence study (n = 24) would have >90% power to conclude that the original dosing regimen (400 mg fasted twice daily) and the low-fat meal dosing regimen (250 mg with a low-fat meal twice daily) are bioequivalent. This report provides the outcome of the implementation of the model-informed drug development strategy to recommend and justify a low-fat meal dosing regimen for pexidartinib that has the potential to improve patient compliance while maintaining drug exposure.

Evaluation of a Low-Fat Low-Calorie Meal on the Relative Bioavailability of Trametinib and Dabrafenib: Results From a Randomized, Open-Label, 2-Part Study in Healthy Participants

In this randomized, open-label, 2-part, 2 × 2 crossover, phase 1 study, the effect of a low-fat low-calorie (LFLC) meal on the relative bioavailability of a trametinib 2-mg tablet or dabrafenib 150-mg capsule was evaluated in healthy participants. Trametinib adjusted geometric mean ratios (90%CI) of fed : fasted for area under the concentration-time curve (AUC) from time 0 to the last quantifiable concentration and AUC from time 0 extrapolated to infinity were 0.76 (0.71-0.82) and 0.82 (0.77-0.88), respectively. For dabrafenib, the adjusted geometric mean ratios of AUC from time 0 to the last quantifiable concentration and AUC from time 0 extrapolated to infinity (90%CI) for fed:fasted were 0.85 (0.79-0.91) and 0.86 (0.80-0.92), respectively. Consumption of an LFLC meal delayed trametinib and dabrafenib absorption, with an increase in time to maximum concentration of ≈15 and ≈30 minutes, respectively, compared to the fasted state. These findings indicate that consumption of an LFLC meal reduced the bioavailability and delayed the absorption of trametinib and dabrafenib, supporting current recommendations to administer both drugs in the fasting state; however, an occasional LFLC meal is unlikely to affect the pharmacokinetics of the drugs once steady state is reached and, by consequence, not likely to alter the overall intended efficacy.

New Oral Antitumor Drugs and Medication Safety in Uro-Oncology: Implications for Clinical Practice Based on a Subgroup Analysis of the AMBORA Trial

Oral antitumor therapeutics (OAT) bear a high risk for medication errors, e.g., due to drug–drug or drug–food interactions or incorrect drug intake. Advanced age, organ insufficiencies, and polymedication are putting uro-oncological patients at an even larger risk. This analysis sets out to (1) investigate the frequency and relevance of medication errors in patients with prostate cancer or renal cell carcinoma treated with OAT and (2) compile recommendations for clinical practice. This post-hoc subgroup analysis used data collected in the randomized AMBORA trial (2017–2020; DRKS00013271). Clinical pharmacologists/pharmacists conducted advanced medication reviews over 12 weeks after initiation of a new oral regimen and assessed the complete medication process for drug–related problems. Medication errors related to either the OAT, prescribed or prescription-free concomitant medication, or food were classified regarding cause and severity. We identified 67 medication errors in 38 patients within the complete medication within 12 weeks. Thereof, 55% were detected at therapy initiation, 27% were caused by the patients, and 25% were drug–drug or drug–food interactions. Problem-prone issues are summarized in a ‘medication safety table’ to provide recommendations for clinical practice in uro-oncology. Tailored strategies including intensified care by clinical pharmacologists/pharmacists should be implemented in clinical practice to improve medication safety.

An Easily Expandable Multi-Drug LC-MS Assay for the Simultaneous Quantification of 57 Oral Antitumor Drugs in Human Plasma

Simple Summary

Oral antitumor therapy has significantly improved clinical outcomes in multiple tumor entities. However, following a standard dosing regime, strong interindividual variability in patients’ plasma concentrations can be observed for many oral antitumor drugs. This results in risks of reduced therapeutic effect and increased side effects. Monitoring these variable plasma concentrations is an important tool in evaluating multiple factors influencing drug exposure and, if necessary, adjusting therapeutic doses. Here, we developed a method for the simultaneous measurement of 57 oral antitumor drug plasma concentrations. Detection and quantification were achieved using liquid chromatography coupled to an Orbitrap mass spectrometer, which can be easily expanded to newly approved oral antitumor drugs in the future. Applicability of the method was proven by measuring 71 plasma samples from 39 patients undergoing oral antitumor therapy. In summary, the developed method provides an important tool for exposure measurements of oral antitumor drugs.

Abstract

Oral anticancer drugs have led to significant improvements in the treatment of multiple tumor entities. However, in patients undergoing oral antitumor therapy, plasma concentrations are highly variable, resulting in risks of reduced therapeutic effects or an increase in side effects. One important tool to reduce this variability is therapeutic drug monitoring. In this work we describe a method to simultaneously quantify the plasma concentrations of 57 oral antitumor agents. Quantification of these drugs was achieved using liquid chromatography coupled to an Orbitrap mass spectrometer. The method was fully validated according to the FDA guidelines and constitutes a simple and robust way for exposure monitoring of a wide variety of oral anticancer drugs. Applicability to clinical routine was demonstrated by the analysis of 71 plasma samples taken from 39 patients. In summary, this new multi-drug method allows simultaneous quantification of 57 oral antitumor drugs, which can be applied to exposure monitoring in clinical studies, taking into account the broad variety of oral antitumor drugs prescribed in clinical routine.

Pooled Analysis of Gastric Emptying in Patients With Obesity: Implications for Oral Absorption Projection

PURPOSE

Gastric emptying time is one of limiting factors that determines the pharmacokinetic properties of drugs administered by mouth. Despite the high prevalence of obesity worldwide, modifications in gastric emptying time have not been systematically addressed in this set of patients. The current analysis aims to quantitatively address obesity-related changes in gastric emptying time of solids, semisolids, and liquids compared with lean individuals, highlighting the relevant pharmacokinetic implications of oral drug absorption in patients with obesity.

METHODS

We searched the Cochrane Library, PubMed, Web of Science, and Embase for all relevant articles published until November 1, 2020. Differences in gastrointestinal variables in relation to gastric emptying between obese and lean individuals were quantified by weighted mean difference (WMD) and ratio of means (RoM). Robustness of the analyses was evaluated by subgroup analysis and publication bias test.

FINDINGS

A total of 17 studies with 906 participants were included. The gastric half-emptying time of solids (WMD, -10.4 minutes; P = 0.001; RoM, 0.90; P = 0.01) and liquids (WMD, -6.14 minutes; P < 0.001; RoM, 0.83, P = 0.03) was significantly shorter in individuals with obesity compared with lean individuals. These findings were confirmed by the subgroup analyses and publication bias tests.

IMPLICATIONS

Our pooled analysis systemically quantifies the differences in gastric half-emptying time between individuals with obesity and lean individuals, facilitating better understanding and prediction of drug absorption in individuals with obesity through physiologically based pharmacokinetic approaches. Obesity is associated with a faster transit of both solids and liquids through the stomach.

Medication Errors During Treatment with New Oral Anticancer Agents: Consequences for Clinical Practice Based on the AMBORA Study

Patients treated with oral anticancer agents (e.g., kinase inhibitors) are a high-risk population for medication errors due to, for example, polymedication, age, and limited adherence. Systematic evaluations regarding frequencies and causes of medication errors and resulting harm are lacking. Our previously published multicenter randomized AMBORA trial revealed that an intensified support by clinical pharmacologists/pharmacists for patients and the treatment team considerably reduced drug-related problems and improved patient-reported outcomes. Using this database, we performed a comprehensive, additional analysis focusing on medication errors related to the patients' complete medication with consideration of the antitumor agents, concomitantly administered drugs, and herb/food intake. Two hundred two patients starting a new oral anticancer drug regardless of the tumor entity were included. Clinical pharmacologists/pharmacists performed advanced medication reviews for 12 weeks. Medication errors were characterized regarding type, cause, patient harm, and the involved medicines. We detected 1.7 medication errors per patient (335/202). Of the medication errors (216/335), 64.5% occurred within the concomitant medication. Patients caused 28.4% of the medication errors. There were 67.8% detected immediately after the start of the new oral regimen, and 14.9% resulted in temporary harm. Drug-drug or drug-food interactions accounted for 24.8% of the medication errors. Patients and physicians need to be addressed in strategies for systematic reduction of medication errors during treatment with new oral antitumor drugs. Clinical decision support systems focusing on drug-drug interactions capture only a minority of the medication errors. Specialists with expertise in clinical pharmacology/pharmacy should support both the treating physicians as well as the patients for improved patient safety.

Population pharmacokinetic analysis of RO5459072, a low water-soluble drug exhibiting complex food-drug interactions

Aims

RO5459072, a cathepsin‐S inhibitor, Biopharmaceutics Classification System class 2 and P‐glycoprotein substrate, exhibited complex, nonlinear pharmacokinetics (PK) while fasted that seemed to impact both the absorption and the disposition phases. When given with food, all nonlinearities disappeared. Physiologically based PK (PBPK) modelling attributed those nonlinearities to dose‐dependent solubilisation and colonic absorption. The objective of this population PK analysis was to complement the PBPK analysis.

Methods

PK profiles in 39 healthy volunteers after first oral dosing (1–600 mg) while fasted or fed in single and multiple ascending dose studies were analysed using population compartmental modelling.

Results

The PK of RO5459072 while fed was characterized by a 1‐compartmental PK model with linear absorption and elimination. The nonlinearities while fasted were captured using dose dependent bioavailability and 2 sequential first‐order absorption phases: one following drug administration and one occurring 11 hours later and only for doses >10 mg. The bioavailability in the first absorption phase increased between 1 and 10 mg and then decreased with dose, in agreement with in vitro dissolution and solubility studies. The remaining fraction of doses to be absorbed by the second absorption phase was found to have a bioavailability similar to that in the first absorption phase.

Conclusion

The population PK model supported that dissolution‐ and solubility‐limited absorption from the proximal and distal intestine alone explains the nonlinear PK of RO5459072 in fasted state and the linear PK in fed state. This work, together with the PBPK analysis, raised our confidence in the understanding of this complex PK.

New Oral Anti-Cancer Drugs and Medication Safety

BACKGROUND

Many oral anti-cancer drugs have come onto the market in the past 20 years. For example, kinase inhibitors, such as the BCR-ABL and BRAF inhibitors, have markedly improved the treatment of chronic myeloid leukemia and melanoma. In this review, we discuss the special challenges posed by poor adherence, drug-drug interactions with other substances, and side effects, among other problems, and the ways in which these challenges can be met.

METHODS

A selective search was carried out in PubMed for original and review articles on the safety of new oral anti-cancer drugs. Guidelines and current Summaries of Product Characteristics (SmPC) were also considered in the analysis.

RESULTS

Review articles have pointed out numerous safety concerns with oral anti-cancer drugs. One of these is adherence, on which highly variable figures are available (with mean non-adherence rates ranging from 0 to 54%). The absorption of approximately half of these drugs is influenced by the patient's diet, and that of approximately 20% by gastric pH (Caution: proton-pump inhibitors may influence bioavailability). 70% of the active substances are metabolized primarily by CYP3A4, which means that their pharmacokinetics can be altered by grapefruit juice and CYP3A4 modulators. The prevention, detection, and treatment of side effects (which can be gastrointestinal, cutaneous, cardiovascular, or other) is a highly important matter.

CONCLUSION

The increasing use of oral anti-cancer drugs confronts patients and treatment teams with special challenges. To optimize treatment outcomes, a multidisciplinary approach should be taken, involving physicians, pharmacists, and nurses. To improve medication safety, medication and side-effect management should be performed, and adherence should be regularly checked and systematically encouraged.

Effect of Food on the Pharmacokinetics of Quizartinib

Quizartinib is an oral, highly potent, and selective type II FMS‐like tyrosine kinase 3 inhibitor in development for acute myeloid leukemia. This parallel‐group study evaluated potential food effects on quizartinib absorption in healthy subjects who received a single 30‐mg dose after overnight fasting (n = 34) or a high‐fat, high‐calorie meal (n = 30). Blood samples were collected through 504 hours after dosing, and pharmacokinetic parameters calculated were maximum observed concentration (C_max) and area under plasma concentration–time curve from time 0 to last quantifiable concentration (AUC_last) and from time 0 to infinity (AUC_inf). Mean quizartinib pharmacokinetic profiles were similar under fasted and fed conditions. The geometric least squares means ratios (%) for fed/fasted and associated 90% confidence intervals (CIs) for C_max, AUC_last, and AUC_inf were 91.58 (82.15‐102.08), 105.39 (90.79‐122.35), and 108.39 (91.54‐128.34), respectively. The 90%CI for the ratio fell within the 80% to 125% limits for C_max and AUC_last, with 90%CI for AUC_inf slightly outside the limits (ie, 128%). Food delayed quizartinib time to C_max by 2 hours. All adverse events were either mild or moderate; no discontinuations due to adverse events occurred. Based on these results, quizartinib can be administered without regard to food.

The Effect of a High-Fat Meal on the Pharmacokinetics of Brigatinib, an Oral Anaplastic Lymphoma Kinase Inhibitor, in Healthy Volunteers

Brigatinib, a next-generation anaplastic lymphoma kinase (ALK) inhibitor, received accelerated approval in the United States for the treatment of patients with metastatic ALK+ non-small-cell lung cancer who have progressed on or are intolerant to crizotinib. A clinical study was conducted to assess the effect of food on brigatinib pharmacokinetics (PK). Healthy subjects received a single oral dose of brigatinib 180 mg (2 × 90-mg tablets) after a 10-hour fast or after a high-fat meal in a 2-period, 2-sequence crossover study. Plasma samples for PK characterization were collected over 168 hours postdose. Twenty-four subjects were enrolled (mean age 44 years; 58% male), with 21 included in the PK-evaluable population. Brigatinib peak concentration was reduced by 13% under fed (high-fat meal) versus fasted conditions, with no effect on area under the concentration-time curve. The median time to peak concentration of brigatinib was longer under fed conditions (5 hours) than in fasted conditions (2 hours). Treatment-emergent adverse events were similar under fasted (48%) and fed (46%) conditions and were of mild intensity. Consumption of a high-fat meal decreased the rate of brigatinib oral absorption but had no impact on the extent of absorption, thereby supporting brigatinib administration without regard to meals. These recommendations are reflected in the US prescribing information for brigatinib.

Unlocking the full potential of lipid-based formulations using lipophilic salt/ionic liquid forms

Lipid-based formulations (LBF) are widely used by industry and accepted by the regulatory authorities for oral drug delivery in the pharmaceutical and consumer healthcare market. Innovation in the LBF field is however needed in order to meet the demands of modern drugs, their more challenging problem statements and growing needs for achieving optimal pharmacokinetics (i.e., no food-effects, low variability) on approval. This review describes a new lipophilic salt / ionic liquid approach in combination with LBF, and how this salt strategy can be used to better tailor the properties of a drug to LBFs. The potential advantages of lipophilic salts are discussed in the context of dose escalation studies during toxicological evaluation, reducing the pill burden, increasing drug absorption of new drugs and in life-cycle management. Commentary on lipophilic salt synthesis, scale-up, LBF design and the regulatory aspects are also provided. These topics are discussed in the broad context of bringing the widely recognized advantages of LBFs to a broader spectrum of drugs.