The International Conference on Harmonisation (ICH) E14 guidance provides recommendations to assess the potential of a drug to delay cardiac repolarization (QT prolongation), including general ...guidelines for cases in which a conventional thorough QT study (TQT) might not be feasible. These guidelines have been updated through the ICH question‐and‐answer process, with the last revision in 2015. We conducted a comprehensive analysis of QT prolongation evaluation of small‐molecule new drug applications (NDAs) approved in oncology between 2011 and 2019 to extract learning experience. The following information was analysed: (1) methods to assess QT prolongation, (2) electrocardiogram data collection, (3) QT‐related label language, and (4) postmarketing requirements. Overall, every NDA included a QT assessment. The concentration‐QTc modeling approach (studies in which QT was not the primary objective) was the most common approach (59%), followed by the TQT and the dedicated QT studies (20% and 21%, respectively). The quality and quantity of the QT assessments were different across NDAs, which suggested relatively large flexibility in the designs and approaches to characterizing QT liability. The QT‐related label language reflected the QT results, but also the safety events and the study design limitations because of the oncology settings. There was no delay in approval because of less robust QTc studies as long as the benefit‐to‐risk ratio of the drug was acceptable, and the implications were reflected in the label. This work offers a structured understanding of the QT evaluation criteria by the Food and Drug Administration and can assist in planning QT prolongation assessments in oncology settings.
The RAS/RAF/MEK/ERK pathway is constitutively activated in many cancers. Selumetinib (AZD6244, ARRY-142886) is an oral, potent and highly selective, allosteric MEK1/2 inhibitor with a short half-life ...that has shown clinical activity as monotherapy in phase I and II studies of advanced cancer. Preclinical data suggest that selumetinib may enhance the activity of chemotherapeutic agents. We assessed the safety, tolerability, and pharmacokinetics (PK) of selumetinib (AZD6244, ARRY-142886) in combination with docetaxel or dacarbazine in patients with advanced solid tumors.
This study was a phase I, open-label, multicenter study in patients aged ≥18 years with advanced solid tumors who were candidates for docetaxel or dacarbazine treatment. Part A of the study (dose escalation) evaluated safety, tolerability, PK, and maximum tolerated dose (MTD) of selumetinib twice daily (BID) with docetaxel 75 mg/m
or dacarbazine 1000 mg/m
administered every 21 days. Patients receiving docetaxel could be administered primary prophylactic granulocyte-colony stimulating factor according to standard guidelines. Part B of the study (dose expansion) further evaluated safety, tolerability, and PK in 12 additional patients at the MTD combinations determined in part A.
A total of 35 patients received selumetinib plus docetaxel, and 25 received selumetinib plus dacarbazine. The MTD of selumetinib was 75 mg BID in combination with either docetaxel (two dose-limiting toxicity DLT events: neutropenia with fever, and thrombocytopenia) or dacarbazine (one DLT event: thrombocytopenia). Common adverse events occurring with each treatment combination were diarrhea, peripheral/periorbital edema, fatigue, and nausea. PK parameters for selumetinib and docetaxel or dacarbazine were similar when administered alone or in combination. Partial responses were reported in 6/35 patients receiving selumetinib plus docetaxel and 4/25 patients receiving selumetinib plus dacarbazine.
The combinations of selumetinib plus docetaxel and selumetinib plus dacarbazine demonstrated manageable safety and tolerability profiles and preliminary signs of clinical activity in patients with advanced solid tumors.
ClinicalTrials.gov NCT00600496; registered 8 July 2009.
Summary
Background
Combinations of molecularly targeted agents may provide optimal anti-tumor activity and improve clinical outcomes for patients with advanced cancers. Selumetinib (AZD6244, ...ARRY-142886) is an oral, potent and highly selective, allosteric inhibitor of MEK1/2, a component of the RAS/RAF/MEK/ERK pathway which is constitutively activated in many cancers. We investigated the safety, tolerability, and pharmacokinetics (PK) of selumetinib in combination with molecularly targeted drugs erlotinib or temsirolimus in patients with advanced solid tumors.
Methods
Two-part study: dose escalation, to determine the maximum tolerated dose (MTD) of selumetinib in combination with erlotinib 100 mg once daily (QD) or temsirolimus 25 mg once weekly, followed by dose expansion at the respective combination MTDs to further investigate safety and anti-tumor effects.
Results
48 patients received selumetinib plus erlotinib and 32 patients received selumetinib plus temsirolimus. The MTD with erlotinib 100 mg QD was selumetinib 100 mg QD, with diarrhea being dose limiting. The most common all grade adverse events (AEs): diarrhea, rash, nausea, and fatigue. Four (8.3%) patients had ≥12 weeks stable disease. The MTD with temsirolimus 25 mg once weekly was selumetinib 50 mg twice daily (BID), with mucositis and neutropenia being dose limiting. The most commonly reported AEs: nausea, fatigue, diarrhea, and mucositis. Ten (31.3%) patients had ≥12 weeks stable disease. The combination PK profiles were comparable to previously observed monotherapy profiles.
Conclusions
MTDs were established for selumetinib in combination with erlotinib or temsirolimus. Overlapping toxicities prevented the escalation of selumetinib to its recommended phase II monotherapy dose of 75 mg BID.
Trial registration:
ClinicalTrials.gov
NCT00600496; registered 8 July 2009.
Abstract Background: Zibotentan (ZD4054) is an oral, specific endothelin A receptor antagonist presently under investigation for the treatment of hormone-resistant prostate cancer. Preclinical in ...vitro studies suggest that zibotentan has the potential to act as a time-dependent inhibitor of the cytochrome P450 isozyme 3A4 (CYP3A4) metabolic pathway. In clinical practice, it is likely that zibotentan will be coadministered with drugs metabolized by this pathway; the potential exists, therefore, that zibotentan-induced drug interactions could occur. Objectives: The primary objective of this study was to evaluate the effect of zibotentan on the pharmaco-kinetics of a clinically relevant dose of midazolam in healthy volunteers. Secondary objectives were to evaluate exposure to zibotentan, ensure the safety of the healthy volunteers dosed, and investigate the effect of zibotentan on the pharmacokinetics of the midazolam metabolites 1-hydroxy midazolam and 4-hydroxy midazolam. The potency of zibotentan as a CYP3A4 inhibitor was also assessed. Methods: This was an open-label, randomized, singlecenter, 2-period, Phase I, crossover study. Volunteers were randomized in a 1:1 ratio to 1 of 2 cohorts. In cohort 1, volunteers received a single dose of midazolam 7.5 mg on day 1 (treatment A) of a 2-day study period. After a minimum 7-day washout period, volunteers received zibotentan 10 mg once daily on days 1 through 7, plus a single dose of midazolam 7.5 mg on day 6 (treatment B) of a 7-day study period. In cohort 2, volunteers received treatment B followed by treatment A, with a minimum 7-day washout period between treatments. AUC0−∞ and Cmax data were expressed as geometric least squares mean ratios and 90% CIs for midazolam + zibotentan:midazolam. A moderate interaction between midazolam and zibotentan was predefined to have occurred if the upper 90% CI of the ratio was >1.5. Adverse events (AEs) were assessed according to the National Cancer Institute's Common Terminology Criteria for Adverse Events version 3. AE data were assessed based on information provided by the volunteer, through open-ended and nonleading verbal questions to the volunteer at each visit, and through observation by the investigational team, other care providers, or relatives. Results: Six volunteers (all white) were included in each cohort (cohort 1, mean SD age, 48 7 years; mean weight, 74 6 kg; cohort 2, mean age, 51 11 years; mean weight, 75 13 kg). Steady-state levels of zibotentan, achieved over 7 days, increased the midazolam AUC0−∞ by 1.2-fold compared with midazolam alone. The upper limits of the 90% CIs for the AUC0−∞ and Cmax ratios were below the predefined level of 1.5 (1.37 and 1.32, respectively). Zibotentan had no apparent effect on the pharmacokinetics of 1-hydroxy midazolam and 4-hydroxy midazolam. Fatigue was reported in 11 volunteers (92%) receiving midazolam monotherapy and 10 (83%) receiving midazolam combined with zibotentan. Headache was reported in all 12 volunteers after zibotentan monotherapy. Conclusions: In this population of healthy male volunteers, once-daily zibotentan 10 mg increased the AUC0−∞ of midazolam 1.2-fold; however, the treatment ratio was below the predefined limit for clinical significance. Zibotentan was well tolerated when given alone or in combination with midazolam. The results indicate that once-daily zibotentan 10 mg acted as a weak inhibitor of the CYP3A4 pathway. ClinicalTrials. gov identifier: NCT00709553.
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