Thorough cardiac QTc interval conductance assessment of a novel oral tranexamic acid treatment for heavy menstrual bleeding

Daily dosing of vismodegib to steady state does not prolong the QTc interval in healthy volunteers

INTRODUCTION

Vismodegib was assessed as being of low risk for QT interval prolongation based on prior nonclinical and clinical experience. A dedicated study was conducted to further assess the potential for vismodegib to prolong the QTc interval.

METHODS AND RESULTS

Given the nonlinear pharmacokinetics of vismodegib, a thorough QTc study as is typically designed was not possible, and an innovative design was employed. This dedicated QTc study was powered to exclude a 20-millisecond change from the baseline QTc interval. The subjects were administered daily oral 150 mg of vismodegib for 7 days, or a single dose of 400 mg of moxifloxacin, with corresponding matching placebos. The upper limits of the 90% confidence intervals for the difference in ΔQTcF between vismodegib and placebo at steady state were <20 milliseconds at all timepoints with a maximum of 10 milliseconds at 12 hours postdose. Exposure-response analysis yielded an estimated slope equal to 0.11 ms/μM, which was not statistically significant. After a single dose of moxifloxacin was administered, the lower limits of the 90% confidence interval of the difference in ΔQTcF between moxifloxacin and placebo were >5 milliseconds from 1-12 hours postdose, thereby establishing assay sensitivity.

CONCLUSIONS

There was no effect of vismodegib on the QTc interval when dosed daily at 150 mg to steady state.

Reducing Heavy Menstrual Bleeding: Safety and Efficacy of Tranexamic Acid

Menorrhagia or Heavy Menstrual Bleeding (HMB) remains a public health challenge among women in the reproductive age group. Anti-fibrinolytics such as tranexamic acid and epsilon aminocaproic acid, play an important role in the medical management of HMB, as HMB is associated with an increase in local fibrinolysis. Lysteda is a novel oral formulation of tranexamic acid which has recently been approved by the US FDA for treatment of HMB. Efficacy of tranexamic acid in the general gynecologic population as well as in women with bleeding disorders is discussed in this review. Safety and adverse effect profile is also addressed for both these populations.

Management of menorrhagia associated with chemotherapy-induced thrombocytopenia in women with hematologic malignancy

Abnormal uterine bleeding in women with a blood dyscrasia, such as leukemia, or who experience thrombocytopenia secondary to myelosuppressive chemotherapy is a clinical condition associated with significant morbidity. Consequently, effective management is necessary to prevent adverse outcomes. Prevention of menorrhagia, defined as heavy regular menstrual cycles with more than 80 ml of blood loss/cycle or a cycle duration longer than 7 days, in this patient population is the goal of therapy. Gonadotropin-releasing hormone analogs (e.g., leuprolide) are promising therapies that have been shown to decrease vaginal bleeding during periods of thrombocytopenia and to have minimal adverse effects other than those associated with gonadal inhibition. In patients who experience menorrhagia despite preventive therapies, or in patients who have thrombocytopenia and menorrhagia at diagnosis, treatment is indicated. For these women, treatment options may include platelet transfusions, antifibrinolytic therapy (e.g., tranexamic acid), continuous high-dose oral contraceptives, cyclic progestins, or other therapies for more refractory patients such as danazol, desmopressin, and recombinant factor VIIa. Hormonal therapies are often the mainstay of therapy in women with menorrhagia secondary to thrombocytopenia, but data for these agents are sparse. The most robust data for the treatment of menorrhagia are for tranexamic acid. Most women receiving tranexamic acid in randomized trials experienced meaningful reductions in menstrual bleeding, and this translated into improved quality of life; however, these trials were not performed in patients with cancer. Further clinical trials are warranted to evaluate both preventive and therapeutic agents for menorrhagia in premenopausal women with cancer who are receiving myelosuppressive chemotherapy.

Effect of nalmefene 20 and 80 mg on the corrected QT interval and T-wave morphology: a randomized, double-blind, parallel-group, placebo- and moxifloxacin-controlled, single-centre study

BACKGROUND

Nalmefene is an orally administered competitive opioid receptor antagonist targeted at reducing alcohol consumption in alcohol-dependent patients. As part of the regulatory requirements for drug approval, the potential of novel compounds for causing unwanted proarrhythmia should be studied in a thoroughly designed clinical QT/corrected QT (QTc) study (International Conference on Harmonisation [ICH] E14 guideline).

OBJECTIVE

This study was designed to evaluate whether nalmefene 20 and 80 mg/day induced changes in cardiac repolarization biomarkers indicative of proarrhythmia (the QTc interval and T-wave morphology).

METHODS

This was a prospective, randomized, double-blind, parallel-group, placebo- and moxifloxacin-controlled, single-centre study carried out in a clinical pharmacology unit. The study included 270 healthy male and female subjects (age 18-45 years). The subjects were randomized to a 7-day treatment period of placebo, nalmefene 20 mg/day or nalmefene 80 mg/day, or placebo for 6 days followed by a single dose of moxifloxacin 400 mg on day 7. Serial triplicate ECGs were obtained over a 24-hour period at protocol-defined time-points. The primary protocol-defined endpoint was the largest time-matched baseline- and placebo-adjusted mean difference in the individually heart rate-corrected QT interval (QTcNi) recorded at any of the 12 ECG time-points distributed over a 24-hour period on day 7 of treatment. Secondary endpoints included a similar analysis using the Fridericia- (QTcF) and Bazett-corrected (QTcB) intervals. An explorative analysis included quantitative assessment of T-wave morphology using the T-wave morphology composite score (MCS) to assess for differences between treatment groups and placebo on day 7 of treatment. The frequency of outliers in the QTc intervals, the pharmacokinetics of nalmefene and the tolerability of nalmefene were also assessed.

RESULTS

Nalmefene was rapidly absorbed with a time to reach maximum plasma concentration of 2.2 hours and a dose-proportionate relationship between dose administered and exposure. The largest baseline- and placebo-adjusted mean changes from baseline in the individualized QTcNi (primary endpoint) were 5.45 ms (90% CI 1.52, 9.37) and 5.57 ms (90% CI 1.62, 9.52) for nalmefene 20 and 80 mg/day, respectively, with study sensitivity confirmed by the expected largest increase in mean QTcNi of 10.15 ms (90% CI 5.67, 14.63) for moxifloxacin. Quantitative assessment using the T-wave MCS demonstrated the largest baseline- and placebo-adjusted increase in MCS to be non-significantly different from the intra-subject variability of triplicate recordings in the placebo group. No deaths or serious adverse events occurred in the study.

CONCLUSION

This thorough QT/QTc study was a negative study in accordance with the ICH E14 guideline, meaning that nalmefene has no clinically relevant effect on the QTc interval and T-wave morphology. The study predicts no concern over proarrhythmia or need for intensive QTc monitoring with the use of nalmefene in clinical practice.

Tranexamic Acid: A Novel Oral Formulation for the Treatment of Heavy Menstrual Bleeding

Tranexamic acid, a synthetic lysine derivative, is an antifibrinolytic drug that prevents the breakdown of fibrin by competitively blocking binding sites of plasminogen. Tranexamic acid is often considered a first-line treatment for the management of heavy menstrual bleeding (HMB). A new oral formulation of tranexamic acid provides a nonhormonal HMB therapy that is safe, effective and well tolerated; is administered only during menstruation; addresses the excessive fibrinolysis implicated in many cases of HMB; and improves women's health-related quality of life by reducing limitations on physical, social and leisure activities. This article provides a summary of the clinical development, therapeutic efficacy and tolerability profile of this novel formulation of tranexamic acid for the treatment of HMB.