Effect of alisertib, an investigational aurora a kinase inhibitor on the QTc interval in patients with advanced malignancies

Primary cilia suppress the fibrotic activity of atrial fibroblasts from patients with atrial fibrillation in vitro

Atrial fibrosis serves as an arrhythmogenic substrate in atrial fibrillation (AF) and contributes to AF persistence. Treating atrial fibrosis is challenging because atrial fibroblast activity is multifactorial. We hypothesized that the primary cilium regulates the profibrotic response of AF atrial fibroblasts, and explored therapeutic potentials of targeting primary cilia to treat fibrosis in AF. We included 25 patients without AF (non-AF) and 26 persistent AF patients (AF). Immunohistochemistry using a subset of the patients (non-AF: n = 10, AF: n = 10) showed less ciliated fibroblasts in AF versus non-AF. Acetylated α-tubulin protein levels were decreased in AF, while the gene expressions of AURKA and NEDD9 were highly increased in AF patients' left atrium. Loss of primary cilia in human atrial fibroblasts through IFT88 knockdown enhanced expression of ECM genes, including FN1 and COL1A1. Remarkably, restoration or elongation of primary cilia by an AURKA selective inhibitor or lithium chloride, respectively, prevented the increased expression of ECM genes induced by different profibrotic cytokines in atrial fibroblasts of AF patients. Our data reveal a novel mechanism underlying fibrotic substrate formation via primary cilia loss in AF atrial fibroblasts and suggest a therapeutic potential for abrogating atrial fibrosis by restoring primary cilia.

Assessment of Effects of Investigational TAK‐931, an Oral Cell Division Cycle 7 Kinase Inhibitor on the QTc Intervals in Patients With Advanced Solid Tumors

TAK‐931, a novel, selective, small‐molecule inhibitor of cell division cycle 7 has been investigated in multiple clinical trials in patients with advanced solid tumors. An integrated analysis using data from 2 clinical studies assessed effects of TAK‐931 on electrocardiogram QT intervals and heart rate (HR). Pharmacokinetic samples and matched triplicate electrocardiogram data were collected in 48 patients with cancer receiving oral administration of TAK‐931 50 or 80 mg once daily. The relationships between TAK‐931 plasma concentrations and the HR‐corrected QT interval via Fridericia (QTcF) or population (QTcP) and HR were analyzed using linear mixed‐effects models with fixed effects for day and time. At the geometric mean maximum TAK‐931 plasma concentrations after administration of 50 mg, an HR change of 3.40 beats per minute (90%CI, 1.86‐4.80) was predicted. Change in QTcF of −3.41 milliseconds (90%CI, −5.77 to −1.17) and QTcP of −2.02 milliseconds (90%CI, −4.15 to 0.0679) were estimated, indicating there was no effect of TAK‐931 on the QT intervals at a recommended phase 2 dose of 50 mg once daily for 14 days in a 21‐day cycle.

Future prospects for mitosis-targeted antitumor therapies

Dysregulation of cell cycle progression is a hallmark of cancer cells. In recent years, efforts have been devoted to the development of new therapies that target proteins involved in cell cycle regulation and mitosis. Novel targeted antimitotic drugs include inhibitors of aurora kinase family, polo-like kinase 1, Mps1, Eg5, CENP-5 and the APC/cyclosome complex. While certain new inhibitors reached the clinical trial stage, most were discontinued due to negative results. However, these therapies should not be readily dismissed. Based on recent advances concerning their mechanisms of action, new strategies could be devised to increase their efficacy and promote further clinical trials. Here we discuss three main lines of action to empower these therapeutic approaches: increasing cell death signals during mitotic arrest, targeting senescent cells and facilitating antitumor immune response through immunogenic cell death (ICD).

The role of Aurora-A in human cancers and future therapeutics

Aurora-A is a mitotic serine/threonine-protein kinase and an oncogene. In normal cells, Aurora-A appears from G2 phase and localizes at the centrosome, where it participates in centrosome replication, isolation and maturation. Aurora-A also maintains Golgi apparatus structure and spindle assembly. Aurora-A undergoes ubiquitination-mediated degradation after the cell division phase. Aurora-A is abnormally expressed in tumor cells and promotes cell proliferation by regulating mitotic substrates, such as PP1, PLK1, TPX2, and LAST2, and affects other molecules through a non-mitotic pathway to promote cell invasion and metastasis. Some molecules in tumor cells also indirectly act on Aurora-A to regulate tumor cells. Aurora-A also mediates resistance to chemotherapy and radiotherapy and is involved in tumor immunotherapy. Clinical trials of Aurora-A molecular inhibitors are currently underway, and clinical transformation is just around the corner.

Pharmacokinetics of the Investigational Aurora A Kinase Inhibitor Alisertib in Adult Patients With Advanced Solid Tumors or Relapsed/Refractory Lymphoma With Varying Degrees of Hepatic Dysfunction

This clinical trial was designed to evaluate the effect of moderate or severe hepatic impairment on the single-dose pharmacokinetics (PK) of the investigational anticancer agent, alisertib, in adult patients with advanced solid tumors or lymphoma. Patients with normal hepatic function (total bilirubin and alanine transaminase [ALT] ≤ upper limit of normal [ULN]), moderate hepatic impairment (1.5 × ULN < total bilirubin ≤ 3 × ULN, with any ALT) or severe hepatic impairment (total bilirubin > 3 × ULN, with any ALT), received a single 50-mg oral dose of alisertib. Blood samples for PK were collected up to 168 hours postdose. Predose samples were also used to assess alisertib plasma protein binding. Patients could continue to receive alisertib for 7 days in 21-day cycles (50, 30, or 10 mg twice daily for normal hepatic function, moderate hepatic impairment, and severe hepatic impairment, respectively). Alisertib was approximately 99% protein bound in all hepatic function groups. Alisertib exposure was similar in moderate and severe hepatic impairment groups, but higher than the normal hepatic function group. The geometric least-squares mean ratios (90% confidence intervals) for unbound alisertib area under the curve extrapolated to infinity for moderate/severe impairment groups versus the normal hepatic function group was 254% (184%, 353%). Patients with moderate or severe hepatic impairment have approximately 150% higher unbound alisertib exposures compared with patients with normal hepatic function. An approximately 60% reduction of the starting dose of alisertib in patients with moderate/severe hepatic impairment is recommended based on pharmacokinetic considerations.