Population Pharmacokinetics of TAK-931, a Cell Division Cycle 7 Kinase Inhibitor, in Patients With Advanced Solid Tumors

Identifying CDC7 as a synergistic target of chemotherapy in resistant small-cell lung cancer via CRISPR/Cas9 screening

There is currently a lack of efficacious treatments for patients with chemo-resistant small-cell lung cancer (SCLC), leading to poor prognoses. We examined a chemo-resistant SCLC cell line using genome-wide CRISPR/Cas9 screening and identified serine/threonine kinase cell division cycle 7 (CDC7) as a potential synergistic target. Silencing CDC7 in chemo-resistant SCLC cells decreased the IC₅₀ and improved the efficacy of chemotherapy. Based on the highest single agent model, the CDC7 inhibitor XL413 had a synergistic effect with both cisplatin and etoposide in chemo-resistant SCLC cells, but had no such effect in chemo-sensitive SCLC cells; the combination of XL413 and chemotherapy significantly inhibited cell growth. Western blot and flow cytometry showed that the combined treatments increased apoptosis, whereas XL413 alone had little effect on apoptosis. An analysis of cell cycle and cyclin protein levels indicated that the combination of XL413 and chemotherapy-induced G1/S phase arrest and DNA damage in chemo-resistant SCLC cells. Xenografted tumor and histoculture drug response assays using patient-derived xenografts showed that XL413 improved the efficacy of chemotherapy in vivo and with SCLC tissues. These results suggest that XL413 exerts a synergistic effect with chemotherapy on chemo-resistant SCLC.

Safety, Tolerability, and Pharmacokinetics of TAK-931, a Cell Division Cycle 7 Inhibitor, in Patients with Advanced Solid Tumors: A Phase I First-in-Human Study

Purpose:

We conducted a first-in-human, dose-escalation study, to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and activity of TAK-931, a cell division cycle 7 inhibitor, in Japanese patients with advanced solid tumors.

Experimental Design:

Patients ages ≥20 years received oral TAK-931: once daily for 14 days in 21-day cycles (schedule A; from 30 mg); once daily or twice daily for 7 days on, 7 days off in 28-day cycles (schedule B; from 60 mg); continuous once daily (schedule D; from 20 mg); or once daily for 2 days on, 5 days off (schedule E; from 100 mg) in 21-day cycles.

Results:

Of the 80 patients enrolled, all had prior systemic treatment and 86% had stage IV disease. In schedule A, 2 patients experienced dose-limiting toxicities (DLTs) of grade 4 neutropenia and the maximum tolerated dose (MTD) was 50 mg. In schedule B, 4 patients experienced DLTs of grade 3 febrile neutropenia (n = 3) or grade 4 neutropenia (n = 1); the MTD was 100 mg. Schedules D and E were discontinued before MTD determination. The most common adverse events were nausea (60%) and neutropenia (56%). Time to maximum plasma concentration of TAK-931 was approximately 1–4 hours postdose; systemic exposure was approximately dose proportional. Posttreatment pharmacodynamic effects correlating to drug exposure were observed. Overall, 5 patients achieved a partial response.

Conclusions:

TAK-931 was tolerable with a manageable safety profile. TAK-931 50 mg once daily days 1–14 in 21-day cycles was selected as a recommended phase II dose and achieved proof of mechanism.

Trial registration ID:

NCT02699749

Significance:

This was the first-in-human study of the CDC7 inhibitor, TAK-931, in patients with solid tumors. TAK-931 was generally tolerable with a manageable safety profile. The recommend phase II dose was determined to be TAK-931 50 mg administered once daily on days 1–14 of each 21-day cycle. A phase II study is ongoing to confirm the safety, tolerability, and antitumor activity of TAK-931 in patients with metastatic solid tumors.

CDC7 as a novel biomarker and druggable target in cancer

Due to the bottlenecks encountered in traditional treatment for tumor, more effective drug targets need to be developed. Cell division cycle 7 kinase plays an important role in DNA replication, DNA repair and recombination signaling pathways. In this review, we first describe recent studies on the role of CDC7 in DNA replication in normal human tissues, and then we integrate new evidence focusing on the important role of CDC7 in replication stress tolerance of tumor cells and its impact on the prognosis of clinical oncology patients. Finally, we comb through the CDC7 inhibitors identified in recent studies as a reference for further research in clinical practice.

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.