Phase I clinical trial of KML001 monotherapy in patients with advanced solid tumors.

BACKGROUND: We evaluated the tolerability, pharmacokinetics (PK) and preliminary efficacy of KML001, an oral trivalent arsenical, as a monotherapy in patients with advanced solid tumors. RESEARCH DESIGN AND METHODS: With a standard 3 + 3 design for dose-escalation stage, the planned dose levels of KML001 were 5, 7.5, 10, 12.5, and 15 mg/day for 28 days. Once the maximum tolerated dose was determined, 22 subjects were additionally enrolled for dose-expansion stage. PK analysis was performed in the 5, 10, and 15 mg/day cohort at the dose-escalation stage and also at the dose-expansion stage. Moreover, response was assessed using the standard RECIST 1.1. RESULTS: A total of 45 Korean subjects were enrolled. No DLT was reported at the dose-escalation stage. Three DLTs, two cases of prolonged QTc interval and one of neutropenia, were reported in the 12.5 mg/day cohort at the dose-expansion stage. Higher total daily doses up to 12.5 mg/day of KML001 resulted in higher trough plasma concentrations. Among the 18 subjects who completed 2 cycles of therapy, 15 had progressive disease and 3 had stable disease. CONCLUSIONS: Doses equal to or greater than 10 mg/day KML001 alone were tolerable and produced plasma concentrations higher than biologically relevant targets.

Disruption of Telomere Integrity and DNA Repair Machineries by KML001 Induces T Cell Senescence, Apoptosis, and Cellular Dysfunctions.

T cells in chronic viral infections are featured by premature aging with accelerated telomere erosion, but the mechanisms underlying telomere attrition remain unclear. Here, we employed human CD4 T cells treated with KML001 (a telomere-targeting drug) as a model to investigate the role of telomere integrity in remodeling T cell senescence. We demonstrated that KML001 could inhibit cell proliferation, cytokine production, and promote apoptosis via disrupting telomere integrity and DNA repair machineries. Specifically, KML001-treated T cells increased dysfunctional telomere-induced foci (TIF), DNA damage marker γH2AX, and topoisomerase cleavage complex (TOPcc) accumulation, leading to telomere attrition. Mechanistically, KML001 compromised telomere integrity by inhibiting telomeric repeat binding factor 2 (TRF2), telomerase, topoisomerase I and II alpha (Top1/2a), and ataxia telangiectasia mutated (ATM) kinase activities. Importantly, these KML001-induced telomeric DNA damage and T cell senescent phenotype and machineries recapitulated our findings in patients with clinical HCV or HIV infection in that their T cells were also senescent with short telomeres and thus more vulnerable to KML001-induced apoptosis. These results shed new insights on the T cell aging network that is critical and essential in protecting chromosomal telomeres from unwanted DNA damage and securing T cell survival during cell crisis upon genomic insult.

KML001, an arsenic compound, as salvage chemotherapy in refractory biliary tract cancers: A prospective study.

BACKGROUND: Sodium meta-arsenite (NaAsO2, KML001) is a potential oral anticancer agent acting on telomerase and telomere length. This prospective study evaluated its safety, tolerability, and effectiveness as salvage chemotherapy in patients with advanced biliary tract cancer (BTC) resistant to gemcitabine-based chemotherapy. METHODS: Forty-four patients (21 women and 23 men) with advanced BTC and failure history of gemcitabine-based chemotherapy, performance status (PS) 0-2, normal cardiac, hepatic, and renal function were enrolled. Daily dose of KML001 (7.5 mg. p.o.) was administered to eligible subjects for 24 weeks divided into six treatment cycles. Response was evaluated bimonthly using CT. RESULTS: After an average of 1.5 months of treatment (range: 0.5-10.0), 3 patients (6.8%) obtained progression-free status, 23 patients (52.3%) had disease progression, and 18 patients (40.9%) dropped out before evaluation. One patient (2.3%) completed six treatment cycles without progression. During the treatment, morphine dosage kept the same or decreased in 20 patients (47.6%). Nine patients (20.5%) experienced grade-3 adverse events (AEs), while no patient experienced grade-4 AEs. The most common AEs were liver enzyme elevation (11/44, 25%) and anemia (10/44, 22.7%). KML001 was discontinued in six patients (13.6%) due to AEs, including liver toxicity (n = 3), QTc prolongation (n = 2), and abdominal pain (n = 1). CONCLUSIONS: KML001 did not have enough anticancer effect on patients with advanced BTC resistant to gemcitabine. However, KML001 was safe and well-tolerable in terms of AEs and pain control when used as salvage therapy. Further studies are needed to establish arsenic agents as a reliable treatment option in patients with BTC.

Phase I and pharmacokinetic evaluation of the anti-telomerase agent KML-001 with cisplatin in advanced solid tumors.

PURPOSE: KML-001 (sodium metaarsenite) displaces hTERT from the nucleus and is synergistic with cisplatin. This phase I trial tested the tolerability, activity and pharmacology of this combination. METHODS: Patients with advanced solid tumors that were "platinum sensitive," PS 0-1, normal renal and hepatic function were eligible. Treatment was with cisplatin 75 mg/m2 day 1 and KML-001 p.o. daily days 1-14 on a 21-day cycle. A standard 3 + 3 design was employed. Blood specimens for arsenic and platinum pharmacokinetics were obtained at 0, 1, 2, 3, 4, 5, 6, 24 h and days 8, 15 and 22. RESULTS: Eighteen patients (7 M, 11 F) were evaluable for the primary endpoint of toxicity. Patients were heavily pretreated for a variety of malignancies (mean number of prior regimens = 3). Sixteen had prior platinum therapy. The dose-limiting toxicity was prolongation of the QTc interval, seen in three patients in cohort 3 (20 mg) (two during cycle 1, one during cycle 2). A documented response was seen in a patient with heavily pretreated SCLC in cohort one. Several other patients had reduction in tumor burden. In addition to the dose-limiting toxicity of QTc prolongation, the most common toxicities observed were nausea and vomiting and cytopenias. Myelosuppression was primarily seen in patients who had undergone prior radiotherapy. CONCLUSIONS: The combination of KML-001 and cisplatin was technically feasible and active. However, the occurrence of significant QTc prolongation led to discontinuation of the trial. This prolongation was likely a result of electrolyte abnormalities resulting from cisplatin superimposed on the known risks of arsenicals and QTc prolongation. Combinations with other platinum agents (e.g., carboplatin) should be considered. This is the first fully reported human trial of KML-001.

Anti-tumoral effect of arsenic compound, sodium metaarsenite (KML001), in non-Hodgkin's lymphoma: an in vitro and in vivo study.

Arsenic compounds have been used in traditional medicine for several centuries. KML001 (sodium metaarsenite; NaAsO2) is an orally bio-available arsenic compound with potential anti-cancer activity. However, the effect of KML001 has not been studied in lymphoid neoplasms. The aim of this study is to evaluate the anti-proliferative effect of KML001 in non-Hodgkin's lymphoma and to compare its efficacy with As2O3. KML001 inhibited cellular proliferation in all tested lymphoma cell lines as well as JurkatR cells (adriamycin-resistant Jurkat cells) in a dose-dependent manner, while As2O3 was not effective. Cell cycle regulatory protein studies have suggested that KML001 induces G1 arrest via p27-induced inhibition of the kinase activities of CDK2, 4, and 6. Treatment of KML001 induced apoptosis in Jurkat and JurkatR cells. The apoptotic process was associated with down-regulation of Bcl-2 (antiapoptotic molecule), up-regulation of Bax (proapoptotic molecule), and inhibition of caspase-3, -8, and -9. In addition, cell signaling including the STAT, PI3K/Akt, MAPK, and NF-κB signal pathways were inhibited in KML001-treated Jurkat and JurkatR cells. Furthermore, targeting the telomere by KML001 was observed in the Jurkat and JurkatR cells. The In vivo anti-tumoral activity of KML001 was confirmed in a xenograft murine model. Interestingly, partial responses were seen in two lymphoma patients treated with 10 mg/day (follicular lymphoma for 16 weeks and mantle cell lymphoma for 24 weeks) without severe toxicities. These findings suggest that KML001 may be a candidate agent for the treatment of de novo, refractory, and relapsed non-Hodgkin's lymphoma patients.

KML001 enhances anticancer activity of gemcitabine against pancreatic cancer cells.

BACKGROUND/AIM: Gemcitabine is a drug commonly used to treat pancreatic cancer but chemoresistance to it is a common clinical issue. KML001 (sodium meta-arsenite) has demonstrated certain antitumor activity. The objective of the study was to evaluate the influence of KML001 on the anticancer activity of gemcitabine against pancreatic cancer cells. MATERIALS AND METHODS: Cell proliferation, migration, and invasion were assessed, as well as the expression of nuclear factor-kappa B (NF-κB) p65, epidermal growth factor receptor (EGFR), matrix metalloproteinase-2 (MMP2), and vascular endothelial growth factor-C (VEGFC) in pancreatic cancer cells. RESULTS: Treatment with a combination of KML001 and gemcitabine resulted in significant inhibition of cell proliferation, migration, and invasion, and significantly reduced EGFR and MMP2 expression compared to gemcitabine treatment-alone. CONCLUSION: Combination treatment of gemcitabine and KML001 could be an effective chemotherapeutic treatment for pancreatic cancer.

KML001 inhibits cell proliferation and invasion in pancreatic cancer cells through suppression of NF-κB and VEGF-C.

Pancreatic cancer is an aggressive malignancy with poor prognosis and the efficacy of chemotherapy is limited. KML001 (sodium meta-arsenite) has been demonstrated to have anticancer activity against some solid cancer cells. The aim of the present study was to determine the effect of KML001 on cell proliferation, migration, and invasion of pancreatic cancer cells. The Dojindo Cell Counting Kit-8 assay was used to determine the inhibition of pancreatic cancer cell proliferation by drugs. Cell migration and invasion were examined using 24-well inserts and Matrigel™-coated invasion chambers. The activity of nuclear factor-kappa B (NF-κB) p65, vascular endothelial growth factor-C (VEGF-C), and matrix metalloproteinase-9 (MMP-9) were measured by enzyme-linked immunosorbent assay (ELISA). KML001 inhibited the proliferation of pancreatic cancer cells in a dose- and time-dependent manner. KML001 also inhibited the migration and invasion of pancreatic cancer cells in a dose-dependent manner. KML001 significantly decreased NF-κB p65 and VEGF-C activities in the pancreatic cancer cells. KML001 inhibited cell proliferation, migration, and invasion in pancreatic cancer cells. Suppression of NF-κB and VEGF-C activation may partly be associated with the anticancer activity of KML001. These results suggest that KML001 could be a novel potential therapeutic agent for treatment of pancreatic cancer.