LEE011

PURPOSE: Esophageal cancer is a lethal disease that is often resistant to therapy. Alterations of YAP1 and CDK6 are frequent in esophageal cancer. Deregulation of both molecules may be responsible for therapy resistance. EXPERIMENTAL DESIGN: Expressions of YAP1 and CDK6 were examined in esophageal cancer cells and tissues using immunoblotting and immunohistochemistry. YAP1 expression was induced in esophageal cancer cells to examine YAP1-mediated CDK6 activation and its association with radiation resistance...

OBJECTIVE: To review the chemistry, pharmacology, pharmacokinetics, safety, and efficacy of ribociclib (LEE011, Kisqali) in hormone receptor-positive/human epidermal growth factor receptor-2-negative (HR+/HER2-) metastatic breast cancer. DATA SOURCES: A PubMed search was performed using the terms 'Ribociclib', 'Kisqali', and 'LEE011' between May 2018 and November 2018. References of published articles and reviews were also assessed for additional information. STUDY SELECTION AND DATA EXTRACTION: English-language preclinical and clinical studies on the chemistry, pharmacology, pharmacokinetics, safety, and efficacy of ribociclib were evaluated...

Inhibition of cyclin-dependent kinases 4 and 6 (CDK4/6) is associated with robust antitumor activity. Ribociclib (LEE011) is an orally bioavailable CDK4/6 inhibitor that is approved for the treatment of hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer, in combination with an aromatase inhibitor, and is currently being evaluated in several additional trials. Here, we report the preclinical profile of ribociclib. When tested across a large panel of kinase active site binding assays, ribociclib and palbociclib were highly selective for CDK4, while abemaciclib showed affinity to several other kinases...

Natural killer/T-cell lymphoma (NKTCL) is an aggressive non-Hodgkin lymphoma that has been facing limited success with conventional treatments, urging for the discovery of alternative strategies. Recent studies including ours have revealed that EZH2 and JAK-STAT signalling pathways are key contributors to NKTCL pathogenesis. In particular, we found that EZH2 is overexpressed and directly transcriptionally activates the CCND1 gene to confer growth advantage. CCND1 codes for cyclin D1, which complexes with CDK4/6 to promote G1 to S phase transition...

OBJECTIVE: To evaluate the existing literature regarding the use of cyclin-dependent kinase (CDK) 4/6 inhibitors in the treatment of hormone receptor-positive advanced breast cancer (ABC). DATA SOURCES: A search of the medical literature was performed using PubMed (2014 to June 2018). Search terms included cyclin-dependent kinase, CDK, breast cancer, palbociclib, ribociclib, abemaciclib, PD0332991, LEE011, and LY2835219. Clinicaltrials.gov was also searched. STUDY SELECTION AND DATA EXTRACTION: Trials with clinical efficacy outcomes evaluating CDK 4/6 inhibitors in the treatment of advanced hormone-positive breast cancer were considered...

The pituitary tumor transforming gene 1 ( PTTG1 ) is implicated in tumor growth, metastasis and drug resistance. Here, we investigated the involvement of PTTG1 in melanoma cell proliferation, invasiveness and response to the BRAF inhibitor (BRAFi) dabrafenib. We also preliminary assessed the potential value of circulating PTTG1 protein to monitor melanoma patient response to BRAFi or to dabrafenib plus trametinib. Dabrafenib-resistant cell lines (A375R and SK-Mel28R) were more invasive than their drug-sensitive counterparts (A375 and SK-Mel28), but expressed comparable PTTG1 levels...

Hallmarks of cancer cells include uncontrolled growth and rapid proliferation; thus, cyclin-dependent kinases are a therapeutic target for cancer treatment. Treating non-small lung cancer cells with sublethal concentrations of the CDK4/6 inhibitors, ribociclib (LEE011) and palbociclib (PD0332991), which are approved by the FDA for anticancer therapies, caused cell cycle arrest in the G1 phase and suppression of poly(ADP-ribose) polymerase 1 (PARP1) transcription by inducing recruitment of the RB1-E2F1-HDAC1-EZH2 repressive complex to the PARP1 promoter...

The RB-E2F1 pathway is an important mechanism of cell-cycle control, and deregulation of this pathway is one of the key factors contributing to tumorigenesis. Cyclin-dependent kinases (CDKs) and Cyclin D have been known to increase in aggressive thyroid cancer. However, there has been no study to investigate effects of a selective CDK 4/6 inhibitor, Ribociclib (LEE011), in thyroid cancer. Performing Western blotting, we found that RB phosphorylation and the expression of Cyclin D are significantly higher in papillary thyroid cancer (PTC) cell lines as well as anaplastic thyroid cancer (ATC) cell lines, compared with normal thyroid cell line and follicular thyroid cancer cell line...

PURPOSE: The cyclin D-cyclin dependent kinase (CDK) 4/6-inhibitor of CDK4 (INK4)-retinoblastoma (Rb) pathway plays a crucial role in cell cycle progression and its dysregulation is an important contributor to endocrine therapy resistance. CDK4/6 inhibitors trigger cell cycle arrest in Rb protein (pRb)-competent cells. Recent years have seen the development of selective CDK4/6 inhibitors, which have delivered promising results of efficacy and manageable safety profiles. The main objective of this review is to discuss preclinical and clinical data to date, and ongoing clinical trials with palbociclib, ribociclib, and abemaciclib in breast cancer...

A series of novel hybrid structure derivatives, containing both LEE011 and Cabozantinib pharmacophore, were designed, synthesized and evaluated. Surprisingly, a compound 4d was discovered that highly exhibited effective and selective activity of CDK9 inhibition with IC50 =12nM. It effectively induced apoptosis in breast and lung cancer cell lines at nanomolar level. Molecular docking of 4d to ATP binding site of CDK9 kinase demonstrated a new hydrogen bonding between F atom of 4-(3-fluorobenzyloxy) group and ASN116 residue, compared with the positive control, LEE011...

Uncontrolled cell division is the hallmark of cancers. Full understanding of cell cycle regulation would contribute to promising cancer therapies. In particular, cyclin-dependent kinases 4/6 (CDK4/6), which are pivotal drivers of cell proliferation by combination with cyclin D, draw more and more attention. Subsequently, extensive studies were carried out to explore drugs inhibiting CDK4/6 and assess the efficacy and safety of these drugs in cancer, especially breast cancer. Due to the insuperable adverse events and the less activity observed in vivo, the drug development of the initial pan-CDK inhibitor flavopiridol was consequently discontinued, and then highly specific inhibitors were extensively researched and developed, including palbociclib (PD0332991), ribociclib (LEE011), and abemaciclib (LY2835219)...

Purpose: The cyclin-dependent kinase (CDK) 4/6 inhibitor, ribociclib (LEE011), displayed preclinical activity in neuroblastoma and malignant rhabdoid tumor (MRT) models. In this phase I study, the maximum tolerated dose (MTD) and recommended phase II dose (RP2D), safety, pharmacokinetics (PK), and preliminary activity of single-agent ribociclib were investigated in pediatric patients with neuroblastoma, MRT, or other cyclin D-CDK4/6-INK4-retinoblastoma pathway-altered tumors. Experimental Design: Patients (aged 1-21 years) received escalating once-daily oral doses of ribociclib (3-weeks-on/1-week-off)...

BACKGROUND: Cyclin-dependent kinase (CDK) 4/6 inhibitor-based therapies have shown great promise in improving clinical outcomes for patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer. OBJECTIVES: 1. Discuss the mode of action of the three CDK4/6 inhibitors in late clinical development: palbociclib (PD-0332991; Pfizer), ribociclib (LEE011; Novartis), and abemaciclib (LY2835219; Lilly). 2...

The cyclin D-cyclin-dependent kinase (CDK) 4/6-p16-retinoblastoma (Rb) pathway is commonly disrupted in cancer, leading to abnormal cell proliferation. Therapeutics targeting this pathway have demonstrated antitumor effects in preclinical and clinical studies. Ribociclib is a selective, orally bioavailable inhibitor of CDK4 and CDK6, which received FDA approval in March 2017 and is set to enter the treatment landscape alongside other CDK4/6 inhibitors, including palbociclib and abemaciclib. Here, we describe the mechanism of action of ribociclib and review preclinical and clinical data from phase I, II, and III trials of ribociclib across different tumor types, within the context of other selective CDK4/6 inhibitors...

BACKGROUND: Overexpression of cyclin D1 dependent kinases 4 and 6 (CDK4/6) is a common feature of many human cancers including leukemia. LEE011 is a novel inhibitor of both CDK4 and 6. To date, the molecular function of LEE011 in leukemia remains unclear. METHODS: Leukemia cell growth and apoptosis following LEE011 treatment was assessed through CCK-8 and annexin V/propidium iodide staining assays. Cell senescence was assessed by β-galactosidase staining and p16(INK4a) expression analysis...

BACKGROUND/AIM: Cyclin-dependent kinases (CDKs) are crucial for cell cycle regulation, and alterations in the cell cycle are often observed in human cancer. CDK4/6 in particular orchestrates G1 phase progression and the G1/S transition. Here, we investigated the in vitro effects of the CDK4/6 inhibitor LEE011 in human neuroendocrine tumor cells. METHODS: The human neuroendocrine tumor cell lines BON1, QGP1, NCI-H727 and GOT1 were treated with different concentrations of LEE011 alone and in combination with 5-fluorouracil and everolimus...

Purpose: Although significant progress has been made in the treatment of T-cell acute lymphoblastic leukemia (T-ALL), many patients will require additional therapy for relapsed/refractory disease. Cyclin D3 (CCND3) and CDK6 are highly expressed in T-ALL and have been effectively targeted in mutant NOTCH1-driven mouse models of this disease with a CDK4/6 small-molecule inhibitor. Combination therapy, however, will be needed for the successful treatment of human disease. Experimental Design: We performed preclinical drug testing using a panel of T-ALL cell lines first with LEE011, a CDK4/6 inhibitor, and next with the combination of LEE011 with a panel of drugs relevant to T-ALL treatment...

Despite remarkable progress in cutaneous melanoma genomic profiling, the mutational landscape of primary mucosal melanomas (PMM) remains unclear. Forty-six PMMs underwent targeted exome sequencing of 111 cancer-associated genes. Seventy-six somatic nonsynonymous mutations in 42 genes were observed, and recurrent mutations were noted on eight genes, including TP53 (13%), NRAS (13%), SNX31 (9%), NF1 (9%), KIT (7%) and APC (7%). Mitogen-activated protein kinase (MAPK; 37%), cell cycle (20%) and phosphatidylinositol 3-kinase (PI3K)-mTOR (15%) pathways were frequently mutated...

PURPOSE: Ribociclib (an oral, highly specific cyclin-dependent kinase 4/6 inhibitor) inhibits tumor growth in preclinical models with intact retinoblastoma protein (Rb+ ). This first-in-human study investigated the MTD, recommended dose for expansion (RDE), safety, preliminary activity, pharmacokinetics, and pharmacodynamics of ribociclib in patients with Rb+ advanced solid tumors or lymphomas. EXPERIMENTAL DESIGN: Patients received escalating doses of ribociclib (3-weeks-on/1-week-off or continuous)...

Clinical and preclinical data support a significant role for inhibitors of the cyclin-dependent kinases (CDKs) 4 and 6 in the treatment of patients with breast cancer. Recently, based on data showing improvement in progression-free survival, the use of palbociclib (Ibrance; Pfizer, Inc.) in combination with endocrine agents was approved to treat patients with hormone receptor-positive advanced disease. Importantly, 2 other CDK4/6 inhibitors, abemaciclib (LY2835219; Lilly) and ribociclib (LEE011; Novartis), are in the late stage of clinical development...