Emerging Role of the DREAM Complex in Cancer and Therapeutic Opportunities

The DREAM (dimerization partner, RB-like, E2F, and multi-vulval class B) complex is an evolutionarily conserved transcriptional repression complex that coordinates nearly one thousand target genes, primarily associated with the cell cycle processes. The formation of the DREAM complex consequently inhibits cell cycle progression and induces cellular quiescence. Given its unique role in cell cycle control, the DREAM complex has gained significant interest across various physiological and pathological contexts, particularly in conditions marked by dysregulated cell cycles, such as cancer. However, the specific cancer types most significantly affected by alterations in the DREAM complex are yet to be determined. Moreover, the possibility of restoring or pharmacologically targeting the DREAM complex as a therapeutic intervention against cancer remains a relatively unexplored area of research and is currently under active investigation. In this review, we provide an overview of the latest advances in understanding the DREAM complex, focusing on its role in cancer. We also explore strategies for targeting the DREAM complex as a potential approach for cancer therapeutics. Advances in understanding the precise role of the DREAM complex in cancer, combined with ongoing efforts to develop targeted therapies, may pave the way for new options in cancer therapy.

Mitigation of CXCL10 secretion by metabolic disorder drugs in microglial-mediated neuroinflammation

Metabolic disorders are associated with several neurodegenerative diseases. We previously identified C-X-C motif chemokine ligand 10 (CXCL10), also known as interferon gamma-induced protein 10 (IP-10), as a major contributor to the type I interferon response in microglial-mediated neuroinflammation. Therefore, we hypothesized FDA-approved metabolic disorder drugs that attenuate CXCL10 secretion may be repurposed as a treatment for neurodegenerative diseases. Screening, dose curves, and cytotoxicity assays in LPS-stimulated microglia yielded treprostinil (hypertension), pitavastatin (hyperlipidemia), and eplerenone (hypertension) as candidates that significantly reduced CXCL10 secretion (in addition to other pro-inflammatory mediators) without impacting cell viability. Altogether, these data suggest metabolic disorder drugs that attenuate CXCL10 as potential treatments for neurodegenerative disease through mitigating microglial-mediated neuroinflammation.

Evaluation of the Pharmacokinetic Drug-Drug Interaction between Micronized Fenofibrate and Pitavastatin in Healthy Volunteers

Dyslipidemia is a major risk factor for development of atherosclerosis and cardiovascular disease (CVD). Effective lipid-lowering therapies has led to CVD risk reduction. This study evaluated the possible pharmacokinetic interactions between fenofibrate, a peroxisome proliferators-activated receptors α agonist, and pitavastatin, a 3-hydoxy-3-methylglutaryl-coenzyme A reductase inhibitor, in healthy Korean subjects. The study design was an open-label, randomized, multiple-dose, three-period, and six-sequence crossover study with a 10-day washout in 24 healthy volunteers. It had three treatments: 160 mg of micronized fenofibrate once daily for 5 days; 2 mg of pitavastatin once daily for 5 days; and 160 mg of micronized fenofibrate with 2 mg of pitavastatin for 5 days. Serial blood samples were collected at scheduled intervals for up to 48 h after the last dose in each period to determine the steady-state pharmacokinetics of both drugs. Plasma concentrations of fenofibric acid and pitavastatin were measured using a validated high-performance liquid chromatography with the tandem mass spectrometry method. A total of 24 subjects completed the study. Pitavastatin, when co-administered with micronized fenofibrate, had no effect on the C_max,ss and AUC_τ,ss of fenofibric acid. The C_max,ss and AUC_τ,ss of pitavastatin were increased by 36% and 12%, respectively, when co-administered with fenofibrate. Combined treatment with pitavastatin and micronized fenofibrate was generally well tolerated without serious adverse events. Our results demonstrated no clinically significant pharmacokinetic interactions between micronized fenofibrate and pitavastatin when 160 mg of micronized fenofibrate and 2 mg of pitavastatin are co-administered. The treatments were well tolerated during the study, with no serious adverse events.

Pitavastatin: A Review in Hypercholesterolemia

Oral pitavastatin (Livalo^®; Livazo^®) is a competitive HMG-CoA reductase inhibitor that is available in the EU for the reduction of elevated total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels in adults with primary hypercholesterolemia and combined (mixed) dyslipidemia. In short-term, phase III or IV studies in this patient population, pitavastatin 1-4 mg once daily was generally no less effective than presumed equipotent dosages of atorvastatin and simvastatin (including in patients with type 2 diabetes or ≥2 cardiovascular risk factors) and was superior to pravastatin (including in patients aged ≥65 years) in lowering LDL-C levels. Pitavastatin provided sustained LDL-C-lowering efficacy over up to 60 weeks' therapy in extension studies, and was associated with short- and longer-term improvements in several other lipid parameters. Short- and longer-term outcomes in studies in Asian patients were consistent with these findings. Pitavastatin was generally well tolerated and did not appear to adversely affect glucose metabolism parameters (e.g. fasting blood glucose, fasting plasma glucose, fasting plasma insulin, glycated hemoglobin) in short- and longer-term prospective and post-marketing surveillance studies in adults. Moreover, in combination with lifestyle modification advice, it was associated with a significant reduction in the risk of progression from impaired glucose tolerance to diabetes relative to lifestyle modification advice alone in a longer-term study in Japanese subjects. Thus, pitavastatin is an effective treatment option in adults with primary hypercholesterolemia and combined (mixed) dyslipidemia, including those at risk of developing type 2 diabetes.

Clinical benefits of pitavastatin: focus on patients with diabetes or at risk of developing diabetes

Despite attaining LDL-cholesterol targets, many patients with diabetes remain at risk of developing cardiovascular events. In addition, treatment with statins has been associated with a slight but significant increased risk of development of diabetes, particularly with high-intensity statins. Pitavastatin is a moderate- to high-intensity statin that effectively reduces LDL-cholesterol levels. Pitavastatin provides a sustained increase of HDL-cholesterol levels that may exhibit a neutral or positive effect on glucose metabolism, may not increase the risk of new-onset diabetes, may exhibit positive effects on renal function and urinary albumin excretion and the risk of drug–drug interactions is low. Therefore, it seems that pitavastatin should preferentially be considered in the treatment of dyslipidemia in diabetic patients or at risk of developing diabetes.

Pitavastatin 4 mg Provides Significantly Greater Reduction in Remnant Lipoprotein Cholesterol Compared With Pravastatin 40 mg: Results from the Short-term Phase IV PREVAIL US Trial in Patients With Primary Hyperlipidemia or Mixed Dyslipidemia

PURPOSE

Remnants are partially hydrolyzed, triglyceride-rich lipoproteins that are implicated in atherosclerosis. We assessed the adequacy of pitavastatin 4 mg and pravastatin 40 mg in reducing atherogenic lipid parameters beyond LDL-C, in particular remnant lipoprotein cholesterol (RLP-C).

METHODS

From the Phase IV, multicenter, randomized, double-blind PREVAIL US (A Study of Pitavastatin 4 mg Vs. Pravastatin 40 mg in Patients With Primary Hyperlipidemia or Mixed Dyslipidemia) trial, we examined lipoprotein cholesterol subfractions using Vertical Auto Profile testing and apolipoproteins B and A-I at baseline and 12 weeks. Participants with primary hyperlipidemia or mixed dyslipidemia had LDL-C levels of 130 to 220 mg/dL and triglyceride levels ≤ 400 mg/dL. In this post hoc analysis, changes in lipid parameters were compared by using ANCOVA.

FINDINGS

Lipoprotein subfraction data were available in 312 patients (pitavastatin, n = 157; pravastatin, n = 155). Pitavastatin promoted a greater reduction in RLP-C than pravastatin (-13.6 [8.7] vs -9.3 [9.5] mg/dL). Furthermore, the pitavastatin group reported greater reductions in both components of RLP-C (both, P < 0.001): intermediate-density lipoprotein cholesterol (-9.5 [6.3] vs -6.4 [6.6] mg/dL) and very low-density lipoprotein cholesterol subfraction 3 (-4.1 [3.5] vs -2.9 [3.8] mg/dL). There were also greater reductions in the major ratios of risk (apolipoprotein B/apolipoprotein A-I and total cholesterol/HDL-C) (both, P < 0.001). There were no significant changes in HDL-C, its subfractions, or natural log lipoprotein(a)-cholesterol. The mean age was 58.8 ± 8.9 years in the pitavastatin group and 57.0 ± 10.2 years in the pravastatin group.

IMPLICATIONS

Compared with pravastatin 40 mg daily, pitavastatin 4 mg provided superior reductions in atherogenic lipid parameters beyond LDL-C, including RLP-C. Future studies are needed investigate the clinical implications of lowering directly measured RLP-C as the principal target. ClinicalTrials.gov identifier: NCT01256476.

Benefit-risk assessment of pitavastatin for the treatment of hypercholesterolemia in older patients

With the practice-shifting changes made with the most recent guidelines for treating blood cholesterol, more older patients may be prescribed statin therapy. Therefore, it is imperative that practitioners have not only a working knowledge of information related to statins, but more specifically to their efficacy and safety in elderly populations. Pitavastatin is the most recent statin to receive regulatory approval. It is indicated for the treatment of primary hyperlipidemia or mixed dyslipidemia as an adjunctive therapy to diet. The overall body of evidence for the efficacy and safety of pitavastatin in elderly patients is small. The available data suggest that the ability of pitavastatin to lower low-density lipoprotein cholesterol in elderly patients is at least similar, and may be greater than that seen in comparatively younger cohorts. Taken together, the limited available data suggest that pitavastatin is effective at improving lipid parameters in elderly patients with a similar safety profile to other agents in the class. Until data become available distinguishing pitavastatin from the other available options, its ultimate role in the hyperlipidemia treatment armamentarium remains unclear.

Effect of high-dose pitavastatin on glucose homeostasis in patients at elevated risk of new-onset diabetes: insights from the CAPITAIN and PREVAIL-US studies

AIMS

Statin treatment may impair glucose homeostasis and increase the risk of new-onset diabetes mellitus, although this may depend on the statin, dose and patient population. We evaluated the effects of pitavastatin 4 mg/day on glucose homeostasis in patients with metabolic syndrome in the CAPITAIN trial. Findings were validated in a subset of patients enrolled in PREVAIL-US.

METHODS

Participants with a well defined metabolic syndrome phenotype were recruited to CAPITAIN to reduce the influence of confounding factors. Validation and comparison datasets were selected comprising phenotypically similar subsets of individuals enrolled in PREVAIL-US and treated with pitavastatin or pravastatin, respectively. Mean change from baseline in parameters of glucose homeostasis (fasting plasma glucose [FPG], glycated hemoglobin [HbA1c], insulin, quantitative insulin-sensitivity check index [QUICKI] and homeostasis model of assessment-insulin resistance [HOMA-IR]) and plasma lipid profile were assessed at 6 months (CAPITAIN) and 3 months (PREVAIL-US) after initiating treatment.

RESULTS

In CAPITAIN (n = 12), no significant differences from baseline in HbA1c, insulin, HOMA-IR and QUICKI were observed at day 180 in patients treated with pitavastatin. A small (4%) increase in FPG from baseline to day 180 (P < 0.05), was observed. In the validation dataset (n = 9), no significant differences from baseline in glycemic parameters were observed at day 84 (all comparisons P > 0.05). Similar results were observed for pravastatin in the comparison dataset (n = 14).

CONCLUSIONS

Other than a small change in FPG in the CAPITAIN study, neutral effects of pitavastatin on glucose homeostasis were observed in two cohorts of patients with metabolic syndrome, independent of its efficacy in reducing levels of atherogenic lipoproteins. The small number of patients and relatively short follow-up period represent limitations of the study. Nevertheless, these data suggest that statin-induced diabetogenesis may not represent a class effect.