A phase I clinical trial of the effect of belinostat on the pharmacokinetics and pharmacodynamics of warfarin

Anticancer clinical efficiency and stochastic mechanisms of belinostat

Cancer progression is strongly affected by epigenetic events in addition to genetic modifications. One of the key elements in the epigenetic control of gene expression is histone modification through acetylation, which is regulated by the synergy between histone acetyltransferases (HATs) and histone deacetylases (HDACs). HDACs are thought to offer considerable potential for the development of anticancer medications, particularly when used in conjunction with other anticancer medications and/or radiotherapy. Belinostat (Beleodaq, PXD101) is a pan-HDAC unsaturated hydroxamate inhibitor with a sulfonamide group that has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of refractory or relapsed peripheral T-cell lymphoma (PTCL) and solid malignancies or and other hematological tissues. This drug modifies histones and epigenetic pathways. Because HDAC and HAT imbalance can lead to downregulation of regulatory genes, resulting in tumorigenesis. Inhibition of HDACs by belinostat indirectly promotes anti-cancer therapeutic effect by provoking acetylated histone accumulation, re-establishing normal gene expressions in cancer cells and stimulating other routes such as the immune response, p27 signaling cascades, caspase 3 activation, nuclear protein poly (ADP-ribose) polymerase-1 (PARP-1) degradation, cyclin A (G2/M phase), cyclin E1 (G1/S phase) and other events. In addition, belinostat has already been discovered to increase p21WAF1 in a number of cell lines (melanoma, prostate, breast, lung, colon, and ovary). This cyclin-dependent kinase inhibitor actually has a role in processes that cause cell cycle arrest and apoptosis. Belinostat's clinical effectiveness, comprising Phase I and II studies within the areas of solid and hematological cancers, has been evidenced through several investigative trials that have supported its potential to be a valuable anti-cancer drug. The purpose of this research was to provide insight on the specific molecular processes through which belinostat inhibits HDAC. The ability to investigate new therapeutic options employing targeted therapy and acquire a deeper understanding of cancer cell abnormalities may result from a better understanding of these particular routes.

Phase 1 study of belinostat and adavosertib in patients with relapsed or refractory myeloid malignancies

PURPOSE

Belinostat is an intravenous histone deacetylase inhibitor with approval for T-cell lymphomas. Adavosertib is a first in class oral Wee1 inhibitor. Preclinical studies of the combination demonstrated synergy in various human acute myeloid leukemia (AML) lines as well as AML xenograft mouse models.

EXPERIMENTAL DESIGN

This was a phase 1 dose-escalation study of belinostat and adavosertib in patients with relapsed/refractory AML and myelodysplastic syndrome (MDS). Patients received both drugs on days 1-5 and 8-12 of a 21-day cycle. Safety and toxicity were monitored throughout the study. Plasma levels of both drugs were measured for pharmacokinetic analysis. Response was determined by standard criteria including bone marrow biopsy.

RESULTS

Twenty patients were enrolled and treated at 4 dose levels. A grade 4 cytokine release syndrome at dose level 4 (adavosertib 225 mg/day; belinostat 1000 mg/m2) qualified as a dose-limiting toxicity event. The most common non-hematologic treatment-related adverse events were nausea, vomiting, diarrhea, dysgeusia, and fatigue. No responses were seen. The study was terminated prior to maximum tolerated dose/recommended phase 2 dose determination.

CONCLUSIONS

The combination of belinostat and adavosertib at the tested dose levels was feasible but without efficacy signals in the relapsed/refractory MDS/AML population.

A Colon-Targeted Adsorbent (DAV132) Does Not Affect the Pharmacokinetics of Warfarin or Clonazepam in Healthy Subjects

DAV132 is a novel colon-targeted adsorbent that prevents the deleterious impact of antibiotics on gut microbiota without modifying their systemic availability. A randomized, Latin-square crossover, open-label trial with 2 substudies in 18 and 24 healthy volunteers evaluated the pharmacokinetic (PK) bioequivalence of warfarin, a drug with a narrow therapeutic index (NTI), and clonazepam, both widely used for the treatment of chronic conditions, with or without coadministration of DAV132 7.5 g. PK parameters observed with single doses of 5 mg warfarin and 1 mg clonazepam when administered alone did not differ with the PK parameters when administered concomitantly with or 1 hour before DAV132. Geometric mean ratios (GMRs) for S-warfarin, R-warfarin, and clonazepam C_max were 102.0, 102.8, and 91.9, respectively, after concomitant administration and 106.5, 107.5, and 95.0, respectively, when administered 1 hour before DAV132. After concomitant administration, GMRs for S-warfarin, R-warfarin, and clonazepam AUC_last were 100.5, 100.2, and 94.9, respectively, and 101.9, 101.8, and 101.3, respectively, when administered 1 hour before DAV132. All GMR 90% confidence intervals fell within the prespecified 80% to 125% limit for bioequivalence, indicating a lack of drug-drug interaction. In conclusion, DAV132 did not affect the systemic exposure of 2 NTI drugs absorbed in the proximal intestine.

The Exceptional Responders Initiative: Feasibility of a National Cancer Institute Pilot Study

BACKGROUND

Tumor molecular profiling from patients experiencing exceptional responses to systemic therapy may provide insights into cancer biology and improve treatment tailoring. This pilot study evaluates the feasibility of identifying exceptional responders retrospectively, obtaining pre-exceptional response treatment tumor tissues, and analyzing them with state-of-the-art molecular analysis tools to identify potential molecular explanations for responses.

METHODS

Exceptional response was defined as partial (PR) or complete (CR) response to a systemic treatment with population PR or CR rate less than 10% or an unusually long response (eg, duration >3 times published median). Cases proposed by patients' clinicians were reviewed by clinical and translational experts. Tumor and normal tissue (if possible) were profiled with whole exome sequencing and, if possible, targeted deep sequencing, RNA sequencing, methylation arrays, and immunohistochemistry. Potential germline mutations were tracked for relevance to disease.

RESULTS

Cases reflected a variety of tumors and standard and investigational treatments. Of 520 cases, 476 (91.5%) were accepted for further review, and 222 of 476 (46.6%) proposed cases met requirements as exceptional responders. Clinical data were obtained from 168 of 222 cases (75.7%). Tumor was provided from 130 of 168 cases (77.4%). Of 117 of the 130 (90.0%) cases with sufficient nucleic acids, 109 (93.2%) were successfully analyzed; 6 patients had potentially actionable germline mutations.

CONCLUSION

Exceptional responses occur with standard and investigational treatment. Retrospective identification of exceptional responders, accessioning, and sequencing of pretreatment archived tissue is feasible. Data from molecular analyses of tumors, particularly when combining results from patients who received similar treatments, may elucidate molecular bases for exceptional responses.

Inhibition of human UDP-glucuronosyltransferase enzyme by belinostat: Implications for drug-drug interactions

Belinostat is a pan-histone deacetylase (HDAC) inhibitor which recently approved for the treatment of relapsed/refractory Peripheral T-cell lymphomas (PTCL). To assess drug-drug interactions (DDIs) potential of belinostat via inhibition of UDP-glucuronosyltransferases (UGTs), the effects of belinostat on UGTs activities were investigated using the non-selective probe substrate 4-methylumbelliferone (4-MU) and trifluoperazine (TFP) by UPLC-MS/MS. Belinostat exhibited a wide range of inhibition against UGTs activities, particularly a potent non-competitive inhibition against UGT1A3, and weak inhibition against UGT1A1, 1A7, 1A8, 2B4 and 2B7. Further, in vitro-in vivo extrapolation (IVIVE) approaches were used to predict the risk of DDI arising from inhibition of UGTs. Our data indicate that the intravenous infusion of belinostat at clinical available dose can contribute a significant increase to the AUC of co-administrated drugs primarily cleared by UGT1A3 or UGT1A1, which will result in potential DDIs. In contrast, oral administrated belinostat is unlikely to cause significant DDIs through inhibition of glucuronidation.

The Roles of Histone Deacetylases and Their Inhibitors in Cancer Therapy

Genetic mutations and abnormal gene regulation are key mechanisms underlying tumorigenesis. Nucleosomes, which consist of DNA wrapped around histone cores, represent the basic units of chromatin. The fifth amino group (Nε) of histone lysine residues is a common site for post-translational modifications (PTMs), and of these, acetylation is the second most common. Histone acetylation is modulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs), and is involved in the regulation of gene expression. Over the past two decades, numerous studies characterizing HDACs and HDAC inhibitors (HDACi) have provided novel and exciting insights concerning their underlying biological mechanisms and potential anti-cancer treatments. In this review, we detail the diverse structures of HDACs and their underlying biological functions, including transcriptional regulation, metabolism, angiogenesis, DNA damage response, cell cycle, apoptosis, protein degradation, immunity and other several physiological processes. We also highlight potential avenues to use HDACi as novel, precision cancer treatments.

Safety and Tolerability of Histone Deacetylase (HDAC) Inhibitors in Oncology

Histone deacetylases (HDACs) are expressed at increased levels in cells of various malignancies, and the use of HDAC inhibitors has improved outcomes in patients with haematological malignancies (T-cell lymphomas and multiple myeloma). However, they are not as effective in solid tumours. Five agents are currently approved under various jurisdictions, namely belinostat, chidamide, panobinostat, romidepsin and vorinostat. These agents are associated with a range of class-related and agent-specific serious and/or severe adverse effects, notably myelosuppression, diarrhoea and various cardiac effects. Among the cardiac effects are ST-T segment abnormalities and QTc interval prolongation of the electrocardiogram, isolated cases of atrial fibrillation and, in rare instances, ventricular tachyarrhythmias. In order to improve the safety profile of this class of drugs as well as their efficacy in indications already approved and to further widen their indications, a large number of newer HDAC inhibitors with varying degrees of HDAC isoform selectivity have been synthesised and are currently under clinical development. Preliminary evidence from early studies suggests that they may be effective in non-haematological cancers as well when used in combination with other therapeutic modalities, but that they too appear to be associated with the above class-related adverse effects. As the database accumulates, the safety, efficacy and risk/benefit of the newer agents and their indications will become clearer.

Hematologic toxicity is rare in relapsed patients treated with belinostat: a systematic review of belinostat toxicity and safety in peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) are an aggressive and diverse group of lymphomas with a T-cell origin. Most patients progress following initial treatment and require salvage therapy. The burden of symptoms is high due to its extra-nodal presentation, high rate of advanced disease, and associated cytopenias combined with its predilection for an elderly population. The disease is generally incurable at relapse in the absence of transplantation and treatment is aimed at prolonging life and reducing disease-related symptoms. Belinostat is a histone deacetylate inhibitor that was granted accelerated approval by the US Food and Drug Administration on July 3, 2014, for the treatment of relapsed PTCL. Here, a systemic review was conducted to assess the safety and efficacy of belinostat. A safety analysis involved 512 patients with relapsed malignancies, and an efficacy analysis focused on patients with relapsed PTCL and included a total of 144 patients. Common adverse events were noted including fatigue (35%), nausea (42.8%), and vomiting (28.5%), but comparatively low rates of grade 3/4 hematologic toxicity overall (6.4%). Efficacy analysis demonstrated an overall response rate of 25.7% and complete responses of 10.4% with the majority of discontinuations occurring for lack of efficacy. Ultimately, these results demonstrate that belinostat has comparable efficacy to other agents used in this setting and is well tolerated in regard to hematologic events, but there is limited data on patient-reported outcomes, reduction in disease-related symptoms, or quality of life.

Histone Deacetylase Inhibition Has Targeted Clinical Benefit in ARID1A-Mutated Advanced Urothelial Carcinoma

Histone deacetylase (HDAC) inhibition has sporadic clinical efficacy in urothelial carcinoma; the genomic basis for clinical response is not known. In two separate phase I clinical trials testing pharmacokinetic aspects of HDAC inhibitors in advanced solid tumors, we identified one patient with advanced urothelial carcinoma who had a complete response to belinostat, and one patient with advanced urothelial carcinoma who had a partial response to panobinostat. The archived tumors of the responders were genomically characterized in comparison to others with urothelial carcinoma on the trials. Urothelial carcinoma cell lines treated with panobinostat and belinostat were studied to elucidate the mechanisms of benefit. Notably, the urothelial carcinoma tumors that responded to HDAC inhibition had ARID1A mutations. ARID1A mutations were also noted in the tumors of three patients who had stable disease as their best response to HDAC inhibition. Corroborating the basis of sensitivity, transcriptional profiling of platinum-resistant ARID1A-mutated HT1197 cells treated with panobinostat reveals negative enrichment for both cyto-proliferative (MYC and E2F targets) and DNA repair gene sets, and positive enrichment for TP53 and inflammatory gene sets. Our study identifies ARID1A loss as a basis for clinical response to pan HDAC inhibition and offers avenues for potential rational therapeutic combinations with HDAC inhibitors in advanced urothelial carcinoma.

The Clinical Pharmacokinetics and Pharmacodynamics of Warfarin When Combined with Compound Danshen: A Case Study for Combined Treatment of Coronary Heart Diseases with Atrial Fibrillation

Warfarin is used as anticoagulant and Compound Danshen prescription (CDP) is able to promote blood circulation. The combination might produce a synergic effect for patients of coronary heart diseases (CHDs) with atrial fibrillation (AF). Whether the combination increases the bleeding risk of warfarin is unclear, so the effects of Compound Danshen dripping pill (CDDP) on the pharmacokinetics (PK) and pharmacodynamics (PD) profiles of warfarin was investigated in patients. The dose and blood concentrations of warfarin, the four indicators of blood coagulation, prothrombin time, activated partial thromboplatin time, thrombin time, fibrinogen, and international normalized ratio value were compared when with and without CDDP treatment. The population PK (PPK) and PPK-PD models were established to assess patient demographics, genetic polymorphisms and CDDP as covariates. And the Seattle Angina Questionnaire was used to evaluate clinical efficacy, and the bleeding risk of combination was analyzed. The results indicated that CDDP had little influence on PK and PD profiles of warfarin in most patients and the combination of CCDP and warfarin would be a promising alternative regime for CHD with AF patients. The study was registered on China Clinical Trial Registry with number ChiCTR-ONRC-13003523.