Response to hydralazine-valproate in a patient with mycosis fungoides

Hydralazine Associated With Reduced Therapeutic Phlebotomy Frequency in a Nationwide Cohort Study: Real-World Effectiveness for Drug Repurposing

Background: Therapeutic phlebotomy, known as scheduled bloodletting, has been the main method for managing erythrocytosis symptoms and thrombocytosis-associated complications in various blood disorders. One of the major indications for phlebotomy is polycythemia vera (PV). The main goal of current treatment strategies for patients who require phlebotomy is to prevent thrombohemorrhagic complications rather than to prolong survival or lessen the risk of myelofibrotic or leukemic progression. Additional cytoreductive therapy is recommended for high-risk PV, for which the common first-line drug is hydroxyurea. However, recent evidence suggests that phlebotomy may not reduce the risk of thrombosis in patients with PV. Further evidence suggests that patients with PV treated with hydroxyurea who require three or more phlebotomy procedures per year have a higher risk of thrombotic complications.

Methods: We hypothesized that a drug-repurposing strategy of utilizing antineoplastic drugs for patients who require phlebotomy would result in greater benefits than would phlebotomy. The antihypertensive hydralazine and the anticonvulsant valproate, which have both been reported to have antineoplastic activity that mimics cytoreductive agents, were selected as candidates for the drug-repositioning strategy in a retrospective cohort study. We measured the hazard ratios (HR) and the frequencies of phlebotomy in patients with prescriptions for hydralazine or valproate or the two drugs in combination by using data from Taiwan’s National Health Insurance Research Database from 2000 to 2015 (n = 1,936,512).

Results: The HRs of undergoing phlebotomy in groups with hydralazine, valproate, and combination hydralazine–valproate prescriptions were reduced to 0.729 (p = 0.047), 0.887 (p = 0.196), and 0.621 (p = 0.022), respectively. The frequency of undergoing phlebotomy decreased from 2.27 to 1.99, 2.01, and 1.86 per person-year (p = 0.015), respectively. However, no significant differences were observed for the hydralazine group or the hydralazine–valproate combination group.

Conclusion: Whether a repurposed drug can serve as a cytoreductive agent for patients who require phlebotomy depends on its risk–benefit balance. We suggest that hydralazine, instead of the hydralazine–valproate combination, is a reasonable alternative for patients who require regular phlebotomy.

Epigenetics of Cutaneous T-Cell Lymphomas

Epigenetic modifications rarely occur in isolation (as single “epigenetic modifications”). They usually appear together and form a network to control the epigenetic system. Cutaneous malignancies are usually affected by epigenetic changes. However, there is limited knowledge regarding the epigenetic changes associated with cutaneous lymphomas. In this review, we focused on cutaneous T-cell lymphomas such as mycosis fungoides, Sézary syndrome, and anaplastic large cell lymphoma. With regard to epigenetic changes, we summarize the detailed chemical modifications categorized into DNA methylation and histone acetylation and methylation. We also summarize the epigenetic modifications and characteristics of the drug for cutaneous T-cell lymphoma (CTCL). Furthermore, we discuss current research on epigenetic-targeted therapy against cutaneous T-cell lymphomas. Although the current method of treatment with histone deacetylase inhibitors does not exhibit sufficient therapeutic benefits in all cases of CTCL, epigenetic-targeted combination therapy might overcome this limitation for patients with CTCL.

Epigenetics-Associated Risk Reduction of Hematologic Neoplasms in a Nationwide Cohort Study: The Chemopreventive and Therapeutic Efficacy of Hydralazine

Background

Although several epigenetic drugs have been reported to have therapeutic efficacy for some hematologic neoplasms (HNs) in clinical trials, few achieved disease-free survival benefit. The traditional drug discovery pathway is costly and time-consuming, and thus, more effective strategies are required. We attempted to facilitate epigenetic drug repositioning for therapy of HNs by screening the Human Epigenetic Drug Database (HEDD) in the web, conducting a bench-work cytotoxicity test and a retrospective nationwide cohort study prior to a clinical trial.

Methods

Four FDA-approved epigenetic drugs with antitumor properties and completion of clinical phase II trials were selected from HEDD. Hydralazine (HDZ) and valproate (VAL) among the four were selected with higher cytotoxicity to HN cells, no matter whether carrying the JAK2V617F mutation or not. Both of them were chosen for a cohort study using the Longitudinal Health Insurance Database (LHID) 2000–2015 (N = 1,936,512), a subset of the National Health Insurance Research Database (NHIRD, N= 25.68 millions) in Taiwan.

Results

In the initial cohort, HDZ or VAL exposure subjects (11,049) and matching reference subjects (44,196) were enrolled according to maximal daily consumption (300/2,100 mg per day of HDZ/VAL). The HN incidence in HDZ and VAL exposure groups reduced from 4.97% to 3.90% (p <.001) and 4.45% (p = .075), respectively. A further cohort study on HDZ at a lower range of the WHO defined daily dose (<34 mg per day) and HN incidence of HDZ exposure subjects (75,612) reduced from 5.01% to 4.16% (p = 1.725 × 10 ^-18) compared to the reference subjects (302,448).

Conclusions

An association of a chronically prescribed HDZ, even prescribed low dose, with reduction of overall incidence rate and in most subgroups of HN was observed in our study. Repositioning HDZ for HN management may be feasible. This is the first nationwide cohort study of the epigenetics-associated risk evaluation of overall HN in the existing literature, showing an effective method with a wider scope to inform contemporary clinical trials of epigenetic drugs in the future.

Efficacy of hydralazine and valproate in cutaneous T-cell lymphoma, a phase II study

OBJECTIVES

To evaluate the activity and safety of hydralazine and valproate (Transkrip) in cutaneous T-cell lymphoma (CTCL).

METHODS

Previously untreated and progressive/refractory CTCL patients received hydralazine at 83 mg or 182 mg/day for slow and rapid acetylators respectively plus magnesium valproate at a total dose of 30 mg/Kg t.i.d daily in continuous 28-day cycles in this phase II study. The primary objective was overall response rate (ORR) measured by the modified severity weighted assessment tool (m-SWAT), secondary end-points were time to response (TTR), time to progression (TTP), duration of response (DOR), progression-free survival (PFS), overall survival (OS) and safety.

RESULTS

Fourteen patients were enrolled (7 untreated and 7 pretreated). ORR was 71% with 50% complete and 21% partial. Two had stable disease and two progressed. At a median follow-up of 36 months (5-52), median TTR was 2 months (1-4); median DOR was 28 months (5-45); median PFS 36 and not reached for OS. There were no differences in median TTR, DOR, and PFS between treated and pretreated patients. Pruritus relieve was complete in 13 out of 14 patients. No grade 3 or 4 toxicities were observed.

CONCLUSION

The combination of hydralazine and valproate is safe, very well tolerated and effective in CTCL.

Hydralazine-valproate: a repositioned drug combination for the epigenetic therapy of cancer

INTRODUCTION

DNA methylation (DNMTi) and histone deacetylase inhibitors (HDACi) are in development for cancer therapy. So far, four epigenetic drugs are approved for myelodysplastic syndrome (MDS) and cutaneous T-cell lymphoma (CTCL). The combination of hydralazine-valproate (TRANSKRIP(™)) is being repositioned as an oral DNMT and HDAC inhibitor.

AREAS COVERED

Brief discussion on the current status of epigenetic drugs and studies published on the preclinical and clinical development of the hydralazine-valproate combination.

EXPERT OPINION

Drug repositioning is a strategy for prompt and cost-efficient drug discovery. There is evidence that combining DNMTi with HDACi would be more efficacious than administering each agent on its own. Hydralazine-valproate is safe when used alone or in combination with chemotherapy or chemoradiation. The fact that both drugs are orally administered is another advantage over current epigenetic drugs. This combination is promising but larger studies are needed. Among these, the randomized Phase III trials in advanced and in locally advanced cervical cancer combined with chemotherapy and cisplatin-radiation respectively, would eventually confirm its efficacy. Studies on MDS and CTCL would also eventually prove the efficacy of hydralazine valproate so that in the coming years hydralazine-valproate could have a role in cancer epigenetic therapy.

Genetic selection of volunteers and concomitant dose adjustment leads to comparable hydralazine/valproate exposure

WHAT IS KNOWN AND OBJECTIVE

Hydralazine is an inhibitor of DNA methyltransferases, whereas valproate interferes with histone deacetylation. In combination, they show a marked synergism in reducing tumour growth as well as development of metastasis and inducing cell differentiation. Hydralazine is metabolized by the highly polymorphic N-acetyltransferase 2. The current pilot study was performed to analyse the pharmacokinetic parameters of a single dose of hydralazine in 24 h (one tablet with 83 mg for slow acetylators and one tablet with 182 mg for fast acetylators) and three fixed doses of valproate (one tablet of controlled liberation with 700 mg every 8 h) in healthy genetically selected volunteers. Selection was performed based on their NAT2 activity as deduced from their genotype.

METHODS

An open label non-randomized single arm study was conducted in two groups of six healthy volunteers of both genders aged 20-45 years with a body mass index 22·2-26·9 which were classified as fast or slow acetylators after genotyping 3 SNPs that cover 99·9% of the NAT2 variants in the Mexican population. Blood samples were collected predose and serially post-dose in an interval of 48 h. Hydralazine and valproate concentrations were determined by ultra-high performance liquid chromatography (UPLC) coupled to tandem mass spectroscopy (MS/MS).

RESULTS AND DISCUSSION

The AUC0-48 h and Cmax of hydralazine were almost identical (1410 ± 560 vs. 1446 ± 509 ng h/mL and 93·4 ± 16·7 vs. 112·5 ± 42·1 ng/mL) in both groups with NAT2 genotype-adjusted doses, whereas the multidose parameters of valproate were not significantly affected neither by the selection of the NAT2 genotype (AUC0-48 h 2064 ± 455 vs. 1896 ± 185 μg h/mL; Cmax 96·4 ± 21·1 vs. 88·8 ± 7·2 μg/mL, for the fast and slow acetylators, respectively) nor the co-administration of 83 or 182 mg of hydralazine.

WHAT IS NEW AND CONCLUSION

Comparable hydralazine exposures (differences in AUC0-inf of only 7%) were observed in this study with genetic selection of volunteers and concomitant dose adjustment. However, the conclusions have yet to be confirmed with a full-powered 2 × 2 crossover study.