A phase II study of epigenetic therapy with hydralazine and magnesium valproate to overcome chemotherapy resistance in refractory solid tumors

BACKGROUND

Epigenetic aberrations lead to chemotherapy resistance; hence, their reversal by inhibitors of DNA methylation and histone deacetylases may overcome it.

PATIENTS AND METHODS

Phase II, single-arm study of hydralazine and magnesium valproate added to the same schedule of chemotherapy on which patients were progressing. Schedules comprised cisplatin, carboplatin, paclitaxel, vinorelbine, gemcitabine, pemetrexed, topotecan, doxorubicin, cyclophosphamide, and anastrozole. Patients received hydralazine at 182 mg for rapid, or 83 mg for slow, acetylators, and magnesium valproate at 40 mg/kg, beginning a week before chemotherapy. Response, toxicity, DNA methylation, histone deacetylase activity, plasma valproic acid, and hydralazine levels were evaluated.

RESULTS

Seventeen patients were evaluable for toxicity and 15 for response. Primary sites included cervix (3), breast (3), lung (1), testis (1), and ovarian (7) carcinomas. A clinical benefit was observed in 12 (80%) patients: four PR, and eight SD. The most significant toxicity was hematologic. Reduction in global DNA methylation, histone deacetylase activity, and promoter demethylation were observed.

CONCLUSIONS

The clinical benefit noted with the epigenetic agents hydralazine and valproate in this selected patient population progressing to chemotherapy' and re-challenged with the same chemotherapy schedule after initiating hydralazine and valproate' lends support to the epigenetic-driven tumor-cell chemoresistance hypothesis (ClinicalTrials.gov Identifier: NCT00404508).

A phase II trial of epigenetic therapy with hydralazine and magnesium valproate associated to doxorubicin and cyclophosphamide for locally advanced breast cancer

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Background: DNA methylation and histone deacetylation are the most studied epigenetic alterations in cancer. Hydralazine and magnesium valproate are proven DNA methylation and histone deacetylase inhibitors respectively that in combination exert antitumor effects by their own and potentate the effect of chemotherapy. Methods: Open label two-stage design phase II trial to evaluate safety and efficacy of hydralazine and magnesium valproate plus chemotherapy in terms of pathologic complete response as neoadjuvant treatment. A total of 42 patients will be accrued. Untreated patients with histological confirmation of breast cancer in clinical stage IIb-IIIa, and hematological, renal and hepatic normal function are elegible. Patients with any collagen disease and any cardiovascular condition were excluded. Treatment consisted on four 21-day courses of doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2 plus epigenetic therapy starting 7 days before the first cycle of chemotherapy and continued until the end of chemotherapy. Oral hydralazine dosed according to acetylator phenotype and magnesium valproate at 30mg/Kg. After chemotherapy patients were evaluated with mammography and then submitted to surgical resection. Results: 17 patients in the first-stage have been accrued. Their characteristics are as follows: Median age 45-y (39–67), 67% were stage IIIa, median size of tumor was 5 cm (3–10 cm). All patients had clinically positive axillary nodes, with median size of 2 cm (1–5 cm), 80% were ductal carcinomas and 80% had either intermediate or high grade; 77% were ER-positive and 30% over-expressed HER2. Hematological toxicity was the most common side effect, neutropenia grade 3/4 was found in 35% of cases, anemia grade 3/4 was present in 15% of cases and most presented transient grade 2 depressed level of consciousness. Seven patients have completed planned treatment, clinical responses were CR 2, PR 4 and SD 1; in 1 of 7 a pathological complete response was seen. Conclusions: Epigenetic therapy with hydralazine and magnesium valproate associated to conventional chemotherapy is well tolerated. Its antitumor efficacy is pending to evaluate.

No significant financial relationships to disclose.