ABSTRACT
Smokers experience aberrant gene promoter methylation in their bronchial cells, which may predispose to the development of neoplasia. Hydralazine is a DNA demethylating agent, and valproic acid is a histone deacetylase inhibitor, and both have modest but synergistic anticancer activity in vitro. We conducted a phase I trial combining valproic acid and hydralazine to determine the maximally tolerated dose (MTD) of hydralazine in combination with a therapeutic dose of valproic acid in patients with advanced, unresectable, and previously treated solid cancers. Twenty females and nine males were enrolled, with a median age of 57 years and a median ECOG performance status of 0. Grade 1 lymphopenia and fatigue were the most common adverse effects. Three subjects withdrew for treatment-related toxicities occurring after the DLT observation period, including testicular edema, rash, and an increase in serum lipase accompanied by hyponatremia in one subject each. A true MTD of hydralazine in combination with therapeutic doses of valproic acid was not reached in this trial, and the planned upper limit of hydralazine investigated in this combination was 400 mg/day without grade 3 or 4 toxicities. A median number of two treatment cycles were delivered. One partial response by Response Evaluation Criteria In Solid Tumors criteria was observed, and five subjects experienced stable disease for 3 to 6 months. The combination of hydralazine and valproic acid is simple, nontoxic, and might be appropriate for chemoprevention or combination with other cancer treatments. This trial supports further investigation of epigenetic modification as a new therapeutic strategy.
ABSTRACT
INTRODUCTION: The epidermal growth factor receptor (EGFR) is a validated target in malignancy; however, patients with wild type EGFR obtain little sustained benefit from anti-EGFR monotherapy. Epigenetic therapy to reactivate tumor suppressor genes may enhance the anti-proliferative effect of erlotinib. This phase I study evaluated the combination of erlotinib and 5-azacytidine for safety and maximal tolerated dose (MTD). METHODS: Thirty patients with advanced solid tumors were treated in a standard 3 + 3 cohort design. Erlotinib was dosed at 150 mg daily, and 5-azacytidine was escalated by increasing the number of daily doses of 75 mg/m(2) per cycle. Patients were followed for dose-limiting toxicity (DLT). Efficacy was assessed by RECIST criteria. RESULTS: Common non-hematologic toxicities included rash, diarrhea, nausea, and fatigue; the majority was ≤ Grade 2. DLTs included conjunctivitis in cohort 1 and infusion reaction in cohort 2. No DLTs occurred in cohorts 3, 4, or 5; however, 2 serious neutropenic infections arose in cohort 5 after cycle 1. Cohort 4 was expanded to 6 patients and was the MTD. Partial response (lung, ovarian) and stable disease occurred in 2 and 11 patients, respectively. Median progression-free survival was 2 months. Two patients with lung and larynx cancer had prolonged stable disease. CONCLUSION: The combination of erlotinib and 5-azacytidine was well tolerated with interesting clinical activity in lung, head and neck, and ovarian cancer. The recommended dose for phase II study is erlotinib 150 mg daily and 5-azacytidine 75 mg/m(2) daily on days 1-4 and 15-18 of a 28-day cycle.
