Study of Vorinostat and Gefitinib in Relapsed/ or Refractory Patients With Advanced Non-small Cell Carcinoma (NSCLC)

Gefitinib is an orally active epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) and produces 8-20% of response rates in patients with advanced non-small cell lung cancer (NSCLC). Vorinostat (suberoylanilide hydroxamic acid \[SAHA\]) is a small-molecule inhibitor of histone deacetylase (HDAC) and induces cell differentiation, cell cycle arrest, and apoptosis in several tumor cells. There is a strong synergistic antiproliferative effect of vorinostat in combination with gefitinib in NSCLC cells. Vorinostat increases expression of E-cadherin and ErbB-3, which results in increased sensitivity to gefitinib. Moreover, In-vitro studies have shown that vorinostat leads to acetylation and disruption of Hsp90, which may lead to decreases in activity of pro-growth and prosurvival client proteins (J Bio Chem 2005;280:26729, Br J Cancer 2006;95:S2). These findings suggest that combination of vorinostat with gefitinib may improve the efficacy of gefitinib in NSCLC.