The single-arm, non-randomized study included 74 patients with advanced disease who had previously failed a median of three systemic therapies. Patients were given 400mg of the HDAC inhibitor once daily until disease progression or intolerable toxicity, with modifications to the dose, as needed, to either 300mg once daily or 300mg once daily for five days per week.
In the study, 30% of the patients responded to treatment with Zolinza (vorinostat, also known as suberoylanilide hydroxamic acid, SAHA), as measured by the objective response rate.
Secondary endpoints from the study included duration of response, time to progression, time to response, and relief from itching. The median response duration for all patients was not reached because the majority of patients continued to respond, but was estimated to be at least four months (118 days). The median time to progression in patients who responded to treatment was also not reached but was estimated to be at least five months (148 days).
In addition, the median time to response was less than two months (55 days) and Zolinza reduced pruritus (itching) in nearly 32% of study participants.
The most common side effects observed in the study were diarrhea, fatigue, nausea, anorexia, dysgeusia and thrombocytopenia.
“These results provide additional evidence of the potential benefit of histone deacetylase inhibitors as a new and promising class of anticancer agents” said Dr Elise Olsen, director of the CTCL Clinic & Research Center at Duke University Medical Center, and lead investigator of the study.