Interim results from a pivotal trial of depsipeptide in cutaneous T-cell lymphoma (CTCL) were reported at the 2006 annual meeting of the American Society of Clinical Oncology (ASCO), held in Atlanta. The data from Gloucester Pharmaceuticals' GPI 04-0001, a trial of depsipeptide as a single agent for patients with CTCL, were presented in a poster presentation at the meeting.
Sean Whittaker, MD, of the St John's Institute of Dermatology at Guy's and St Thomas' NHS Foundation Trust, London, discussed results from 40 patients enrolled in the trial. Of the 28 patients currently evaluable for response, an overall response rate of 36% (10/28) was reported, including a 7% complete response rate and a 29% partial response rate. Dr. Whittaker noted that depsipeptide had demonstrated consistent clinical activity and manageable toxicity in patients with CTCL in the trial.
"Given the medical need for new therapies in CTCL, we are pleased by the overall response rate of 36% and by the complete responses we have seen in some patients," said William McCulloch, MB, FRCP, executive vice-president and chief medical officer at Gloucester Pharmaceuticals. "We are also encouraged by the median time to response observed with the drug and improvements in quality-of-life measures such as pruritus relief.
'Significant New Treatment'
Dr. McCulloch noted that similar data were reported at the American Society of Hematology annual meeting in December 2005, when the National Cancer Institute found a 37% overall response rate in its phase II trial of depsipeptide as a single agent treatment for CTCL. "The fact that we are noting a similar response rate, including complete responses, in our own pivotal trial supports our belief that depsipeptide has the potential to be a significant new treatment for patients with CTCL," he concluded.
Depsipeptide (FK228) is a novel agent in a new class of anticancer drugs known as histone deacetylase inhibitors. It has received both fast-track and orphan drug designation for CTCL by the US Food and Drug Administration as monotherapy for CTCL patients who have relapsed, or become refractory to, at least one prior systemic therapy.