Pharmacyclics Reports Interim Results From Phase I/II Study For PCI-24781

Pharmacyclics has reported interim results from a Phase I/II study showing safety and clinical activity in patients with relapsed / recurrent non-hodgkin’s lymphoma (NHL) treated with its HDAC inhibitor PCI-24781 as a single agent.

PCI-24781 is an oral pan-HDAC inhibitor which is currently in multiple clinical trials for solid and hematological malignancies (PCYC-0401 single center, solid tumor cancer patients IV administered drug; PCYC-0402 multi-center, solid cancer patients orally administered; PCYC-0403 multicenter, lymphoma cancer patients orally administered).

The company claims that the compound has been optimised for the combination of potency and pharmacokinetics (PK), and has potent anti-tumor activity in a variety of preclinical tumor models and also has demonstrated safety and clinical benefit in human solid tumors.

In a review of the data at the end of the Phase I dose-escalation portion of the current lymphoma trial, it was revealed that PCI-24781 has shown strong signs of efficacy with minimal toxicity as a single agent in lymphoma, with one complete response, 4 partial responses, one diffuse large B-cell lymphoma, one mantle cell lymphoma) and 6 stable disease in 16 patients evaluated for response (after 2 cycles).

Reportedly, the patients enrolled in the trial were pre-treated and had diverse histologies, including follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma.

In the study, a total of 25 patients were enrolled, with five still on study after 5-10 cycles of treatment. The dose and schedule have been optimised for the Phase II portion of the study.

Andrew Evens, principal investigator of the study, said: “At completion of the Phase I stage of this clinical trial, PCI-24781 showed encouraging clinical activity as a mono-therapy in relapsed/refractory non-Hodgkin’s lymphoma including several complete and partial remissions.”