US-based biopharmaceutical firm Syndax Pharmaceuticals’ entinostat has advanced into the second stage of Phase II of the ENCORE 601 clinical trial for the treatment of patients with non-small cell lung cancer (NSCLC).
Entinostat is an oral, small molecule inhibitor of histone deacetylase (HDAC), with direct effects on both cancer and immune regulatory cells.
The move comes after the drug has met the pre-specified objective response threshold in the cohort, including patients with disease progression on or after programmed death receptor-1 (PD-1) therapy and/or programmed death ligand 1 (PD-L1).
The Phase Ib/II ENCORE 601 trial is designed to assess entinostat in combination with Merck's anti-PD-1 blocking therapy Keytruda (pembrolizumab) in two different NSCLC patient cohorts.
One cohort comprised patients who had previously progressed on PD-1 or PD-L1 therapy, while the other included patients naïve to PD-1 or PD-L1 therapy.
Syndax chief executive officer Briggs Morrison said: "We are pleased to report that the entinostat-Keytruda treatment combination has generated objective responses in patients whose disease has progressed on or after PD-1 antagonist therapies.
"This data, along with the responses we observed in the melanoma cohort earlier in the year, gives us additional confidence in the ability of entinostat to enhance the patient's response to immunotherapy.”
The criteria for advancement into the definitive stage of the Phase II trial is that a minimum of two out of 20 patients who had progressed on, or three out of 13 patients naïve to PD-1 or PD-L1 therapy must show an objective response to the combination therapy.
The cohort with patients who had previously progressed on PD-1 or PD-L1 will now be re-opened for enrolment.
Estimated to be completed in the first half of next year, the cohort will recruit a total of 56 patients.
Syndax expects to determine the expansion of naïve to PD-1 or PD-L1 therapy patient cohort in upcoming months.