A clinical trial exploring entinostat in combination with Merck’s Keytruda (pembrolizumab) in non-small cell lung cancer (NSCLC) patients who progressed despite checkpoint-blocking treatment, met the required response threshold to advance into its next stage.
The Phase 1b/2 trial (NCT02437136) will reopen patient recruitment immediately, entinostat’s developer — Syndax Pharmaceuticals — announced.
“PD-1 therapies have offered important clinical benefit to patients with NSCLC, but unfortunately only a subset of patients respond. There is tremendous need for new combinations to further improve responses to PD-1 therapies,” Matthew D. Hellmann, MD, said in a press release. Hellmann is a medical oncologist and immunotherapy expert at Memorial Sloan Kettering Cancer Center,
“The early data here with several objective responses to the entinostat-pembrolizumab combination in patients with NSCLC who previously progressed on PD-1 therapy is promising and certainly worth additional investigation,” Hellmann added.
The trial, called ENCORE 601, also includes patients who never have been treated with drugs targeting the PD-1 or PD-L1 checkpoint molecules.
The pre-specified threshold stated that to advance to the second, Phase 2 stage, two or more of the previously treated NSCLC patients, or at least three of the 13 treatment-naïve patients, needed to have an objective response, partial or complete, to the combination treatment.
The company did not disclose the exact number of patients who had an objective response, but announced that the final enrollment of NSCLC patients who progressed despite earlier treatment with PD-1 or PD-L1-targeting drugs will include 56 patients. Syndax expects the enrollment to be complete by mid-2018.
The company likely will be able to determine, later this quarter, whether the trial also will expand the group of previously untreated NSCLC patients.
“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,” said Briggs W. Morrison, MD, and CEO of Syndax.
“This data, along with the responses we observed in the melanoma cohort earlier in the year, give us additional confidence in the ability of entinostat to enhance the patient’s response to immunotherapy. We look forward to providing additional details on these patient responses at an appropriate scientific forum.”
Entinostat is an orally given compound, which potentially boosts the body’s immune response to tumors. The ENCORE 601 trial also examines the drug in patients with melanoma and a type of colorectal cancer.
In addition, other trials focus on entinostat in combination with Tecentriq (atezolizumab), Bavencio (avelumab), and Aromasin (exemestane) in other cancer forms.
