Shares of Syndax Pharmaceuticals Inc (NASDAQ:SNDX) fell Tuesday after the biotech released disappointing updated results from its Phase 2 study dubbed ENCORE 601 that evaluated its lead product candidate Entinostat in combination with Merck & Co’s (NYSE:MRK) Keytruda for treating non-small cell lung cancer patients previously treated with both chemotherapy and PD-(L)1 therapy.
At the time of data cut-off, there were seven confirmed partial responses among the overall population of 72 efficacy-evaluable patients, for a 10% objective response rate, a median duration of response of 5.3 months, and a median progression free survival of 2.8 months, the company said.
“The results did not meet the prespecified objective response rate endpoint. Six of the seven responders had low or negative PD-(L)1 expression at study entry,” the company said in a statement.
The stock fell 5.4% to $6.84 midday Tuesday.
"The observation of durable responses seen with the entinostat-pembrolizumab combination in NSCLC patients previously treated with both chemotherapy and PD-(L)1 therapy is an important result, and we look forward to more fully characterizing patient selection tools to identify those who are most likely to respond," said Syndax co-founder and Chief Scientific Officer Peter Ordentlich.
Syndax CEO Briggs Morrison said the company would communicate its plans for entinostat in this indication in the fourth quarter.
Separately, Syndax has already demonstrated that the delivery of entinostat in combination with hormone therapy can result in improvements in overall survival in advanced hormone receptor positive, or HR+, breast cancer patients, which has earlier led to Breakthrough Therapy Designation by the FDA for that indication.
The Waltham, Massachusetts clinical-stage biopharmaceutical company focuses on developing therapies for a range of cancers.
Contact Uttara Choudhury at [email protected]