Immutep (IMMP) said Thursday its investigational drug eftilagimod alpha, or efti, combined with Merck's (MRK) Keytruda and doublet chemotherapy achieved a response rate of 60.8% and disease control rate of 90.2% in patients with advanced or metastatic non-squamous non-small cell lung cancer in an investigator-initiated trial.

The company said the 60.8% response rate regardless of PD-L1 expression is a "substantial improvement" from the historical control of 48%.

Safety continues to be favorable for the triple combination, the company said.

Immutep said it expects to present additional data from the trial at a medical conference within the year.

Shares of Immutep climbed 9.3% in recent premarket activity Thursday, while Merck shares added 1%.