Immutep (ASX:IMM) said a systematic evaluation of five clinical trials of eftilagimod alfa (efti), an antigen-presenting cell (APC) activator, in combination with standard-of-care therapies in late-stage cancer patients showed a significant increase in circulating absolute lymphocyte count (ALC) compared to standard-of-care alone, according to a Thursday Australian bourse filing.

The company said increased ALC was significantly associated with improved clinical outcomes, with ALC responders in the efti plus standard-of-care group showing a clinically meaningful median overall survival improvement of 7.7 months compared to ALC non-responders, with no corresponding association observed in the standard-of-care alone group.

"The findings link the immune-activating effect of efti measured in patients' blood with meaningful and significant survival improvements observed in previous clinical trials," said Immutep's Chief Scientific Officer, Frederic Triebel, adding that the studies highlighted a key connection with efti's mechanism of action and clinical efficacy.

The company's shares fell 2% in recent Thursday trade.