Shares in biotech Immutep have surged after global pharmaceutical giant Merck reported that a trial of its drug Keytruda had improved the overall survival rate of patients with non-small cell lung cancer.

Separately, Immutep and Merck are jointly evaluating the combination of Immutep’s immunotherapy product, eftilagimod alpha, with Merck’s Keytruda to treat lung, head and neck, and ovarian cancers.

Shares in Immutep were 0.2 cents, or 8.3 per cent, higher at 2.6 cents at 1254 AEST.

The Merck phase III trial using just Keytruda as the first-line treatment for locally advanced or metastatic non-small cell lung cancer resulted in longer overall survival among patients, compared to chemotherapy treatment.

Merck is involved in more than 700 trials evaluating Keytruda as a treatment for a wide variety of cancers, either as a stand-alone treatment or in conjunction with other drugs or treatments.

In March, Immutep shares jumped more than 16 per cent when it announced its collaboration with Merck.

Immutep said at the time that the trial of the combined drugs could lead to more rapid drug development subject to successful outcomes.

The phase II trial of up to 120 patients is expected to start in the second half of 2018 in medical centres in Europe and the US.