Immutep (IMMP) said Monday that its Eftisarc-neo mid-stage study of eftilagimod alfa with radiotherapy plus Keytruda has met its primary endpoint and "significantly exceeded" the trial's prespecified 35% tumor hyalinization/fibrosis.

The company said the trial enrolled 38 participants and found that the novel combination with eftilagimod alfa resulted in a median 51.5% tumor hyalinization/fibrosis in patients with soft tissue sarcoma.

The trial showed a "very good safety profile" for the therapy, with results obtained across multiple soft tissue sarcoma subtypes, the company said.

Shares of the company were down 1.9% in recent Monday premarket activity.