Immutep (ASX:IMM) said that a median overall survival of 17.6 months was achieved in cohort B of the TACTI-003 phase IIb trial, which is evaluating its eftilagimod alfa drug candidate in combination with MSD's anti-PD-1 therapy Keytruda, or pembrolizumab, as a potential first-line therapy for recurrent/metastatic head and neck squamous cell carcinoma patients with PD-L1 expression below 1, according to a Monday Australian bourse filing.

The overall survival in 31 evaluable patients with a data cut-off of March 31 compares favorably to historical results from the two current standard-of-care approaches, per the filing.

The antigen-presenting cell activator eftilagimod alfa, in combination with pembrolizumab, continues to be well-tolerated with no new safety signals, the filing said. It has fast fast-track designation in recurrent/metastatic head and neck squamous cell carcinoma.

Immutep requested a meeting with the US Food and Drug Administration to discuss the next steps, including potential paths to approval, the filing said.