Friday, Immutep Limited ( IMMP ) released results from Cohort B of the TACTI-003 (KEYNOTE-PNC-34) Phase 2b trial of eftilagimod alfa (efti) in combination with Merck & Co Inc ( MRK ) Keytruda (pembrolizumab) as first-line treatment of recurrent or metastatic head and neck squamous cell carcinoma patients with negative PD-L1 expression.

The updated efficacy and safety data was presented at the ESMO Virtual Plenary session.

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The investigational immuno-oncology (IO) combination utilizing efti and Keytruda achieved an objective response rate (ORR) of 35.5% (11 of 31 evaluable patients) and a disease control rate (DCR) of 58.1%.

The company says the results are among the highest recorded for a chemotherapy-free approach in negative PD-L1 patients and compare favorably to a historical control of 5.4% ORR and 32.4% DCR from anti-PD-1 monotherapy.

Additionally, the IO combination attained a high complete response rate of 9.7% (3 of 31 patients). This compares favorably to a historical control of 0% from anti-PD-1 monotherapy in 1L HNSCC patients with a Combined Positive Score (CPS)