Immutep has shared positive results from an ongoing phase 2b study of its investigational LAG-3 immunotherapy eftilagimod alfa (efti) in a subset of head and neck cancer patients.
The TACTI-003 (KEYNOTE-PNC-34) trial has been evaluating the candidate in combination with Merck & Co’s – known as MSD outside the US and Canada – anti-PD-1 therapy Keytruda (pembrolizumab) as first-line treatment for recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) patients with negative PD-L1 expression.
Approximately 600,000 new cases of HNSCC are diagnosed globally every year, with the disease most often occurring in men in their 50s or 60s.
According to results presented at the European Society for Medical Oncology Virtual Plenary, the combination achieved an objective response rate (ORR) of 35.5% in 11 evaluable patients and a disease control rate (DCR) of 58.1%.
The figures are among the highest recorded for a chemotherapy-free approach in negative PD-L1 patients, Immutep said, adding that they “compare favourably” to a historical control of 5.4% ORR and 32.4% DCR from anti-PD-1 monotherapy.
The immuno-oncology combination also demonstrated a high complete response rate of 9.7% in three patients, versus a historical control of 0% from anti-PD-1 monotherapy.
Robert Metcalf, medical oncologist and clinician scientist, the Christie NHS Foundation Trust, who presented the data, said: “The high response rate from this novel immunotherapy combination is well above other treatment approaches without chemotherapy… The clinically meaningful response rate and high unmet medical need warrant further investigation of [efti] plus [Keytruda] in this patient population.”
Beyond negative PD-L1 patients, the TACTI-003 study is evaluating the combination in recurrent or metastatic HNSCC patients with PD-L1-positive tumours. Efti is also being assessed in a variety of other solid tumours, including non-small cell lung cancer (NSCLC) and metastatic breast cancer.
The latest data for the candidate comes just under a month after Merck received expanded approval from the US Food and Drug Administration for the use of Keytruda in adults with primary advanced or recurrent endometrial carcinoma.
Keytruda holds approvals to treat a wide range of cancers, including specific cases of cervical cancer, bladder cancer, biliary tract cancer, NSCLC and renal cell carcinoma. There are also currently more than 1,600 trials studying the therapy, including one evaluating it in combination with Merck and Moderna’s investigational skin cancer vaccine.