Immutep's LAG-3 candidate promising for head and neck cancer

Immutep has announced encouraging findings from its ongoing phase 2b trial of the investigational LAG-3 immunotherapy, eftilagimod alfa (efti), in a subset of head and neck cancer patients. The TACTI-003 (KEYNOTE-PNC-34) trial is examining the effectiveness of efti combined with Merck & Co’s anti-PD-1 therapy, Keytruda (pembrolizumab), which is also known as MSD outside of the United States and Canada. This combination is being tested as a first-line treatment for patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) who have negative PD-L1 expression.

Head and neck squamous cell carcinoma is a significant global health issue, with approximately 600,000 new cases diagnosed annually. The disease predominantly affects men in their 50s and 60s.

The recent results, presented at the European Society for Medical Oncology Virtual Plenary, showed promising outcomes. The combination therapy achieved an objective response rate (ORR) of 35.5% in 11 evaluable patients and a disease control rate (DCR) of 58.1%. These rates are notable, especially considering that this is a chemotherapy-free treatment approach for patients with negative PD-L1 expression. These results are considerably higher compared to historical controls, which reported an ORR of 5.4% and a DCR of 32.4% from anti-PD-1 monotherapy.

Additionally, the combination therapy demonstrated a high complete response rate of 9.7% in three patients, compared to a historical control rate of 0% from anti-PD-1 monotherapy.

Robert Metcalf, a medical oncologist and clinician scientist at the Christie NHS Foundation Trust, presented the data and commented on the significance of the findings. He highlighted the high response rate from this novel immunotherapy combination, noting that it exceeds other treatment approaches that do not involve chemotherapy. Metcalf emphasized the clinically meaningful response rate and the high unmet medical need in this patient population, suggesting that further investigation of the efti and Keytruda combination is warranted.

Beyond patients with negative PD-L1 expression, the TACTI-003 study is also evaluating the combination therapy in patients with recurrent or metastatic HNSCC who have PD-L1-positive tumors. Additionally, efti is being investigated in various other solid tumors, including non-small cell lung cancer (NSCLC) and metastatic breast cancer.

This latest data on efti comes shortly after Merck received expanded approval from the U.S. Food and Drug Administration for the use of Keytruda in adults with primary advanced or recurrent endometrial carcinoma. Keytruda already holds approvals to treat a wide range of cancers, such as specific cases of cervical cancer, bladder cancer, biliary tract cancer, NSCLC, and renal cell carcinoma. Currently, there are over 1,600 ongoing trials studying Keytruda, including research on its effectiveness in combination with Merck and Moderna's investigational skin cancer vaccine.