Immutep’s protein-based cancer treatment has succeeded in a mid-stage study in patients with head and neck squamous cell carcinoma, spurring discussions with regulators on a path forward.
The Phase 2b trial investigated Immutep’s eftilagimod alpha — efti for short — plus Merck’s Keytruda in first-line HNSCC, including patients with tumors that do not express PD-L1. At the March 11 cutoff date, the combo achieved a 35.5% objective response rate in PD-L1 negative patients (11 of 31), with three experiencing complete response. The regimen also reached a disease control rate of 58.1%, according to a Friday release.
The results are “among the highest recorded for a chemotherapy-free approach” in this setting, according to Immutep, which presented the data at ESMO’s Virtual Plenary session on Thursday.
Since the data were from an open-label trial, the company pointed to a 2022 article published in the Journal of Clinical Oncology that noted anti-PD-1 monotherapy only delivered a 5.4% ORR and 32.4% DCR in the same setting. No new safety signals were observed compared with previous studies.
The company’s shares were up around 20% to AU$0.36 on the Australian stock exchange Friday.
Efti is a LAG-3 protein and MHC class II agonist designed to trigger both innate and adaptive immunity in people with cancer, according to Immutep. With the latest data in hand, the Australian biotech is set to review next steps in HNSCC with regulatory agencies.
Last month, Immutep unveiled plans to move the combination plus chemotherapy into a 750-subject Phase 3 trial in first-line non-small cell lung cancer (NSCLC) patients, regardless of PD-L1 expression. Around the same time, it secured around $100 million in a fundraise. Immutep will be responsible for running the registrational NSCLC test, with Merck supplying Keytruda.