Robert Metcalf, MD, PhD, The Christie NHS Foundation Trust, Manchester, U.K., stated, “The high response rate from this novel immunotherapy combination is well above other treatment approaches without chemotherapy. It matches historical response rates from chemotherapy-based treatments but without the associated toxicities. This is really significant for patients with head and neck squamous cell carcinomas who have a CPS less than one and for whom chemotherapy is the current first line treatment. Achieving complete responses in this group bodes well for this immunotherapy combination’s future potential, especially given the positive trend in response durability. The clinically meaningful response rate and high unmet medical need warrant further investigation of eftilagimod plus pembrolizumab in this patient population.”
Durability of Responses and Favourable Safety
Durability of responses is tracking well as has been seen in other clinical trials when efti is combined with KEYTRUDA. Over 50% of patients in Cohort B received treatment for at least six months with three additional patients nearing this threshold at the time of data cut off (11 March 2024). The combination also continues to have a favourable safety profile with no new safety signals observed.
This new data adds to the body of evidence that efti’s novel activation of antigen-presenting cells provides a strong boost to the immune system, enhancing the potential of immune checkpoint inhibitors such as KEYTRUDA. Importantly, as the only MHC Class II agonist in clinical development today, efti is generating a broad anti-cancer immune response in a unique and safe manner across all levels of PD-L1 expression, especially in patients with negative expression (CPS <1).
Next Steps
Based on the encouraging efficacy and high unmet medical need, Immutep will discuss the path forward with regulatory agencies. Efti has received FDA Fast Track designation in 1L HNSCC regardless of PD-L1 expression. The prevalence for CPS <1, CPS 1-19, and CPS >20 PD-L1 expression levels are approximately 20%, 30%, and 50% of the HNSCC patient population, respectively.3
Webcast Details
Immutep will host a webcast to discuss the clinical data. A replay of the webcast will be available under the Events section of Immutep’s website after the event.
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| Date/Time: | | Friday, July 12, at 9am AEST (7pm ET July 11) |
| Register: | | Link to register for webcast |
| Questions: | | Investors are invited to submit questions in advance via immutep@morrowsodali.com |
KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.
About the TACTI-003 Trial
The TACTI-003 (KEYNOTE-PNC-34) trial is an ongoing Phase IIb study evaluating eftilagimod alfa (efti), Immutep’s proprietary soluble LAG-3 protein and MHC Class II agonist, in combination with MSD’s (Merck & Co., Inc., Rahway, NJ, USA) anti-PD-1 therapy KEYTRUDA® (pembrolizumab) as first line treatment of recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). The randomized Cohort A portion of the study is evaluating efti in combination with pembrolizumab as compared to pembrolizumab monotherapy in patients with PD-L1 positive (Combined Positive Score [CPS] ≥1) tumours, whereas Cohort B is evaluating efti in combination with pembrolizumab in patients with PD-L1 negative tumours.
