Immutep Quarterly Activities Report - Seite 2

In addition, a statistically significant OS benefit was observed in the efti group in key pre-defined patient groups. In patients under 65 years of age, a +7.1 months survival benefit was observed in the efti group which reported a median OS of 21.9 months vs. 14.8 months in the placebo group, reflecting nearly 50% longer survival. Similarly, in patients with a low starting monocyte count, a +9.4 months survival benefit was observed in the efti group, with a median OS of 22.4 months vs. 12.9 months in the placebo group, 74% longer. Importantly there was a statistically significant increase of cytotoxic CD8 T-Cells in the efti arm versus the control arm and patients with those increased cells had, in general, a better OS. It is the first time that an antigen presenting cell activator (APC activator) has delivered meaningful OS data in a randomised, double blind setting.

The proportion of patient events has advanced to ~ 68% currently and Immutep is on track to report final OS data and Overall Response Rates (ORR) by mid calendar year 2021.

TACTI-002 - Phase II clinical trial
In November 2020, Immutep presented very encouraging results from its TACTI-002 phase II trial of efti at the Society for Immunotherapy of Cancer's (SITC) Congress. TACTI-002 is being conducted in collaboration with Merck & Co., Inc., Kenilworth, NJ, USA (known as “MSD” outside the United States and Canada) and is called Keynote-798 by MSD.

More mature ORRs for Parts A and C were reported at SITC and continued to be very favourable. Immutep reported a 39.4% ORR in patients with 1^st line Non-small Cell Lung Cancer (NSCLC) and 43.5% in patients with 2^nd line head and neck squamous cell carcinoma (HNSCC), on an evaluable patient basis. Five patients (two with 1^st line NSCLC and three with 2^nd line HNSCC) reported a complete disappearance of all lesions, known as a Complete Response.

First data from patients with 2^nd line NSCLC (Part B) who are PD-1 resistant was also reported at SITC. This group showed encouraging efficacy for low PD-L1 expressing patients who do not typically respond to immune checkpoint (PD-L1) therapy.

Following the encouraging results presented at SITC, Immutep and MSD expanded the TACTI-002 study by 74 additional patients with 1^st line NSCLC, creating a stage 3 for Part A. Recruitment for this new stage opened in late December 2020.

In addition, Immutep completed recruitment of 2^nd line HNSCC patients for Part C of the trial in early January 2021.

Further data from TACTI-002 is expected in H1 2021.