Genexine announced top-line results from the KEYNOTE-899 phase 1b/2 clinical trial of GX-I7 (efineptakin alfa) in combination with pembrolizumab. The results indicated that GX-I7 in combination with pembrolizumab was safe and well tolerated and demonstrated promising early anti-tumor activity in patients with R/R metastatic TNBC. Genexine presented these data in a poster presentation at the American Society of Clinical Oncology (ASCO) annual meeting taking place from June 3-7, 2022.

Top-line data showed that GX-17 in combination with pembrolizumab was safe and well tolerated in the overall phase 1b/2 trial. For the phase 2 expansion cohort GX-I7 was administered at a dose of 1,200 µg/kg in nine-week intervals combined with pembrolizumab at 200 mg administered every three weeks. Observed ORRs with GX-17 in combination pembrolizumab were 15.7% (8/51) for phase 1b and 21.2% (7/33) for phase 2. Of the 25 patients who had an evaluable PD-L1 from a biopsy sample, 40.0% (10/25) were PD-L1 positive (CPS=10).

Notably, the ORR in patients who were PD-L1 positive was 60% (6/10). Absolute lymphocyte count and the number of CD4+ and CD8+ T cells were significantly increased, while NLRs and proportion of Treg in CD4+ T cells were significantly decreased in patients receiving GX-I7 720 µg/kg or higher. GX-I7 (efineptakin alfa), discovered and developed by Genexine, is a hybrid Fc-fused long-acting recombinant human IL-7 which plays an essential role in the development and homeostasis of T-cells.

T-cells play an important role in fighting cancer by recognizing cancer cells and killing them directly or indirectly by communicating with other immune cells. As a T-cell amplifier, GX-I7 may boost the immune system and help eradicate tumor cells more effectively. GX-I7 may modulate multiple steps in the cancer immunity cycle to overcome resistance to current immunotherapy.

By working synergistically with leading and emerging immuno-oncology therapeutics, GX-I7 may broaden, deepen, and prolong anti-tumor responses in cancer patients.