FS118: Rescuing Checkpoint Inhibitor (CPI)-Treatment Failures

Despite the clinical progress made with PD-(L)1 therapies, the upregulation of other immune checkpoints in cancer, such as lymphocyte-activation gene 3 (LAG-3), plays an important role in promoting resistance to these drugs. Therapeutic antibodies that target the immune checkpoints (LAG-3) and PD-1 have shown increased clinical anti-tumor activity when given in combination. FS118 has shown in clinical trials and preclinical studies that it blocks both PD-L1 and LAG-3 simultaneously and has an additional mechanism of action to promote the shedding of LAG-3 from the surface of immune cells. 

Our Approach for Overcoming PD-1 Resistance with FS118:

  • First-in-class LAG-3/PD-L1 mAb2 bispecific antibody
  • Well tolerated to date with low immunogenicity up to the highest dose evaluated (20mg/kg)
  • Early signs of clinical efficacy in a highly pre-treated patient population, particularly in patients with acquired resistance to PD-1 pathway blockade
  • Pharmacodynamic activity demonstrated by sustained increased levels of soluble LAG-3 and an increase in immune cell numbers
  • A proof-of-concept Phase II study will be initiated in patients with PD-1 resistant head and neck cancer patients