In this study, the combination of the PGE2 inhibition (through the EP4 receptor antagonist CR6086) with the immune checkpoint blockade (through the anti-PD-1 AGEN2034) is being evaluated. CR6086 is a potent and selective, orally bioavailable, targeted immunomodulator small molecule acting as an EP4 receptor antagonist. AGEN2034 (balstilimab) is a novel, fully human monoclonal immunoglobulin G4 antibody, designed to block programmed cell death 1 (PD-1) from interacting with its ligands (PD-L) PD-L1 and PD-L2, currently being developed for the treatment of advanced malignancies. EP4 receptor antagonists turn the status of the tumor microenvironment into a favourable one, i.e. immune-responsive, representing thus a rational therapeutic approach in combination with ICIs in primarily refractory cancers.
This Phase Ib/IIa study has been designed according to a 3+3 dose escalation/dose expansion design. A dose expansion will be conducted at both the intermediate and high dose levels, if tolerated, with the purpose of generating additional and more robust safety and preliminary efficacy data. No control arm was included, as the target patient population of this study consists of patients in whom the overall survival is less than 6 months and treatment options are very limited and often poorly tolerated, making unlikely that the study results can be significantly biased.