ATP-128

This is a multi-center, non-randomised Phase 1b study to evaluate the safety and tolerability of ATP128 alone or in combination with BI 754091 and of heterologous prime-boost ATP128 + VSV-GP128 in combination with BI 754091.
ATP128 is a self-adjuvanted chimeric recombinant protein vaccine being developed in combination with programmed cell death 1 (PD-1) blockade for the treatment of microsatellite stable (MSS) patients not responding to PD-1 blockade. The PD-1 inhibitor being tested with ATP128 is the BI 754091 (Ezabenlimab) compound which belongs to the human immunoglobulin G4 (IgG4) subclass of antibodies.
VSV-GP is a recombinant chimeric vesicular stomatitis virus (VSV, Indiana strain Rhabdoviridae) which carries the envelope glycoprotein (GP) of the visceral non neurotropic WE-HPI strain of the Lymphocytic choriomeningitis virus (LCMV, Arenaviridae) instead of the native VSV glycoprotein (G) and is developed as integral part of the prime-boost regimen together with ATP128.
The Sponsor plans to enrol 96 patients with histologically or cytologically confirmed stage IV colorectal cancer coming form three different patient populations:
Cohort 1a: 6 patients with stage IV colorectal cancer (CRC) having failed standard of care (SoC) therapies
Cohorts 1b, 2a, 2c: 30 patients with stage IV microsatellite stable/mismatch repair-proficient (MSS/MMRp) CRC being in stable disease (SD) or partial response (PR) after first line of SoC (4-6 months duration at minimum)
Cohorts 2b, 4b: 30 patients with stage IV MSS/MMRp liver-limited disease
Patients eligible for this study will be enrolled in one of the 8 cohorts depending on their disease:
Patients in Cohort 1a will receive ATP128 as single agent
Patients in Cohorts 1b, 2a, 2b, 2c will receive ATP128 in combination with BI 754091
Patients in Cohorts 3, 4a, 4b will receive ATP128 and VSV-GP128 in combination with BI 754091