- Phase 1a (dose escalation) - patients who have received all therapy known to confer clinical benefit (including PD-1 therapies, if relevant), or for whom no therapy of proven efficacy exists, or who are not amenable to standard therapies. Patients with PD-1 experience must have a minimum of 60 days between the last dose of the previous PD-1 and Cycle 1 Day 1 of BI 754091 treatment. Phase 1b (dose expansion) - patients who are anti-PD-1 naïve but have failed conventional treatment (excluding anti-PD-1 treatment), or for whom no therapy of proven efficacy exists, or who are not amenable to standard therapies.