RBN-2397 in Combination With Pembrolizumab in Patients With SCCL

RBN-2397 inhibits PARP7, an enzyme that is switched on by cancer stresses, such as the toxins in cigarette smoke. Cancer cells use PARP7 to hide from the immune system by stopping the cell from sending a signal (Type 1 interferon) that tells the immune system that something is wrong and to kill the cell. RBN-2397 has been shown in animal and human studies to inhibit tumor growth and also shuts down the "don't kill me" signal the tumor is sending to evade the immune system. The purpose of this study is to determine if RBN-2397 in combination with pembrolizumab (a PD-1 inhibitor) has the ability to restore the response to treatment in patients with SCCL that have been previously treated with a PD-1/PD-1 ligand (PD-L1) inhibitor and have had a response followed by disease progression. The Phase 1b portion of the study will assess the safety of RBN-2397 in combination with pembrolizumab (a PD-1 inhibitor) and define the dose of RBN-2397 to be used in combination with pembrolizumab for the Phase 2. The Phase 2 portion of the study will assess the anti-tumor activity of RBN-2397 in combination with pembrolizumab.