Prot #KRT-232-103: A Phase 1b/2, Open-Label Study Evaluating the Safety and Efficacy of KRT-232 in Patients with p53 Wild-Type (p53WT) Merkel Cell Carcinoma (MCC) Who Have Failed Anti-PD-1 or Anti-PD-L1 Immunotherapy, or in Combination with Avelumab in MC