Efficacy of pembrolizumab in patients with advanced cancer of unknown primary (CUP): a phase 2 non-randomized clinical trial ============================================================================================================================ * Kanwal P Raghav * Bettzy Stephen * Daniel D Karp * Sarina A Piha-Paul * David S Hong * Dipti Jain * Dilichukwu O Chudy Onwugaje * Abdulrahman Abonofal * Anneleis F Willett * Michael Overman * Brandon Smaglo * Ryan W Huey * Funda Meric-Bernstam * Gauri R Varadhachary * Aung Naing