RecruitingPhase 2Drug trialPembrolizumab and Olaparib Treatment for Relapsed or Refractory Peripheral T-Cell LymphomaThe goal of this clinical trial is to evaluate the efficacy and safety of Pembrolizumab in combination with Olaparib in participants with relapsed/refractory Peripheral T-cell Lymphoma (PTCL). The study mainly aims to evaluate: * objective response rate (ORR) as per Cheson response criteria assessed by the independent central review * overall survival and progression-free survival * adverse events by CTCAE version 5.0 The administration of Pembrolizumab and Olaparib to participants will occur on Day 1 of each 3-week dosing cycle and will continue until disease progression or unacceptable toxicity, up to 35 cycles. Treatment with Olaparib will proceed continuously from Day 1 of Cycle 1, in 3-week dosing cycles in parallel with Pembrolizumab, up to 35 cycles, unless specific withdrawal/discontinuation criteria are met. After the end of treatment, each subject will be followed for 30 days for adverse event (AE) monitoring (serious AEs \[SAEs\] will be collected for 90 days after the end of treatment or 30 days after the end of treatment if the subject initiates new anticancer therapy, whichever is earlier).