Pembrolizumab and Olaparib Treatment for Relapsed or Refractory Peripheral T-Cell Lymphoma

All trial interventions will be administered on an outpatient basis where possible. Pembrolizumab 200 mg will be administered as a 30 minute IV infusion every 3 weeks. Sites should make every effort to target infusion timing to be as close to 30 minutes as possible. However, given the variability of infusion pumps from site to site, a window of -5 minutes and +10 minutes is permitted (i.e., infusion time is 30 minutes: -5 min/+10 min). Preparation of the pembrolizumab infusion fluid and administration of infusion solution will follow standard institutional practice. Olaparib will be administered at a dose of 300 mg (two 150-mg tablets) PO bid, for a total daily dose of 600 mg. Olaparib treatment should begin on the same day as Cycle 1, Day 1 of pembrolizumab treatment, with the first dose administered after the pembrolizumab IV infusion and the second dose approximately 12 hours later. Subsequent Olaparib treatments will be taken PO bid at approximately the same time in the morning and evening on a continuous daily dosing schedule. Capsules/tablets should be taken approximately 12 hours apart and may be taken in relationship to food as per local prescribing information. Capsules/tablets must be swallowed whole and should not be chewed, dissolved, or opened. Capsules that appear deformed or show evidence of leakage should not be taken. Subjects must be instructed that if they miss a dose or vomit any time after taking a dose, they should take their next dose at its scheduled time. Subjects should not take an extra dose to make up for a missed dose. Subjects must be instructed to record all doses (missed or vomited doses) in a dosing diary supplied by the site. Subjects should avoid eating grapefruit or Seville oranges or drinking grapefruit juice or Seville orange juice while taking Olaparib. The mandatory Safety Follow-Up Visit should be conducted approximately 30 days after the last dose of study intervention or before the initiation of a new anti-cancer treatment, whichever comes first. Participants who complete the protocol-required cycles of study intervention of who discontinue study intervention for a reason other than disease progression will begin the Efficacy Follow-Up Phase and should be assessed every 12 weeks (± 7 days) by radiologic imaging to monitor disease status. Every effort should be made to collect information regarding disease status until the start of new anti-cancer therapy, disease progression, death, end of the study or if the participant begins retreatment with Pembrolizumab. Participants who completed all efficacy assessments and/or will not have further efficacy assessments must enter the Survival Follow-up Phase. Participant survival follow-up status will be assessed approximately every 12 weeks to assess for survival status until death, withdrawal of consent, or the end of the study, whichever occurs first.