- Prior chemotherapy or other systemic anticancer therapy within 4 weeks prior to start of olaparib treatment, 6 weeks for nitrosoureas or mitomycin. Exceptions include: Anti-hormonal treatment for ER positive or PR positive breast cancer is allowed until 7 days prior to treatment with olaparib, exposure to an investigational agent within 30 days or 5 half-lives (whichever is the longer) prior to start of olaparib treatment is not allowed, prior receipt of biologics targeting T cell co-regulatory proteins and/or immune checkpoints is not allowed. Examples include MEDI4736 or other PD1 or PD-L1 or PD-L2 inhibitors or anti-CTLA4 therapy, previous treatment with a PARP inhibitor, is not allowed.