Background: Ovarian cancer remains the most lethal gynaecological malignancy and there is an urgent need for the development of further therapies to improve patient survival. Tumour infiltrating lymphocyte (TIL) therapy has shown clear efficacy in immunogenic cancers, and TIL can be readily expanded ex vivo from samples of high grade serous ovarian cancer (HGSOC). Antibodies against checkpoint proteins are effective in increasing TIL yield and functional response from ovarian cancer TIL cultures, potentially increasing TIL product efficacy. However, it is unknown whether blockade of other key checkpoints, including programmed death ligand-1 (PD-1), T cell immunoglobulin mucin-3 (TIM-3) and lymphocyte activation gene-3 (LAG-3) increase TIL yield in ex vivo cultures from HGSOC samples.Materials and Methods: TIL cultures were generated from fresh tissue samples and were incubated with CD3/CD28 Dynabeads® and IL-2. TIL were grown with or without the addition of 10µg/mL αPD-1, αTIM-3 or αLAG-3 antibodies as either single or repeated applications for 19 days. The phenotype of cultures was analysed by multiparameter flow cytometry. Interferon gamma (IFN-ᵧ) release in response to TIL co-culture with autologous tumour cultures or digests was measured by ELISA. Results: In keeping with previous findings the majority of TIL expressed at least one checkpoint protein. Specifically, TIL expressing PD-1 and TIM-3 retained a functional phenotype with co expression of OX40 and CD28. Expansion of TIL was increased following a single exposure to αPD-1 (1.20 fold) and αLAG-3 (1.31 fold) which was most marked in cultures with otherwise low proliferation. There was no additional increase in proliferation following repeated dosing. In co-culture with autologous tumour, TIL grown in the presence of checkpoint inhibitors showed increased IFN-ᵧ release suggesting increased functional activity in individual cultures. However, this response was not uniform across all cultures. Conclusions: These data suggests that initial blockade of checkpoint proteins is effective in increasing the yield of TIL expanded from HGSOC tumours, suggesting that checkpoint inhibition during TIL manufacture may be a useful method of increasing expansion efficiency.

Purpose: A single maintenance course of a poly(ADP-ribose) polymerase inhibitor (PARPi) improves progression-free survival (PFS) in germline BRCA1/2-mutant high-grade serous ovarian cancer (gBRCAm-HGSOC). The feasibility of a second maintenance course of PARPi was unknown. Patients and Methods: Phase II trial with two entry points (EP1, EP2). Patients were recruited prior to rechallenge platinum. Patients with relapsed, gBRCAm-HGSOC were enrolled at EP1 if they were PARPi-naïve. Patients enrolled at EP2 had received their first course of olaparib prior to trial entry. EP1 patients were re-treated with olaparib after RECIST complete/partial response (CR/PR) to platinum. EP2 patients were re-treated with olaparib +/- cediranib after RECIST CR/PR/stable disease to platinum and according to platinum-free interval. Co-primary outcomes were the proportion of patients who received a second course of olaparib and the proportion who received olaparib re-treatment for ≥6 months. Functional homologous recombination deficiency (HRD), somatic copy-number alteration (SCNA) and BRCAm reversions were investigated in tumour and liquid biopsies. Results: Twenty-seven patients were treated (EP1=17,EP2=10) and 19 were evaluable. Twelve patients (63%) received a second course of olaparib and 4/12 received olaparib re-treatment for ≥6 months. Common grade ≥2 adverse events during olaparib re-treatment were anaemia, nausea and fatigue. No cases of MDS/AML occurred. Mean duration of olaparib treatment and re-treatment differed (12.1 versus 4.4 months; p<0.001). Functional HRD and SCNA did not predict PFS. A BRCA2m reversion was detected in a post-olaparib liquid biopsy. Conclusion: A second course of olaparib can be safely administered to women with gBRCAm-HGSOC but is only modestly efficacious.

Introduction For patients with advanced epithelial ovarian cancer, complete surgical cytoreduction remains the strongest predictor of outcome. However, identifying patients who are likely to benefit from such surgery remains elusive and to date few surgical outcome prediction tools have been validated. Here we attempted to externally validate a promising three protein signature, which had previously shown strong association with suboptimal surgical debulking (AUC 0.89, accuracy 92.8%), (Riester, M., et al., (2014)). Methods 238 high-grade epithelial ovarian cancer samples were collected from patients who participated in a large multicentre trial (ICON5). Samples were collected at the time of initial surgery and before randomisation. Surgical outcome data were collated from prospectively collected study records. Immunohistochemical scores were generated by two independent observers for the three proteins in the original signature (POSTN, CXCL14 and pSmad2/3). Predictive values were generated for individual and combination protein signatures. Results When assessed individually, none of the proteins showed any evidence of predictive affinity for suboptimal surgical outcome in our cohort (AUC POSTN 0.55, pSmad 2/3 0.53, CXCL 14 0.62). The combined signature again showed poor predictive ability with an AUC 0.58. Conclusions Despite showing original promise, when this protein signature is applied to a large external cohort, it is unable to accurately predict surgical outcomes. This could be attributed to overfitting of the original model, or differences in surgical practice between cohorts.

<p>Supplementary Methodology.</p>

<p>Kaplan Meier curves.</p>