A phase II evaluation of the potent, highly selective PARP inhibitor veliparib in the treatment of persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer in patients who carry a germline BRCA1 or BRCA2 mutation - An NRG Oncology/Gynecologic Oncology Group study.

BACKGROUND: Veliparib is a potent small molecule inhibitor of PARP-1/2, which is cytotoxic in tumor cells with deficiencies in BRCA1 or BRCA2. We studied the clinical activity and toxicity of veliparib in ovarian cancer patients carrying a germline BRCA1 or BRCA2 mutation (gBRCA). METHODS: Eligibility included three or fewer prior chemotherapy regimens, measurable disease and no prior use of a PARP inhibitor. Veliparib was administered at 400mg orally BID with one cycle being 28days. The two-stage Simon design was capable of detecting a 25% response probability with 90% power while controlling alpha=10% (at a 10% assumed null response probability). RESULTS: The median age of the 50 eligible patients was 57years (range 37-94) and 14, 18, and 18 patients had 1, 2, and 3 prior therapies respectively. Thirty patients (60%) were platinum-resistant. The median number of cycles administered was 6 (1-27). There was one grade 4 thrombocytopenia. Grade 3 adverse events were: fatigue (n=3), nausea (2), leukopenia (1), neutropenia (1), dehydration (1), and ALT (1). Grade 2 events >10% were: nausea (46%), fatigue (26%), vomiting (18%), and anemia (14%). The proportion responding was 26% (90% CI: 16%-38%, CR: 2, PR: 11); for platinum-resistant and platinum-sensitive patients the proportion responding was 20% and 35%, respectively. The most common reason for treatment discontinuation was progression (62%). Twenty-nine patients are alive; two with SD remain on veliparib. The median PFS is 8.18months. CONCLUSIONS: The single agent efficacy and tolerability of veliparib for BRCA mutation-associated recurrent ovarian cancer warrants further investigation.

Tissue-based immune monitoring I: tumor core needle biopsies allow in-depth interrogation of the tumor microenvironment.

We sought to assess the feasibility and reproducibility of performing tissue-based immune characterization of the tumor microenvironment using CT-compatible needle biopsy material. Three independent biopsies were obtained intraoperatively from one metastatic epithelial ovarian cancer lesion of 7 consecutive patients undergoing surgical cytoreduction using a 16-gauge core biopsy needle. Core specimens were snap-frozen and subjected to immunohistochemistry (IHC) against human CD3, CD4, CD8, and FoxP3. A portion of the cores was used to isolate RNA for 1) real-time quantitative (q)PCR for CD3, CD4, CD8, FoxP3, IL-10 and TGF-beta, 2) multiplexed PCR-based T cell receptor (TCR) CDR3 Vß region spectratyping, and 3) gene expression profiling. Pearson's correlations were examined for immunohistochemistry and PCR gene expression, as well as for gene expression array data obtained from different tumor biopsies. Needle biopsy yielded sufficient tissue for all assays in all patients. IHC was highly reproducible and informative. Significant correlations were seen between the frequency of CD3+, CD8+ and FoxP3+ T cells by IHC with CD3ε, CD8A, and FoxP3 gene expression, respectively, by qPCR (r=0.61, 0.86, and 0.89; all p< 0.05). CDR3 spectratyping was feasible and highly reproducible in each tumor, and indicated a restricted repertoire for specific TCR Vß chains in tumor-infiltrating T cells. Microarray gene expression revealed strong correlation between different biopsies collected from the same tumor. Our results demonstrate a feasible and reproducible method of immune monitoring using CT-compatible needle biopsies from tumor tissue, thereby paving the way for sophisticated translational studies during tumor biological therapy.

Tissue-based immune monitoring II: multiple tumor sites reveal immunologic homogeneity in serous ovarian carcinoma.

The presence of tumor-infiltrating lymphocytes (TILs) in epithelial ovarian cancer indicates a host antitumor response and is associated with improved survival. We wished to determine the extent to which TIL density differs from site to site within a given patient. We initially studied multiple paired metastases from serous ovarian carcinoma obtained at the time of primary debulking. The expression of genes in specific immune-related pathways was profiled on a pilot set of five patients. We then used immunohistochemistry and quantitative PCR to estimate the density of CD3+, CD8+, and FoxP3+ TILs in these same tumors. To extend the findings to a larger cohort, we semiquantitatively measured intraepithelial and stromal TILs in a tissue microarray (TMA) containing both primary tumors and metastases from 50 patients. In the pilot group, genes related to antimicrobial signaling and TGF-beta signaling showed between-site heterogeneity, whereas cytokines and antigen presentation transcripts were more homogeneous in any given patient. IHC and qPCR for T cell markers were concordant. In the TMA cohort, 2-way ANOVA showed that TIL heterogeneity between sites was present in some but not all patients. The stroma of extra-ovarian metastases showed significantly greater TIL infiltration than ovarian sites. A simulation showed that at clinically meaningful levels of precision, up to 3% of patients will be misclassified for intraepithelial TILs by a single biopsy. In conclusion, between-site heterogeneity exists in some patients with metastatic serous ovarian cancer. The predictive value of biopsies should be considered in clinical trial design.