Hunter Green

Interferon response and epigenetic modulation by SMARCA4 mutations drive ovarian tumor immunogenicity

Cell-intrinsic mechanisms of immunogenicity in ovarian cancer (OC) are not well understood. Damaging mutations in the SWI/SNF chromatin remodeling complex, such as SMARCA4 (BRG1), are associated with improved response to immune checkpoint blockade; however, the mechanism by which this occurs is unclear. We found that SMARCA4 loss in OC models resulted in increased cancer cell–intrinsic immunogenicity, characterized by up-regulation of long-terminal RNA repeats, increased expression of interferon-stimulated genes, and up-regulation of antigen presentation machinery. Notably, this response was dependent on STING, MAVS, and IRF3 signaling but was independent of the type I interferon receptor. Mouse ovarian and melanoma tumors with SMARCA4 loss demonstrated increased infiltration and activation of cytotoxic T cells, NK cells, and myeloid cells in the tumor microenvironment. These results were recapitulated in BRG1 inhibitor–treated SMARCA4- proficient tumor models, suggesting that modulation of chromatin remodeling through targeting SMARCA4 may serve as a strategy to overcome cancer immune evasion.

Basket study of oral progesterone antagonist onapristone extended-release in combination with anastrozole in progesterone receptor-positive recurrent adult-type granulosa cell tumor of the ovary

We sought to determine the safety and efficacy of the oral progesterone antagonist onapristone in combination with anastrozole in patients with recurrent progesterone receptor-positive adult-type granulosa cell tumor of the ovary. This was a single-institution phase II study of patients with progesterone receptor-positive adult-type granulosa cell tumor who received at least 1 prior line of chemotherapy. Patients were enrolled from November 2021 to August 2022 and tissue was evaluated for progesterone receptor status via immunohistochemistry. Eligible patients had progesterone receptor expression ≥1% on tissue collected within 3 years of enrollment. Patients received 50 mg of onapristone extended-release twice daily and 1 mg of anastrozole by mouth daily until progression of disease or discontinuation of treatment. Adverse events were graded by Common Terminology Criteria for Adverse Events version 5.0. The primary end point was the overall response rate by Response Evaluation Criteria in Solid Tumors version 1.1. Secondary end points were response duration, clinical benefit rate, progression-free survival, and safety. Fourteen patients with adult-type granulosa cell tumor enrolled and completed stage 1 accrual. There were no objective responses seen during the study period. The study was closed when further development of onapristone extended-release was discontinued. All 14 patients were evaluable, with median progression-free survival of 3.6 months (range; 1.7-7.1), a 6-month progression-free survival rate of 28.6% (range; 8.8%-52.4%), a 12-month progression-free survival rate of 10.7% (range; 0.8%-35.4%), and a clinical benefit rate of 42.9% (range; 17.7%-71.7%). The study did not meet its primary end point. Although the combination of onapristone extended-release and anastrozole was well-tolerated, there were no objective responses in patients with progesterone receptor-positive adult-type granulosa cell tumor.

Evolution and Co-occurrence of PI3K Pathway Gene Mutations in Endometrial Carcinoma Molecular Subtypes at the Single-Cell Level

Abstract Purpose: The PI3K pathway is altered in >85% of endometrioid endometrial carcinomas (EEC), with multiple mutations commonly co-occurring. Yet, the therapeutic effects of single-agent PI3K pathway inhibitors have been limited. We used single-cell sequencing to determine whether co-occurring PTEN, PIK3CA, and/or PIK3R1 somatic mutations in EECs stratified by molecular subtype originated through convergent or linear evolution. Experimental Design: Banked frozen EECs with co-occurring PI3K pathway mutations of no specific molecular profile (NSMP; n = 5), mismatch repair–deficient (MMRd; n = 3), and POLE (n = 3) subtypes were selected for single-nucleus DNA sequencing targeting hotspot variants of 64 cancer-related genes and the PTEN, PIK3R1, and PIK3CA coding sequences. EEC cell lines and nonmalignant samples were used to define error rates and filter false-positive calls. Results: Single-nucleus analyses (n = 50,009 cells) revealed that in NSMP EECs, the co-occurring PIK3CA, PIK3R1, and/or PTEN mutations affected nearly all cells through linear evolution. MMRd EECs displayed higher levels of genetic heterogeneity, harboring PI3K pathway gene mutations in subsets of cells ranging from 3.9% to 96%. POLE EECs had the highest level of clonal diversity and harbored multiple, minor subclonal structures in all cases, through convergent evolution. We found a clear distinction between nearly clonal PI3K pathway gene alterations (>95%) and multiple, minor mutually exclusive subclones only affecting 1.4% to 27% of the tumor cells sequenced. Conclusions: Our exploratory, hypothesis-generating analysis suggests that PI3K pathway alterations evolve distinctly in MMRd/POLE compared with NSMP EECs, which may have therapeutic consequences. Further studies on the signaling output and PI3K pathway inhibitor response in EECs with subclonal PI3K pathway alterations are warranted.

Ongoing genome doubling shapes evolvability and immunity in ovarian cancer

Single-cell whole-genome sequencing of 30,260 tumour genomes from 70 samples across 41 patients in the SPECTRUM cohort reveals that ongoing whole-genome doubling drives tumour evolvability and immune evasion in high-grade serous ovarian cancer.

Nivolumab for mismatch-repair-deficient or hypermutated gynecologic cancers: a phase 2 trial with biomarker analyses

AbstractProgrammed death-1 (PD-1) inhibitors are approved for therapy of gynecologic cancers with DNA mismatch repair deficiency (dMMR), although predictors of response remain elusive. We conducted a single-arm phase 2 study of nivolumab in 35 patients with dMMR uterine or ovarian cancers. Co-primary endpoints included objective response rate (ORR) and progression-free survival at 24 weeks (PFS24). Secondary endpoints included overall survival (OS), disease control rate (DCR), duration of response (DOR) and safety. Exploratory endpoints included biomarkers and molecular correlates of response. The ORR was 58.8% (97.5% confidence interval (CI): 40.7–100%), and the PFS24 rate was 64.7% (97.5% one-sided CI: 46.5–100%), meeting the pre-specified endpoints. The DCR was 73.5% (95% CI: 55.6–87.1%). At the median follow-up of 42.1 months (range, 8.9–59.8 months), median OS was not reached. One-year OS rate was 79% (95% CI: 60.9–89.4%). Thirty-two patients (91%) had a treatment-related adverse event (TRAE), including arthralgia (n = 10, 29%), fatigue (n = 10, 29%), pain (n = 10, 29%) and pruritis (n = 10, 29%); most were grade 1 or grade 2. Ten patients (29%) reported a grade 3 or grade 4 TRAE; no grade 5 events occurred. Exploratory analyses show that the presence of dysfunctional (CD8+PD-1+) or terminally dysfunctional (CD8+PD-1+TOX+) T cells and their interaction with programmed death ligand-1 (PD-L1)+ cells were independently associated with PFS24. PFS24 was associated with presence of MEGF8 or SETD1B somatic mutations. This trial met its co-primary endpoints (ORR and PFS24) early, and our findings highlight several genetic and tumor microenvironment parameters associated with response to PD-1 blockade in dMMR cancers, generating rationale for their validation in larger cohorts.ClinicalTrials.gov identifier: NCT03241745.