Abstract A04: Real-world usage of NGS testing in high-grade serous ovarian cancer (HGSOC)—the landscape is quickly changing

Introduction: The Precision Medicine Initiative (PMI) study at the University of Alabama at Birmingham (UAB) was developed to include next-generation sequencing (NGS) as part of patients’ standard of care and to follow them prospectively. The objective of this study was to analyze how the usage of NGS in patients with high-grade serous ovarian cancer (HGSOC) affected their management.

Methods: Between 5/2015–2/2019, 224 ovarian cancer patients (167 HGSOC) signed informed consent and were enrolled. Archival tissue was sent to Foundation Medicine for NGS analysis; 324 genes, including genes involved in homologous recombination repair deficiency (HRD genes), microsatellite instability (MSI) status, and tumor mutation burden (TMB) were assessed. A subset of these patients were tested for LOH status and PD-L1 expression. Demographics including germline BRCA status, treatments, duration of targeted therapy, and platinum sensitivity were collected. Correlation between LOH status and both germline and somatic mutations in HRD genes was analyzed, in addition to the correlation between PD-L1 positivity and MSI status and TMB.

Results: 62% (103/167) of HGSOC patients had at least 1 targetable mutation and 40 patients received targeted therapy. 16% (27/167) were germline BRCA+ (gBRCAm+), 12 (10%) somatic BRCA + (sBRCAm+), and 120 wtBRCA. Of the gBRCAm+ patients, 81% were platinum sensitive, compared to 66% of all patients. 22% (36/167) of patients underwent LOH testing: 39% (14/36) were LOH-high. 43% (6/14) of LOH-high patients had an alteration in one of the HRD genes. Of the LOH-low patients, 23% (5/22) harbored mutations in HRD genes: (3) BRCA2, (2) CHEK2. 7% (8/114) of platinum-sensitive patients were placed on PARPi maintenance therapy after two or more lines of platinum-based therapy. Of the s/gBRCA+ patients, 24% (11/39) received PARPi monotherapy; 8 received both maintenance PARPi and monotherapy. 33% (13/167) of patients received a non-PARPi targeted therapy based on their NGS testing. Patients on maintenance PARPi received it for an average of 560 days (range 345-890 days), PARPi monotherapy: 254 days (range 30-750 days), and non-PARP targeted therapy: 186 days (range 24- 435 days). PD-L1 staining was completed for 38 patients; 6 patients had a PD-L1 Tumor Proportion Score > 1, although none of the patients were MSI-H or high TMB and none received immunotherapy.

Conclusions: NGS testing potentially affected the treatment of 23.9% of HGSOC patients. Our division has developed a streamlined mechanism for HGSOC patients to undergo routine NGS testing with limited out-of-pocket patient cost regardless of insurance status. Given the recent upfront approval of PARPi maintenance for all HGSOC who are s/gBRCAm+, we have now integrated both germline and somatic testing during front-line therapy. More information will be required to further elucidate how LOH status affects treatment decisions and outcomes for patients.

Citation Format: Nidhi Goel, Angelina I. Londono, Naveed Farrukh, Hannah M. Beer, Brandon Roane, Jaclyn Arquiette, Warner K. Huh, Charles A. Leath III, Rebecca C. Arend. Real-world usage of NGS testing in high-grade serous ovarian cancer (HGSOC)—the landscape is quickly changing [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A04.

Ofranergene obadenovec (VB-111) in platinum-resistant ovarian cancer; favorable response rates in a phase I/II study are associated with an immunotherapeutic effect

OBJECTIVE

Report final results of a phase I/II study of VB-111, a targeted anti-cancer gene therapy with a dual mechanism: anti angiogenic/vascular disruption and induction of an anti-tumor directed immune response, in combination with paclitaxel in patients with platinum-resistant ovarian cancer.

METHODS

Study NCT01711970 was a prospective, open label, dose escalation study assessing combination treatment of VB-111 and weekly paclitaxel. In the Phase I part of the study, patients were treated with escalating doses of intravenous VB-111 and paclitaxel. In Phase 2, patients were treated with therapeutic doses of VB-111 and paclitaxel 80 mg/m². Assessments included safety, overall survival (OS), progression free survival (PFS), and tumor response (CA-125 and RECIST).

RESULTS

21 patients with recurrent platinum-resistant ovarian cancer were enrolled. 17/21 received the therapeutic dose. Patients had a median of 3 prior lines of therapy. Half of the subjects were platinum refractory, and half were previously treated with antiangiogenics. No DLTs were observed. VB-111 was well tolerated and associated with mild flu-like symptoms. In the therapeutic dose cohort, a 58% CA-125 GCIG response rate was seen in evaluable patients. The median OS was 16.6 months in patients treated with therapeutic dose compared to 5.8 months in sub-therapeutic dose (p = 0.028). Tumor specimens taken after treatment demonstrated tumor infiltrated with cytotoxic CD8 T-cells in regions of apoptotic cancer cells.

CONCLUSIONS

Treatment with VB-111 in combination with paclitaxel was safe and well tolerated. Favorable tumor responses and overall survival outcomes were associated with induction of an immunotherapeutic effect.