Hendrickson, Andrea E. Wahner

5553 Background: In patients with high-grade ovarian cancer in first-line setting, predictive factors of bevacizumab efficacy are needed, for selecting patients. In ICON-7 trial, a poor tumor intrisic chemosensitivity (defined by unfavorable modeled CA-125 kinetic ELIMination rate constant KELIM) was a predictive biomarker. Among patients with high-risk diseases, only those with unfavorable KELIM had survival benefit from bevacizumab (mOS: 29.7 vs 20.6 months, HR = 0.78)(Colomban. JNCI CS 2020). The objective was to perform an external validation in GOG-0218 trial (NCT00262847). Methods: In GOG-0218, 1,873 patients were treated with carboplatin-paclitaxel +/- concurrent bevacizumab/placebo followed by a 15 month maintenance. Patient KELIM values were estimated with longitudinal CA-125 kinetics during the first 100 chemotherapy days. The association between KELIM score (categorized as favorable ≥ 1, or unfavorable < 1) and efficacy of bevacizumab (bevacizumab-concurrent + maintenance, vs placebo) for PFS and OS was assessed using univariate/multivariate analyses, in a Training set with 2/3 patients managed the investigators, and then a Validation set with all patients, managed by NGR-GOG. Results: KELIM was assessable in 1,662 patients with ≥ 3 CA-125 available values. In both sets, the patients with unfavorable KELIM derived benefit from bevacizumab compared to placebo (Training: PFS, HR = 0.65 [0.54-0.80]; OS, HR = 0.80 [0.65-0.99]; Validation: PFS, HR = 0.69 [0.59-0.82]; OS, HR = 0.87 [0.73-1.03]), whilst those with favorable KELIM had no benefit from bevacizumab (Training: PFS, HR = 0.96 [0.75-1.23]; OS, HR = 1.05 [0.80-1.37]; Validation, PFS, HR = 0.96 [0.79-1.17]; OS HR = 1.11 [0.89-1.84]). The highest benefit was observed in patients with high-risk diseases (stage IV or sub-optimally resected stage III) characterized by unfavorable KELIM, for PFS (Learning (n = 276): mPFS: 9.0 vs 5.2 months, HR = 0.61 [0.48-0.78]; Validation (n = 433): mPFS: 9.1 vs 5.6 months, HR = 0.64 [0.53-0.78]), and for OS (Learning (n = 278): mOS: 38.9 vs 27.9 months, HR = 0.72 [0.56-0.93], Validation set (n = 438): mOS: 35.1 vs 29.1 months, HR = 0.79 [0.65-0.97]). Conclusions: This validation analysis of GOG-0218 trial confirms the outcomes of ICON-7 trial about the association between poor tumor chemosensitivity and benefit from concurrent + maintenance bevacizumab, suggesting that bevacizumab is mainly effective in patients with poorly chemosensitive diseases. No benefit was found in patients with favorable KELIM. The patients who derived the highest benefit from bevacizumab in PFS and OS (OS absolute benefit ̃ 6 to 9 months) were those with high-risk diseases (stage IV, or incompletely resected stage III) associated with an unfavorable KELIM score (calculator on https://www.biomarker-kinetics.org/CA-125).

The poly(ADP-ribose) binding protein CHFR regulates cellular responses to mitotic stress. The deubiquitinase UBC13, which regulates CHFR levels, has been associated with better overall survival in paclitaxel-treated ovarian cancer. Despite the extensive use of taxanes in the treatment of ovarian cancer, little is known about expression of CHFR itself in this disease. In the present study, tissue microarrays containing ovarian carcinoma samples from 417 women who underwent initial surgical debulking were stained with anti-CHFR antibody and scored in a blinded fashion. CHFR levels, expressed as a modified H-score, were examined for association with histology, grade, time to progression (TTP) and overall survival (OS). In addition, patient-derived xenografts from 69 ovarian carcinoma patients were examined for CHFR expression and sensitivity to paclitaxel monotherapy. In clinical ovarian cancer specimens, CHFR expression was positively associated with serous histology (p = 0.0048), higher grade (p = 0.000014) and higher stage (p = 0.016). After correction for stage and debulking, there was no significant association between CHFR staining and overall survival (p = 0.62) or time to progression (p = 0.91) in patients with high grade serous cancers treated with platinum/taxane chemotherapy (N = 249). Likewise, no association between CHFR expression and paclitaxel sensitivity was observed in ovarian cancer PDXs treated with paclitaxel monotherapy. Accordingly, differences in CHFR expression are unlikely to play a major role in paclitaxel sensitivity of high grade serous ovarian cancer.

Abstract Acquired PARP inhibitor (PARPi) resistance in BRCA1- or BRCA2-mutant ovarian cancer often results from secondary mutations that restore expression of functional protein. RAD51C is a less commonly studied ovarian cancer susceptibility gene whose promoter is sometimes methylated, leading to homologous recombination (HR) deficiency and PARPi sensitivity. For this study, the PARPi-sensitive patient-derived ovarian cancer xenograft PH039, which lacks HR gene mutations but harbors RAD51C promoter methylation, was selected for PARPi resistance by cyclical niraparib treatment in vivo. PH039 acquired PARPi resistance by the third treatment cycle and grew through subsequent treatment with either niraparib or rucaparib. Transcriptional profiling throughout the course of resistance development showed widespread pathway level changes along with a marked increase in RAD51C mRNA, which reflected loss of RAD51C promoter methylation. Analysis of ovarian cancer samples from the ARIEL2 Part 1 clinical trial of rucaparib monotherapy likewise indicated an association between loss of RAD51C methylation prior to on-study biopsy and limited response. Interestingly, the PARPi resistant PH039 model remained platinum sensitive. Collectively, these results not only indicate that PARPi treatment pressure can reverse RAD51C methylation and restore RAD51C expression, but also provide a model for studying the clinical observation that PARPi and platinum sensitivity are sometimes dissociated.

Abstract BACKGROUND: Patients with ROC have limited treatment options in later lines of therapy, as many become platinum-resistant or -ineligible. Poly(ADP-ribose) polymerase inhibitor (PARPi) treatment is one option, however these agents are currently not approved for BRCAwt patients in the treatment setting. Niraparib, a PARPi, has demonstrated increased progression-free survival vs placebo as maintenance therapy for platinum-responsive ROC. Niraparib was effective regardless of BRCAmut or homologous recombination deficiency (HRD) status, although an increased treatment effect was observed in the HRDpos population. QUADRA (NCT02354586) evaluated niraparib treatment in heavily pretreated ROC patients, regardless of BRCAmut or HRD status, platinum sensitivity, or prior PARPi use. METHODS: Eligible patients had grade 2-3 serous ROC, ≥3 prior chemotherapy lines, and measurable disease. Patients were evaluated for BRCAmut and HRD status (MyChoice HRD Test). Patients received niraparib 300 mg once daily until progression; dose could be lowered to 200 mg or 100 mg due to treatment-emergent adverse events (TEAEs). The primary endpoint was objective response rate (ORR) per RECIST v1.1 in patients treated in 4th or 5th line who were HRDpos, platinum sensitive, and PARPi naïve. RESULTS: 463 patients were treated. Of these, 161 were platinum refractory, 151 platinum resistant, and 120 platinum sensitive to their last line of platinum therapy. Of note, 83 patients were primary platinum resistant or refractory (42 and 41, respectively). Median number of prior lines of therapy was 4 (range 2-16), and 27% of patients were treated in 6th or later line. 100% of patients received prior platinum, 99.6% received prior taxane, 81% received prior doxorubicin, 63% received prior bevacizumab, and 59% received prior gemcitabine. In the primary efficacy population (N=45), ORR was 29% (95% CI: 16-44, P=0.0003), disease control rate (DCR) was 71% (95% CI: 56-84), and duration of response (DOR) was 9.2 months (95% CI: 5.9-NE); overall survival (OS) was not reached (95% CI: 18.5-NE). The efficacy outcomes in all 456 patients with measurable disease at baseline treated in 4th or later line demonstrated a DCR of 49% with 2 complete responses (CR), 36 partial responses (PR), and 187 patients with stable disease (SD). The responses were durable with a median DOR of 9.4 months, a clinical benefit rate (CR+PR+SD) at 16 weeks of 29%, and median OS of 17.2 months (95% CI: 14.9-19.8) among all patients treated in 4th or later line. 266 (57.5%) patients had grade ≥3 treatment-related TEAEs. Grade ≥3 thrombocytopenia event (thrombocytopenia or decreased platelet count) by dose at onset of the event was 27.5% at 300 mg, 4.7% at 200 mg, and 2.7% at 100 mg. The other most common grade ≥3 TEAEs were anemia (26.3%) and neutropenia (8.2%). Hematologic TEAEs were most frequent in the first month and decreased in frequency and severity after dose reduction during months 2-3. CONCLUSIONS: Niraparib demonstrated durable anticancer activity in this heavily treated (≥3 lines) ROC population, including platinum-resistant or BRCAwt patients. Toxicities were consistent with previous niraparib studies. DISCLOSURE Funded by TESARO, Inc. Citation Format: Kathleen Moore, Angeles Secord, Melissa Geller, David Miller, Noelle Cloven, Gini Fleming, Andrea E. Wahner Hendrickson, Masoud Azodi, Paul Disilvestro, Amit Oza, Mihaela Cristea, Jonathan S. Berek, John Chan, Yong Li, Kaiming Sun, Katarina Luptakova, Ursula A. Matulonis, Bradley J. Monk. QUADRA: A PHASE 2, OPEN-LABEL, SINGLE-ARM STUDY TO EVALUATE SINGLE-AGENT NIRAPARIB TREATMENT IN PATIENTS WITH RELAPSED OVARIAN CANCER (ROC) WHO HAVE RECEIVED ≥3 PRIOR CHEMOTHERAPY REGIMENS [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr NT-101.

e17518 Background: Morbidity and mortality for patients with cervical cancer has improved significantly over the past few decades with modern multimodal therapy. However, neuroendocrine carcinoma of the uterine cervix (NCUC), which accounts for 1-2% of cervical cancers, remains a deadly subtype. In this study, we combine data from Mayo Clinic (MC) and the University of Iowa Hospitals and Clinics (UIHC) to provide information on tumor characteristics, treatment, and outcomes. Methods: The electronic medical record was reviewed for patients with NCUC from MC and UIHC. Data on diagnosis, treatment, and outcomes were collected through chart review. Primary endpoints included progression-free survival (PFS) and overall survival (OS). Secondary endpoints included median survival, survival at 1 year after surgery, and survival at 1 year by first line chemotherapy agent. Kaplan-Meier survival analysis was used to estimate median PFS, median survival, and OS. Fisher’s test analysis was used to calculate survival at 1 year after surgery and by first line chemotherapy agent. Results: There were 62 patients (MC: 26, UIHCC: 36) with NCUC stage I-IV (stage I: 29, stage II: 9, stage III: 7, stage IV: 14, unknown: 3). Median age of diagnosis was 47 years (range 21-77 years). By subtype, 47 were small cell (76%), 9 were large cell (15%), and 6 were unknown/undetermined (9%). The initial treatment modalities for each patient are outlined in the table. 28 patients had complete/partial response or stable disease from first line treatment, while 10 patients had disease progression. Of the patients who initially responded or had stable disease, 16 later progressed (57%) with a median time to progression of 15 months. Median follow up was 65.1 months with a median OS of 28.5 months. Median survival for those with stage I was 40.9 months, stage II: 54.6 months, stage III: 8.75 months, and stage IV: 11.7 months. There was a significant difference in overall survival at 1 year between those who received surgery and those who did not in stage I/II ( p = 0.01). There was no significant difference in overall survival at 1 year for those who received surgery in stage III/IV. There was no statistical difference in survival at 1 year for carboplatin or cisplatin in combination with etoposide as first line chemotherapy agent. Conclusions: NCUC is an aggressive malignancy that is usually progressive despite multimodal therapy. Our study demonstrated a median overall survival of 28.5 months and 5-year survival rate of 21%. Our study showed a survival benefit at 1 year for those who receive surgery with stage I/II NCUC. There was no significant survival benefit at 1 year between carboplatin or cisplatin in combination with etoposide as first line agent.[Table: see text]

5554 Background: A better understanding regarding the burden of treatment side effects in patients with gynecological malignancies could help guide symptom interventions and oncologic therapy decision-making. We aim to inform understanding of symptom burden in epithelial ovarian cancer (EOC) by analyzing patient-reported symptom data from patients treated for this condition over a 16-month period. Methods: Patients receiving medical oncology care at Mayo Clinic Rochester and at Midwest Mayo Clinic Health System community sites have received symptom-focused surveys prior to each medical oncology visit since March 28, 2019 through the Enhanced Electronic Health Record Facilitated Cancer Symptom Control Study (E2C2). These surveys, administered either through the electronic medical record portal or on a clinic tablet prior to each oncology office visit, no more frequently than every 2 weeks, include six linear analogue scales measuring sleep disturbance, pain, anxiety, emotional distress, and fatigue (SPADE), as well as physical dysfunction on a scale of 0 (none) to 10 (as bad as you can imagine). Scores of 0-3 were considered mild symptoms, 4-6 moderate symptoms, and 7-10 severe symptoms. We collected survey results from March 28, 2019 to July 20, 2020 for patients with EOC and reviewed the number of surveys per patient in addition to the average symptom scores. Results: From March 2019 to July 2020, for patients with EOC, there were 2974 encounter-based surveys from 762 patients. The number of surveys completed by each patient ranged from 1-20. The following number of patients returned the correlating number of surveys: 1 survey:240 patients; 2 surveys:145; 3 surveys:79; 4 surveys:56; 5 surveys:58; 6 surveys:45; 7 surveys:38; 8 surveys:27; 9 surveys:22; ≥10 surveys:52. The average score from all surveys for each symptom was: 2.41 for sleep disturbance, 2.03 for pain, 2.32 for anxiety, 1.97 for emotional distress, 3.26 for fatigue, and 2.50 for physical dysfunction. Please see the table for the proportion of surveys that reported symptoms as mild, moderate, or severe. Conclusions: Fatigue and physical dysfunction were reported most frequently in patients with EOC, while emotional distress and pain were reported least frequently. 20% of surveys reported moderate to severe emotional distress, while 40% reported moderate to severe fatigue. A targeted approach to symptom management is needed for patients undergoing EOC evaluation and treatment. Our next steps in this analysis include an assessment of potential predictors of greater symptom burden (e.g., specific treatments, age, and other clinical and sociodemographic characteristics). Clinical trial information: NCT03892967. [Table: see text]

Epithelioid hemangioendothelioma (EHE) is a rare vascular neoplasm which typically originates from liver, lung, or bone. Due to the low incidence of disease, the most effective treatment is not easily studied and much of the information known about EHE has been learned through case reports and case series. In this case, we will present an uncommon form of primary soft tissue EHE with local recurrence, bone metastasis, and lymphangitic spread to the lungs leading to respiratory failure. Imaging of the chest was atypical for EHE with intraseptal thickening and hilar lymphadenopathy. Respiratory failure was progressive despite aggressive multimodal treatment. This case highlights an unusually aggressive recurrence and metastasis of primary soft tissue EHE with atypical pulmonary imaging findings.

Abstract Background Aberrant lipogenicity and deregulated autophagy are common in most advanced human cancer and therapeutic strategies to exploit these pathways are currently under consideration. Group III Phospholipase A2 (sPLA2-III/PLA2G3), an atypical secretory PLA2, is recognized as a regulator of lipid metabolism associated with oncogenesis. Though recent studies reveal that high PLA2G3 expression significantly correlates with poor prognosis in several cancers, however, role of PLA2G3 in ovarian cancer (OC) pathogenesis is still undetermined. Methods CRISPR-Cas9 and shRNA mediated knockout and knockdown of PLA2G3 in OC cells were used to evaluate lipid droplet (LD) biogenesis by confocal and Transmission electron microscopy analysis, and the cell viability and sensitization of the cells to platinum-mediated cytotoxicity by MTT assay. Regulation of primary ciliation by PLA2G3 downregulation both genetically and by metabolic inhibitor PFK-158 induced autophagy was assessed by immunofluorescence-based confocal analysis and immunoblot. Transient transfection with GFP-RFP-LC3B and confocal analysis was used to assess the autophagic flux in OC cells. PLA2G3 knockout OVCAR5 xenograft in combination with carboplatin on tumor growth and metastasis was assessed in vivo. Efficacy of PFK158 alone and with platinum drugs was determined in patient-derived primary ascites cultures expressing PLA2G3 by MTT assay and immunoblot analysis. Results Downregulation of PLA2G3 in OVCAR8 and 5 cells inhibited LD biogenesis, decreased growth and sensitized cells to platinum drug mediated cytotoxicity in vitro and in in vivo OVCAR5 xenograft. PLA2G3 knockdown in HeyA8MDR-resistant cells showed sensitivity to carboplatin treatment. We found that both PFK158 inhibitor-mediated and genetic downregulation of PLA2G3 resulted in increased number of percent ciliated cells and inhibited oncogenesis. Mechanistically, we found that PFK158-induced autophagy targeted PLA2G3 to restore primary cilia in OC cells. Of clinical relevance, PFK158 also induces percent ciliated cells in human-derived primary ascites cells and reduces cell viability with sensitization to chemotherapy. Conclusions Taken together, our study for the first time emphasizes the role of PLA2G3 in regulating the OC metastasis. This study further suggests the therapeutic potential of targeting phospholipases and/or restoration of PC for future OC treatment and the critical role of PLA2G3 in regulating ciliary function by coordinating interface between lipogenesis and metastasis.

Abstract Objectives: Cognitive computing has the potential to improve efficiency and accuracy of clinical trial enrollment using artificial intelligence. The cognitive computing clinical trial matching (CTM) system used for this study utilizes natural language processing to derive patient and tumor attributes from structured and unstructured electronic medical record (EMR) data. The attributes are matched to complex eligibility criteria in trial protocols. This CTM system has been implemented in our gynecologic oncology practice, for which there is lower representation of ethnic minorities, elderly, and uninsured in National Cancer Institute-sponsored trials. Methods: A clinical research coordinator (CRC) used the CTM system to screen patients for potential clinical trials one day prior to their clinic visit. Trial matches were shared with gynecologic oncology clinicians to raise awareness for study opportunities and assist in treatment decisions. Clinicians were surveyed regarding their experience with the CTM system prepared matches. The identical patients were evaluated by a clinician using the traditional manual screening method. Results: Seventeen patients with new diagnosis, recent resection, or restaging scans were screened for 41 potential gynecologic, phase I, and supportive care clinical trials. Trial screening by the CRC using the CTM system resulted in a total of 119 matched trials (mean: 7 trials/patient) compared to the clinician-generated list of 271 matched trials (mean: 16 trials/patient). The CRC using the CTM system spent an average of 18 minutes/patient (range: 7 to 40 minutes) compared to the clinician average of 22 minutes/patient (range: 7 to 37 minutes). A survey of 8 gynecologic oncology clinicians reported they were willing to spend an average of 8 minutes/patient (range: 1 to 15 minutes) to screen patients for trial eligibility. On independent review, discrepancies occurred when the clinician identified trials that the CRC excluded due to inclusion/exclusion criteria or were unknowingly closed to accrual. In addition, the CRC identified trials that were inadvertently missing from the clinician’s list of active protocols. Consistent with these observations, 100% of surveyed clinicians (8 of 8) agreed that “The CTM system has helped to include and exclude trials prior to discussion with patients.” Conclusions: Use of the CTM system by a CRC was superior to a clinician alone for the accuracy and efficiency of screening clinical trial eligibility. This process improved the identification of trials that a clinician might otherwise miss and the exclusion of trials that were not available or appropriate for patients. The CTM system can reduce the burden of clinicians and research staff to screen patients. Additional research is needed to determine if the process can improve clinical trial enrollment in gynecologic cancers. Citation Format: Thanh P. Ho, Jane M. Helgeson, Angela L. Andring, Jennifer C. Reed, Venessa L. Boyle, Nigar Sofiyeva, Konstantinos Leventakos, Tufia C. Haddad, Andrea E. Wahner Hendrickson, Saravut (John) Weroha. Implementation of cognitive computing to match clinical trials in gynecologic cancers: A single-institution experience [abstract]. In: Proceedings of the AACR Special Conference on Advancing Precision Medicine Drug Development: Incorporation of Real-World Data and Other Novel Strategies; Jan 9-12, 2020; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_1):Abstract nr 01.

e18097 Background: AB160 is a 160 nm nano-immunoconjugate consisting of nab-paclitaxel (NP) nanoparticles non-covalently coated with bevacizumab (BEV) for targeted delivery into tissues expressing high levels of vascular-endothelial growth factor (VEGF). Both taxanes (GOG-0129C, GOG-0126R, GOG-0127V) and BEV (GOG-0229E, AURELIA, GOG-0227C) have demonstrated clinical activity in previously treated metastatic endometrial cancer (EC), ovarian cancer (OC), and cervical cancer (CC), respectively. Methods: A 3+3 phase I trial was conducted in patients with EC, platinum-resistant OC and CC who had prior systemic treatment for metastatic disease to determine the maximum tolerated dose of AB160 administered intravenously on days 1, 8 and 15 of a 28-day cycle. The starting dose level (DL1) was NP at 125 mg/m2 with BEV at 50 mg/m2. There were 2 higher dose levels: DL2 (NP at 150 mg/m2 with BEV at 60 mg/m2) and DL3 (NP at 175 mg/m2 with BEV at 70 mg/m2). Dose limiting toxicities (DLT) included grade (G) 4 neutropenia or anemia, PLT < 25,000, serum creatinine ≥2 times baseline, G2-4 neurologic toxicity or G3-4 non-hematologic toxicities. Disease evaluations were conducted after every 2 treatment cycles using RECIST criteria. Patients were treated until disease progression or intolerability. Samples were collected for pharmacokinetic (PK) studies. Results: Nine women 41 – 74 years of age (median 57) have enrolled (5 with EC and 4 with OC); data are available for the first 8. No DLTs have been observed among the 3 women enrolled on DL1, 3 women on DL2, and 2 women on DL3. All 3 patients on DL3 continue on treatment. The other 6 patients have discontinued due to adverse reactions (3), progression (2), and patient choice (1). The median number of cycles administered is 6 (4-14). The most common severe (G3/4) toxicities include neutropenia (37.5%) and leukopenia (25%). There have been 5 partial responses (62.5%): 1 on DL1 and 2 each on DL2 and DL3. PK evaluation is pending. Conclusions: AB160 therapy is safe and demonstrates promising clinical activity in patients with previously treated metastatic gynecologic malignancies. Further clinical testing is being pursued in this patient population. Clinical trial information: NCT02020707.