Identification of patients with ovarian cancer who are experiencing the highest benefit from bevacizumab in first-line setting based on their tumor intrinsic chemosensitivity (KELIM): GOG-0218 validation study

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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).

Pharmacokinetic and pharmacodynamic analysis of adavosertib in advanced ovarian cancer

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Background: Adavosertib (AZD-1775) is a potent small molecule inhibitor of Wee-1, currently in clinical development. In a double-blind, placebo-controlled, phase 2 trial (NCT02151292), adavosertib and gemcitabine significantly prolonged progression-free survival (PFS) and overall survival (OS) in patients with recurrent platinum-resistant or platinum-refractory high grade serous ovarian cancer (HGSOV) compared to gemcitabine alone. We investigated whether plasma and intra-tumoral adavosertib concentrations correlated with survival in these patients. Methods: Adavosertib was administered orally on Days 1, 2, 8, 9, 15 and 16 at 175 mg per day, and gemcitabine was administered on Days 1, 8 and 15 at 1000 mg/m2 every 28 days. Serial blood samples were collected on Day 1 of cycle 1 after adavosertib administration. Tumor biopsies were taken 1-2 weeks after initiation of study treatments. Plasma and tumor adavosertib concentrations were determined using validated HPLC-MS/MS. Patients were divided into groups with plasma or tumor adavosertib concentrations above or below the biologically active concentration (BAC) of 125 ng/ml (Leijen et al, J Clin Onco 2016). Survival was described using the Kaplan-Meier method. Results: Among 61 HGSOV patients who received adavosertib, plasma samples were available in 47, and tumor samples were available in 31 patients. Among 25 non-HGSOV patients (exploratory cohort), plasma and tumor samples were available in 21 and 17 patients respectively. The mean maximum adavosertib concentration (Cmax) was 355.3 ± 120.9 ng/ml and 358.6 ± 117.9 ng/ml respectively. Cmax was above BAC in all patients. The mean tumor adavosertib concentration was 609.2 ± 1129.2 ng/ml (range: 0.47 – 5501 ng/ml) for HGSOV patients, and 964.2 ± 1611.2 ng/ml (range: 0.22 – 6116 ng/ml) for non-HGSOV patients. There was no correlation between Cmax and tumor adavosertib concentrations. In HGSOV, the median PFS was 5.8 months for patients with tumor concentrations above BAC, and 3.5 months for those with tumor concentrations below BAC (Hazard ratio (HR): 0.46, 95% confidence interval: 0.19 – 1.14, p = 0.06). No difference in PFS was seen in non-HGSOV patients according to tumor adavosertib concentration. Tumor adavosertib concentration did not correlate with OS. Conclusions: Although Cmax was above BAC in all patients, there was a high variability in tumor adavosertib concentrations. In HGSOV, higher tumor adavosertib concentration was associated with a trend towards improved PFS, but not OS. Our results indicate that the current adavosertib dosing regimen may not produce the desired concentrations in tumors for some patients, and further optimization may be needed.

Symptom identification and management in epithelial ovarian cancer

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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]

A multicenter analysis of treatment and outcomes in neuroendocrine carcinoma of the uterine cervix (NCUC)

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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]

A phase I trial of nab-paclitaxel/bevacizumab (AB160) nano-immunoconjugate therapy for metastatic gynecological malignancies: MC1371 (NCT02020707)

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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.

Results of a phase 2 trial of ribociclib and letrozole in patients with either relapsed estrogen receptor (ER)-positive ovarian cancers or relapsed ER-positive endometrial cancers

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Background: Single agent aromatase inhibitor (AI) therapy is associated with limited clinical activity in ovarian cancer (OC) and endometrial cancers (EC). AI therapy was associated with a progression free survival (PFS) at 12 weeks of only 20% in relapsed OC (Bowman et al, 2002) and a median PFS of 1 month in relapsed EC (Rose et al, 2000). In Estrogen Receptor (ER) positive metastatic breast cancer, clinical studies had shown a significant prolongation of PFS with the addition of the cyclin kinase 4/6 inhibitor ribociclib to AI (Hortobagyi et al, 2016). Here, we report the results of a phase 2 clinical trial of the combination of ribociclib and letrozole in patients with relapsed ER positive OC or EC. Objectives: Primary endpoint was the proportion of patients with relapsed ER positive OC or EC alive and progression-free after 12 weeks of therapy (PFS12) with the combination of ribociclib given at a dose of 400 mg orally daily and letrozole 2.5 mg orally daily. A PFS of 45% was considered a favorable result based on the data referenced above from Bowman et al. Methods: Eligibility criteria included patients with relapsed ER positive OC or EC, with measurable disease, not previously treated with ribociclib or AIs. Xenografts were created from CT guided tumor biopsies at baseline to assess feasibility. Results: A total of 40 patients were enrolled (20 with OC and 20 with EC) ) with a median age of 61 years (range: 30-82) and 64.5 (range: 52-75) in the OC and EC groups respectively. Among the OC patients, 17 had high grade serous carcinomas and 3 had low grade serous carcinomas. 11 EC patients had endometrioid cancers (3 with grade 1 tumors) and 9 had high grade serous tumors. Ten out of 20 OC patients and 11/20 EC patients were alive and progression-free at 12 weeks (PFS12 of 50 and 55%, respectively). The most common grade 3 or higher adverse events (occurring in at least 5 pts) were leukopenia (18%), lymphopenia (18%), neutropenia (13%), and fatigue (13%). 34 tumor biopsies were suitable for injection into mice and 44% engrafted. ER expression persisted through multiple passages in mice. Two of three EC PDX models exhibited improved PFS with letrozole/ribociclib compared to letrozole alone. Conclusions: The combination of ribociclib and letrozole is associated with a promising 50% and 55% PFS12 in patients with ER positive relapsed OC or EC respectively. Creation of xenograft tumor models from CT guided biopsies of OC and EC tumors was feasible. Clinical trial information: NCT02657928.

A randomized double-blind placebo-controlled phase II trial comparing gemcitabine monotherapy to gemcitabine in combination with adavosertib in women with recurrent, platinum resistant epithelial ovarian cancer: A trial of the Princess Margaret, California, Chicago and Mayo Phase II Consortia

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Background: Platinum resistant ovarian cancer (OC) remains a therapeutic challenge. High grade serous OC (HGSOC) harbors TP53 mutations leading to increased dependency on S- and G2-phase checkpoints. Wee1 inhibition with Adavosertib (AZD 1775) (A) induces G2 checkpoint escape. Gemcitabine (G) is an antimetabolite therapy and blocks the progression of cells through the G1/S phase. We hypothesized that combining G+A would be synergistic and overcome resistance. Methods: We conducted a multicentre double-blind 2:1 randomized phase 2 trial to assess the progression free survival (PFS) in women with recurrent platinum-resistant/refractory HGSOC receiving G+A or G+placebo (P) (NCT02151292). Eligibility required measurable disease and feasibility of paired tumor biopsies; no limitation in prior lines of therapy. Non HGSOC histologic subtypes were enrolled in a separate non-randomized exploratory cohort. A/P was given orally at 175mg QD on D1-2, D8-9 and D15-16 with G 1000mg/m² IV D1, D8 and D15 in a 28-day cycle until progression or unacceptable AE. Tumor staging was scheduled every 8 weeks. TP53 mutations were analyzed on archival tissue with Sanger sequencing, TAm-Seq and IHC. TP53 mutation will be also assessed in circulating tumor DNA (ctDNA). Whole exome and RNA sequencing were performed on paired tumor tissues. Results: 124 patients (pts) with median of 3 prior lines of therapy (range 1-10) from 12 centres across Canada and US were enrolled between Sep 2014 to May 2018, with 99 pts randomized (65 in Arm G+A and 34 in G+P). 5 pts were ineligible; 64 pts have died. The median follow-up was 14.3 months. Main related AE was hematologic toxicity (Anemia G≥3: 31% in G+A vs 18% in G+P; Thrombocytopenia G≥3: 31% vs 6%; Neutropenia G≥3: 62% vs 30%). PFS was significantly improved from 3.0 to 4.6 months (HR 0.56 (95%CI: 0.35-0.90, p=0.015 Log rank). There was a significant improvement in overall survival (OS) from 7.2 to 11.5 months (HR 0.56 (95%CI: 0.34-0.92, P=0.022). Partial response by RECIST 1.1 was observed in 13 (21%) and 1 (3%) pts for Arms G+A and G+P, respectively (p=0.02). From the 25 pts in the exploratory cohort, 3 (12%) partial responses were observed. Final results will be reported at the meeting. Conclusion: Addition of adavosertib to gemcitabine in women with platinum resistant/refractory OC improved response rate, PFS and OS with manageable toxicity. Clinical trial information: NCT02151292.

The role of CHFR expression in ovarian cancer and response to taxane therapy

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Background: CHFR, an E3 ubiquitin ligase that regulates Aurora A and Pololike Kinase 1, plays a critical role in the cellular response to mitotic stress. In particular, cells containing CHFR arrest in G2 when microtubule dynamics are disrupted. Conversely, low CHFR expression is associated with hypersensitivity to mitotic spindle poisons in breast cancer cell lines. Despite the extensive use of taxanes in front line treatment of epithelial ovarian cancer (EOC), little is known about CHFR expression in this disease. We examined CHFR expression and its relationship with clinical characteristics and outcome in women with EOC. Methods: Pretreatment EOC samples from women enrolled in the Mayo Clinic Biospecimen Resource for Ovarian Cancer Research who underwent initial surgical debulking between 1999-2009 were stained in triplicate with anti-CHFR antibodies. Samples were scored in a blinded fashion for CHFR expression. Associations between CHFR staining and histology, grade, and stage were assessed using chi-squared tests; associations between CHFR and overall survival (OS) or time to disease recurrence (TTR) were assessed using Cox proportional hazards models. Results: Samples from 354 women were stained; median age at diagnosis was 60.5 (range 21-93). At a median follow-up of 67 months, 221 women (62%) had died. Across all patients, moderate/strong CHFR staining was associated with poor OS (HR = 1.39, 95% CI: 1.07-1.81, p = 0.015). Moreover, moderate/strong CHFR expression was strongly associated with serous histology (p < 0.0001), high grade (p < 0.0001) and advanced stage (p = 0.0002). To assess whether the association between CHFR expression and OS was related to taxane sensitivity, a subgroup analysis was performed in the subset of patients (N=131) with high-grade serous EOC who received initial platinum/taxane chemotherapy. Moderate/strong CHFR expression failed to correlate with OS (HR=0.91, 95% CI: 0.57-1.45, p = 0.68) or TTR from the start of chemotherapy (HR = 0.85, 95% CI: 0.55-1.31, p = 0.55) in this subset. Conclusions: CHFR expression is associated with poor OS and adverse clinical characteristics in patients with EOC but does not appear to be related to taxane sensitivity in high-grade serous tumors.