A phase III, multicenter, randomized study of olvimulogene nanivacirepvec followed by platinum-doublet chemotherapy and bevacizumab compared with platinum-doublet chemotherapy and bevacizumab in women with platinum-resistant/refractory ovarian cancer

BACKGROUND

Treatment options for patients with platinum-resistant/refractory ovarian cancers are limited and only marginally effective. The development of novel, more effective therapies addresses a critical unmet medical need. Olvimulogene nanivacirepvec (Olvi-Vec), with its strong immune modulating effect on the tumor microenvironment, may provide re-sensitization to platinum and clinically reverse platinum resistance or refractoriness in platinum-resistant/refractory ovarian cancer.

PRIMARY OBJECTIVE

The primary objective is to evaluate the efficacy of intra-peritoneal Olvi-Vec followed by platinum-based chemotherapy and bevacizumab in patients with platinum-resistant/refractory ovarian cancer.

STUDY HYPOTHESIS

This phase III study investigates Olvi-Vec oncolytic immunotherapy followed by platinum-based chemotherapy and bevacizumab as an immunochemotherapy evaluating the hypothesis that such sequential combination therapy will prolong progression-free survival (PFS) and bring other clinical benefits compared with treatment with platinum-based chemotherapy and bevacizumab.

TRIAL DESIGN

This is a multicenter, prospective, randomized, and active-controlled phase III trial. Patients will be randomized 2:1 into the experimental arm treated with Olvi-Vec followed by platinum-doublet chemotherapy and bevacizumab or the control arm treated with platinum-doublet chemotherapy and bevacizumab.

MAJOR INCLUSION/EXCLUSION CRITERIA

Eligible patients must have recurrent, platinum-resistant/refractory, non-resectable high-grade serous, endometrioid, or clear-cell ovarian, fallopian tube, or primary peritoneal cancer. Patients must have had ≥3 lines of prior chemotherapy.

PRIMARY ENDPOINT

The primary endpoint is PFS in the intention-to-treat population.

SAMPLE SIZE

Approximately 186 patients (approximately 124 patients randomized to the experimental arm and 62 to the control arm) will be enrolled to capture 127 PFS events.

ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS

Expected complete accrual in 2024 with presentation of primary endpoint results in 2025.

TRIAL REGISTRATION

NCT05281471.

Pembrolizumab plus Chemotherapy in Advanced Endometrial Cancer

BACKGROUND

Standard first-line chemotherapy for endometrial cancer is paclitaxel plus carboplatin. The benefit of adding pembrolizumab to chemotherapy remains unclear.

METHODS

In this double-blind, placebo-controlled, randomized, phase 3 trial, we assigned 816 patients with measurable disease (stage III or IVA) or stage IVB or recurrent endometrial cancer in a 1:1 ratio to receive pembrolizumab or placebo along with combination therapy with paclitaxel plus carboplatin. The administration of pembrolizumab or placebo was planned in 6 cycles every 3 weeks, followed by up to 14 maintenance cycles every 6 weeks. The patients were stratified into two cohorts according to whether they had mismatch repair-deficient (dMMR) or mismatch repair-proficient (pMMR) disease. Previous adjuvant chemotherapy was permitted if the treatment-free interval was at least 12 months. The primary outcome was progression-free survival in the two cohorts. Interim analyses were scheduled to be triggered after the occurrence of at least 84 events of death or progression in the dMMR cohort and at least 196 events in the pMMR cohort.

RESULTS

In the 12-month analysis, Kaplan-Meier estimates of progression-free survival in the dMMR cohort were 74% in the pembrolizumab group and 38% in the placebo group (hazard ratio for progression or death, 0.30; 95% confidence interval [CI], 0.19 to 0.48; P<0.001), a 70% difference in relative risk. In the pMMR cohort, median progression-free survival was 13.1 months with pembrolizumab and 8.7 months with placebo (hazard ratio, 0.54; 95% CI, 0.41 to 0.71; P<0.001). Adverse events were as expected for pembrolizumab and combination chemotherapy.

CONCLUSIONS

In patients with advanced or recurrent endometrial cancer, the addition of pembrolizumab to standard chemotherapy resulted in significantly longer progression-free survival than with chemotherapy alone. (Funded by the National Cancer Institute and others; NRG-GY018 ClinicalTrials.gov number, NCT03914612.).

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of gynecologic cancer

Advanced gynecologic cancers have historically lacked effective treatment options. Recently, immune checkpoint inhibitors (ICIs) have been approved by the US Food and Drug Administration for the treatment of cervical cancer and endometrial cancer, offering durable responses for some patients. In addition, many immunotherapy strategies are under investigation for the treatment of earlier stages of disease or in other gynecologic cancers, such as ovarian cancer and rare gynecologic tumors. While the integration of ICIs into the standard of care has improved outcomes for patients, their use requires a nuanced understanding of biomarker testing, treatment selection, patient selection, response evaluation and surveillance, and patient quality of life considerations, among other topics. To address this need for guidance, the Society for Immunotherapy of Cancer (SITC) convened a multidisciplinary panel of experts to develop a clinical practice guideline. The Expert Panel drew on the published literature as well as their own clinical experience to develop evidence- and consensus-based recommendations to provide guidance to cancer care professionals treating patients with gynecologic cancer.

Characteristics of early-stage endometrial cancer and factors that influence disease recurrence

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Background: Early-stage endometrial cancer (EEC) with FIGO stage I-II generally has a favorable prognosis and overall survival (OS). However, up to 10% of EEC patients (pts) relapse and risk factors for recurrence remain unclear. We evaluated clinical and histopathologic characteristics of EEC and correlated them with OS and recurrence free survival (RFS) through a single-center retrospective analysis. Methods: We conducted a retrospective chart review on 511 pts with EEC identified by our cancer registry from 1/1/2009 to 12/31/2019. The two main histologic groups were endometrioid adenocarcinomas (E) and other subtypes (O) including carcinosarcoma, undifferentiated, and clear cell carcinomas. Papillary serous histology was excluded. Histopathologic and clinical findings recorded included age, FIGO stage and grade, tumor size, presence of recurrence, adjuvant therapies received, percent of myometrial invasion (MI), and lymphovascular invasion (LVI). OS and RFS were estimated, and each predictor was compared using the log-rank test. The association between OS and each continuous characteristic was examined using the Cox proportional hazards model. Factors significantly associated with OS and RFS in the univariable analysis (p < 0.05) were included in a multivariable analysis to examine the joint effects of those factors on survival. Results: A total of 511 cases were reviewed. The analysis included 501 pts (E = 485, O = 16), of which 47 had recurrent disease (E = 45, O = 2) and 17 had died without recurring (E = 15, O = 2) as of their last follow-up. Overall median age was 63 years. Factors significantly associated with recurrence in the multivariable analysis were FIGO grade, (Hazard Ratios (HR): Grade 2 vs 1: 1.95, 95% CI: 1.06-3.58, p = 0.0320, Grade 3 vs 1: 2.88, 95% CI: 1.50-5.52, p = 0.0015), LVI (HR: 2.03, 95% CI: 1.10-3.75, p = 0.0244), and greater than 50% of MI (HR: 3.15, 95% CI: 1.35-7.36, p = 0.0080). The overall RFS was 92% and 86% at three and five years, respectively. On univariate analysis, among pts with a measurable tumor size (n = 446), larger tumors were not significantly associated with OS (p = 0.65) but was associated with increased recurrence (HR 1.22, 95% CI: 1.10-1.37, for a unit increase, p = 0.0003). On univariate analysis, pts who received adjuvant therapy were more likely to recur (p = 0.0002) with RFS of 86% and 76% at three and five years respectively, versus RFS of 94% and 90%, for those who did not. Conclusions: We confirmed the clinical and histopathologic characteristics that are currently considered to increase risk of recurrence in EEC. On multivariate analysis, risk of recurrence was associated with FIGO grades 2 and 3, presence of LVI, and > 50% MI. A limitation of this study is the lack of molecular analysis. Further molecular stratification may help us identify the subset of pts who are at high risk of recurrence, enabling customized adjuvant therapy in EEC.

Evaluation of immunohistochemical expression of mismatch repair proteins in endometrioid and seromucinous borderline ovarian tumors a 10-year experience in a large health care institution

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Background: Borderline tumors (BT) are atypical proliferation of epithelium in the ovary in the absence of destructive stromal invasion, representing for 15% of all epithelial ovarian cancers. [1] Around 10% of the ovarian tumors are hereditary, and approximately 10% of all the hereditary forms of epithelial ovarian tumors are result of a loss of DNA mismatch repair (MMR). [2] Endometrioid borderline tumor (EBT) and Seromucinous borderline tumors (SMBT) are rare tumors in ovary and there is limited literature available on immunohistochemical (IHC) expression of Mismatch repair proteins(MMRP)in these tumors.[3, 4] The aim of this study is to evaluate IHC expression of MMRP in EBT and SMBT of ovary. Methods: Pathology database was searched for ovarian Endometrioid borderline tumor (EBT) and Seromucinous borderline tumor (SMBT) for a 10-year period (2010-2020). The cohort consisted of 10 EBT (6 of which had focal microinvasion or carcinoma) and 12 SMBT(2 of which had focal carcinoma ). For comparison, 1 borderline Brenner. 15 serous borderline tumors (SBT) and 15 mucinous borderline tumors (MBT) were also included. After reviewing slides, a block with adequate borderline tumor was selected for IHC stains. For the cases with carcinoma, two different blocks with each component were selected. In all selected blocks, IHC stains for four MMRP (MLH1, PMS2, MSH2, MSH6) were performed. The complete absence of nuclear staining in tumor cells was considered as “loss” of the MMRP expression. Any “weak” or “focal” nuclear staining was considered intact. Results: Total 53 cases were evaluated for MMRP IHC. All cases had intact MMRP expression. In cases with carcinoma, both components (BT and carcinoma) have intact MMR IHC expression. See table. Conclusions: Our study did not show loss of MMRP IHC expression in EMT or SMBT. However, our study consisted of a small number of cases. Multi Institutional study with a large number of cases can be helpful in future to further evaluate the role of MMRP IHC in EMT and SMBT. [Table: see text]

Retrospective analysis of ovarian cancer patients treated with PARP inhibitors

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Background: Over the last few years, targeted therapy has become the mainstay maintenance treatment of patients with ovarian cancer including patients with BRCA1 or BRCA2 mutations. Poly ADP ribose polymerase (PARP) inhibitors are effective in the treatment of patients who are in complete or partial remission. PARP inhibitors are known to cause hematological adverse events (AEs), but have not been compared directly to each other. Methods: We conducted a single institution, IRB approved, retrospective study on patients who were treated with PARP inhibitors from December 2016 to October 2020. Patients were stratified according to which PARP inhibitor they received. Our primary objective was to assess the incidence of hematological and non-hematological adverse events associated with the use of PARP inhibitor therapy used in patients with ovarian cancer. Data from absolute neutrophil count, hemoglobin and platelet count during the first 2 cycles were graded for hematologic toxicity according to CTCAE v 5.0. Results: A total of 126 patients received a PARP inhibitor during the study time frame. 34 were excluded and 92 patients were included for analysis. Median age of patients were 64.3 (range, 33.8 to 92.3) years, 66 (71.7%) white, and 84 (91.3%) had an ECOG PS of 0/1. Thirty-one (33.7%) of patients received niraparib and 61 (66.3%) of patients received olaparib. Patients in the niraparib group experienced more hematologic AEs, with 11 (35.5%) (95% CI 19.2-54.6), 20 (64.5%) (95% CI 45.4-80.8), and 18 (58.1%) (95% CI 39.1-75.5) experiencing neutropenia, anemia, thrombocytopenia, respectively. Eight (13.1%) (95% CI 5.8-24.2), 24 (39.3%) (95% CI 27.1-52.7), 16 (26.2%) (95% CI 15.8-39.1) patients in the olaparib group experienced neutropenia, anemia, thrombocytopenia, respectively. Conclusions: This single institution retrospective study outlines the hematological toxicities observed between two PARP inhibitors. Although there are four PARP inhibitors approved by FDA, our data compared only two of the four (as they were the most commonly prescribed PARP inhibitors in our institution). Our results suggested that niraparib tended to be associated with a higher risk for hematologic toxicities than olaparib. Our data showed anemia as the most common hematologic toxicity which was consistent with what has been widely documented in the literature.

A single-center analysis of adjuvant sequential versus ‘sandwich’ chemoradiotherapy for patients with stage III endometrial cancer

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Background: To determine if the sequencing of chemotherapy with external beam radiotherapy (EBRT) in the adjuvant setting for FIGO stage III endometrial cancer impacts 2-year progression free survival (PFS). Methods: As part of our Gynecologic Oncology Multidisciplinary Group's initiative to establish an institutional guideline for the adjuvant treatment of Stage III endometrial cancer, we reviewed 144 cases identified by our cancer registry and departmental database. Treatment regimens were divided into three categories: sequential therapy with six cycles of carboplatin/taxane followed by EBRT, concurrent cisplatin for two cycles with EBRT followed by four cycles of carboplatin/taxane, or ‘sandwich’ therapy with three cycles of carboplatin/taxane followed by EBRT followed by three cycles of carboplatin/taxane. The published results of the phase III GOG-258 study called into question the efficacy of concurrent chemoradiation. Therefore, we only compared sequential versus ‘sandwich’ therapy using a Chi-Square analysis. We conducted a retrospective chart review to assess if patients were able to complete the prescribed six cycles and EBRT, and then measured their PFS at two years. We hypothesized that there would be no difference in PFS between the two groups. Results: There were no significant differences in clinical or pathologic factors between patients treated with either regimen. Ninety-four patients (65%) had stage IIIC disease. The majority of patients received six cycles of paclitaxel with carboplatin. Median EBRT dose was 45 Gy. There was no statistically significant difference in the estimated 2-year PFS between the sequential and ‘sandwich’ groups, which were 82% and 82.5%, respectively (p = 0.84). Conclusions: Adjuvant chemoradiation for FIGO stage III endometrial cancer given sequentially or in a ‘sandwich’ fashion appears to offer equally excellent early clinical patient outcomes.

A retrospective review on extended carboplatin infusion and incidence of hypersensitivity reaction in gynecologic malignancies in a single institution

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Background: Carboplatin has been the standard treatment for advanced gynecologic malignancies in the first line setting as well as treatment of relapsed disease. Carboplatin induced hypersensitivity reaction (HSR) is observed more frequently in a second line setting and symptoms can range from rash to life threatening symptoms such as anaphylaxis, which could preclude further treatment. A retrospective study by O’Cearbhaill showed HSR rate with extended infusion protocol to be 3.4%. However, two subsequent prospective studies by Lax and O’Cearbhaill did not find that extended infusion reduced the risk or severity of HSR. We reviewed the incidence of HSR with three hour extended-infusion carboplatin at our institution. Methods: Our practice at the Monter Cancer Center changed from standard 1 hour carboplatin retreatment infusion to extended-infusion in 2011. We reviewed charts of 162 patients from 2011 to present who received a three hour extended infusion of carboplatin. All patients received prophylactic H1 and H2 blockers along with steroids. HSR was determined in two ways: 1) Identifying patients who reported clinical symptoms of HSR. 2) Identifying which patients had received diphenhydramine, hydrocortisone and/or epinephrine as indicated for an infusion reaction. Results: 162 patients were identified: 83 with ovarian cancer, 44 with uterine cancer, and 16 with fallopian tube cancer, 10 with primary peritoneal cancer, and 9 with cervical/vulvar cancer. Most had relapsed disease and were previously treated for stage IV (35%), or stage III (47%) with platinum doublet chemotherapy at least six months prior. Only 1 out of 162 (0.6%) had a grade 1 reaction with hives and was treated with dexamethasone and diphenhydramine. She was previously treated with carboplatin 17 months prior. Her current HSR occurred during her fifth cycle of retreatment. She was not re challenged with the drug and elected not to undergo desensitization. Conclusions: Hypersensitivity reactions develop in about 12-33% of women retreated with carboplatin peaking at eight cycles (Lax et al.). The mechanism behind HSR is unclear but considered to be from repeated exposure to free platinum metal concentration. Incidence of HSR at our institution was lowest ever-reported at 0.6%, suggesting that our extended infusion protocol with the appropriate premedication is appropriate for carboplatin-retreat patients. Further prospective studies to evaluate this regimen is warranted.

Safety and efficacy outcomes for patients ages 65 and older treated with dose-dense chemotherapy for epithelial ovarian cancer

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Background: Dose-dense chemotherapy is increasingly more utilized in the adjuvant treatment of patients (pts) with epithelial ovarian, fallopian tube, or primary peritoneal carcinoma (EOC), as compared to the conventional q3 week chemotherapy regimen. The safety and tolerability of the dose-dense regimen in pts ≥65 yrs old has not been well studied. We performed a retrospective analysis of pts with stage II-IV EOC treated at our institution with either regimen. Methods: We identified pts with stage II-IV EOC treated at Northwell Health from 2010-2015 who received adjuvant chemotherapy with the dose-dense (carboplatin q3 weeks/weekly paclitaxel) or the conventional (carboplatin and paclitaxel q3 weeks) regimen. Pts who received IP chemotherapy were excluded. Demographics, adverse events (AEs), dose delays/reductions and efficacy outcomes were evaluated. Results: 38 pts received conventional chemotherapy (median age 68 yrs) and 29 pts received dose-dense chemotherapy (median age 61 yrs). There were no differences in the frequency of grade ≥3 hematologic toxicities b/w the two arms. There were no differences in delayed or missed doses between the two arms but a higher proportion of dose reductions in the dose-dense arm ( P= 0.0472). Among pts treated in the dose-dense arm, 87.5% of women < 65 yrs old had at least one grade ≥3 AE when compared to 38.5% of women ≥ 65 yrs old ( P= 0.0161). There were no differences in dose delays, dose reductions, or missed doses when compared by age in the dose-dense arm. In the dose-dense arm, stage III-IV pts < 65 yrs old had a median time to progression (TTP) of 13.0 mo (95% CI, 6.7-13.8) and a median overall survival (OS) of 48.3 months (95% CI, 11.5-48.3). Pts ≥ 65 yrs old had a median TTP of 10.9 mo (95% CI, 8.7-12.7) and median OS of 35.9 mo (95% CI, 30.8-not reached). There was no difference in TTP ( P= 0.2154) or OS ( P= 0.9260) between the two cohorts. Conclusions: Our institutional experience of administering dose-dense adjuvant chemotherapy to women with EOC suggests that this regimen is likely safe in women ≥ 65 yrs old, with similar efficacy outcomes and should be considered for this population. Further study with larger sample sizes and in prospective trials is warranted.

Correlation of in vitro chemotherapy drug resistance assay to clinical response to carboplatin and paclitaxel combination chemotherapy in ovarian carcinoma

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Background: Carboplatin sensitivity in drug resistance assays has been shown to be an independent predictor of longer progression free interval with conflicting results in overall survival. We evaluated in vitro drug resistance for carboplatin and paclitaxel combination and its correlation with progression free survival (PFS) and overall survival (OS). Methods: From April 1, 2006 to December 12, 2011, in vitro drug resistance assays were sent after cytoreductive surgery for primary epithelial ovarian cancer. Patients were analyzed according to drug resistance scoring system of low drug resistance (S), intermediate drug resistance (I), and extreme drug resistance (R). Retrospective chart review was performed to evaluate PFS and OS. The Kaplan Meier product limit method was used to estimate OS and PFS. Survival curves were compared between groups using the log rank test. Results: From a total of 142 patients: 57 were S, 52 I, and 33 R; 77% were responsive (S+I) to carboplatin and paclitaxel combination. At median follow-up of 18 months, PFS and OS rates were 58.1 and 91.3% respectively for S, 66.1 and 78.7% for I, and 43.2% and 84.3% for R. At 36 months, the PFS and OS rates were 52.3 and 61.1% for S, 51.3 and 55.3% for I and 39.3% and 48.7% for R. There was OS advantage between the S and I compared to R. There were no significant differences in PFS curves (p<0.281) or OS curves (p<0.46). Conclusions: Although sensitivity to carboplatin/ paclitaxel resulted in longer OS, the results were not statistically significant. Our cohorts were small and we may not have had the power to capture statistical significance. A larger multicenter analysis would be needed to further evaluate this finding. In addition, one of the regimens our patients received on relapse was bevacizumab which was not evaluated in the in vitro assay sensitivity assay. Bevacizumab has also been included in first line treatment in combination with platinum/ taxane regimen. Future analysis of in vitro assays may need to include biologics.

Streptococcus suis Type 2 Infection in Swine in Ontario: A Review of Clinical and Pathological Presentations

Over an 18 month period Streptococcus suis type 2 was isolated in pure or mixed culture in 19 disease outbreaks in pigs. Morbidity and case fatality were variable. Clinical signs were of a nervous or respiratory disease or of death with no premonitory signs. Gross and microscopic findings included one or more of fibrinous polyserositis, fibrinous or hemmorhagic bronchopneumonia, purulent meningitis, myocardial necrosis, focal myocarditis and valvular endocarditis. Brain, cerebrospinal fluid and lung were most reliable sites for isolation of the organism.