Top advances of the year: Cervical cancer

The year 2023 was an extraordinary year for the further development and expansion of novel treatments for all patients with cervical cancer, ranging from early stage to later stage and metastatic or recurrent disease. Individuals with early-stage disease will benefit from less invasive surgery with subsequent improvement in quality of life. The effectiveness of immunotherapy has been demonstrated in upfront, locally advanced cervical cancer and confirmed in advanced metastatic disease. Induction chemotherapy will play a role in some patients with locally advanced disease, particularly those in low resource areas of the world. Novel therapeutics including antibody-drug conjugates have shown efficacy even in pretreated patients. As we continue to explore innovative therapeutics in this space, however, we must also continue to improve the diversity of clinical trial accrual to allow for generalizable results. At the same time, we must focus on eradicating this disease with appropriate screening and vaccination.

Phase II trial of pembrolizumab and epacadostat in recurrent clear cell carcinoma of the ovary: An NRG oncology study GY016

INTRODUCTION

Early reports of PD-1 inhibition in ovarian clear cell carcinomas (OCCC) demonstrate promising response. We evaluated the combination of pembrolizumab and IDO-1 inhibitor epacadostat in patients with recurrent OCCC.

METHODS

This single arm, two-stage, phase 2 trial included those with measurable disease and 1-3 prior regimens. Patients received intravenous pembrolizumab 200 mg every 3 weeks and oral epacadostat 100 mg twice a day. Primary endpoint was overall response rate (ORR), secondary endpoints were toxicity, progression-free survival (PFS) and overall survival (OS). The study was powered to detect an absolute 25% increase in response (15% to 40%).

RESULTS

Between September 28, 2018 and April 10, 2019, 14 patients enrolled at first stage. Rate of accrual was 2.3 patients per month. Median age was 65 years (44-89), 10 (71.4%) had ≥2 prior regimens. ORR was 21% (95% CI 5-51%) within 7 months of study entry with 3 partial responses, and 4 had stable disease (disease control rate 50%). Median PFS was 4.8 months (95% CI: 1.9-9.6), OS 18.9 months (95% CI: 1.9-NR). Most common grade ≥ 3 adverse events were electrolyte abnormalities and gastrointestinal pain, nausea, vomiting, bowel obstruction. In July 2019, the study reached the pre-specified criteria to re-open to second stage; however, the study closed prematurely in February 2021 due to insufficient drug supply.

CONCLUSIONS

Pembrolizumab and epacadostat demonstrated an ORR of 21% in this small cohort of recurrent OCCC. The rapid rate of accrual highlights the enthusiasm and need for therapeutic studies in patients with OCCC.

Pembrolizumab or placebo with chemoradiotherapy followed by pembrolizumab or placebo for newly diagnosed, high-risk, locally advanced cervical cancer (ENGOT-cx11/GOG-3047/KEYNOTE-A18): a randomised, double-blind, phase 3 clinical trial

BACKGROUND

Pembrolizumab has shown efficacy in persistent, recurrent, or metastatic cervical cancer. The effect of chemoradiotherapy might be enhanced by immunotherapy. In this phase 3 trial, we assessed the efficacy and safety of adding pembrolizumab to chemoradiotherapy in locally advanced cervical cancer.

METHODS

In this randomised, double-blind, placebo-controlled, phase 3 ENGOT-cx11/GOG-3047/KEYNOTE-A18 clinical trial, adults (age ≥18 years) at 176 medical centres in 30 countries with newly diagnosed, high-risk, locally advanced cervical cancer were randomly assigned (1:1) using an interactive voice-response system with integrated web response to receive 5 cycles of pembrolizumab (200 mg) or placebo every 3 weeks plus chemoradiotherapy, followed by 15 cycles of pembrolizumab (400 mg) or placebo every 6 weeks. Randomisation was stratified by planned external beam radiotherapy type (intensity-modulated radiotherapy or volumetric-modulated arc therapy vs non-intensity-modulated radiotherapy or non-volumetric-modulated arc therapy), cervical cancer stage at screening (International Federation of Gynecology and Obstetrics 2014 stage IB2-IIB node positive vs stage III-IVA), and planned total radiotherapy (external beam radiotherapy plus brachytherapy) dose (<70 Gy vs ≥70 Gy equivalent dose in 2 Gy fractions). Primary endpoints were progression-free survival per Response Evaluation Criteria in Solid Tumours version 1.1-by investigator or by histopathologic confirmation of suspected disease progression-and overall survival. Primary analysis was conducted in the intention-to-treat population, which included all randomly allocated participants. Safety was assessed in the as-treated population, which included all randomly allocated patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT04221945, and is closed to new participants.

FINDINGS

Between June 9, 2020, and Dec 15, 2022, 1060 participants were randomly assigned to treatment, with 529 assigned to the pembrolizumab-chemoradiotherapy group and 531 to the placebo-chemoradiotherapy group. At data cutoff (Jan 9, 2023), median follow-up was 17·9 months (IQR 11·3-22·3) in both treatment groups. Median progression-free survival was not reached in either group; rates at 24 months were 68% in the pembrolizumab-chemoradiotherapy group versus 57% in the placebo-chemoradiotherapy group. The hazard ratio (HR) for disease progression or death was 0·70 (95% CI 0·55-0·89, p=0·0020), meeting the protocol-specified primary objective. Overall survival at 24 months was 87% in the pembrolizumab-chemoradiotherapy group and 81% in the placebo-chemoradiotherapy group (information fraction 42·9%). The HR for death was 0·73 (0·49-1·07); these data have not crossed the boundary of statistical significance. Grade 3 or higher adverse event rates were 75% in the pembrolizumab-chemoradiotherapy group and 69% in the placebo-chemoradiotherapy group.

INTERPRETATION

Pembrolizumab plus chemoradiotherapy significantly improved progression-free survival in patients with newly diagnosed, high-risk, locally advanced cervical cancer.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co (MSD).

Large bowel recurrence of endometrial adenocarcinoma years after treatment: A single-institution case series and review of the literature

Endometrial cancer (EC) is the most common gynecologic cancer in the United States. A majority of new cases are diagnosed as low-grade International Federation of Gynecology and Obstetrics (FIGO) Stage I, with a recurrence risk cited as less than 9 % in the first 2-3 years post-treatment. In this case series, we present three unique cases of patients with FIGO 2009 Stage I EC who all went on to present with pelvic colonic recurrences years after their initial treatment, two of the patients outside of the 5-year standard surveillance period. These presentations are described in the context of the available literature on EC colonic recurrence. A review of the literature suggests a previously cited association between endometriosis and unusual recurrence locations may not be as important of a risk factor as previously considered, as most of the cases in the series had no clinical or pathologic history of endometriosis. In addition, most of the included cases did not report a history of endometriosis and 60% of the cohort had received postoperative adjuvant radiation and still went on to experience locoregional recurrence. Further study on the associations between endometriosis, MMR status and EC recurrence, particularly for uncommon anatomic recurrence sites, are warranted to ensure appropriate and timely treatment.

Presence of low volume metastases does not alter management in node-negative, early-stage cervical cancer patients who underwent postoperative adjuvant therapy: A retrospective cohort study

Objective

This study sought to determine if patients with early stage cervical cancer who possessed intermediate-high risk factors (defined by Peters or Sedlis criteria) and had pathologically negative lymph nodes at the time of surgery had higher rates of low volume metastases (LVM) on retrospective ultrastaging.

Methods

This IRB-approved retrospective cohort study collected data via chart review on early stage, surgically-treated node-negative cervical cancer patients who underwent postoperative adjuvant therapy, treated at a single institution from January 2011 through June 2021. Nodal blocks were retrospectively ultrastaged per standard protocol. Descriptive statistics were performed for analysis.

Results

Over the 10-year study period, n = 20 patients met study inclusion criteria. Most patients were white with squamous cell histology, with a mean number of 25.15 (SD = 12) nodes examined on initial pathologic evaluation. 85 % (n = 17) patients were pathologic stage IB. 85 % of the cohort were recommended for adjuvant radiation, with the remaining 15 % for cisplatin-based chemoradiation. LVM in the form of micrometastasis was retrospectively identified in one patient (5 %) who had received whole pelvic radiation and recurred locally within the irradiated field.

Conclusions

This small retrospective series of surgically managed cervical cancer with intermediate-high risk tumor factors identified only 1 patient with LVM, representing 5% of the total population. The biologic importance of ITC and LVM remains unclear in cervical cancer, however this investigation highlights the low incidence even when all nodes are evaluated in a higher risk cohort. The presence of LVM would not have changed management decisions based on this retrospective analysis.

How far is too far? Cancer prevention and clinical trial enrollment in geographically underserved patient populations

Despite dedicated efforts to improve equitable access to cancer care in the United States, disparities in cancer outcomes persist, and geographically underserved patients remain at an increased risk of cancer with lower rates of survival. The critical evaluation of cancer prevention inequities and clinical trial access presents the opportunity to outline novel strategies to incrementally improve bookended access to gynecologic cancer care for geographically underserved patients. Cancer prevention strategies that can be addressed in the rural patient population mirror priorities in the Healthy People 2030 objectives and include increased identification of high risk individuals who may benefit from increased cancer screening and risk reduction, increasing the proportion of people who discuss interventions to prevent cancer, such as HPV vaccination, with their provider, and increasing the proportion of adults who complete evidence based cancer screening. Barriers to accrual to clinical trials for rural patients overlap significantly with the same barriers to obtaining health care in general. These barriers include: lack of facilities and specialized providers; lack of robust health infrastructure; inability to travel; and financial barriers. In this review, we will discuss current knowledge and opportunities to improve cancer prevention initiatives and clinical trial enrollment in geographically underserved populations with a focus on rurality.

Mirvetuximab Soravtansine in FRα-Positive, Platinum-Resistant Ovarian Cancer

BACKGROUND

Mirvetuximab soravtansine-gynx (MIRV), a first-in-class antibody-drug conjugate targeting folate receptor α (FRα), is approved for the treatment of platinum-resistant ovarian cancer in the United States.

METHODS

We conducted a phase 3, global, confirmatory, open-label, randomized, controlled trial to compare the efficacy and safety of MIRV with the investigator's choice of chemotherapy in the treatment of platinum-resistant, high-grade serous ovarian cancer. Participants who had previously received one to three lines of therapy and had high FRα tumor expression (≥75% of cells with ≥2+ staining intensity) were randomly assigned in a 1:1 ratio to receive MIRV (6 mg per kilogram of adjusted ideal body weight every 3 weeks) or chemotherapy (paclitaxel, pegylated liposomal doxorubicin, or topotecan). The primary end point was investigator-assessed progression-free survival; key secondary analytic end points included objective response, overall survival, and participant-reported outcomes.

RESULTS

A total of 453 participants underwent randomization; 227 were assigned to the MIRV group and 226 to the chemotherapy group. The median progression-free survival was 5.62 months (95% confidence interval [CI], 4.34 to 5.95) with MIRV and 3.98 months (95% CI, 2.86 to 4.47) with chemotherapy (P<0.001). An objective response occurred in 42.3% of the participants in the MIRV group and in 15.9% of those in the chemotherapy group (odds ratio, 3.81; 95% CI, 2.44 to 5.94; P<0.001). Overall survival was significantly longer with MIRV than with chemotherapy (median, 16.46 months vs. 12.75 months; hazard ratio for death, 0.67; 95% CI, 0.50 to 0.89; P = 0.005). During the treatment period, fewer adverse events of grade 3 or higher occurred with MIRV than with chemotherapy (41.7% vs. 54.1%), as did serious adverse events of any grade (23.9% vs. 32.9%) and events leading to discontinuation (9.2% vs. 15.9%).

CONCLUSIONS

Among participants with platinum-resistant, FRα-positive ovarian cancer, treatment with MIRV showed a significant benefit over chemotherapy with respect to progression-free and overall survival and objective response. (Funded by ImmunoGen; MIRASOL ClinicalTrials.gov number, NCT04209855.).

Niraparib and dostarlimab for the treatment of recurrent platinum-resistant ovarian cancer: results of a Phase II study (MOONSTONE/GOG-3032)

OBJECTIVE

This study assessed the efficacy, safety, and health-related quality of life (HRQoL) of the treatment regimen of dostarlimab, a programmed death-1 inhibitor, combined with niraparib, a poly (ADP-ribose) polymerase inhibitor, in patients with BRCA wild type (BRCAwt) recurrent platinum-resistant ovarian cancer (PROC) who had previously received bevacizumab treatment.

METHODS

This Phase II, open-label, single-arm, multicenter study, conducted in the USA, enrolled patients with recurrent PROC to receive niraparib and dostarlimab until disease progression or unacceptable toxicity (up to 3 years). A preplanned interim futility analysis was performed after the first 41 patients had undergone ≥1 radiographic evaluation (approximately 9 weeks from the first treatment).

RESULTS

The prespecified interim futility criterion was met and the study was therefore terminated. For the 41 patients assessed, the objective response rate (ORR) was 7.3% (95% confidence interval: 1.5-19.9); no patients achieved a complete response, 3 patients (7.3%) achieved a partial response (duration of response; 3.0, 3.8, and 9.2 months, respectively), and 9 patients (22.0%) had stable disease. In total, 39 patients (95.1%) experienced a treatment-related adverse event, but no new safety issues were observed. HRQoL, assessed using FOSI, or Functional Assessment of Cancer Therapy - Ovarian Symptom Index scores, worsened over time compared with baseline scores.

CONCLUSIONS

The study was terminated due to the observed ORR at the interim futility analysis. This highlights a need for effective therapies in treating patients with recurrent BRCAwt PROC.

Phase IIa Study of PLX2853 in Gynecologic Cancers With Known ARID1A Mutation and Phase Ib/IIa Study of PLX2853/Carboplatin in Platinum-Resistant Epithelial Ovarian Cancer

PURPOSE

The Bromodomain and Extra-Terminal (BET) domain proteins facilitate the development of many human cancers via epigenetic regulation. BET inhibitors may be effective in reversing platinum resistance in ovarian cancer (OC) and may generate synthetic lethality with ARID1A loss. PLX2853 is an orally active, small-molecule inhibitor of BET bromodomain-mediated interactions that exhibits low nanomolar potency in blocking all four BET family members.

METHODS

We conducted a multicenter and open-label study with two parallel arms: a phase IIa study of PLX2853 monotherapy in patients with advanced gynecologic malignancies with an ARID1A mutation and a phase Ib/IIa combination study of PLX2853 plus carboplatin in women with platinum-resistant OC. The primary objectives were safety and tolerability for phase Ib and efficacy for both phase IIa portions. Thirty-four of 37 enrolled patients completed at least one post-baseline response assessment.

RESULTS

Of the 14 evaluable patients on the monotherapy arm, 1 (7.1%) achieved a best overall response of partial response (PR), 5 (35.7%) had stable disease (SD), and 8 (57.1%) had progressive disease (PD). Of the 20 evaluable patients on the combination arm, 1 (5.0%) had PR, 9 (45.0%) had SD, and 10 (50%) had PD.

CONCLUSION

This study confirmed the safety profile of PLX2853 and demonstrated the feasibility of combination with carboplatin. Although these results did not meet the prespecified response criteria, evidence of clinical activity highlights the rationale for further exploration of BET inhibitors in patients with ARID1A-mutated gynecologic malignancies, possibly in combination with agents targeting potential feedback mechanisms such as the PI3K pathway.

DKK1 is a predictive biomarker for response to DKN-01: Results of a phase 2 basket study in women with recurrent endometrial carcinoma

PURPOSE

Dickkopf-1 (DKK1) is a Wnt signaling modulator promoting tumor growth, metastasis, angiogenesis, and immunosuppression by regulating innate immunity. DKK1 is over-expressed in gynecologic cancers and is associated with shortened survival. DKN-01 is a humanized monoclonal antibody with DKK1 neutralizing activity that may provide clinical benefit to patients whose tumors have overexpression of DKK1 or Wnt genetic alterations.

METHODS

We conducted an open-label, Phase 2 basket study with 2-stage design in patients with endometrial carcinoma (EC) and platinum-resistant/refractory epithelial ovarian cancer. DKN-01 was administered either as monotherapy or in combination with weekly paclitaxel at investigator's discretion. All patients underwent NGS testing prior to enrollment; tumor tissue was also tested for DKK1 expression by RNAscope pre-treatment and after cycle 1 if available. At least 50% of patients were required to have a Wnt signaling alteration either directly or tangentially. This publication reports results from the EC population overall and by DKK1-expression.

RESULTS

DKN-01 monotherapy and in combination with paclitaxel was more effective in patients with high DKK1-expressing tumors compared to low-expressing tumors. DKN-01 monotherapy demonstrated an objective response rate [ORR] of 25.0% vs. 0%; disease control rate [DCR] of 62.5% vs. 6.7%; median progression-free survival [PFS] was 4.3 vs. 1.8 months, and overall survival [OS] was 11.0 vs. 8.2 months in DKK1-high vs DKK1-low patients. Similarly, DKN-01 in combination with paclitaxel demonstrated greater clinical activity in patients with DKK1-high tumors compared to DKK1-low tumors: DCR was 55% vs. 44%; median PFS was 5.4 vs. 1.8 months; and OS was 19.1 vs. 10.1 months. Wnt activating mutations correlated with higher DKK1 expression. DKN-01 was well tolerated as a monotherapy and in combination with paclitaxel.

CONCLUSIONS

Collectively, data demonstrates promising clinical activity of a well-tolerated drug, DKN-01, in EC patients with high tumoral DKK1 expression which frequently corresponded to the presence of a Wnt activating mutation. Future development will focus on using DKN-01 in DKK1-high EC patients in combination with immunotherapy.

Top advances of the year: Cervical cancer

Cervical cancer continues to affect women in the United States and throughout the world despite an effective vaccine against human papillomavirus and cancer screening programs. For the women who develop cervical cancer, surgery, radiation, and chemotherapy have been the mainstays of treatment for years. Recently, novel therapeutics have been developed that offer new treatment opportunities for women living with advanced and/or recurrent disease. Immunotherapy has become an important tool against cervical cancer with the approval of pembrolizumab in the second line for advanced or recurrent disease. Checkpoint inhibitors have recently been approved in the front line for advanced and/or recurrent disease in combination with chemotherapy, and they are being studied in the front line in combination with chemoradiation. Antibody-drug conjugates-specifically tisotumab vedotin (TV)-also have recently received Food and Drug Administration (FDA) approval, and TV is currently being studied in combination with checkpoint inhibitors and with carboplatin. Tumor-infiltrating lymphocytes have been studied in early-phase trials and have shown promise in small patient series. Despite these new therapies, there continue to be racial, ethnic, and socioeconomic inequities with respect to access to care, access to and participation in clinical trials, and survival in the United States as well as globally. New FDA guidance requires researchers to work to reduce disparities by including women of more diverse backgrounds in clinical trials. Finally, as progress continues to be made in the treatment of established disease, prevention through vaccination and screening remains paramount. PLAIN LANGUAGE SUMMARY: The treatment of cervical cancer remains a significant problem in the United States and especially worldwide. Although early cases can be cured, cervical cancer that has spread remains difficult to treat. The past few years have seen significant advances in new therapies and combinations of therapies for women with advanced or recurrent disease. Although this is excellent news for these women, cervical cancer is a preventable disease through screening with Papanicolaou smears and vaccination with the human papillomavirus vaccine. By improving access to and acceptance of screening and vaccination, we can eradicate cervical cancer in the United States and the world.

Overcoming disparities to improve cancer care: The story of cervical cancer

Effective screening and vaccination programs can potentially eliminate cervical cancer in the future; however, to accomplish this goal, we have to be able to offer services to all girls and women. In particular, women who live in rural areas and women who have low socioeconomic status are at highest risk. Efforts are required to improve access to care at all levels for these women at risk.

Evaluating the risk of post-operative abscess formation following use of hemostatic agents at time of hysterectomy

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Use of hemostatic agent at time of hysterectomy is not associated with post-operative abscess formation in this small study.

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Hemostatic agent use is associated with increased post-operative emergency room visits and readmissions.

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Overuse of hemostatic agents at time of hysterectomy may contribute to post-operative adverse events.

Objective

At an academic institution in rural Virginia, we noticed a trend of increased re-admissions for postoperative pelvic abscesses. The primary study objective was to determine if intraoperative use of hemostatic agents (HA) was associated with postoperative abscess formation in patients undergoing hysterectomy.

Methods

Retrospective chart review identified women who underwent hysterectomy by a Gynecologic Oncologist for any indication at a single institution from January 1, 2019 through December 31, 2019. Patient and surgical characteristics were abstracted and comparisons were made among those who received any HA and those that did not. The relationship between intraoperative HA use and postoperative pelvic abscess formation was determined using multivariate logistic regression. Secondary outcomes evaluated included the presence of other major post-operative adverse events.

Results

428 hysterectomies were identified with a postoperative pelvic abscess rate of 3.7 %. Abscesses were identified in 4 (2.2 %) of cases without vs 12 (4.9 %) of cases with HA use with a logistic regression model demonstrating no significant difference in the groups (OR = 2.10, p = 0.22). Data showed an increase in presentation to the Emergency Department (ED) (OR = 3.43, p = 0.002 adjusted) and higher odds of readmission within 30 days of surgery (OR = 3.19, p = 0.03) with HA use.

Conclusions

No association was found between HA use and abscess formation; however, data showed HA use was associated with increased odds of presentation to the ED and readmission to the hospital within 30 days of surgery. Given the potential negative impact on patient outcomes, use of these products at time of hysterectomy should be made with careful consideration.

Treatment patterns and real-world clinical outcomes in patients with advanced endometrial cancer that are non-microsatellite instability high (non-MSI-high) or mismatch repair proficient (pMMR) in the United States

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First study to describe real-world outcomes in non-MSI-H/pMMR aEC patients who progressed following prior systemic therapy.

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MSI/MMR testing was near universal in aEC patients in the US, reflecting the increased awareness of biomarker status.

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Patients on second-line chemo or hormonal therapy had poor clinical outcomes: median OS of 10 months and rwPFS of 5 months.

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Data suggest an unmet medical need in this population between 2016 and 2019.

Objective

Microsatellite instability (MSI) due to defective DNA mismatch repair has emerged as an actionable biomarker in advanced endometrial cancer (aEC). Currently, there are no treatment patterns and outcomes data in non-MSI-high (non-MSI-H) or mismatch repair proficient (pMMR) aEC patients following prior systemic therapy (FPST). Our goal was to describe real-world data in this population in the US in 2019 and prior years.

Methods

Endometrial Cancer Health Outcomes (ECHO) is a retrospective patient chart review study conducted in the US. Patients with non-MSI-H/pMMR aEC and progression between 06/01/2016–06/30/2019 FPST were eligible. Data collected included patient demographics, clinical and treatment characteristics, and clinical outcomes. Kaplan-Meier analyses were performed to estimate time to treatment discontinuation, real-world progression-free survival (rwPFS), and overall survival (OS), separately by treatment category.

Results

A total of 165 eligible patients initiated second-line therapy with chemotherapy ± bevacizumab (n = 140) or hormonal therapy (n = 25). Median age was 66.0 years at aEC diagnosis, 70.2% were Stage IIIB-IV, 40.0% had ECOG ≥ 2 at second-line therapy initiation. Median rwPFS was 5.0 months (95% CI: 4.0–6.0) for patients receiving chemotherapy ± bevacizumab and 5.5 months (95% CI: 3.0–29.0) for those receiving hormonal therapy. Median OS was 10.0 months (95% CI: 8.0–13.0) and 9.0 months (95% CI: 6.0-NA) in these groups, respectively.

Conclusions

Non-MSI-H/pMMR patients who initiated second-line therapy with chemotherapy ± bevacizumab or hormonal therapy had poor clinical outcomes with a median survival less than 1 year and rwPFS less than 6 months. This was the first study to define the clinical unmet need in patients with non-MSI-H/pMMR aEC with conventional therapy.

A phase II trial of bevacizumab and rucaparib in recurrent carcinoma of the cervix or endometrium

OBJECTIVE

The aim of this study was to examine the tolerability and efficacy of combination bevacizumab rucaparib therapy in patients with recurrent cervical or endometrial cancer.

PATIENTS & METHODS

Thirty-three patients with recurrent cervical or endometrial cancer were enrolled. Patients were required to have tumor progression after first line treatment for metastatic, or recurrent disease. Rucaparib was given at 600 mg BID twice daily for each 21-day cycle. Bevacizumab was given at 15 mg/kg on day 1 of each 21-day cycle. The primary endpoint was efficacy as determined by objective response rate or 6-month progression free survival.

RESULTS

Of the 33 patients enrolled, 28 were evaluable. Patients with endometrial cancer had a response rate of 17% while patients with cervical cancer had a response rate of 14%. Median progression free survival was 3.8 months (95% C·I 2.5 to 5.7 months), and median overall survival was 10.1 months (95% C·I 7.0 to 15.1 months). Patients with ARID1A mutations displayed a better response rate (33%) and 6-month progression free survival (PFS6) rate (67%) than the entire study population. Observed toxicity was similar to that of previous studies with bevacizumab and rucaparib.

CONCLUSIONS

The combination of bevacizumab with rucaparib did not show significantly increased anti-tumor activity in all patients with recurrent cervical or endometrial cancer. However, patients with ARID1A mutations had a higher response rate and PFS6 suggesting this subgroup may benefit from the combination of bevacizumab and rucaparib. Further study is needed to confirm this observation. No new safety signals were seen.

An Exploratory Study of Neoadjuvant Cetuximab Followed by Cetuximab and Chemoradiotherapy in Women With Newly Diagnosed Locally Advanced Cervical Cancer

OBJECTIVES

This study explored the feasibility of cetuximab with chemoradiation in women with cervical carcinoma and evaluated fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) to assess early response to cetuximab (NCT00292955).

PATIENTS AND METHODS

Eligible patients with International Federation of Gynecology and Obstetrics (FIGO) stage IB-IVB invasive carcinoma of the uterine cervix were treated on 1 of 3 dose levels (DL). DL1 consisted of neoadjuvant cetuximab, then concurrent radiotherapy with cetuximab 250 mg/m2/cisplatin 40 mg/m2, followed by weekly cetuximab. DL2 consisted of radiotherapy with cetuximab 200 mg/m2 and cisplatin 30 mg/m2. DL3 consisted of radiotherapy with cetuximab 250 mg/m2 and cisplatin 30 mg/m2. Patients underwent 18F-FDG-PET/CT before treatment, after neoadjuvant cetuximab, and at the end of treatment.

RESULTS

Of the 21 patients enrolled, 9, 3, and 9 were treated in DL1, DL2, and DL3, respectively. DL1 required dose reductions due to gastrointestinal toxicities. DL2 and 3 were tolerated with 1 dose-limiting toxicity (grade 4 renal failure) at DL3. Following 3 weekly treatments of neoadjuvant cetuximab in DL1, 7 patients had maximum standardized uptake value changes on 18F-FDG-PET/CT consistent with response to cetuximab. Of the 12 patients with locally advanced disease, eleven evaluable patients had no evidence of disease on 18F-FDG-PET/CT at treatment end. Five-year progression-free survival and overall survival rates for all patients were 57.5% and 58.5%, respectively.

CONCLUSIONS

Cetuximab with cisplatin 30 mg/m2 and radiotherapy was tolerated. 18F-FDG-PET/CT demonstrated early evidence of response to neoadjuvant cetuximab. With advances in precision oncology and the recent approval of pembrolizumab in metastatic cervical cancer, dual-target inhibition with an epidermal growth factor receptor inhibitor may be a promising treatment in the future.

A randomized phase II study of bevacizumab and weekly anetumab ravtansine or weekly paclitaxel in platinum-resistant or refractory ovarian cancer NCI trial#10150

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Background: Mesothelin and its binder, antigen-CA125, are highly expressed in high grade serous and endometrioid ovarian cancers (HGOC) and, can inhibit paclitaxel-induced cell death. Anetumab ravtansine (AR) is a fully-human antibody directed at the mesothelin antigen, conjugated to a tubulin polymerization inhibitor. We assessed the safety and activity of the combination AR/bevacizumab (ARB) versus weekly paclitaxel/bevacizumab (PB) in patients (pts) with platinum resistant HGOC. Methods: An initial run-in phase I assessed the safety of ARB. After determination of the recommended phase 2 dose (RP2D), a multicenter 1:1 randomized phase 2 trial was designed to evaluate the progression free survival (PFS) in pts with platinum resistant/refractory HGOC. Pts were stratified by platinum resistant or refractory and prior bevacizumab (bev). Eligibility required measurable disease and mesothelin tested positive centrally on archival tissue by IHC. No limitation on the number of prior lines of therapy. A futility analysis was planned at 35 PFS events. The control arm was weekly intravenous paclitaxel 80mg/m2 with bev 10mg/kg every 2 weeks. A CT was performed every 8 weeks for RECIST1.1 assessment. The toxicities were reported according to CTCAE version 5.1. NCT03587311. Results: 7 pts were enrolled in the run-in phase 1 and the RP2D determined as bev (10mg/kg) biweekly with AR (2.2mg/kg) weekly on a 28 day-cycle. In the phase 2, 57 pts were enrolled, 28 pts in the ARB and 29 pts in the control group. The positivity rate for mesothelin screening was 88%. Pts were heavily pre-treated, median prior lines of 3 (range (1-9) with 24 pts received prior bev (42%) and 13 pts were platinum refractory (7 in ARB and 6 in PB). At the time of 35 PFS events, one CR and 4 PR were observed (ORR = 18%) in the ARB arm, versus no CR and 16 PR in the weekly PB (ORR = 55%). The estimated median PFS was 5.3 (95% CI: 3.7-7.4) months for ARB and 9.6 (95% CI: 7.4-17.4) months for PB (HR = 1.7(95% CI: 0.9-3.4)). The median number of cycles were 4 (1, 29) and 8 (1, 19) respectively. The most common treatment-related AEs in the ARB arm were mostly grade 1/2 increase AST (71%) and ALT (64%), thrombocytopenia (61%), fatigue (57%), and peripheral neuropathy (46%). In the PB arm, the most common treatment-related AE were anemia (66%), neutropenia (59%), epistaxis (48%), fatigue (45%) and peripheral neuropathy (45%). Conclusions: At the time of futility analysis, weekly PB had better outcome than weekly ARB leading to the study termination. Molecular and blood analyses are on-going to assess potential biomarkers of response. This study highlights the importance of randomization in assessment of novel therapies and potential for re-challenge with bevacizumab. These data show that weekly PB is an effective regimen and can be considered as the control arm in platinum resistant HGOC. Clinical trial information: NCT03587311.

MOONSTONE/GOG-3032: Interim analysis of a phase 2 study of niraparib + dostarlimab in patients (pts) with platinum-resistant ovarian cancer (PROC)

5573

Background: PROC is poorly responsive to anticancer therapy. PARP inhibitors such as niraparib may increase neoantigen load and synergize with anti-PD-1 agents. TOPACIO reported a preliminary objective response rate (ORR: 18%) and disease control rate (DCR: 65%) to niraparib + pembrolizumab in pts with OC of any BRCA status. MOONSTONE sought to determine efficacy in pts without BRCA mutation ( BRCAm). Methods: In this phase 2 open-label, single-arm study, eligible pts received 1–3 prior lines of therapy including platinum, taxane, and bevacizumab, had RECIST v1.1 radiographic progression within 6 mo of last platinum line and had no known germline BRCAm. Pts were treated with niraparib 300/200 mg PO daily (based on weight/platelets) and 500 mg dostarlimab IV Q3W (cycles 1–4) followed by 1000 mg Q6W until disease progression, toxicity or consent withdrawal. Programmed death-ligand 1 (PD-L1) positive status was determined by Ventana SP263 assay using visually-estimated combined positive score ≥5%. The primary endpoint was investigator-assessed ORR per RECIST v1.1. Secondary endpoints included duration of response (DOR), progression-free survival (PFS), DCR, and safety. Futility was prespecified as ≤5 responses in the first 40 pts. Results: At interim analysis (data cutoff Oct 6, 2021), 41 pts were enrolled; median age was 65.0 y (range 35–77). At baseline, 8 (20%)/22 (54%)/11 (27%) pts had received 1/2/3 prior lines of therapy, respectively; 26 (63%) pts had primary resistance to platinum therapy and 15 (37%) were sensitive to first platinum treatment. Overall, tumors were PD-L1+/PD-L1–/unknown in 13 (32%)/25 (61%)/3 (7%), respectively. Efficacy results are shown in the Table. Treatment-related adverse events were reported in 95% of pts, most commonly nausea (56%), fatigue (34%), vomiting (32%), and anemia (29%). Conclusions: PROC remains difficult to treat; the ORR observed with niraparib + dostarlimab did not reach the threshold for 2nd-stage accrual in this cohort of pts with PROC, no known BRCAm, and prior bevacizumab treatment. PD-L1 status did not predict response; HRD testing is in process. Although DCR was 29%, futility was declared based on low ORR. The safety of the combination was similar to the safety profile of each monotherapy. Clinical trial information: NCT03955471. [Table: see text]

Study to evaluate intraperitoneal (IP) ONCOS-102 with systemic durvalumab in patients with peritoneal disease who have epithelial ovarian (OC) or metastatic colorectal cancer (CRC): Phase 2 results

2600

Background: Locoregional treatment with oncolytic viruses may be used to improve the efficacy of immune checkpoint inhibitors at both treated and distant tumor sites. This study evaluated the combination of IP-administered ONCOS-102, an oncolytic adenovirus encoding for granulocyte macrophage colony stimulating factor (GM-CSF), with systemic durvalumab (durva) in patients (pts) with advanced OC or CRC who have failed prior chemotherapy. Methods: This open-label study (NCT02963831) evaluated ONCOS-102 (IP 3 x 1011 VP in 500ml saline [recommended phase 2 dose] weekly x 6) + durva (IV 1500 mg every 4 weeks x 12). One dose of cyclophosphamide was given prior to first ONCOS-102 dose. Phase 2 evaluated the activity of the combination using Simon’s 2-stage MINIMAX design. In MINIMAX stage 1, if ≥ 5 of 18 OC pts or ≥ 1 of 13 CRC pts met the efficacy criteria (progression free at end of week 24), 15 additional OC pts or 14 additional CRC pts were to be enrolled in stage 2. The efficacy endpoint would be met if ≥ 11 OC pts or ≥ 4 CRC pts remained progression free at 24 weeks. Safety, response rate and progression-free survival (PFS) by RECIST 1.1, overall survival (OS), and immunologic effects in tumors were evaluated. ITT population = all pts who received at least one dose of durva or ONCOS-102; per protocol (PP) population = all pts who received at least 60% of ONCOS-102 doses and at least 1 durva dose in the first 2 cycles. Results: In MINIMAX stage 1, the OC cohort did not meet the efficacy criteria and was closed. For CRC, stage 1 efficacy criteria were achieved and the cohort was opened for stage 2. As of the 14 Dec 2021 cutoff, CRC enrollment was complete, and all pts were followed for 24 weeks or until progression or off study. Two pts were progression free at 24 weeks (see table). Treatment-related adverse events (TRAEs) occurring in > 30% pts were vomiting, nausea, fatigue, chills, and pyrexia. There were no grade 4 or 5 TRAEs. Grade 3 TRAEs were reported in 8 pts, 2 in the OC cohort and 6 in CRC. All grade 3 TRAEs occurred in no more than 1 pt for each AE except abdominal pain, which occurred in 2 pts. Conclusions: The combination of IP ONCOS-102 and durva was well tolerated. The study did not meet its efficacy endpoint. Evaluation of pre- and on-therapy translational parameters is ongoing. Clinical trial information: NCT02963831. [Table: see text]

Treatment patterns and outcomes among patients with microsatellite stable (MSS) advanced endometrial cancer in the United States: Endometrial Cancer Health Outcomes (ECHO) retrospective chart review Study

5581

Background: Traditional platinum-based systemic chemotherapy continue to be the SOC for aEC in the first line. Phase 2 clinical trials of chemotherapy (GOG 129 series) and some targeted therapies (229 series) for second line advanced endometrial cancer (aEC) have proved disappointing. Recently the treatment landscape for aEC patients has significantly changed with newer targeted therapies focusing on the microsatellite instability (MSI) status of endometrial tumors. The objective of the ECHO study was to describe real-world treatment patterns and outcomes in non-MSI-high or DNA mismatch repair proficient (pMMR) aEC patients in clinical practice in the United States (US) prior to 2019. Methods: The ECHO study is a multicenter, retrospective chart review study in women diagnosed with aEC in the US. Data were obtained from medical records of adult women (≥18 years) diagnosed with advanced or inoperable aEC (stages III or IV) with known MSI status, who had received at least one prior systemic therapy and progressed between July 1, 2016 – June 30, 2019. De-identified patient data extracted by treating oncologists included patient demographics, clinical and treatment characteristics, and clinical outcomes. Kaplan-Meier analyses were performed to estimate real-world progression-free survival (rwPFS) and overall survival (OS). Results: A total of 124 non-MSI-high or pMMR aEC patients who had progression following first line therapy were included in this interim analysis. Average age was 63 years, 62.9% White/Caucasian, 16.9% Hispanic/Latino, and 86% had ECOG ≤1. Metastases were observed in 70% of patients at diagnosis, with the most common metastatic sites being lung (47.6%), liver (32.3%), and distant lymph nodes (29%). As 2nd line therapy, 69% of patients received mono or combination chemotherapy (primarily with doxorubicin), 13% hormonal therapy, and 18% targeted therapy ± chemotherapy. Median duration of 2nd line therapy was 4 months. The majority (86.3%) discontinued 2nd line therapy, with disease progression the most common reason (66.4%). A quarter (26.6%) of patients initiated an additional line of therapy. Median rwPFS from initiation of 2nd line therapy was 5 months (95% confidence interval [CI]: 4-9). Median OS from initiation of 2nd line therapy was 12 months (95%CI: 9-18). Estimated OS rates from initiation of 2nd line therapy at 6, 12, and 24 months were 66%, 47%, and 30%, respectively. Conclusions: In this retrospective, chart review study, patients with non-MSI-high/pMMR aEC in the US who failed at least one systemic therapy had poor prognosis on subsequent therapies. There continues to be a significant unmet need in this group of women. Novel therapies are needed that delay progression and/or improve overall survival and further research is indicated to explore this.

A phase II trial of bevacizumab and rucaparib in recurrent carcinoma of the cervix or endometrium

5527

Background: Treatment options for patients with recurrent cervical and endometrial cancer remain limited. Even with optimum care, median survival has stalled at 12-17 months. The PARP inhibitor rucaparib has demonstrated activity in both BRCA wild-type and mutant cancers. Furthermore, preclinical studies suggest a synergistic effect of PARP inhibitors and antiangiogenic agents. We hypothesized that the combination of rucaparib and the VEGF inhibitor bevacizumab would yield a clinically-significant anti-cancer effect in patients with persistent or recurrent cervical or endometrial carcinoma. Methods: NCT03476798 is a phase II trial of adults with histologically-documented carcinoma of the cervix or endometrium. Patients with evaluable lesions who had undergone at least one prior line of systemic therapy, had adequate performance status and organ function, with a life expectancy of at least three months were eligible. Biopsies were obtained prior to treatment initiation for assessment of baseline tumor biomarkers, including ARID1A mutation status. Each cycle comprised 21 days. Rucaparib was administered orally at 600 mg, twice daily. Bevacizumab was administered by IV at 15 mg/kg on day 1 of each cycle. The primary objective was to estimate the proportion of patients with persistent or recurrent cervical or endometrial cancer who survive progression-free for at least six months (PFS6). Kaplan-Meier analysis was used to estimate progression-free survival. Results: There were 28 evaluable patients; six had cervical and 22 had endometrial cancer. Median age was 60.5 years (range, 30-74). Self-reported patient races were White (82.1%), Black (10.7%), and Native American (7.1%). Self-identified Hispanic or Latina patients comprised 3.6% of the cohort. Twenty-two of 28 patients had progressive disease by six months [survival distribution function estimate = 0.214 (lower CI, 0.087; upper CI, 0.378)]. Of the six patients who achieved PFS6, one had cervical and five had endometrial cancer. Six patients had a mutation in the ARID1A gene and those patients achieved PFS6 at a rate of 66.7%. Conclusions: The study hypothesis was evaluated in a two-stage design, and the interim analysis occurred once 28 evaluable patients were enrolled. In order to move on to the second stage, at least seven patients needed to remain progression-free at six months, but only six did. Thus, the study was ended after the interim analysis. The combination of rucaparib and bevacizumab did not provide the expected clinical benefit in this cohort of patients, but may warrant further exploration in patients with ARID1A mutations. Clinical trial information: NCT03476798.

Phase 1/2 first-in-human (FIH) study of CPI-0209, a novel small molecule inhibitor of enhancer of zeste homolog 2 (EZH2) in patients with advanced tumors

3104

Background: Enhancer of Zeste homolog 2 (EZH2) is a histone methyltransferase and the catalytic subunit of Polycomb Repressive Complex 2 (PRC2). EZH2 is frequently overexpressed in cancers and correlates with poor prognosis. CPI-0209 is an oral, small molecule, second-generation, selective inhibitor of EZH2 designed to achieve comprehensive target coverage through extended on-target residence time. The compound demonstrates more potent anti-tumor activity in preclinical cancer models, compared to first-generation EZH2 inhibitors. CPI-0209 is currently being evaluated in a Phase 1/2, open-label, FIH study (NCT04104776). Methods: Patients (pts) with advanced tumors were enrolled in a 3+3 design. Primary objective is to determine maximum tolerated dose (MTD) and/or recommended phase 2 dose (RP2D) of CPI-0209. Secondary objectives are to evaluate the safety, PK, and PD in pts who received CPI-0209 QD in 28 days cycles (C). Results: As of December 16, 2020, 33 pts were treated: pancreatic cancer (n = 6), mesothelioma, breast, colorectal, and ovarian cancer (n = 5 each), leiomyosarcoma, melanoma, cholangiocarcinoma, prostate, bladder, endometrial clear cell and gastric cancer (n = 1 each). Pts received CPI-0209 at 50 mg (n = 4), 100 mg, 137.5 mg, and 187.5 mg (n = 6 each), 225 mg (n = 7), and 275 mg (n = 4) daily dose. Median treatment duration was 43 days (range 1-239); 4 pts are ongoing. Median age was 64 yrs (range 24-79); 15 (45%) pts were male. Patients were heavily pretreated, with 67% of pts had ≥ 3 prior lines of therapy. No dose limiting toxicities have been observed. The most frequent treatment-emergent adverse events (TEAEs) (≥10%) were fatigue (27%), diarrhea (24%), nausea (21%), abdominal pain, alopecia, anemia, thrombocytopenia, and dysgeusia (15% each), and vomiting, headache, decreased appetite, and alkaline phosphatase increased (12% each); usually grade 1 or 2 in severity. Thrombocytopenia was dose-dependent and not associated with bleeding or clinical sequalae. Three pts (9%) discontinued CPI-0209 due to TEAEs. Comprehensive target engagement (assessed by global reduction in H3K27me3 levels in monocytes) was observed within the first cycle at all dose levels. CPI-0209 also increased the expression of PRC2-controlled gene sets in blood in a dose-dependent manner. Updated safety, PK, PD, and preliminary efficacy results from Phase 1 will be presented. Conclusions: CPI-0209 achieved robust PD effects and a PK-PD relationship has been established. CPI-0209 monotherapy was generally well tolerated, and treatment related AEs were manageable and reversible. The MTD has not been reached. Clinical trial information: NCT04104776.

A Surgical Window Trial Evaluating Medroxyprogesterone Acetate with or without Entinostat in Patients with Endometrial Cancer and Validation of Biomarkers of Cellular Response

PURPOSE

This surgical window of opportunity (window) study assessed the short-term effect of medroxyprogesterone acetate (MPA) alone versus MPA plus the histone deacetylase (HDAC) inhibitor entinostat on regulation of progesterone receptor (PR) in women with newly diagnosed endometrioid endometrial adenocarcinoma.

PATIENTS AND METHODS

This multisite, randomized, open-label surgical window study treated women intramuscularly on day 1 with 400 mg MPA. Entinostat given 5 mg by mouth on days 1, 8, and 15 was randomly assigned with equal probability. Surgery followed on days 21-24. Pretreatment and posttreatment tissue was assessed for PR H-scores, Ki-67 levels, and histologic response.

RESULTS

Fifty patients were accrued in 4 months; 22 and 20 participants had PR evaluable pretreatment and posttreatment slides in the MPA and MPA/entinostat arms, respectively. Median posttreatment PR H-scores were significantly lower than pretreatment H-scores in both arms but did not differ significantly (MPA: 247 vs. 27, MPA/entinostat 260 vs. 23, respectively, P = 0.87). Decreased Ki-67 was shown in 90% treated with MPA/entinostat compared with 68% treated with MPA alone (P = 0.13). Median PR H-score decreases were larger when Ki-67 was decreased (208) versus not decreased (45). The decrease in PR pretreatment versus posttreatment was associated with loss of Ki-67 nuclear staining, consistent with reduced cellular proliferation (P < 0.008).

CONCLUSIONS

This surgical window trial rapidly accrued in a multisite setting and evaluated PR as its primary endpoint and Ki-67 as secondary endpoint. Despite no immediate effect of entinostat on PR in this short-term study, lessons learned can inform future window and treatment trials.

Post hoc analyses of GOG 9923: Does BRCA status affect toxicities?: An NRG oncology study

OBJECTIVE

To evaluate how women with epithelial ovarian cancer (EOC), dichotomized by BRCA status, tolerate intravenous (IV) or intraperitoneal (IP) chemotherapy given with veliparib and bevacizumab (bev) on a GOG phase I study (GOG 9923, NCT00989651).

METHODS

This is an unplanned, post hoc analysis of an IRB approved, multi-institutional, prospective study (GOG 9923). Clinical characteristics and toxicity data based on BRCA status were evaluated and descriptive statistics were used to summarize baseline patient characteristics and toxicities. The Kaplan Meier method was used to generate survival estimates.

RESULTS

Four hundred twenty-four patients were evaluable. Patients were treated with IV carboplatin, paclitaxel, and bev every 21 days (regimen 1), weekly IV paclitaxel with carboplatin and bev (regimen 2) or IV paclitaxel and bev with IP cisplatin (regimen 3). Bev was continued as maintenance in all arms. Within each of these regimens, veliparib was given either twice daily for the entirety of each cycle (continuous) or on days -2 to 5 (intermittent). Ten percent of patients treated on regimen 1, 12% on regimen 2, and 19.8% on regimen 3 had BRCA-associated tumors. Patients with BRCA-associated tumors, when compared to wild type, experienced similar rates of anemia, febrile neutropenia (, abdominal pain, colonic perforation, nausea, vomiting, and peripheral sensory neuropathy. Median progression free survival (PFS) was not significantly different between BRCA-associated and wild type cancers (HR 0.96, CI 0.65-1.42), though this study's primary aim was not to evaluate outcomes.

CONCLUSIONS

Germline BRCA mutations positively affect chemosensitivity in EOC, but whether differences in toxicities among BRCA-associated and BRCA wild type tumors existed was previously not reported. In this population with newly diagnosed ovarian cancer no differences in reported toxicity between the two groups was observed.

Abstract PO020: Approval for the proliferative marker Ki-67 as an integrated biomarker for endometrial cancer in NRG study GY011

Introduction: NRG Study GY011 is a surgical window trial of medroxy-progesterone acetate (MPA) +/- entinostat (E), a histone deacetylase inhibitor hypothesized to upregulate PR levels through epigenetic modifications. The principal goal of this trial was to determine the impact of treatment on the level as well as the activity of progesterone receptors (PR) in women with endometrial cancer. However, a reliable marker for PR activity was needed, and the most promising choice was Ki-67. To be approved for inclusion in the study as an integrated biomarker, Ki-67 had to first undergo rigorous evaluation by the participating pathologists with oversight by the NIH Biomarker Review Committee. Methods: Fifty patients were enrolled on GY011, and specimen collection was planned by biopsy prior to receiving study drugs and by tissue sample at the time of the hysterectomy. There were 42 pre-drug administration specimens with tumor for analysis and 1 without and 43 hysterectomy specimens with tumor. Ki-67 immunohistochemistry performed on pre and post drug specimens was evaluated by three experienced reviewers (MS, KC and AR) using a qualitative approach, blinded to treatment arm. Pre and post-drug samples for each individual patient were compared and scored as increased, decreased, or unchanged. The Fleiss kappa statistic was chosen as the measure of concordance as it allows for more than two reviewers and more than two categories. Percent agreement and standard weighted kappa statistics were calculated for individual pairs of reviewers. Results: There was very good concordance between reviewers using the qualitative comparison of post to pre-drug Ki-67 staining with Fleiss’ Kappa of 0.91 and weighted Kappa’s ranging between 0.85 and 0.95. Reviewers 1 and 2 had the highest level of concordance. Reviewer agreement ranged from 0.92 to 0.98. The reviewer-specific (marginal) score distributions were similar. Each reviewer scored about 80% (79.5%-82.5%) of pairs as decreasing, with the remainder split similarly between no change (7.5%-10%) and increasing (10%-12.8%). Conclusion: Based upon the high concordance between reviewers, the NIH Biomarker Review Committee approved Ki-67 as an integrated biomarker for GY011, setting the stage for its use as an approved biomarker of therapeutic effectiveness in future endometrial cancer trials.

Citation Format: Megan I. Samuelson, Virginia Filiaci, Kelley Carrick, Anand Rajan KD, William H. Rodgers, Kristina W. Thiel, Linda R. Duska, Kimberly K. Leslie. Approval for the proliferative marker Ki-67 as an integrated biomarker for endometrial cancer in NRG study GY011 [abstract]. In: Proceedings of the AACR Virtual Special Conference: Endometrial Cancer: New Biology Driving Research and Treatment; 2020 Nov 9-10. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(3_Suppl):Abstract nr PO020.

Results of an early safety analysis of a study of the combination of pembrolizumab and pelvic chemoradiation in locally advanced cervical cancer

BACKGROUND

Immune checkpoint inhibitors are being considered for locally advanced cervical cancer (LACC) together with standard-of-care pelvic chemoradiation (CRT). However, the safety of the combination and its optimal schedule are unknown. Defining the safety of the combination is a primary objective of a study examining concurrent and sequential schedules. This article presents a safety analysis that was fully accrued and met reporting requirements.

METHODS

Pembrolizumab was given after CRT (arm 1) or during CRT (arm 2) according to a randomized phase 2 design. Patients who were 18 years old or older and had LACC (stages IB-IVA according to the 2009 International Federation of Gynecology and Obstetrics system) were randomized 1:1 to the treatment regimens. The CRT was identical in the 2 arms. Pembrolizumab was administered every 3 weeks for 3 doses; no maintenance was allowed. All patients receiving any treatment were evaluated for safety. Safety assessments included the incidence and severity of adverse events (AEs) and the occurrence of protocol-defined dose-limiting toxicity (DLT) through 30 days after the last pembrolizumab infusion.

RESULTS

As of August 2019, 52 of the 88 planned patients had completed treatment and were evaluable for toxicity. Treatment-related grade 2 or higher toxicity was experienced by 88%; 11 had at least 1 grade 4 AE, and another 23 had at least 1 grade 3 AE. Grade 1 or higher diarrhea was reported in 34 patients (65%; 50% of these were grade 1), and there was no difference between arms (63% in arm 1 vs 68% in arm 2). Two patients experienced 3 DLTs. Most patients completed cisplatin (100% in arm 1 vs 82% in arm 2); 83% in both arms completed all pembrolizumab.

CONCLUSIONS

Preliminary results support the safety and feasibility of adding pembrolizumab to pelvic CRT concurrently or sequentially.

LAY SUMMARY

Pembrolizumab is a humanized antibody against programmed cell death protein 1 that is used in cancer immunotherapy. Preliminary data suggest that pembrolizumab can be safely combined with chemotherapy and pelvic radiation in the treatment of locally advanced cervical cancer. Future studies of the addition of immunotherapy to traditional chemoradiation are planned to determine the best way to deliver the treatment and whether any improvement is seen with the addition of immunotherapy to traditional therapy.

Berzosertib plus gemcitabine versus gemcitabine alone in platinum-resistant high-grade serous ovarian cancer: a multicentre, open-label, randomised, phase 2 trial

BACKGROUND

High-grade serous ovarian cancers show increased replication stress, rendering cells vulnerable to ATR inhibition because of near universal loss of the G1/S checkpoint (through deleterious TP53 mutations), premature S phase entry (due to CCNE1 amplification, RB1 loss, or CDKN2A mRNA downregulation), alterations of homologous recombination repair genes, and expression of oncogenic drivers (through MYC amplification and other mechanisms). We hypothesised that the combination of the selective ATR inhibitor, berzosertib, and gemcitabine could show acceptable toxicity and superior efficacy to gemcitabine alone in high-grade serous ovarian cancer.

METHODS

In this multicentre, open-label, randomised, phase 2 study, 11 different centres in the US Experimental Therapeutics Clinical Trials Network enrolled women (aged ≥18 years) with recurrent, platinum-resistant high-grade serous ovarian cancer (determined histologically) and Eastern Cooperative Oncology Group performance status of 0 or 1, who had unlimited previous lines of cytotoxic therapy in the platinum-sensitive setting but no more than one line of cytotoxic therapy in the platinum-resistant setting. Eligible patients were randomly assigned (1:1) to receive intravenous gemcitabine (1000 mg/m²) on day 1 and day 8, or gemcitabine plus intravenous berzosertib (210 mg/m²) on day 2 and day 9 of a 21-day cycle until disease progression or intolerable toxicity. Randomisation was done centrally using the Theradex Interactive Web Response System, stratified by platinum-free interval, and with a permuted block size of six. Following central randomisation, patients and investigators were not masked to treatment assignment. The primary endpoint was investigator-assessed progression-free survival, and analyses included all patients who received at least one dose of the study drugs. The study is registered with ClinicalTrials.gov, NCT02595892, and is active but closed to enrolment.

FINDINGS

Between Feb 14, 2017, and Sept 7, 2018, 88 patients were assessed for eligibility, of whom 70 were randomly assigned to treatment with gemcitabine alone (36 patients) or gemcitabine plus berzosertib (34 patients). At the data cutoff date (Feb 21, 2020), the median follow-up was 53·2 weeks (25·6-81·8) in the gemcitabine plus berzosertib group and 43·0 weeks (IQR 23·2-69·1) in the gemcitabine alone group. Median progression-free survival was 22·9 weeks (17·9-72·0) for gemcitabine plus berzosertib and 14·7 weeks (90% CI 9·7-36·7) for gemcitabine alone (hazard ratio 0·57, 90% CI 0·33-0·98; one-sided log-rank test p=0·044). The most common treatment-related grade 3 or 4 adverse events were decreased neutrophil count (14 [39%] of 36 patients in the gemcitabine alone group vs 16 [47%] of 34 patients in the gemcitabine plus berzosertib group) and decreased platelet count (two [6%] vs eight [24%]). Serious adverse events were observed in ten (28%) patients in the gemcitabine alone group and nine (26%) patients in the gemcitabine plus berzosertib group. There was one treatment-related death in the gemcitabine alone group due to sepsis and one treatment-related death in the gemcitabine plus berzosertib group due to pneumonitis.

INTERPRETATION

To our knowledge, this is the first randomised study of an ATR inhibitor in any tumour type. This study shows a benefit of adding berzosertib to gemcitabine in platinum-resistant high-grade serous ovarian cancer. This combination warrants further investigation in this setting.

FUNDING

US National Cancer Institute.

Phase I/II study to evaluate systemic durvalumab + intraperitoneal (IP) ONCOS-102 in patients with peritoneal disease who have epithelial ovarian (OC) or metastatic colorectal cancer (CRC): Interim phase I clinical and translational results

3017

Background: Metastasis to the peritoneal cavity is associated with end-stage disease in many cancers, including OC and CRC, both of which exhibit poor responses to checkpoint inhibitors. Locoregional treatment with oncolytic viruses may be used to improve the efficacy of checkpoint inhibitors at both treated and distant tumor sites. This study evaluates the combination of IP-administered ONCOS-102, an oncolytic adenovirus encoding for granulocyte macrophage colony stimulating factor (GMCSF), with systemic durvalumab, an anti PD-L1 antibody, in patients with peritoneal disease who have histologically confirmed OC or metastatic CRC and have failed prior standard therapies. Methods: This ongoing Phase 1/2, open-label study (NCT02963831) evaluates safety and antitumor/biologic activity of durvalumab (1500 mg IV, every 4 weeks x 12) + ONCOS-102 (IP, weekly x 6); cyclophosphamide is given pre first ONCOS-102 dose. Phase 1 uses a 3+3 design to evaluate the ONCOS-102 dose (1 or 3 x 1011 VP) to be given with durvalumab. Phase 2 evaluates the activity of the combination using Simon’s 2-stage MINIMAX design. Safety, response rate by RECIST 1.1, and immunological effects in tumors were evaluated for Phase 1; the current abstract reports on the phase 1 results. Results: Enrollment opened 7 Sep 2017; data cutoff, 1 Nov 2019. There were 17 patients treated in Phase 1: 8 CRC, 9 ovarian; 94% female; median age, 56 [37-77] years; ECOG PS0, 47%; ECOG PS1, 53%. There were no DLTs. Grade 3 treatment-related AEs included hypokalemia (n = 2); anemia, myocarditis, increased GGT, and influenza like illness (n = 1 each). There were 4 deaths due to PD. One patient had durable confirmed partial response and remains on treatment > 1 year; 4 patients had stable disease as best overall response. Two patients remained on treatment at data cutoff. Analysis of pre- and on-treatment tumor biopsies revealed changes in the tumor-infiltrating immune cells and PD-L1 expression, including an increase in tumor-infiltrating CD8 T cells in 5 of 11 evaluable patients. Conclusions: Combination of durvalumab and IP ONCOS-102 was safe, and no DLTs were observed. Preliminary analyses demonstrate evidence of biologic and clinical activity. Phase 2 enrollment is ongoing. Clinical trial information: NCT02963831 .

ENGOT-cx11/KEYNOTE-A18: A phase III, randomized, double-blind study of pembrolizumab with chemoradiotherapy in patients with high-risk locally advanced cervical cancer

TPS6096

Background: High-risk locally advanced cervical cancer has a poor prognosis, and more than half of patients recur in 2 y. External beam radiotherapy (EBRT) with concurrent chemotherapy followed by brachytherapy is the standard of care for locally advanced cervical cancer. The immunostimulatory activity of the PD-1 inhibitor pembrolizumab (pembro) may be enhanced by concurrent chemoradiotherapy (CRT). After the KEYNOTE-158 study, in which pembro showed durable antitumor activity, pembro monotherapy was approved for patients with PD-L1–positive recurrent or metastatic cervical cancer who progressed during or after chemotherapy. ENGOT-cx11/KEYNOTE-A18 (NCT04221945) is a phase III, randomized, placebo-controlled study evaluating pembro with concurrent CRT for the treatment of locally advanced cervical cancer. Methods: Approximately 980 patients with high-risk (FIGO 2014 stage IB2-IIB with node-positive disease or stage III-IVA), locally advanced, histologically confirmed cervical cancer who have not received systemic therapy, immunotherapy, definitive surgery, or radiation will be randomized 1:1 to receive either 5 cycles of pembro 200 mg every 3 wk (Q3W) + CRT followed by 15 cycles of pembro 400 mg Q6W or 5 cycles of placebo Q3W + CRT followed by 15 cycles of placebo Q6W. The CRT regimen includes 5 cycles (with optional 6th dose) of cisplatin 40 mg/m2 Q1W + EBRT followed by brachytherapy. Randomization is stratified by planned EBRT type (intensity-modulated radiotherapy [IMRT] or volumetric-modulated arc therapy [VMAT] vs non-IMRT or non-VMAT), cancer stage at screening (stage IB2-IIB vs III-IVA), and planned total radiotherapy dose. Treatment will continue until the patient has received 20 cycles of pembro (5 cycles 200 mg Q3W, 15 cycles 400 mg Q6W) vs placebo (~2 y) or until disease progression, unacceptable toxicity, or withdrawal. Primary endpoints are PFS per RECIST v1.1 by blinded independent central review and OS. Secondary endpoints are PFS at 2 y, OS at 3 y, complete response at 12 wk, ORR, PFS and OS in PD-L1–positive patients, EORTC QLQ-C30 and QLQ-CX24, and safety. Enrollment is ongoing. Clinical trial information: NCT04221945.

ENGOT-OV44/FIRST study: a randomized, double-blind, adaptive, phase III study of standard of care (SOC) platinum-based therapy ± dostarlimab followed by niraparib ± dostarlimab maintenance as first-line (1L) treatment of stage 3 or 4 ovarian cancer (OC)

TPS6101

Background: Despite surgery and CT (paclitaxel + carboplatin ± bevacizumab [bev]), 5-year survival rates remain low for patients (pts) with FIGO stage 3 or 4 OC. Niraparib is a poly (ADP-ribose) polymerase (PARP) inhibitor that has recently demonstrated efficacy in 1L therapy. Dostarlimab (TSR-042) is an anti-programmed death (PD)-1 humanized monoclonal antibody that has shown clinical activity as monotherapy in early phase trials. The currently enrolling ENGOT-OV44/FIRST study will compare efficacy and safety of CT + dostarlimab + niraparib ± bev (Arm 3) vs CT + niraparib ± bev (Arm 2). Methods: Eligible pts are ≥18 years of age, with FIGO stage 3 or 4 non-mucinous epithelial OC, ECOG performance status < 2, and tumor tissue available for PD-1 ligand (PD-L1) testing. After cycle 1 of CT, pts are stratified by concurrent bev use, BRCA mutation/homologous recombination repair status, and disease burden, then randomized 1:2 into trial Arms 2 and 3 (Table). Dostarlimab is administered at 500 mg IV Q3W during the CT period, then 1000 mg IV Q6W during the maintenance period. Niraparib dosing is 200 mg PO QD for pts with baseline bodyweight (BW) < 77 kg and/or platelet count (PC) < 150,000/µL, or 300 mg QD for pts with baseline BW ≥77 kg and PC ≥150,000/µL. The dual primary endpoints are PFS, based on investigator assessment per RECIST v1.1, in both PD-L1+ and all patients. Initially the study enrolled pts to Arm 1. This arm was discontinued following positive results from the PRIMA/ENGOT-OV26/GOG-3012 and PAOLA-1/ENGOT-OV25 studies. This allows investigators to offer the current standard of care to all patients. Clinical trial information: NCT03602859, EUDRACT 2018-000413-20. [Table: see text]

A randomized phase II study of cabozantinib and nivolumab versus nivolumab in recurrent endometrial cancer

6010

Background: The efficacy of treatment for recurrent endometrial cancer (EC) remains limited. Vascular endothelial growth factor and inflammatory chemokines are proangiogenic factors and immune modulators involved in immune suppression. Reprogramming the tumor microenvironment by combining antiangiogenic and immunotherapy (IO) could enhance antitumor responses. Methods: A 2:1 randomized phase 2 trial compared the combination of cabozantinib and nivolumab (Arm A) versus nivolumab (Arm B) in recurrent EC. Primary endpoint was progression free survival (PFS) assessed by RECIST 1.1 (NCT03367741). Women with recurrent measurable EC were eligible. There were no limits on prior therapy, but at least one prior platinum-based chemotherapy was required. Patients (pts) were stratified according to MSI status and assessed by CT every 8 weeks. Cabozantinib was given at 40 mg daily (Arm A) and nivolumab at 240 mg, on D1 and D15 of a 28-day cycle for 4 cycles, followed by 480 mg every 4 weeks (Arms A & B). Pts with carcinosarcoma or prior IO were enrolled in an exploratory cohort and received combination treatment (Arm C). A baseline biopsy was required for all pts. CyTOF analysis was performed on fresh biopsies. Results: 76 evaluable pts were enrolled (Arm A: 36, Arm B: 18, Arm C: 9 carcinosarcoma, and 20 post IO including 7 pts crossed over from Arm B). 55% of pts had received ≥3 prior lines of therapy. Two pts were MSI high in Arm A and none in Arm B. The Kaplan-Meier estimated median PFS was 5.3 (95% CI: 3.5-9.5) months in Arm A and 1.9 (95% CI: 1.6-3.8) months in Arm B, with a log-rank p = 0.07, which met the significance level of 0.1 used for sample size calculation. Objective response rate (ORR) was 25% for Arm A and 16.7% for Arm B; stable disease (SD) was seen in 44.4% vs 11.1%, respectively. Clinical benefit (ORR+SD) was significantly higher in arm A vs B (p < 0.001). In Arm C-carcinosarcoma, one patient had a partial response (11.9 months duration) and four SD. In Arm C-prior IO, six pts responded and eight had SD. The most common related AEs in Arm A were diarrhea (47.2%), elevated liver enzymes (44.4%), fatigue (38.9%), anorexia, hypertension, and nausea (30.6%), mainly grade 1/2. Preliminary CyTOF analysis across treatment arms identified multiple immune subsets for further interrogation including activated CD8+ and CD4+ T cells. Conclusions: Cabozantinib plus nivolumab demonstrates improved PFS compared to nivolumab in heavily pre-treated women with recurrent EC. In-depth CyTOF analysis of the tumor microenvironment to identify predictive immune biomarkers of response is ongoing. Clinical trial information: NCT03367741.

A randomized phase II evaluation of weekly gemcitabine plus pazopanib versus weekly gemcitabine alone in the treatment of persistent or recurrent epithelial ovarian, fallopian tube or primary peritoneal carcinoma

OBJECTIVE

Angiogenesis inhibition is a valuable strategy for ovarian cancer (EOC). Pazopanib (paz) is a potent small molecular inhibitor of VEGF-1, -2, -3, PDGFR, c-kit, and has activity as a single agent in ovarian cancer. We designed a trial to assess the benefit of adding paz to gemcitabine (gem) in patients with recurrent EOC.

METHODS

An open-label, randomized, multi-site, phase 2 trial was conducted (NCT01610206) including patients with platinum resistant or sensitive disease, ≤ 3 prior lines of chemotherapy, and measurable/evaluable disease. Patients were randomly assigned to weekly gem 1000 mg/m² on days 1 and 8 of a 21 day cycle, with or without paz 800 mg QD, stratified by platinum sensitivity and number of prior lines (1 vs 2 or 3). The primary endpoint was PFS.

RESULTS

148 patients were enrolled 2012-2017. Median age was 63 years (30-82); 60% were platinum resistant; median surveillance was 13 months (0.4-54 months). Median PFS was 5.3 (95% CI, 4.2-5.8) vs 2.9 months (95% CI, 2.1-4.1) in the gem arm. The PFS effect was most pronounced in the platinum resistant group (5.32 vs 2.33 months Tarone-Ware p < 0.001). There was no difference in OS. Overall RR (PR 20% vs 11%, Chi-squre p = 0.02) and DCR (80% vs 60%, Chi-square p < 0.001) were higher in the combination. High grade AEs in the combination arm included ≥ Grade 3: hypertension (15%), neutropenia (35%), and thrombocytopenia (12%).

CONCLUSIONS

The addition of paz to gem enhanced anti-tumor activity; those with platinum-resistant disease derived the most benefit from combination therapy, even in the setting of receiving prior bevacizumab.

Chemotherapy alone may have equivalent survival as compared to suboptimal surgery in advanced endometrial cancer patients

Objective

To describe outcomes in patients with advanced endometrial cancer treated with chemotherapy only and compare them to patients treated with a combination of chemotherapy and surgery.

Methods

Retrospective chart review for all patients diagnosed with stage III and IV endometrial cancer from January 1, 2000 to December 31, 2015. We abstracted relevant demographic and clinical data. Kaplan-Meier analysis was used to create survival curves; Cox proportional hazards regression model was used to identify prognostic factors.

Results

Ninety-six patients met inclusion criteria; the median age was 64.5. Seventy patients were treated with combination therapy and 26 with chemotherapy alone. For the entire group, median overall survival (OS) was significantly different between groups (22.3 months surgery versus 9.8 months chemotherapy only, p = 0.0002). After multivariable analysis, having carcinosarcoma (HR 3.84 95% CI 2.64-5.03, p = 0.03), having grade 3 disease (HR 4.95 95% CI 3.70-6.18, p = 0.01), and having chemotherapy only (HR 4.13 95% CI 3.23-5.02, p = 0.002) were associated with increased mortality. When analysis was restricted to just patients who had a suboptimal debulking or chemotherapy alone, median OS was equivalent similar at 9.4 and 9.8 months (p = 0.46).

Conclusion

For advanced endometrial cancer patients, surgery in addition to chemotherapy confers a survival advantage except when optimal debulking cannot be achieved.

A phase I study of intravenous or intraperitoneal platinum based chemotherapy in combination with veliparib and bevacizumab in newly diagnosed ovarian, primary peritoneal and fallopian tube cancer

BACKGROUND

Improvements in disease free survival for epithelial ovarian, peritoneal or fallopian tube cancer (EOC) will only come with improved primary therapy. Incorporation of poly-ADP-ribose inhibitors (PARPi) in the frontline setting may represent one strategy. This study sought to determine the maximum tolerated and feasible doses of the PARPi veliparib in combination with chemotherapy for EOC.

METHODS

A phase I, 3 + 3 dose escalation evaluated dose-limiting toxicities (DLTs) in cycles 1-2. Once <2/6 patients experienced a DLT, that dose level expanded to evaluate feasibility over 4 cycles. This study opened 10/2009 and closed 8/2016. Eligible patients had untreated, stage II-IV EOC. Veliparib was added either continuous (day 1-21) or intermittent (day - 2 to 5) during 6 cycles of chemotherapy. Three chemotherapy backbones were evaluated (2 intravenous (q3week and weekly) and 1 intraperitoneal (IP)) all inclusive of bevacizumab with and as maintenance to 22 cycles.

FINDINGS

Dose evaluations for 424 treated patients were available. Regimen 1 (q3 week), continuous (Reg1c) the maximum tolerated dose (MTD) was 250 mg veliparib BID and feasible dose was 150 mg BID. For regimen 1, intermittent (Reg1i) the MTD and feasible dose were 400 and 250 mg BID. For Reg2c (weekly paclitaxel) the MTD and feasible dose were 150 mg BID. For Reg2i the MTD and feasible dose were 250 and 150 mg BID. For Reg3c (IP) the MTD and feasible dose were 150 mg BID and for Reg3i (IP), the MTD and feasible dose were 400 mg and 300 mg BID.

INTERPRETATION

The feasible dose for Reg1c, 2c, 2i and 3c was 150 mg po BID. For Reg1i and 3i the dose was pushed to 250 and 300 mg po BID respectively. There is no apparent difference in efficacy between continuous and intermittent dosing indicating that the higher doses achieved in intermittent dosing may not be needed. (NCT00989651).

FUNDING

National Cancer Institute.

Quality Initiative to Improve Compliance With Perioperative Anticoagulation

PURPOSE

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in gynecologic oncology surgical patients. Many centers use neuraxial analgesia (NA), which affects the timing of prophylactic anticoagulation. In 2012, we determined that the rate of VTE in patients undergoing laparotomy with NA was higher than in those who received alternative pain control. In addition, compliance with preoperative anticoagulation guidelines was only 40%. We undertook a quality initiative (QI) project to increase compliance to 80% in NA cases and maintain 90% in non-NA cases.

METHODS

A multidisciplinary working group designed and deployed a QI intervention bundle. Compliance was defined as the receipt of a prophylactic dose of anticoagulant within 1 hour after NA or before skin incision regardless of anesthesia type. Data were abstracted from the medical record after the study period. Cases from the year before QI were used for comparison. Primary outcome was compliance and secondary outcome was the rate of VTE.

RESULTS

One hundred women were treated under the QI project and 182 historical cases (HCs) were used for comparison. Overall compliance improved (96% QI v 73% HC; P < .001). This difference was marked in cases with NA (95% QI v 40% HC; P < .001) and remained stable in non-NA cases (97% QI v 91% HC; P = .29). The overall rate of VTE, independent of anesthesia type, remained unchanged (2.1% HC v 0% QI; P = .3).

CONCLUSION

Relatively simple and inexpensive initiatives to improve routine processes within the surgical pathway are feasible and attract staff participation. Such efforts are likely to translate into greater levels of patient safety.

ENGOT-OV44/FIRST study: A randomized, double-blind, adaptive, phase III study of platinum-based therapy with dostarlimab (TSR-042) + niraparib versus standard-of-care (SOC) platinum-based therapy as first-line treatment of stage 3/4 non-mucinous epithelial ovarian cancer (OC)

TPS5600

Background: Despite surgery and SOC therapy (paclitaxel and carboplatin ± bevacizumab[bev]), 5-year survival rates remain low for patients (pts) with FIGO stage 3/4 OC. Niraparib (ZEJULA) is the first selective poly(ADP-ribose) polymerase inhibitor (PARPi) approved in the US and Europe for maintenance treatment in pts with recurrent OC regardless of BRCAmut status. Preclinical data suggest synergy with PARPi + anti-PD-1 blockade. Niraparib + pembrolizumab has shown clinical efficacy in pts with platinum-resistant or secondary refractory OC regardless of biomarker status. Dostarlimab is an anti–PD-1 humanized monoclonal with clinical activity as monotherapy in early phase trials. The primary objective of the currently enrolling FIRST trial is to compare PFS (per RECIST v1.1) in pts treated with SOC + dostarlimab + niraparib to SOC. Methods: Eligible pts (up to 912) are FIGO stage 3 (with residual disease, CC0 high risk, or planned neoadjuvant therapy) or stage 4, non-mucinous epithelial OC and ECOG score < 2. After 1 cycle of SOC, pts are stratified by concurrent bev use, BRCAmut/HRR status, and disease burden then randomized as 1:1:2 to 1 of 3 arms (Table). An innovative feature of ENGOT-OV44/FIRST (NCT03602859; EUDRACT 2018-000413-20) is the pre-planned adaptive study design to adapt the control arm to the evolving SOCs in OC, allowing pts in the control arm to receive up to date SOC. These adaptations will occur when practice-changing data are released. Following publication of SOLO1 results, BRCAmut pts will only be randomized to arm 2 or 3 to ensure they receive niraparib. Further adaptations may be incorporated as new data become available, leading to stop randomization in arm 1 or 2 of pts based on their biomarker status. Clinical trial information: NCT03602859. [Table: see text]

A phase I study of veliparib incorporated into front-line platinum based cheotherpy and bevacizumab in epithelial ovarian cancer (NCT00989651): A GOG/nrg trial

5523

Background: Veliparib, a poly-(ADP-ribose)-polymerase inhibitor, increases anti-tumor activity when combined with platinum chemotherapy and has monotherapy activity in BRCA deficient tumors. This study was done to determine the recommended phase II dose (RP2D) of veliparib in combination with front line treatment for epithelial ovarian cancer (EOC). Methods: Eligible patients had newly diagnosed, stage II-IV EOC. Six regimens were evaluated, 3 variations of chemo delivery with either continuous (D1-21) or intermittent (days-2-5) veliparib BID. Chemo included 1: IV q3week carboplatin (C) (AUC 6) and paclitaxel(T) (175mg/m2); 2, IV q3week C (AUC 6) and weekly T(80mg/m2); and 3, IV T (135mg/m2, day 1), IP cisplatin (75mg/m2, day 1 or 2) and IP T (60mg/m2, day 8). Bevacizumab 15mg/kg started cycle 2 and continued as monotherapy cycles 7-22. A 3+3 dose escalation design evaluated dose-limiting toxicities (DLTs) in cycles 1 and 2. Once < 2/6 patients experienced a DLT, that dose level was expanded to evaluate feasibility over 4 cycles. Results: The study accrued 424 treated patients. For regimen 1, continuous (Reg1c) the maximum tolerated dose (MTD) was 250mg veliparib BID but the feasible dose was found to be 150mg BID. For regimen 1, intermittent (Reg1i) the MTD and feasible dose were 400 and 250mg BID respectively. For Reg2c the MTD and feasible dose were the same at 150mg BID. For Reg2i the MTD and feasible dose were 250 and 150mg BID respectively. For Reg3c the MTD and feasible dose are both 150mg BID and for Reg3i, the MTD was 400mg BID and the feasible dose felt to be 300mg BID. Median PFS by residual disease and BRCA status is: (Positive residual disease) 14.6, 19.1 and 16.9 months for BRCA+, BRCAwt and BRCA ukn respectively. For no gross residual disease the PFS is NR, 34.2 and 24.5 months respectively. Conclusions: Given the difficulty with toxicity not defined as a DLT, the RP2D for all regimens is veliparib 150mg BID. This data informed the dose that moved into the phase III trial GOG 3005/Velia: NCT02470585. Velia also incorporated maintenance veliparib instead of maintenance bevacizumab among all high grade serous patients (BRCA+ and wt). These results will determine utilization of veliparib in this space. Clinical trial information: NCT00989651.

A phase II randomized study of avelumab plus entinostat versus avelumab plus placebo in patients (pts) with advanced epithelial ovarian cancer (EOC)

5511

Background: Preclinical evidence suggests that combining avelumab (A), a human anti-PD-L1 monoclonal antibody, and entinostat (E), a class I selective histone deacetylase (HDAC) inhibitor, may increase tumor immunogenicity and responsivity to checkpoint inhibition. This study evaluated whether A+E would lead to improved progression free survival (PFS) vs A in pts with advanced EOC. Methods: Pts with EOC which had progressed or recurred after 1st-line platinum-based chemotherapy and received 3- 6 lines of therapy were randomized 2:1 to receive A (10 mg/kg IV Q2W) plus E (5 mg PO QW) or A plus placebo (P). Treatment continued until disease progression (PD) or unacceptable toxicity. The primary endpoint was PFS (investigator-assessed, RECIST 1.1), stratifying on the presence/absence of bulky disease (tumor ≥ 50 mm) and platinum-refractory disease. The hypothesis was that the combination would reduce the hazard of PD or death by 43%, representing a 75% improvement in median PFS. 97 events (from 120 pts) provided 90% power with 1-sided significance level of 0.10. Secondary endpoints included ORR, duration and time to response, toxicity, clinical benefit rate, and OS. Results: 126 pts were enrolled, median age 63 yrs (range 43-82), median 4 prior lines, 83% serous histology. Median PFS was 1.64 and 1.51 mos for A+E and A+P, respectively (p = 0.31; HR 0.90, 95% CI: 0.58-1.39). No significant differences in ORR (6% vs 5%), or OS (NE vs 11.3 mos) were observed. 4 pts (3%) had clear cell EOC, with no responses observed. The incidence of related adverse events (AEs) was higher in the A+E arm compared to A+P (any grade: 93% vs 78%, Grade 3/4: 41% vs 10%), and the most frequent (≥20%) related AEs with A+E were fatigue (46%), nausea (31%), diarrhea (26%), anemia (26%), and chills (20%). Grade 3/4 related AEs occurring in ≥5% with A+E were fatigue (9%), and neutropenia (8%). 47% of pts in A+E arm required E dose holds/reductions. Discontinuations due to AEs were similar between arms (21% vs 17.5% for A+E and A+P, respectively), as was duration of study therapy (median 4 and 5 cycles started). Conclusions: In pts with heavily pretreated EOC, median PFS was not prolonged when E was added to A compared to A alone and the combination resulted in greater toxicity. Clinical trial information: NCT02915523.

Interpreting Randomized Clinical Trials in Gynecologic Oncology Surgery: Does One Size Fit All?

Randomized clinical trials (RCTs) are considered the gold standard of clinical research. They are designed to eliminate bias and to produce objective and generalizable results about new treatment paradigms. Although RCTs have recognized limitations, including long completion time and high cost, they also have transformed clinical research and improved the quality of health care by rigorously evaluating countless new treatment options. Surgical RCTs present their own unique set of limitations including an inability to standardize surgical technique and expertise; an inability to overcome enrollment bias by enrolling surgeons; and a lack of generalizability with respect to institutional resources and abilities. Here, we discuss surgical RCTs in two domains: upfront management of advanced ovarian cancer and surgical management of early-stage cervical cancer. Familiarity with the abundant retrospective data available for both of these clinical scenarios as well as recognition of the strengths and limitations of surgical RCTs are critical to determine the best treatment for an individual patient.

Alisertib in Combination With Weekly Paclitaxel in Patients With Advanced Breast Cancer or Recurrent Ovarian Cancer: A Randomized Clinical Trial

Importance

There is an unmet medical need for the treatment of recurrent ovarian cancer, and new approaches are needed to improve progression-free survival (PFS) and overall survival.

Objective

This phase 1/2 study evaluated the activity of alisertib in combination with weekly paclitaxel in patients with breast (phase 1) and ovarian cancer (phase 1 and phase 2).

Design, Setting, and Participants

An open-label phase 1 and randomized phase 2 clinical trial conducted from April 16, 2010, for phase 1 and March 28, 2012, to August 12, 2013, for phase 2 was conducted at 33 sites (United States, France, and Poland). Data are reported from a cutoff date of August 12, 2014, with a median duration of follow-up of 7.2 months in the alisertib plus paclitaxel arm and 4.6 months in the paclitaxel arm. A total of 191 women with advanced breast (phase 1 only) or recurrent ovarian cancer were enrolled, including 142 patients randomized to alisertib plus paclitaxel (n = 73) or paclitaxel alone (n = 69) in the phase 2 study.

Interventions

Patients were randomized 1:1 stratified by platinum-free interval (refractory, 0-6 months, 6-12 months) and prior weekly taxane treatment (yes, no) to receive alisertib 40 mg twice per day orally and 3 days on and 4 days off for 3 weeks, plus paclitaxel (60 mg/m2 intravenously, days 1, 8, and 15), or weekly paclitaxel 80 mg/m2 intravenously in 28-day cycles.

Main Outcomes and Measures

Primary endpoint was PFS; primary efficacy analysis and safety analysis used modified intention to treat (mITT) population (all randomized patients who received ≥1 dose of study drug).

Results

The median age for the 191 patients enrolled in phase 1 was 59 (range, 29-75) years. The median age for the 142 patients enrolled in phase 2 was 63 (range, 30-81) years for patients receiving alisertib plus paclitaxel and 61 (range, 41-81) years for patients receiving paclitaxel. At data cutoff, 107 (75%) patients had a documented PFS event; 52 (71%) in the alisertib plus paclitaxel arm, and 55 (80%) in the paclitaxel arm. Median PFS was 6.7 months with alisertib plus paclitaxel vs 4.7 months with paclitaxel (HR, 0.75; 80% CI, 0.58-0.96; P = .14; 2-sided P value cutoff = .20 to be considered worthy of further investigation). Drug-related grade 3 or higher adverse events were reported in 63 (86%) vs 14 (20%) patients in the alisertib plus paclitaxel and paclitaxel arms, including 56 (77%) vs 7 (10%) neutropenia, 18 (25%) vs 0 stomatitis, and 10 (14%) vs 2 (3%) anemia; 54 (74%) vs 17 (25%) had adverse events leading to dose reductions. Two patients died during the study (1 in each arm); neither death was considered related to study drug.

Conclusions and Relevance

The primary endpoint, PFS, significantly favored alisertib plus paclitaxel over paclitaxel alone. Further investigation is warranted.

Trial Registration

ClinicalTrials.gov identifier: NCT01091428.

Emerging biomarkers in ovarian granulosa cell tumors

OBJECTIVE

Although the majority of ovarian granulosa cell tumors can be successfully managed with surgery, a subset require chemotherapy for residual and recurrent disease. The benefit of chemotherapy in this population, however, remains controversial. There is therefore interest in the development of more tolerable and effective treatment options for advanced ovarian granulosa cell tumors. We report the use of immunohistochemistry to investigate how biomarkers could inform clinical trials in granulosa cell tumors with an emphasis on emerging androgen antagonistic, immunotherapeutic, and anti-angiogenic approaches.

METHODS

Immunohistochemistry for androgen receptor, the immune markers programmed cell death ligand 1, indoleamine-2,3 dioxygenase, and cluster of differentiation 8, and the vascular marker cluster of differentiation 31 were evaluated on formalin-fixed paraffin-embedded whole tissue sections from 29 cases of adult-type granulosa cell tumors. Results were evaluated with clinicopathologic variables including recurrence.

RESULTS

59% of granulosa cell tumors were androgen receptor-positive, suggesting a potential role for anti-androgen therapy in this tumor type. In contrast, the targetable immune modulatory molecules programmed cell death ligand 1 and indoleamine-2,3 dioxygenase were scarcely expressed, with no cases showing tumorous programmed cell death ligand 1 and a single case demonstrating very focal tumorous indoleamine-2,3 dioxygenase staining. A minority of cases expressed programmed cell death ligand 1 in occasional tumor-associated macrophages and indoleamine-2,3 dioxygenase in peritumoral vessels. Tumor-infiltrating cytotoxic T cells were also scarce in granulosa cell tumors, arguing against a significant role for immunotherapy in the absence of additional immunostimulation. Cluster of differentiation 31 immunostaining revealed a range of vascular densities across granulosa cell tumors, and future studies evaluating the role of vascular density as a predictor of response to angiogenesis inhibition are warranted. None of the biomarkers investigated were significantly correlated with recurrence, and the only clinicopathologic feature significantly correlated with outcome was stage at presentation.

CONCLUSIONS

Biomarker data suggest that many ovarian granulosa cell tumors could be candidates for anti-androgen therapy, while the potential role for immunotherapy appears more limited. Vascular density could be useful for identifying optimal candidates for angiogenesis inhibition. Incorporation of these biomarkers into clinical trials could help optimize patient selection.

Cervical cancer care in rural Virginia: The impact of distance from an academic medical center on outcomes & the role of non-specialized radiation centers

OBJECTIVE

To determine whether distance to a tertiary care facility affects outcomes for locally advanced cervical cancer and to evaluate the impact of receiving care at non-specialized centers in rural communities.

METHODS

Retrospective, single institution study of patients with locally advanced cervical cancer managed with chemo-radiation from January 1, 2000 to June 1, 2014. Kaplan-Meier survival curves and Cox proportional hazard models were used to compare progression free and overall survival for patients by median distance to the tertiary care facility (<72 miles or >72 miles) and facility where treatment was received.

RESULTS

180 patients met inclusion criteria. There was no difference in PFS or OS between the travel distance cohorts. When compared by location of external beam radiation, patients treated at outside facilities were older (p = 0.02) and significantly more likely to be insured (95.6% versus 71.7%, p < 0.0002). There were more recurrences among patients treated at outside facilities (31.1% versus 15.8%) but this was non-significant (p = 0.24). On multivariable analysis, FIGO stage and insurance status were associated with overall survival. Uninsured patients had a significantly increased hazard risk of death as compared to privately insured patients (HR 3.85 95% CI 3.07-4.64, p = 0.0008).

CONCLUSIONS

Median distance to a tertiary care facility had no significant impact on PFS or OS, however treating facility for radiation may influence recurrence rates. Having non-private insurance or being uninsured is significantly associated with increased risk of death and speaks to the many barriers these patients face.