Disparities in clinical trial enrollment at a Canadian comprehensive cancer center: A 15-year retrospective study

INTRODUCTION

Disparities in clinical trials (CTs) enrollment perpetuate inequities in treatment access and outcomes, but there is a paucity of Canadian data. The objective of this study was to examine disparities in cancer CT enrollment at a large Canadian comprehensive cancer center.

METHODS

Retrospective study of CT enrollment among new patient consultations from 2006 to 2019, with follow-up to 2021 (N = 154,880), with the primary outcome of enrollment as a binary variable. Factors associated with CT enrollment were evaluated using multivariable Bayesian hierarchical logistic regression with random effects for most responsible physician (MRP) and geography, adjusted for patient characteristics (sex, age, language, geography, and primary care provider [PCP]), area-level marginalization (residential instability, material deprivation, dependency, and ethnic concentration), disease (cancer site and stage), and MRP (department, sex, language, and training). A sensitivity analysis of the cumulative incidence of enrollment was conducted to account for differences in disease type and follow-up length.

RESULTS

CT enrollment was 11.2% overall, with a 15-year cumulative incidence of 18%. Lower odds of enrollment were observed in patients who were female (adjusted odds ratio [AOR], 0.82; 95% confidence interval [CI], 0.78-0.86), ≥65 years (AOR vs. <40, 0.61; 95% CI, 0.56-0.66), non-English speakers (0.72; 95% CI, 0.67-0.77), living ≥250 km away (AOR vs. <15 km, 0.71; 95% CI, 0.62-0.80), and without a PCP. Disease characteristics accounted for the largest proportion of observed variation (20.8%), with significantly greater odds of enrollment in patients with genitourinary cancers and late-stage disease.

CONCLUSION

Significant sociodemographic disparities were observed, suggesting the need for targeted strategies to increase diversity in access to cancer CTs in Canada.

Antibody-Drug Conjugates: Advancing from Magic Bullet to Biological Missile

Precision drug development is focusing on targeting tumor cell surface proteins for therapeutic delivery, maximizing biomarker identified on-target damage to the tumor while minimizing toxicity. A recent article demonstrated high expression of B7-H4 antigen on resistant ovarian cancer cells and described preclinical activity of B7-H4-directed antibody-drug conjugate. See related article by Gitto et al., p. 1567.

High grade adverse event reporting and enrolment in gynecologic oncology clinical trials

OBJECTIVE

The primary objective is to assess factors associated with treatment related high grade (CTCAE grade ≥ 3) adverse event (AE) reporting among participants in gynecologic oncology clinical trials.

METHODS

All AEs recorded in the Princess Margaret Clinical Trial adverse event database between 01/2016 and 12/2018 were evaluated. Gynecologic oncology clinical trials assessing systemic therapy were included. Inferential statistics on risk factors of related grade ≥ 3 adverse event reporting and GEE logistic models with Odds Ratios (OR) were performed. Multivariable analysis adjusting for age, clinical trial phase, sponsor, and therapy type.

RESULTS

The gynecology cancer clinical trials accrued 317 unique patients (359 nested on trials) in 42 systemic therapy trials. In the period, 17,175 related AEs were reported in the gynecological cancer trials, 7.4% were grade ≥ 3. On multivariable analysis, no odds differences of grade ≥ 3 related AEs were detected according to study phase. Patients in immunotherapy clinical trials had lower odds of related grade ≥ 3 AEs than patients on targeted or other therapy (adjusted OR [aOR] 0.43; 95% CI 0.24-0.75). There was greater odds of related grade ≥ 3 AEs in clinical trials assessing combination vs single therapeutics (aOR 2.26, 95% CI 1.34-3.80). Patients aged ≥65 (aOR 1.77; 95% CI 1.08-2.89) had greater odds of related grade ≥ 3 AEs than patients aged 50 to 65 years. When compared to other disease sites, the odds of having a grade  ≥ 3 related AE reported in gynecology clinical trials was no different.

CONCLUSIONS

In this cohort, factors influencing the odds of related grade ≥ 3 AE reporting in gynecologic trials included type of therapy and age. The study phase did not correlate with odds of high-grade AE reporting.

Methodical Manipulation of the TME in Ovarian Cancer

The complex interplay between ovarian cancer cells and the tumor microenvironment (TME) modulates progression, with dynamic cellular interactions influenced by external modulators, including neoadjuvant chemotherapy (NACT). A recent article described the alterations within the TME following NACT, either with or without bevacizumab, in ovarian cancer. See related article by Tavira et al., p. 176.

Heterogeneity and treatment landscape of ovarian carcinoma

Ovarian carcinoma is characterized by heterogeneity at the molecular, cellular and anatomical levels, both spatially and temporally. This heterogeneity affects response to surgery and/or systemic therapy, and also facilitates inherent and acquired drug resistance. As a consequence, this tumour type is often aggressive and frequently lethal. Ovarian carcinoma is not a single disease entity and comprises various subtypes, each with distinct complex molecular landscapes that change during progression and therapy. The interactions of cancer and stromal cells within the tumour microenvironment further affects disease evolution and response to therapy. In past decades, researchers have characterized the cellular, molecular, microenvironmental and immunological heterogeneity of ovarian carcinoma. Traditional treatment approaches have considered ovarian carcinoma as a single entity. This landscape is slowly changing with the increasing appreciation of heterogeneity and the recognition that delivering ineffective therapies can delay the development of effective personalized approaches as well as potentially change the molecular and cellular characteristics of the tumour, which might lead to additional resistance to subsequent therapy. In this Review we discuss the heterogeneity of ovarian carcinoma, outline the current treatment landscape for this malignancy and highlight potentially effective therapeutic strategies in development.

Molecular Results and Potential Biomarkers Identified from the Phase 3 MILO/ENGOT-ov11 Study of Binimetinib versus Physician Choice of Chemotherapy in Recurrent Low-Grade Serous Ovarian Cancer

PURPOSE

We present the results of a post hoc tumor tissue analysis from the phase 3 MILO/ENGOT-ov11 study (NCT01849874).

PATIENTS AND METHODS

Mutation/copy-number analysis was performed on tissue obtained pre-randomization. The Kaplan-Meier method was used to estimate progression-free survival (PFS). Unbiased univariate analysis, Cox regression, and binary logistic regression were used to test associations between mutation status and outcomes, including PFS and binary response by local RECIST 1.1.

RESULTS

MILO/ENGOT-ov11 enrolled 341 patients, ranging in age from 22 to 79, from June, 2013 to April, 2016. Patients were randomized 2:1 to binimetinib or physician's choice of chemotherapy (PCC). The most commonly altered gene was KRAS (33%). In 135 patients treated with binimetinib with response rate (RR) data, other detected MAPK pathway alterations included: NRAS (n = 11, 8.1%), BRAF V600E (n = 8, 5.9%), RAF1 (n = 2, 1.5%), and NF1 (n = 7, 5.2%). In those with and without MAPK pathway alterations, the RRs with binimetinib were 41% and 13%, respectively. PFS was significantly longer in patients with, compared with those without, MAPK pathway alterations treated with binimetinib [HR, 0.5; 95% confidence interval (CI) 0.31-0.79]. There was a nonsignificant trend toward PFS improvement in PCC-treated patients with MAPK pathway alterations compared with those without (HR, 0.82; 95% CI, 0.43-1.59).

CONCLUSIONS

Although this hypothesis-generating analysis is limited by multiple testing, higher RRs and longer PFS were seen in patients with low-grade serous ovarian cancer (LGSOC) treated with binimetinib, and to a lesser extent in those treated with PCC, who harbored MAPK pathway alterations. Somatic tumor testing should be routinely considered in patients with LGSOC and used as a future stratification factor.

First-in-human Study of AZD5153, A Small-molecule Inhibitor of Bromodomain Protein 4, in Patients with Relapsed/Refractory Malignant Solid Tumors and Lymphoma

AZD5153, a reversible, bivalent inhibitor of the bromodomain and extraterminal family protein BRD4, has preclinical activity in multiple tumors. This first-in-human, phase I study investigated AZD5153 alone or with olaparib in patients with relapsed/refractory solid tumors or lymphoma. Adults with relapsed tumors intolerant of, or refractory to, prior therapies received escalating doses of oral AZD5153 once daily or twice daily continuously (21-day cycles), or AZD5153 once daily/twice daily continuously or intermittently plus olaparib 300 mg twice daily, until disease progression or unacceptable toxicity. Between June 30, 2017 and April 19, 2021, 34 patients received monotherapy and 15 received combination therapy. Dose-limiting toxicities were thrombocytopenia/platelet count decreased (n = 4/n = 2) and diarrhea (n = 1). The recommended phase II doses (RP2D) were AZD5153 30 mg once daily or 15 mg twice daily (monotherapy) and 10 mg once daily (intermittent schedule) with olaparib. With AZD5153 monotherapy, common treatment-emergent adverse events (TEAE) included fatigue (38.2%), thrombocytopenia, and diarrhea (each 32.4%); common grade ≥ 3 TEAEs were thrombocytopenia (14.7%) and anemia (8.8%). With the combination, common TEAEs included nausea (66.7%) and fatigue (53.3%); the most common grade ≥ 3 TEAE was thrombocytopenia (26.7%). AZD5153 had dose-dependent pharmacokinetics, with minimal accumulation, and demonstrated dose-dependent modulation of peripheral biomarkers, including upregulation of HEXIM1. One patient with metastatic pancreatic cancer receiving combination treatment had a partial response lasting 4.2 months. These results show AZD5153 was tolerable as monotherapy and in combination at the RP2Ds; common toxicities were fatigue, hematologic AEs, and gastrointestinal AEs. Strong evidence of peripheral target engagement was observed.

Treatment of Ovarian Cancer Beyond PARP Inhibition: Current and Future Options

Ovarian cancer is the leading cause of gynecological cancer death. Improved understanding of the biologic pathways and introduction of poly (ADP-ribose) polymerase inhibitors (PARPi) during the last decade have changed the treatment landscape. This has improved outcomes, but unfortunately half the women with ovarian cancer still succumb to the disease within 5 years of diagnosis. Pathways of resistance to PARPi and chemotherapy have been studied extensively, but there is an unmet need to overcome treatment failure and improve outcome. Major mechanisms of PARPi resistance include restoration of homologous recombination repair activity, alteration of PARP function, stabilization of the replication fork, drug efflux, and activation of alternate pathways. These resistant mechanisms can be targeted to sensitize the resistant ovarian cancer cells either by rechallenging with PARPi, overcoming resistance mechanism or bypassing resistance pathways. Augmenting the PARPi activity by combining it with other targets in the DNA damage response pathway, antiangiogenic agents and immune checkpoint inhibitors can potentially overcome the resistance mechanisms. Methods to bypass resistance include targeting non-cross-resistant pathways acting independent of homologous recombination repair (HRR), modulating tumour microenvironment, and enhancing drug delivery systems such as antibody drug conjugates. In this review, we will discuss the first-line management of ovarian cancer, resistance mechanisms and potential strategies to overcome these.

Identifying Mechanisms of Resistance by Circulating Tumor DNA in EVOLVE, a Phase II Trial of Cediranib Plus Olaparib for Ovarian Cancer at Time of PARP Inhibitor Progression

PURPOSE

To evaluate the use of blood cell-free DNA (cfDNA) to identify emerging mechanisms of resistance to PARP inhibitors (PARPi) in high-grade serous ovarian cancer (HGSOC).

EXPERIMENTAL DESIGN

We used targeted sequencing (TS) to analyze 78 longitudinal cfDNA samples collected from 30 patients with HGSOC enrolled in a phase II clinical trial evaluating cediranib (VEGF inhibitor) plus olaparib (PARPi) after progression on PARPi alone. cfDNA was collected at baseline, before treatment cycle 2, and at end of treatment. These were compared with whole-exome sequencing (WES) of baseline tumor tissues.

RESULTS

At baseline (time of initial PARPi progression), cfDNA tumor fractions were 0.2% to 67% (median, 3.25%), and patients with high ctDNA levels (>15%) had a higher tumor burden (sum of target lesions; P = 0.043). Across all timepoints, cfDNA detected 74.4% of mutations known from prior tumor WES, including three of five expected BRCA1/2 reversion mutations. In addition, cfDNA identified 10 novel mutations not detected by WES, including seven TP53 mutations annotated as pathogenic by ClinVar. cfDNA fragmentation analysis attributed five of these novel TP53 mutations to clonal hematopoiesis of indeterminate potential (CHIP). At baseline, samples with significant differences in mutant fragment size distribution had shorter time to progression (P = 0.001).

CONCLUSIONS

Longitudinal testing of cfDNA by TS provides a noninvasive tool for detection of tumor-derived mutations and mechanisms of PARPi resistance that may aid in directing patients to appropriate therapeutic strategies. With cfDNA fragmentation analyses, CHIP was identified in several patients and warrants further investigation.

Assessment of Homologous Recombination Deficiency in Ovarian Cancer

Accurately assessing homologous recombination deficiency (HRD) to use as a predictive biomarker is an area of intense research in ovarian cancer. Validated assays have demonstrated utility in determining maintenance therapy following platinum sensitive chemotherapy. Novel functional assays promise the potential to reflect HRD in real time and predict response to PARP inhibitors. See related articles by Pikkusaari et al., p. 3110 and Blanc-Durand et al., p. 3124.

A phase I study of the Wee1 kinase inhibitor adavosertib (AZD1775) in combination with chemoradiation in cervical, upper vaginal, and uterine cancers

OBJECTIVE

Wee1 kinase is a crucial regulator of the G2/M checkpoint which prevents entry of damaged DNA into mitosis. Adavosertib (AZD1775), a selective inhibitor of Wee1, induces G2 escape and increases cytotoxicity when combined with DNA damaging agents. We aimed to evaluate the safety and efficacy of adavosertib in combination with definitive pelvic radiotherapy and concurrent cisplatin in patients with gynecological cancers.

METHODS

A multi-institutional, open-label phase I trial was designed to assess dose escalation (3+3 design) of adavosertib in combination with standard chemoradiation. Eligible patients with locally advanced cervical, endometrial or vaginal tumors were treated with a 5-week course of pelvic external beam radiation 45-50 Gy in 1.8-2 Gy daily fractions plus concurrent weekly cisplatin 40 mg/m2 and adavosertib 100 mg/m2 on days 1, 3 and 5 of each week during chemoradiation. The primary endpoint was to determine the recommended phase II dose of adavosertib. Secondary endpoints included toxicity profile and preliminary efficacy.

RESULTS

Ten patients were enrolled (nine locally advanced cervical and one endometrial cancer). Two patients experienced a dose-limiting toxicity at dose level 1 (adavosertib 100 mg by mouth daily on days 1, 3 and 5), including one patient with grade 4 thrombocytopenia, and one with treatment hold >1 week due to grade 1 creatinine elevation and grade 1 thrombocytopenia. At dose level -1 (adavosertib 100 mg by mouth daily on days 3 and 5), one out of five patients enrolled had a dose-limiting toxicity in the form of persistent grade 3 diarrhea. The overall response rate at 4 months was 71.4%, including four complete responses. At 2 years follow-up, 86% of patients were alive and progression-free.

CONCLUSION

The recommended phase II dose could not be determined due to clinical toxicity and early trial closure. Preliminary efficacy appears promising, yet selecting the adequate dose/schedule in combination chemoradiation warrants further investigation to limit overlapping toxicities.

Mirvetuximab Soravtansine in Platinum-Resistant Ovarian Cancer

Ovarian cancer is the second leading cause of death from gynecologic malignancies worldwide. Management of platinum-resistant disease is challenging and clinical outcomes with standard chemotherapy are poor. Over the past decades, significant efforts have been made to understand drug resistance and develop strategies to overcome treatment failure. Antibody drug conjugates (ADCs) are a rapidly growing class of oncologic therapeutics, which combine the ability to target tumor-specific antigens with the cytotoxic effects of chemotherapy. Mirvetuximab soravtansine is an ADC comprising an IgG1 monoclonal antibody against the folate receptor alpha (FRα) conjugated to the cytotoxic maytansinoid effector molecule DM4 that has shown promising clinical activity in patients with FR-α-positive ovarian cancer. This review summarizes current evidence of mirvetuximab soravtansine in platinum-resistant ovarian cancer, focusing on clinical activity, toxicity, and future directions.

An Attempt to Stretch the Benefit: Rechallenge with PARP Inhibitors in Ovarian Cancer

PARP inhibitors exploit synthetic lethality in homologous recombination-deficient (HDR) cells and are standard-of-care treatment in newly diagnosed and relapsed epithelial ovarian cancer (EOC). A recent article demonstrated that a second course of olaparib can be safely administered to women with BRCA-mutated EOC. See related article by Morgan et al., p. 2602.

Symptom screening with Targeted Early Palliative care (STEP) versus usual care for patients with advanced cancer: a mixed methods study

PURPOSE

Although early palliative care is recommended, resource limitations prevent its routine implementation. We report on the preliminary findings of a mixed methods study involving a randomized controlled trial (RCT) of Symptom screening with Targeted Early Palliative care (STEP) and qualitative interviews.

METHODS

Adults with advanced solid tumors and an oncologist-estimated prognosis of 6-36 months were randomized to STEP or symptom screening alone. STEP involved symptom screening at each outpatient oncology visit; moderate to severe scores triggered an email to a palliative care nurse, who offered referral to in-person outpatient palliative care. Patient-reported outcomes of quality of life (FACT-G7; primary outcome), depression (PHQ-9), symptom control (ESAS-r-CS), and satisfaction with care (FAMCARE P-16) were measured at baseline and 2, 4, and 6 months. Semi-structured interviews were conducted with a subset of participants.

RESULTS

From Aug/2019 to Mar/2020 (trial halted due to COVID-19 pandemic), 69 participants were randomized to STEP (n = 33) or usual care (n = 36). At 6 months, 45% of STEP arm patients and 17% of screening alone participants had received palliative care (p = 0.009). Nonsignificant differences for all outcomes favored STEP: difference in change scores for FACT-G7 = 1.67 (95% CI: -1.43, 4.77); ESAS-r-CS = -5.51 (-14.29, 3.27); FAMCARE P-16 = 4.10 (-0.31, 8.51); PHQ-9 = -2.41 (-5.02, 0.20). Sixteen patients completed qualitative interviews, describing symptom screening as helpful to initiate communication; triggered referral as initially jarring but ultimately beneficial; and referral to palliative care as timely.

CONCLUSION

Despite lack of power for this halted trial, preliminary results favored STEP and qualitative results demonstrated acceptability. Findings will inform an RCT of combined in-person and virtual STEP.

Chasing Immune Checkpoint Inhibitors in Ovarian Cancer: Novel Combinations and Biomarker Discovery

A deep understanding of the tumor microenvironment and the recognition of tumor-infiltrating lymphocytes as a prognostic factor have resulted in major milestones in immunotherapy that have led to therapeutic advances in treating many cancers. Yet, the translation of this knowledge to clinical success for ovarian cancer remains a challenge. The efficacy of immune checkpoint inhibitors as single agents or combined with chemotherapy has been unsatisfactory, leading to the exploration of alternative combination strategies with targeted agents (e.g., poly-ADP-ribose inhibitors (PARP)and angiogenesis inhibitors) and novel immunotherapy approaches. Among the different histological subtypes, clear cell ovarian cancer has shown a higher sensitivity to immunotherapy. A deeper understanding of the mechanism of immune resistance within the context of ovarian cancer and the identification of predictive biomarkers remain central discovery benchmarks to be realized. This will be critical to successfully define the precision use of immune checkpoint inhibitors for the treatment of ovarian cancer.

Emerging peptide therapeutics for the treatment of ovarian cancer

INTRODUCTION

The discovery of therapeutic proteomic targets has resulted in remarkable advances in oncology. Identification of functional and hallmark peptides in ovarian cancer can be leveraged for diagnostic and therapeutic targeting. These targets are expressed in different tumor cell locations, making them excellent candidates for theranostic imaging, precision therapeutics, and immunotherapy. The ideal target is homogeneously overexpressed in malignant cells with no expression in healthy cells, thereby avoiding off-tumor bystander toxicity. Several peptides are currently undergoing extensive evaluation for the development of vaccines, antibody-drug conjugates, monoclonal antibodies, radioimmunoconjugates, and cell therapy.

AREAS COVERED

This review focuses on the significance of peptides as promising targets in ovarian cancer. English peer-reviewed articles and abstracts were searched in MEDLINE, PubMed, Embase, and major conference databases.

EXPERT OPINION

Peptides and proteins expressed in tumor cells are an exciting area of research with great potential and may significantly influence precision therapeutics and immunotherapeutic strategies. Accurate utilization of peptide expression as a predictive biomarker has the potential to greatly enhance treatment precision. The ability to measure receptor expression paves the way for its use as a predictive biomarker for therapeutic targeting and requires critical validation of sensitivity and specificity for each indication to guide therapy.

Maveropepimut-S, a DPX-based immune-educating therapy, shows promising and durable clinical benefit in patients with recurrent ovarian cancer, a phase 2 trial

PURPOSE

Patients with platinum resistant ovarian cancer (OvCa) respond poorly to existing therapies. Hence there is a need for more effective treatments.

METHODS

The DeCidE1 trial is a multicenter, randomized, open-label, single-arm phase 2 study to evaluate the safety and effectiveness of maveropepimut-S (MVP-S) with cyclophosphamide (CPA) in patients with recurrent ovarian cancer. Median follow-up for evaluable subjects was 4.4 months. Data were collected from March 2019 to June 2021. Subjects received two injections of 0.25 mL MVP-S 3 weeks apart, followed by one 0.1 mL doses, every 8 weeks up to progression. Oral CPA, 50 mg twice daily, was administered in repeating weekly on and off cycles.

RESULTS

Twenty-two patients were enrolled. Median age was 58 years (38-78 years). Among the evaluable population, ORR was 21% (90% CI, 7.5%-41.9%), with a DCR of 63% (90% CI, 41.8%-81.3%), including 4 (21%) patients with partial responses, 8 (42%) stable disease, and 7 (37%) progressive disease. The ORRs were consistent across subgroups based on platinum-sensitivity, and DCR was higher in the platinum-resistant subpopulation. Four stable disease patients maintained clinical benefit up to 25 months. Most treatment related adverse events (TRAEs) were grade 1 and 2 (87% of unique events). Most common AEs were injection site reactions. Eight subjects reported grade 3 and no grade 4 AEs. Survivin-specific T cell responses were observed in treated patients with clinical benefit.

CONCLUSIONS

MVP-S with intermittent low-dose CPA is well-tolerated, with clinical benefit for patients with recurrent OvCa. Observed responses are irrespective of the platinum status.

Clinical outcome and biomarker assessments of a multi-centre phase II trial assessing niraparib with or without dostarlimab in recurrent endometrial carcinoma

This multi-centre, non-randomized, open-label, phase II trial (NCT03016338), assessed niraparib monotherapy (cohort 1, C1), or niraparib and dostarlimab (cohort 2, C2) in patients with recurrent serous or endometrioid endometrial carcinoma. The primary endpoint was clinical benefit rate (CBR), with ≥5/22 overall considered of interest. Secondary outcomes were safety, objective response rate (ORR), duration of response, progression free survival and overall survival. Translational research was an exploratory outcome. Potential biomarkers were evaluated in archival tissue by immunohistochemistry and next generation sequencing panel. In C1, 25 patients were enrolled, and CBR was 20% (95% CI: 9-39) with median clinical benefit duration of 5.3 months. The ORR was 4% (95% CI: 0-20). In C2, 22 patients were enrolled, and the CBR was 31.8% (95% CI: 16-53) with median clinical benefit duration of 6.8 months. The ORR was 14% (95% CI: 3-35). No new safety signals were detected. No significant association was detected between clinical benefit and IHC markers (PTEN, p53, MMR, PD-L1), or molecular profiling (PTEN, TP53, homologous recombination repair genes). In conclusion, niraparib monotherapy did not meet the efficacy threshold. Niraparib in combination with dostarlimab showed modest activity.

Inhibition of nicotinamide dinucleotide salvage pathway counters acquired and intrinsic poly(ADP-ribose) polymerase inhibitor resistance in high-grade serous ovarian cancer

Epithelial ovarian cancer is the most lethal gynecological malignancy, owing notably to its high rate of therapy-resistant recurrence in spite of good initial response to chemotherapy. Although poly(ADP-ribose) polymerase inhibitors (PARPi) have shown promise for ovarian cancer treatment, extended therapy usually leads to acquired PARPi resistance. Here we explored a novel therapeutic option to counter this phenomenon, combining PARPi and inhibitors of nicotinamide phosphoribosyltransferase (NAMPT). Cell-based models of acquired PARPi resistance were created through an in vitro selection procedure. Using resistant cells, xenograft tumors were grown in immunodeficient mice, while organoid models were generated from primary patient tumor samples. Intrinsically PARPi-resistant cell lines were also selected for analysis. Our results show that treatment with NAMPT inhibitors effectively sensitized all in vitro models to PARPi. Adding nicotinamide mononucleotide, the resulting NAMPT metabolite, abrogated the therapy-induced cell growth inhibition, demonstrating the specificity of the synergy. Treatment with olaparib (PARPi) and daporinad (NAMPT inhibitor) depleted intracellular NAD+ , induced double-strand DNA breaks, and promoted apoptosis as monitored by caspase-3 cleavage. The two drugs were also synergistic in mouse xenograft models and clinically relevant patient-derived organoids. Therefore, in the context of PARPi resistance, NAMPT inhibition could offer a promising new option for ovarian cancer patients.

Molecular Monitoring in Endometrial Cancer-Ready for Prime Time?

SUMMARY

Efforts are under way to define the role of minimally invasive strategies for molecular monitoring and risk stratification in endometrial cancer. A recent publication aims to define the association between circulating tumor DNA level and disease stage in patients with newly diagnosed endometrial cancer and determine whether sequencing of longitudinal cell-free DNA samples can be used for disease monitoring and detection of progression or recurrence. These results accelerate the current knowledge of molecular follow-up in endometrial cancer. See related article by Ashley et al., p. 410.

Management of Malignant Bowel Obstruction: An Innovative Proactive Outpatient Nurse-Led Model of Care for Patients With Advanced Gynecologic Cancer

BACKGROUND

Malignant bowel obstruction (MBO) in patients with advanced gynecologic cancer (GyCa) can negatively impact clinical outcomes and quality of life. Oncology nurses can support these patients with adequate tools/processes.

PROBLEM

Patients with GyCa with/at risk of MBO endure frequent emergency or hospital admissions, impacting patient care.

APPROACH

Optimizing oncology nurses' role to improve care for patients with GyCa with/at risk of MBO, the gynecology oncology interprofessional team collaborated to develop a proactive outpatient nurse-led MBO model of care (MOC).

OUTCOMES

The MBO MOC involves a risk-based algorithm engaging interdisciplinary care, utilizing standardized tools, risk-based assessment, management, and education for patients and nurses. The MOC has improved patient-reported confidence level of bowel self-management and decreased hospitalization. Following education, nurses demonstrated increased knowledge in MBO management.

CONCLUSIONS

An outpatient nurse-led MBO MOC can improve patient care and may be extended to other cancer centers, fostering collaboration and best practice.

Clinical and molecular characteristics of ARIEL3 patients who derived exceptional benefit from rucaparib maintenance treatment for high-grade ovarian carcinoma

OBJECTIVE

ARIEL3 (NCT01968213) is a placebo-controlled randomized trial of the poly(ADP-ribose) polymerase inhibitor rucaparib as maintenance treatment in patients with recurrent high-grade ovarian carcinoma who responded to their latest line of platinum therapy. Rucaparib improved progression-free survival across all predefined subgroups. Here, we present an exploratory analysis of clinical and molecular characteristics associated with exceptional benefit from rucaparib.

METHODS

Patients were randomized 2:1 to receive rucaparib 600 mg twice daily or placebo. Molecular features (genomic alterations, BRCA1 promoter methylation) and baseline clinical characteristics were evaluated for association with exceptional benefit (progression-free survival ≥2 years) versus progression on first scan (short-term subgroup) and other efficacy outcomes.

RESULTS

Rucaparib treatment was significantly associated with exceptional benefit compared with placebo: 79/375 (21.1%) vs 4/189 (2.1%), respectively (p < 0.0001). Exceptional benefit was more frequent among patients with favorable baseline clinical characteristics and with carcinomas harboring molecular evidence of homologous recombination deficiency (HRD). A comparison between patients who derived exceptional benefit from rucaparib and those in the short-term subgroup revealed both clinical markers (no measurable disease at baseline, complete response to latest platinum, longer penultimate platinum-free interval) and molecular markers (BRCA1, BRCA2, RAD51C, and RAD51D alterations and genome-wide loss of heterozygosity) significantly associated with exceptional benefit.

CONCLUSIONS

Exceptional benefit in ARIEL3 was more common in, but not exclusive to, patients with favorable clinical characteristics or molecular features associated with HRD. Our results suggest that rucaparib can deliver exceptional benefit to a diverse set of patients with recurrent high-grade ovarian carcinoma.

Ad hoc Analysis of the Phase III ENGOT-OV16/NOVA Study: Niraparib Efficacy in Germline BRCA Wild-type Recurrent Ovarian Cancer with Homologous Recombination Repair Defects

In this analysis, we examined the relationship between progression-free survival (PFS) and mutation status of 18 homologous recombination repair (HRR) genes in patients in the non-germline BRCA-mutated (non-gBRCAm) cohort of the ENGOT-OV16/NOVA trial (NCT01847274), which evaluated niraparib maintenance therapy for patients with recurrent ovarian cancer. This post hoc exploratory biomarker analysis was performed using tumor samples collected from 331 patients enrolled in the phase III ENGOT-OV16/NOVA trial's non-gBRCAm cohort. Niraparib demonstrated PFS benefit in patients with either somatic BRCA-mutated (sBRCAm; HR, 0.27; 95% confidence interval, CI, 0.08–0.88) or BRCA wild-type (BRCAwt; HR, 0.47; 95% CI, 0.34–0.64) tumors. Patients with BRCAwt tumors with other non-BRCA HRR mutations also derived benefit from niraparib (HR, 0.31; 95% CI, 0.13–0.77), as did patients with BRCAwt/HRRwt (HRR wild-type) tumors (HR, 0.49; 95% CI, 0.35–0.70). When patients with BRCAwt/HRRwt tumors were further categorized by genomic instability score (GIS), clinical benefit was observed in patients with homologous recombination–deficient (GIS ≥ 42; HR, 0.33; 95% CI, 0.18–0.61) and in patients with homologous recombination–proficient (HRp; GIS &lt; 42; HR, 0.60; 95% CI, 0.36–0.99) disease. Although patients with sBRCAm, other non-BRCA HRR mutations, or GIS ≥ 42 benefited the most from niraparib treatment, PFS benefit was also seen in HRp (GIS &lt; 42) patients without HRR mutations. These results support the use of niraparib in patients with recurrent ovarian cancer regardless of BRCA/HRR mutation status or myChoice CDx GIS.

Significance:

We retrospectively evaluated the mutational profile of HRR genes in tumor samples from 331 patients from the non-germline BRCA-mutated cohort of the phase III NOVA trial of patients with platinum-sensitive high-grade serous ovarian cancer. Patients with non-BRCA HRR mutations generally benefited from second-line maintenance treatment with niraparib compared with placebo.

Patient self-reporting of tolerability using PRO-CTCAE in a randomized double-blind, placebo-controlled phase II trial comparing gemcitabine in combination with adavosertib or placebo in patients with platinum resistant or refractory epithelial ovarian carcinoma

BACKGROUND

A double-blind, randomized, placebo-controlled, phase 2 trial assessed gemcitabine in combination with the wee1 inhibitor adavosertib or placebo in platinum resistant or refractory high grade serous ovarian cancer (HGSOC), demonstrating improved progression free and overall survival favouring the adavosertib/gemcitabine arm. An exploratory objective of the study included the PRO-CTCAE assessment, to capture self-reporting of frequency, severity and/or interference of symptomatic adverse events (syAEs).

METHODS

PRO-CTCAE items at baseline, days 1 and 15 of each cycle and off treatment, were completed in two centres, with the objective of characterizing syAEs in the first three months of therapy. The maximum post-baseline score proportion for each syAE was tabulated per patient. The 12-week area under the curve (AUC12w) as a measure of syAE over-time and incremental AUC12w (iAUC12w) for adjustment to baseline syAEs.

RESULTS

Sixty-one patients were approached for PRO-CTCAE surveys and 55 were evaluable. Among patients with HGSOC, 28 received gemcitabine/adavosertib (arm A) and 19 gemcitabine/placebo (arm B). Survey completion rates were high. The proportion of participants with positive (≥1) PRO-CTCAE scores was higher for difficulty swallowing with gemcitabine/adavosertib (arm A 35.7% vs arm B 5.3%, p = 0.02). The high score (≥3) syAEs showed more frequent diarrhea with gemcitabine/adavosertib (arm A 25% vs arm B 0%, p = 0.03). The proportions of worsening syAEs over time were higher in patients receiving gemcitabine/adavosertib for difficulty swallowing (arm A 35.7% vs arm B 5.3%; p = 0.03) and fatigue severity (arm A 71.43% vs arm B 42.1%; p = 0.04).

CONCLUSIONS

The longitudinal assessment of patient self-reported tolerability showed greater difficulty swallowing and fatigue severity in patients receiving gemcitabine/adavosertib, compared to gemcitabine/placebo. PRO-CTCAE provides complementary and objective assessment of drug tolerability from a patient's perspective.

Taking the Road Less Traveled: Following Molecular Trail Markers

Targeted therapy largely remains an unmet therapeutic need for low-grade serous ovarian carcinomas. However, recent advances in molecular characterization are beginning to change the landscape. A recent article highlights the association of genetic alterations with clinical outcomes, widening the scope of novel targeted therapies. See related article by Manning-Geist et al., p. 4456.

Clinical research in ovarian cancer: consensus recommendations from the Gynecologic Cancer InterGroup

The Gynecologic Cancer InterGroup (GCIG) sixth Ovarian Cancer Conference on Clinical Research was held virtually in October, 2021, following published consensus guidelines. The goal of the consensus meeting was to achieve harmonisation on the design elements of upcoming trials in ovarian cancer, to select important questions for future study, and to identify unmet needs. All 33 GCIG member groups participated in the development, refinement, and adoption of 20 statements within four topic groups on clinical research in ovarian cancer including first line treatment, recurrent disease, disease subgroups, and future trials. Unanimous consensus was obtained for 14 of 20 statements, with greater than 90% concordance in the remaining six statements. The high acceptance rate following active deliberation among the GCIG groups confirmed that a consensus process could be applied in a virtual setting. Together with detailed categorisation of unmet needs, these consensus statements will promote the harmonisation of international clinical research in ovarian cancer.

Double Trouble: Whole-Genome Doubling Distinguishes Early from Late Ovarian Cancer

Dramatic differences in outcome between early- and late-stage high-grade serous ovarian cancer (HGSC) suggest perhaps distinct genetic origins due to differences in exposures to mutational processes. Evidence to support this hypothesis was recently reported by comparative analysis of copy-number signatures between early- and late-stage HGSCs. See related article by Cheng et al., p. 2911.

Efficacy of subsequent chemotherapy for patients with BRCA1/2-mutated recurrent epithelial ovarian cancer progressing on olaparib versus placebo maintenance: post-hoc analyses of the SOLO2/ENGOT Ov-21 trial

BACKGROUND

In the SOLO2 trial (ENGOT Ov-21; NCT01874353), maintenance olaparib in patients with platinum-sensitive relapsed ovarian cancer (PSROC) and BRCA mutation significantly improved progression-free survival (PFS) and prolonged overall survival (OS). Following disease progression on olaparib, efficacy of subsequent chemotherapy remains unknown.

PATIENTS AND METHODS

We conducted a post-hoc hypothesis-generating analysis of SOLO2 data to determine the efficacy of different chemotherapy regimens following RECIST disease progression in patients who received olaparib or placebo. We evaluated time to second progression (TTSP) calculated from the date of RECIST progression to the next progression/death.

RESULTS

The study population comprised 147 patients who received chemotherapy as their first subsequent treatment after RECIST progression. Of these, 69 (47%) and 78 (53%) were originally randomized to placebo and olaparib arms, respectively. In the placebo-treated cohort, 27/69 and 42/69 received non-platinum and platinum-based chemotherapy, respectively, compared with 24/78 and 54/78, respectively, in the olaparib-treated cohort. Among patients treated with chemotherapy (N = 147), TTSP was significantly longer in the placebo than in the olaparib arm: 12.1 versus 6.9 months [hazard ratio (HR) 2.17, 95% confidence interval (CI) 1.47-3.19]. Similar result was obtained on multivariable analysis adjusting for prognostic factors at RECIST progression (HR 2.13, 95% CI 1.41-3.22). Among patients treated with platinum-based chemotherapy (n = 96), TTSP was significantly longer in the placebo arm: 14.3 versus 7.0 months (HR 2.89, 95% CI 1.73-4.82). Conversely, among patients treated with non-platinum-based chemotherapy (n = 51), the TTSP was comparable in the placebo and olaparib arms: 8.3 versus 6.0 months (HR 1.58, 95% CI 0.86-2.90).

CONCLUSIONS

Following progression from maintenance olaparib in the recurrent setting, the efficacy of platinum-based subsequent chemotherapy seems to be reduced in BRCA1/2-mutated patients with PSROC compared to patients not previously receiving poly (ADP-ribose) polymerase inhibitors (PARPi). The optimal strategy for patients who relapse after PARPi is an area of ongoing research.

A Pan-Canadian Consensus Statement on First-Line PARP Inhibitor Maintenance for Advanced, High-Grade Serous and Endometrioid Tubal, Ovarian, and Primary Peritoneal Cancers

The majority of patients with advanced, high-grade epithelial-tubo ovarian cancer (EOC) respond well to initial treatment with platinum-based chemotherapy; however, up to 80% of patients will experience a recurrence. Poly(ADP-ribose) Polymerase (PARP) inhibitors have been established as a standard of care maintenance therapy to prolong remission and prevent relapse following a response to first-line platinum-chemotherapy. Olaparib and niraparib are the PARP inhibitors currently approved for use in the first-line maintenance setting in Canada. Selection of maintenance therapy requires consideration of patient and tumour factors, presence of germline and somatic mutations, expected drug toxicity profile, and treatment access. This paper discusses the current clinical evidence for first-line PARP inhibitor maintenance therapy in patients with advanced, high-grade EOC and presents consensus statements and a treatment algorithm to aid Canadian oncologists on the selection and use of PARP inhibitors within the Canadian EOC treatment landscape.

Measure of Ovarian Symptoms and Treatment concerns (MOST) indexes and their associations with health-related quality of life in recurrent ovarian cancer

PURPOSE

The Measure of Ovarian Symptoms and Treatment (MOST) concerns is a validated patient-reported symptom assessment tool for assessing symptom benefit and adverse effects of palliative chemotherapy in women with recurrent ovarian cancer (ROC). We aimed to examine (i) how symptoms within MOST symptom indexes track together (i.e. co-occur) and (ii) the association between MOST symptom indexes and key aspects of health-related quality of life (HRQL).

METHOD

A prospective cohort of women with ROC completed the MOST-T35, EORTC QLQ-C30 and EORTC QLQ-OV28 at baseline and before each cycle of chemotherapy. Analyses were conducted on baseline and end-of-treatment data. Exploratory factor analysis and hierarchical cluster analysis identified groups of co-occurring symptoms. Path models examined associations between MOST symptom indexes and HRQL.

RESULTS

Data from 762 women at baseline and 681 at treatment-end who completed all 22 symptom-specific MOST items and at least one HRQL measure were analysed. Four symptom clusters emerged at baseline and treatment-end: abdominal symptoms, symptoms associated with peripheral neuropathy, nausea and vomiting, and psychological symptoms. Psychological symptoms (MOST-Psych) and symptoms due to disease (ovarian cancer) or treatment (MOST-DorT) were associated with poorer scores on QLQ-C30 and OV28 functioning domains and worse overall health at both time points.

CONCLUSION

Four MOST symptom clusters were consistent across statistical methods and time points. These findings suggest that routine standardized assessment of psychological and physical symptoms in clinical practice with MOST plus appropriate symptom management referral pathways is an intervention for improving HRQL that warrants further research.

ATHENA–MONO (GOG-3020/ENGOT-ov45): A randomized, double-blind, phase 3 trial evaluating rucaparib monotherapy versus placebo as maintenance treatment following response to first-line platinum-based chemotherapy in ovarian cancer

LBA5500

Background: While PARP inhibitors have shown efficacy as first-line (1L) maintenance treatment for patients (pts) with ovarian cancer (OC), questions remain about the pt population that may benefit from their use. ATHENA (NCT03522246) was designed to test if rucaparib may be effective as 1L maintenance treatment in a broad pt population, including those without BRCA mutations or other evidence of homologous recombination deficiency (HRD), or high-risk clinical characteristics such as residual disease. Here we report results from the ATHENA–MONO comparison of rucaparib vs placebo. Methods: Pts with stage III–IV high-grade OC who had completed cytoreductive surgery (R0 permitted) and 4–8 cycles of 1L platinum-doublet (bevacizumab allowed with chemotherapy) with a response were randomized 4:1 to oral rucaparib 600 mg BID or placebo. Pts were stratified by HRD status (as determined by FoundationOne CDx), residual disease status after chemotherapy, and timing of surgery. The primary endpoint of investigator-assessed PFS per RECIST was assessed in a step-down procedure first in the HRD population (BRCA mutant or BRCA wild-type/loss of heterozygosity [LOH] high carcinoma) and then in the intent-to-treat (ITT) population. Blinded independent central review (BICR)–assessed PFS was a stand-alone, secondary endpoint. PFS in BRCA mutant and HRD-negative pts (BRCA wild-type/LOH low) were exploratory endpoints. Results: As of Mar 23, 2022 (visit cutoff), 427 and 111 pts were randomized to rucaparib monotherapy or placebo (median time on treatment, 14.7 and 9.9 mo). PFS data are shown in the Table. Most common grade ≥3 TEAEs were anemia (rucaparib, 28.7% vs placebo, 0%), neutropenia (14.6% vs 0.9%), and ALT/AST increased (10.6% vs 0.9%). Rucaparib dose reduction, interruption, and discontinuation due to TEAEs occurred in 49.4%, 60.7%, and 11.8% of pts. Conclusions: Rucaparib monotherapy is effective as 1L maintenance with significant benefit vs placebo observed in the ITT and HRD populations, as well as the non-nested subgroup of pts without known HRD. Clinical trial information: NCT03522246. [Table: see text]

ENGOT-ov60/GOG-3052/RAMP 201: A phase 2 study of VS-6766 (RAF/MEK clamp) alone and in combination with defactinib (FAK inhibitor) in recurrent low-grade serous ovarian cancer (LGSOC)

TPS5615

Background: Low-grade serous ovarian cancer (LGSOC) constitutes up to 10% of all ovarian cancer and has clinical and molecular characteristics distinct from high-grade serous ovarian cancer. Approximately a third of patients (pts) with recurrent LGSOC harbor KRAS mutations (mt) and pts with KRAS wild-type (wt) LGSOC may have mutations in NRAS, BRAF, or other RAS pathway-associated genes. Prior clinical studies with single agent MEK inhibitors have shown response rates of 16-26% in recurrent LGSOC. VS-6766 is a unique small molecule RAF/MEK clamp that inhibits both RAF and MEK activities by trapping them in inactive complexes. This mechanism of blockade has been shown to limit compensatory MEK activation, thereby potentially enhancing efficacy of MEK inhibition. Focal adhesion kinase (FAK) activation is a putative resistance mechanism to RAF and MEK inhibition, and defactinib, a small molecule inhibitor of FAK, has shown synergistic anti-tumor activity with VS-6766 in preclinical models, including organoids from LGSOC pts. Furthermore, FAK inhibition combined with VS-6766 induces tumor regression in a KRAS mt ovarian cancer xenograft model. The combination of VS-6766 and defactinib is currently being evaluated in the ongoing Investigator Sponsored FRAME study (NCT03875820). In this proof-of-concept study, durable objective responses (ORR = 46%; 11/24) have been reported in recurrent LGSOC pts, including pts who have had a prior MEK inhibitor (Banerjee ESMO 2021) and the combination of VS-6766 + defactinib has received FDA Breakthrough Therapy Designation for recurrent LGSOC. These initial preclinical and clinical results support the ongoing phase 2 ENGOT-ov60/GOG-3052 in recurrent LGSOC. Methods: This is an international phase 2, adaptive, multicenter, randomized, open label study designed to evaluate the efficacy and safety of VS-6766 vs VS-6766 in combination with defactinib currently open to enrollment (NCT04625270). The study will be conducted in two parts. Part A will determine the optimal regimen based on confirmed overall response rate (independent radiology review) in KRAS mt and KRAS wt LGSOC. Part B will determine the efficacy of the optimal regimen identified in Part A in KRAS mt and KRAS wt LGSOC. The minimum expected enrollment is 104 pts, 52 pts with KRAS mt and 52 KRAS wt (64 pts in Part A and 40 pts in Part B). Pts will be randomized to receive VS-6766 (4.0 mg orally (PO), twice weekly 3 wks on, 1 wk off) or VS-6766 with defactinib (VS-6766 3.2 mg PO, twice weekly + defactinib 200 mg PO BID 3 wks on, 1 wk off) till progression. Key inclusion criteria include histologically confirmed LGSOC, known KRAS mutation status, prior systemic therapy including platinum for metastatic disease and up to 1 prior line of MEK inhibitor therapy permitted. Part A of this study has completed enrollment and Part B is currently enrolling pts. Clinical trial information: NCT04625270.

Efficacy and safety of rucaparib maintenance treatment in patients from ARIEL3 with platinum-sensitive, recurrent ovarian carcinoma not associated with homologous recombination deficiency

5544

Background: In ARIEL3 (NCT01968213), rucaparib maintenance treatment led to significant improvement vs placebo for the primary endpoint of investigator-assessed progression-free survival (PFS) in patients (pts) with platinum-sensitive, recurrent ovarian carcinoma responsive to the last line of platinum therapy (Coleman et al. Lancet. 2017;390:1949–61). The largest benefit was observed in pts with carcinomas with a BRCA mutation or high loss of heterozygosity (LOH), a marker of homologous recombination deficiency (HRD). However, rucaparib also improved PFS in pts with carcinomas negative by HRD test (ie, BRCA wild-type with low LOH), a subset of pts for which there is no identified molecular mechanism conferring PARP inhibitor sensitivity. Among these pts (rucaparib, n = 107; placebo, n = 54), median PFS was 6.7 vs 5.4 months, respectively (HR, 0.58 [95% CI 0.40–0.85]; P= 0.0049), and 31.8% vs 4.3% were progression-free at 1 yr. In this post hoc exploratory analysis, we further evaluated the efficacy of rucaparib maintenance vs placebo in this subset of pts. Methods: Pts were randomized 2:1 to oral rucaparib (600 mg BID) or placebo. For this analysis, investigator-assessed PFS and safety were evaluated in pts with HRD-negative carcinoma, defined as BRCA wild-type with genomic LOH < 16% using Foundation Medicine’s T5 NGS assay. Results: Visit cutoff dates for efficacy and safety were Apr 15, 2017, and Dec 31, 2019. Across subgroups based on demographic or disease characteristics, the trend of rucaparib benefit vs placebo was consistently observed in pts with HRD-negative carcinoma (Table). The safety profile of rucaparib in the HRD-negative population was consistent with that of the overall safety population reported previously. Conclusions: Rucaparib maintenance reduced risk of progression in pts with ovarian carcinomas, including those not associated with HRD, regardless of clinical prognostic factors. [Table: see text]

Randomized controlled trial (RCT) of symptom screening with targeted early palliative care (STEP) versus usual care in patients with advanced cancer

e24084

Background: To direct limited specialized palliative care resources to patients in greatest need, we developed STEP (Symptom screening with Targeted Early Palliative care). STEP entails symptom screening (ESAS-r) at each oncology clinic visit and triggered alerts (for moderate-high physical and psychological symptoms) to a nurse who calls the patient to offer a palliative care clinic (PCC) visit. We conducted a phase III RCT to assess the impact of STEP versus usual care on quality of life and other patient-reported outcomes (PROs). Methods: Adults with advanced cancer were recruited from medical oncology clinics at the Princess Margaret Cancer Centre, Toronto, Canada. Consenting patients with oncologist-assessed ECOG 0-2 and estimated survival of 6-36 months were enrolled and block randomized (stratified by tumour site and symptom severity) to STEP or usual care. Participants completed measures of quality of life (FACT-G7), depression (PHQ-9), symptom control (ESASr-CS), and satisfaction with care (FAMCARE-P16) at baseline, 2, 4 and 6 months. The primary outcome was FACT-G7 at 6 months, with a planned sample size of 261/arm. Results: From 8/2019 to 3/2020, 69 patients were enrolled: 33 randomized to STEP and 36 to usual care. The trial was then halted permanently due to the COVID-19 pandemic, owing to substantial changes to elements of STEP (shift to virtual symptom screening and palliative care) and usual care (shift to virtual oncology care). Median age was 64 years (range 25-87) and 62% (43/69) were women; study arms were balanced at baseline except gender, with more women randomized to STEP. Within the STEP arm, 20 (61%) participants triggered a nurse’s call to offer a PCC visit, of whom 13 attended the clinic at least once. All outcomes tended to be better in the STEP arm compared to usual care, particularly depression and satisfaction with care at 6 months; however, results were not statistically significant (Table). Conclusions: STEP holds promise for improving quality of life and other PROs in patients with advanced cancer and effectively directing early palliative care towards those who need it most. In response to the pandemic, an online version of STEP has been developed and a further trial is in progress. Clinical trial information: NCT03987906. [Table: see text]

Pembrolizumab, maveropepimut-S, and low-dose cyclophosphamide in advanced epithelial ovarian cancer: Results from phase 1 and expansion cohort of PESCO trial

5505

Background: Platinum-resistant ovarian cancer (PROC) continues to have a poor prognosis. Maveropepimut-S (MVP-S, namely DPX-Survivac) leverages the lipid-based DPX delivery platform to educate a specific and persistent T cell-based immune response to 5 HLA-restricted peptides from survivin, a cancer-related protein commonly upregulated in several cancers. MVP-S in combination with Pembrolizumab (Pemb) and low-dose Cyclophosphamide (CPA) is expected to enhance immune response. This trial aims to assess the safety and efficacy of this regimen in patients (pts) with PROC. Methods: Phase 1 escalation cohort allowed all PROC subtypes and comprised 2 dose levels (DL) of MVP-S with 1 initial dose 0.25 mL followed by boosters of 0.25 mL (DL1) or 0.5mL (DL2) SC q6w, combined with CPA (50 mg BID every other week) and Pemb (200 mg q3w). Dose escalation was performed using 3+3 design. Dose-limiting toxicities (DLT) were defined as G4 non-hematologic, ≥G3 persistent non-hematologic toxicity, laboratory value or febrile neutropenia; ≥G2 persistent injection site skin ulceration ( > 1wk) or allergic/immune reactions by CTCAE v4.03. DL was considered safe if ≤1 DLT occurred in 6 pts until 21 days after initial and first boosting dose. Pts with high-grade serous (HGSOC) or endometrioid ovarian cancer were allowed in the Phase 2 expansion cohort (P2EC) and treated with the Recommended Phase 2 Dose (RP2D). Response was assessed every 6 wks. Activity in P2EC was defined as at least 2/10 partial response (PR) or stable disease (SD) for 12 wks according to RECIST 1.1. Primary endpoint is overall response rate (ORR), and secondary includes safety, PFS, and OS. Biopsies and blood draws were performed prior to and on treatment for genomic analysis, immune profiling and ctDNA. Results: Twenty-six pts were enrolled, 24 were evaluable for safety (8 DL1, 6 DL2, and 10 in P2EC). HGSOC represented 62% of phase I and 100% of P2EC. Median age was 61y (49-78). Pts received a median of 4 (1-7) prior lines of therapy. Median cycles of MVP-S were 2 (1-8). Toxicity G4/G3/G2 occurred in 1/3/7 pts of DL1 and 0/3/6 of DL2. G3/G2 immune-related AE (irAE) and injection site reactions (ISR) were observed in 1/1 and 1/3 pts treated at DL1, and in 1/0 and 2/2 pts at DL2, respectively. DL1 was selected as RP2D due to the occurrence of nephritis and ISR G3 at DL2. No AEs were qualified as DLT. On the P2EC, 5 G3 (1 irAE, 0 ISR) and 28 G2 (0 irAE, 3 ISR) toxicities were observed. At Phase 1, one pt with MSI-High clear cell subtype has ongoing CR after 26 mos of follow-up, 2 pts had PR and 6 SD.There were 1 PR and 3 SD on P2EC, of which 1 and 2, respectively, achieved response > 12wks. Conclusions: The combination of MVP-S, low-dose CPA, and Pemb was tolerable and met the efficacy endpoint in the expansion cohort in heavily treated PROC. Immuno-genomic correlative analyses are ongoing. Clinical trial information: NCT03029403. [Table: see text]

Randomized phase III study of maintenance selinexor versus placebo in endometrial cancer (ENGOT-EN5/GOG-3055/SIENDO): Impact of subgroup analysis and molecular classification

5511

Background: Endometrial cancers (ECs) are stratified into four molecular categories: wild type TP53 with non-specific molecular profile typically with microsatellite stability (NSMP, p53wt/MSS), DNA polymerase ε exonuclease domain-mutated (POLEmut), microsatellite instability high (MSI) and TP53 abnormal (p53abn). These are associated with specific prognoses. Selinexor (SEL) is a specific XPO1 inhibitor that leads to the nuclear retention and activation of tumor suppressor proteins (TSP) including p53. SEL showed improved progression-free survival (PFS) over placebo (PLB) in the stratification adjusted results of the ENGOT-EN5/GOG-3055/SIENDO study (NCT03555422; ESMO 2022). Methods: The SIENDO study is a prospective, multicenter, double-blind, placebo-controlled, phase 3 study of SEL (80 mg once weekly) vs. PLB (2:1 randomization) as maintenance therapy in 263 patients (pts) with advanced or recurrent EC after one line of taxane-platinum therapy with partial or complete remission. TP53 mutations and MSI were assessed by centralized targeted sequencing and local immunohistochemistry. Classification was based on sequencing 648 genes on tumor samples from 172 pts (107 on SEL), assigned first by POLEmut, then MSI, then p53abn or p53wt (NSMP). Preliminary exploratory analyses based on molecular classification were prespecified in the trial. Results: The SIENDO study resulted in a median progression-free survival (PFS) of 5.7 months (SEL) vs. 3.8 months (PLB), with a stratification adjusted (eCRF) hazard ratio (HR) of 0.70 (p =.024; and a stratification non-adjusted (IRT) HR of 0.76 (p=0.063). Among the 172 patients who underwent molecular classification, those on SEL (107 pts) were classified as follows: 37 (35%) NSMP, 2 (2%) POLEmut, 18 (17%) MSI, and 50 (46%) p53abn. A similar distribution was seen in those on PLB (65 pts): 20 (31%) NSMP; 4 (6%) POLEmut; 8 (12%) MSI; 33 (51%) p53abn. Subgroup analysis of pts with TP53wt showed a PFS of 13.7 mo with SEL vs. 3.7 mo with PLB (HR 0.375; 95% CI, 0.210-0.670; nominal p =.0003) and pts with MSS/pMMR disease had a PFS of 6.9 mo with SEL vs. 5.4 with PLB (HR 0.593; 95% CI, 0.388-0.905, nominal p =.007). An analysis of patients with NSMP (p53wt, MSS) showed a substantial difference in PFS for SEL vs. PLB: medians NR and 3.71 months, respectively (HR 0.163; 95% CI, 0.060-0.444; nominal p <.0001). Analyses of the other 3 molecular categories did not show significant differences in PFS between SEL and PLB. Additional biomarker identification studies assessing tumor genetics and epigenetics are ongoing. Conclusions: SEL showed improved PFS over PLB in the SIENDO study based on the stratification adjusted analysis. As an indirect p53 activator, preliminary exploratory subgroup analyses of SEL showed improvement over PLB amongst the patients with TP53wt, MSS, and the NSMP EC comprising approximately 50% of patients with advanced/recurrent EC. Clinical trial information: NCT03555422.

Maintenance olaparib in patients (pts) with platinum-sensitive relapsed ovarian cancer (PSROC) by somatic (s) or germline (g) BRCA and other homologous recombination repair (HRR) gene mutation status: Overall survival (OS) results from the ORZORA study

5519

Background: In the SOLO2 (NCT01874353) trial, maintenance olaparib provided clinically meaningful improvement in OS for PSROC pts with a gBRCA mutation (m) compared with placebo (median 51.7 vs 38.8 months [mo], respectively). The ORZORA trial (NCT02476968) assessed efficacy and safety of maintenance olaparib in PSROC pts with a BRCAm (s or g) or a non-BRCA HRRm. Median progression-free survival (18.0 mo, BRCAm; 16.4, non-BRCA HRRm) was reported at primary data cutoff (DCO). We report final OS analyses. Methods: We conducted an open-label, single-arm, multicenter study of PSROC pts in response to platinum-based chemotherapy (PBC) after ≥2 prior lines of PBC. Pts underwent prospective central screening for tumor BRCAm status (myChoice CDx, Myriad Genetic Laboratories, Inc.), then central gBRCAm testing (BRACAnalysis CDx, Myriad Genetic Laboratories, Inc.) to determine s or g status. An exploratory cohort comprised of pts with predefined non-BRCA HRRm (FoundationOne CDx, Foundation Medicine, Inc.). Pts received maintenance olaparib (400 mg bid; capsules) until progression. OS and time to second progression (PFS2) were secondary endpoints. Results: 181 pts were enrolled (BRCAm n = 145 [s, n = 55; g, n = 87; s/g status unknown, n = 3]; non-BRCA HRRm, n = 33; unassigned, n = 3). At DCO (June 25, 2021), median OS follow-up in censored pts was 42.6 mo in BRCAm and 39.3 mo in non-BRCA HRRm pts. OS and PFS2 are reported in the Table. PBC was received as a subsequent therapy by 33.1% BRCAm, 32.7% sBRCAm, 33.3% gBRCAm, and 45.5% non-BRCA HRRm pts. 177 pts received ≥1 dose of olaparib and were included in safety analyses; 6.2% of pts discontinued because of adverse events (AEs). 37.9% of pts reported grade ≥3 AEs, the most common being anemia (16.4%). Since primary DCO, one new primary malignancy and four myelodysplastic syndrome events occurred. Conclusions: In final OS analyses, maintenance olaparib capsules showed consistent clinical activity in BRCAm and sBRCAm PSROC pts. Exploratory analyses suggest similar activity in non-BRCA HRRm pts. No new safety signals were observed. Findings highlight that PSROC pts, beyond those with a gBRCAm, can benefit from maintenance olaparib. Clinical trial information: NCT02476968. [Table: see text]

Pharmacokinetic and pharmacodynamic analysis of adavosertib in advanced ovarian cancer

5579

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

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

5514

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.

Integrated safety summary of single-agent mirvetuximab soravtansine in patients with folate receptor α (FRα)-positive recurrent ovarian cancer: Phase 1 and 3 clinical trials

5574

Background: Available chemotherapies for platinum-resistant ovarian cancer (PROC) have limited clinical activity and considerable toxicity. Mirvetuximab soravtansine (MIRV) is a first-in-class antibody drug conjugate (ADC) comprising a folate receptor alpha (FRα)-binding antibody, cleavable linker, and the maytansinoid payload DM4, a potent tubulin-targeting agent that has demonstrated significant anti-tumor activity in this difficult to treat population. The objective is to characterize the tolerability profile of MIRV in a pooled analysis of experience when administered as monotherapy in patients (pts) with FRα positive recurrent ovarian cancer. Methods: Retrospective pooled analysis included pts enrolled across three studies: phase 1 first-in-human, phase 3 FORWARD I, and phase 3 SORAYA. Analysis included pts with FRα positive recurrent ovarian cancer and those pts with low, medium, and high FRα expression by immunohistochemistry (Roche FOLR1 Assay ≥ 25% of cells with PS2+ staining intensity). All pts received intravenous MIRV at 6 mg/kg, adjusted ideal body weight, on Day 1 of a 21-day cycle until disease progression or unacceptable toxicity. Results: 464 pts were included from 15 countries, with key characteristics: median age 63 yrs, 87% 1-3 prior therapies, 91% platinum free interval ≤6 months, 65% prior bevacizumab, and 25% prior PARPi. The most common treatment-related adverse events (TRAE) (all grade, grade 3+) included blurred vision (42%, 3%), nausea (40%, 2%), diarrhea (33%, 2%), fatigue (31%, 2%), keratopathy (26%, 3%), and dry eye (22%, 1%). TRAEs leading to a dose delay or reduction occurred in 33% and 21% of pts, respectively. Seven % discontinued due to a TRAE. Four pts ( < 1%) discontinued MIRV due to an ocular event. Ninety % of pts with a grade 2+ blurred vision resolved to grade 0 or 1, 93% of pts with grade 2+ keratopathy resolved to grade 0 or 1. No corneal ulcers or perforation have been reported and no patient with a serious ocular event has been reported to have permanent sequelae. Conclusions: In a pooled analysis of 464 patients, MIRV monotherapy has a differentiated and predictable safety profile consisting primarily of low grade and reversible gastrointestinal and ocular events. These events were managed with supportive care and dose modifications if needed, with a low rate of treatment-related discontinuation. The safety profile of MIRV in recurrent ovarian cancer along with the anti-tumor activity in PROC (32.4% ORR Matulonis SGO 2022) support a favorable benefit/risk in this population. Clinical trial information: NCT01609556, NCT04296890, NCT02631876.

OZM-114: Phase Ib expansion study of CX-5461in patients with solid tumors and BRCA2 and/or PALB2 mutation

TPS5621

Background: Pre-clinical and clinical data demonstrate that CX-5461 selectively kills HR deficient cancer cells through stabilizing G4 structures and inducing replication-dependent DNA damage. Phase 1 studies suggest CX-5461 has clinical activity and warrants further investigation in HR-deficient tumors, including those with pathogenic BRCA2 and PALB2 mutation. The recommended phase 2 dose (RP2D) requires further refinement to establish the chronic tolerable dose for further phase 2 trials, particularly regarding the incidence of ocular toxicity. The doses of 325mg/m2 and 250mg/m2 were selected for this study expansion cohorts because it is well within the efficacy range and below the first occurrence of ocular toxicity in a previous study. Methods: This is an open-label, multi-center, phase 1b study designed to determine a tolerable dose of CX-5461 in patients with ovarian, pancreatic, prostate, and breast cancers for Phase II trials. Eligible patients will be enrolled into two cohorts: A) Main cohort (target accrual: 32 patients) and B) Exploratory cohorts (target accrual: 20 patients), see table-1 below. The primary outcomes include assessment of: 1) Safety and tolerability of CX-5461, in particular to determine late onset ocular toxicity 2) Anti-tumor activity of CX-5461 in patients with solid tumors and germline BRCA2 and/or PALB2 mutation, and 3) Effect of CX-5461 on Quality of Life measures. Secondary outcomes include evaluation of :1) Safety: CTCAE v 5.0, SAEs, dose modifications due to AEs, 2) Activity: best overall response from tumor evaluations performed every 2 cycles, according to RECIST v1.1, and duration of response., and 3) patient-reported outcomes: PRO (PRO-CTCAE v1.0 questionnaires to evaluate cutaneous, gastrointestinal, visual/perceptual, cardio/circulatory, sleep/wake and miscellaneous symptoms. Exploratory Objectives include assessment of: 1) anti-tumor activity of CX-5461 in patients with ovarian cancer and pathogenic/likely-pathogenic BRCA1 mutation and/or other HRD-associated somatic mutation, and 2) molecular profile of tumors and predictive value of mutational signatures in predicting response or resistance to CX-5461. Clinical trial information: NCT04890613. [Table: see text]

Repurposing Itraconazole and Hydroxychloroquine to Target Lysosomal Homeostasis in Epithelial Ovarian Cancer

Drug repurposing is an attractive option for oncology drug development. Itraconazole is an antifungal ergosterol synthesis inhibitor that has pleiotropic actions including cholesterol antagonism, inhibition of Hedgehog and mTOR pathways. We tested a panel of 28 epithelial ovarian cancer (EOC) cell lines with itraconazole to define its spectrum of activity. To identify synthetic lethality in combination with itraconazole, a whole-genome drop-out genome-scale clustered regularly interspaced short palindromic repeats sensitivity screen in two cell lines (TOV1946 and OVCAR5) was performed. On this basis, we conducted a phase I dose-escalation study assessing the combination of itraconazole and hydroxychloroquine in patients with platinum refractory EOC (NCT03081702). We identified a wide spectrum of sensitivity to itraconazole across the EOC cell lines. Pathway analysis showed significant involvement of lysosomal compartments, the trans-golgi network and late endosomes/lysosomes; similar pathways are phenocopied by the autophagy inhibitor, chloroquine. We then demonstrated that the combination of itraconazole and chloroquine displayed Bliss defined synergy in EOC cancer cell lines. Furthermore, there was an association of cytotoxic synergy with the ability to induce functional lysosome dysfunction, by chloroquine. Within the clinical trial, 11 patients received at least one cycle of itraconazole and hydroxychloroquine. Treatment was safe and feasible with the recommended phase II dose of 300 and 600 mg twice daily, respectively. No objective responses were detected. Pharmacodynamic measurements on serial biopsies demonstrated limited pharmacodynamic impact. In vitro, itraconazole and chloroquine have synergistic activity and exert a potent antitumor effect by affecting lysosomal function. The drug combination had no clinical antitumor activity in dose escalation.

Significance

The combination of the antifungal drug itraconazole with antimalarial drug hydroxychloroquine leads to a cytotoxic lysosomal dysfunction, supporting the rational for further research on lysosomal targeting in ovarian cancer.

Interobserver and intraobserver variability of RECIST assessment in ovarian cancer

OBJECTIVES

Measurement of Response Evaluation Criteria In Solid Tumors (RECIST) relies on reproducible unidimensional tumor measurements. This study assessed intraobserver and interobserver variability of target lesion selection and measurement, according to RECIST version 1.1 in patients with ovarian cancer.

METHODS

Eight international radiologists independently viewed 47 images demonstrating malignant lesions in patients with ovarian cancer and selected and measured lesions according to RECIST V.1.1 criteria. Thirteen images were viewed twice. Interobserver variability of selection and measurement were calculated for all images. Intraobserver variability of selection and measurement were calculated for images viewed twice. Lesions were classified according to their anatomical site as pulmonary, hepatic, pelvic mass, peritoneal, lymph nodal, or other. Lesion selection variability was assessed by calculating the reproducibility rate. Lesion measurement variability was assessed with the intra-class correlation coefficient.

RESULTS

From 47 images, 82 distinct lesions were identified. For lesion selection, the interobserver and intraobserver reproducibility rates were high, at 0.91 and 0.93, respectively. Interobserver selection reproducibility was highest (reproducibility rate 1) for pelvic mass and other lesions. Intraobserver selection reproducibility was highest (reproducibility rate 1) for pelvic mass, hepatic, nodal, and other lesions. Selection reproducibility was lowest for peritoneal lesions (interobserver reproducibility rate 0.76 and intraobserver reproducibility rate 0.69). For lesion measurement, the overall interobserver and intraobserver intraclass correlation coefficients showed very good concordance of 0.84 and 0.94, respectively. Interobserver intraclass correlation coefficient showed very good concordance for hepatic, pulmonary, peritoneal, and other lesions, and ranged from 0.84 to 0.97, but only moderate concordance for lymph node lesions (0.58). Intraobserver intraclass correlation coefficient showed very good concordance for all lesions, ranging from 0.82 to 0.99. In total, 85% of total measurement variability resulted from interobserver measurement difference.

CONCLUSIONS

Our study showed that while selection and measurement concordance were high, there was significant interobserver and intraobserver variability. Most resulted from interobserver variability. Compared with other lesions, peritoneal lesions had the lowest selection reproducibility, and lymph node lesions had the lowest measurement concordance. These factors need consideration to improve response assessment, especially as progression free survival remains the most common endpoint in phase III trials.

Phase 1b expansion study of CX-5461 in patients with solid tumors and BRCA2 and/or PALB2 mutation

TPS622

Background: BRCA and PALB2 proteins play important roles in the maintenance of genomic stability as they are essential for error-free repair of double-stranded DNA breaks, while deficiency of these proteins promotes error-prone DNA repair, chromosomal instability and carcinogenesis. Inherited mutations in BRCA genes predispose to various early onset cancers. Poly(ADP-ribose) polymerase inhibitors (PARPi) inducing synthetic lethality in tumors with homologous recombination (HR)-mediated DNA repair deficiencies have been approved for treatment in patients with germline BRCA-mutated metastatic pancreatic adenocarcinoma. Unfortunately, resistance to PARPi associated with multiple mechanisms can be observed over time, suggesting a prominent unmet need for the development of new treatment options. CX-5461, a G-quadruplex stabilizer, employs an alternative mechanism in destabilizing the DNA replication fork to promote DNA damage resulting in cancer cell lethality in HR-deficient (HRD) tumors, thus represent a promising therapeutic strategy for patients with defects in HR-repair. Methods: A prior phase I dose escalation study has been completed for CX-5461 (CCTG IND.231, NCT02719977) but additional safety data are required to define the chronic tolerable dose for phase 2 trials. Therefore, a phase Ib expansion trial was designed for two doses preselected from our previous phase I trial to determine the final recommended phase II dose (RP2D) by evaluating safety, tolerability and objective response rate in a more selected population. This trial will enroll patients in two cohorts; the main cohort recruiting patients with pancreatic, breast, ovarian or prostate cancer with germline BRCA2 and/or PALB2 mutation, and an exploratory cohort recruiting ovarian cancer patients with BRCA1 and/or other HRD-associated mutations. Major eligibility criteria include documented evidence of pathogenic or likely pathogenic germline mutation in BRCA2 and/or PALB2 for main cohort patients, documented evidence of pathogenic or likely pathogenic germline mutation or a clinically actionable somatic mutation in BRCA1 and/or other HRD-associated mutation for exploratory cohort. Patients with non-adenocarcinoma histology of pancreatic cancer, known photosensitivity disorders of the skin, or patients with ophthalmological conditions will not be enrolled. An initial 16 eligible patients for the main cohort and 10 eligible patients for the exploratory cohort will be enrolled in parallel to receive CX-5461 at 250mg/m2, delivered via IV infusion on Day 1 and Day 8 of a 28-day cycle. Upon completion of the initial arms with no safety concerns, another two arms will open to enroll an additional 16 patients for the main cohort and 10 patients for the exploratory cohort to receive CX-5461 at 325mg/m2 of the same dosing schedule. Clinical trial information: NCT04890613.

Symptom burden and quality of life with chemotherapy for recurrent ovarian cancer: the Gynecologic Cancer InterGroup-Symptom Benefit Study

Objective

The Gynecologic Cancer InterGroup (GCIG)-Symptom Benefit Study was designed to evaluate the effects of chemotherapy on symptoms and health-related quality of life (HRQL) in women having chemotherapy for platinum resistant/refractory recurrent ovarian cancer (PRR-ROC) and potentially platinum sensitive with ≥3 lines of chemotherapy (PPS-ROC ≥3).

Methods

Participants completed the Measure of Ovarian Cancer Symptoms and Treatment (MOST) and European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire QLQ-C30 questionnaires at baseline and every 3–4 weeks until progression. Participants were classified symptomatic if they rated ≥4 of 10 in at least one-third of symptoms in the MOST index. Improvement in MOST was defined as two consecutive scores of ≤3 in at least half of the symptomatic items at baseline. Improvement in HRQL was defined as two consecutive scores ≥10 points above baseline in the QLQ-C30 summary score scale (range 0–100).

Results

Of 948 participants enrolled, 910 (96%) completed baseline questionnaires: 546 with PRR-ROC and 364 with PPS-ROC ≥3. The proportions of participants symptomatic at baseline as per MOST indexes were: abdominal 54%, psychological 53%, and disease- or treatment-related 35%. Improvement was reported in MOST indexes: abdominal 40%, psychological 35%, and disease- or treatment-related 38%. Median time to improvement in abdominal symptoms occurred earlier for PRR-ROC than for PPS-ROC ≥3 (4 vs 6 weeks, p=0.044); median duration of improvement was also similar (9.0 vs 11.7 weeks, p=0.65). Progression-free survival was longer among those with improvement in abdominal symptoms than in those without (median 7.2 vs 2.5 months, p<0.0001). Improvements in HRQL were reported by 77/448 (17%) with PRR-ROC and 61/301 (20%) with PPS-ROC ≥3 (p=0.29), and 102/481 (21%) of those with abdominal symptoms at baseline.

Conclusion

Over 50% of participants reported abdominal and psychological symptoms at baseline. Of those, 40% reported an improvement within 2 months of starting chemotherapy. Approximately one in six participants reported an improvement in HRQL. Symptom monitoring and supportive care is important as chemotherapy palliated less than half of symptomatic participants.

Brief family history questionnaire to screen for Lynch syndrome in women with newly diagnosed non-serous, non-mucinous ovarian cancers

OBJECTIVES

While ovarian cancer is the third most common Lynch syndrome-associated cancer in women, there is no established screening strategy to identify Lynch syndrome in this population. The objective of this study was to assess whether the 4-item brief Family History Questionnaire can be used as a screening tool to identify women with ovarian cancer at risk of Lynch syndrome.

METHODS

In this prospective cohort study, participants with newly diagnosed non-serous, non-mucinous ovarian cancer completed the brief Family History Questionnaire, extended Family History Questionnaire, and had tumors assessed with immunohistochemistry for mismatch repair proteins, MLH1 methylation, and microsatellite instability testing. All underwent universal germline testing for Lynch syndrome. Performance characteristics were compared between the brief Family History Questionnaire, extended Family History Questionnaire, immunohistochemistry±MLH1 methylation, and microsatellite instability testing.

RESULTS

Of 215 participants, 169 (79%) were evaluable with both the brief Family History Questionnaire and germline mutation status; 12 of these 169 were confirmed to have Lynch syndrome (7%). 10 of 12 patients (83%) with Lynch syndrome were correctly identified by the brief Family History Questionnaire, compared with 6 of 11 (55%) by the extended Family History Questionnaire, 11 of 13 (85%) by immunohistochemistry±MLH1 methylation, and 9 of 11 (82%) by microsatellite instability testing. The sensitivity, specificity, positive predictive values, and negative predictive values of the brief Family History Questionnaire were 83%, 65%, 15%, and 98%, respectively. A combined approach with immunohistochemistry and the brief Family History Questionnaire correctly identified all 12 patients with Lynch syndrome. The brief Family History Questionnaire was more sensitive than the extended Family History Questionnaire and took <10 min for each patient to complete.

CONCLUSIONS

The brief Family History Questionnaire alone or combined with immunohistochemistry may serve as an adequate screening strategy, especially in centers without access to universal tumor testing.