Abstract “Platinum resistant” ovarian cancer was historically defined as disease recurrence within 6 months of completion of first-line platinum-based chemotherapy, although this is now more broadly ...applied to also include patients progressing within 6 months after multiple lines of chemotherapy. However, this definition ignores the heterogeneity and complexity of the spectrum of diseases that comprise “platinum resistant ovarian cancer” (PROC) and is innately flawed as it was initially derived using methods of detection of recurrence that would now be regarded as outdated. The outcome of patients with PROC is generally poor, with low response rates to further chemotherapy and a median survival of less than 12 months, but this is unpredictable and can be quite variable from study to study. This review outlines the complexity of PROC, examines how this impacts on the interpretation of the results of clinical trials, and explores how the definition may be improved. We also briefly describe the mechanisms of platinum resistance, the results of clinical trials to date as well as treatment options for patients with PROC and highlight the need for better methods of assessing clinical benefit in this poor prognostic sub group of patients.
Niraparib is an oral poly(adenosine diphosphate ADP-ribose) polymerase (PARP) 1/2 inhibitor that has shown clinical activity in patients with ovarian cancer. We sought to evaluate the efficacy of ...niraparib versus placebo as maintenance treatment for patients with platinum-sensitive, recurrent ovarian cancer.
In this randomized, double-blind, phase 3 trial, patients were categorized according to the presence or absence of a germline BRCA mutation (gBRCA cohort and non-gBRCA cohort) and the type of non-gBRCA mutation and were randomly assigned in a 2:1 ratio to receive niraparib (300 mg) or placebo once daily. The primary end point was progression-free survival.
Of 553 enrolled patients, 203 were in the gBRCA cohort (with 138 assigned to niraparib and 65 to placebo), and 350 patients were in the non-gBRCA cohort (with 234 assigned to niraparib and 116 to placebo). Patients in the niraparib group had a significantly longer median duration of progression-free survival than did those in the placebo group, including 21.0 vs. 5.5 months in the gBRCA cohort (hazard ratio, 0.27; 95% confidence interval CI, 0.17 to 0.41), as compared with 12.9 months vs. 3.8 months in the non-gBRCA cohort for patients who had tumors with homologous recombination deficiency (HRD) (hazard ratio, 0.38; 95% CI, 0.24 to 0.59) and 9.3 months vs. 3.9 months in the overall non-gBRCA cohort (hazard ratio, 0.45; 95% CI, 0.34 to 0.61; P<0.001 for all three comparisons). The most common grade 3 or 4 adverse events that were reported in the niraparib group were thrombocytopenia (in 33.8%), anemia (in 25.3%), and neutropenia (in 19.6%), which were managed with dose modifications.
Among patients with platinum-sensitive, recurrent ovarian cancer, the median duration of progression-free survival was significantly longer among those receiving niraparib than among those receiving placebo, regardless of the presence or absence of gBRCA mutations or HRD status, with moderate bone marrow toxicity. (Funded by Tesaro; ClinicalTrials.gov number, NCT01847274 .).
BackgroundDostarlimab is a humanized monoclonal antibody that binds with high affinity to PD-1, resulting in inhibition of binding to PD-L1 and PD-L2. We report interim data from patients with ...endometrial cancer (EC) participating in a phase I trial of single-agent dostarlimab.MethodsGARNET, an ongoing, single-arm, open-label, phase I trial of intravenous dostarlimab in advanced solid tumors, is being undertaken at 123 sites. Two cohorts of patients with EC were recruited: those with dMMR/MSI-H disease (cohort A1) and those with proficient/stable (MMRp/MSS) disease (cohort A2). Patients received dostarlimab 500 mg every 3 weeks for 4 cycles, then dostarlimab 1000 mg every 6 weeks until disease progression. The primary endpoints were objective response rate (ORR) and duration of response (DOR) per RECIST V.1.1, as assessed by blinded independent central review.ResultsScreening began on April 10, 2017, and 129 and 161 patients with advanced EC were enrolled in cohorts A1 and A2, respectively. The median follow-up duration was 16.3 months (IQR 9.5–22.1) for cohort A1 and 11.5 months (IQR 11.0–25.1) for cohort A2. In cohort A1, ORR was 43.5% (95% CI 34.0% to 53.4%) with 11 complete responses and 36 partial responses. In cohort A2, ORR was 14.1% (95% CI 9.1% to 20.6%) with three complete responses and 19 partial responses. Median DOR was not reached in either cohort. In the combined cohorts, the majority of treatment-related adverse events (TRAEs) were grade 1–2 (75.5%), most commonly fatigue (17.6%), diarrhea (13.8%), and nausea (13.8%). Grade≥3 TRAEs occurred in 16.6% of patients, and 5.5% discontinued dostarlimab because of TRAEs. No deaths were attributable to dostarlimab.ConclusionDostarlimab demonstrated durable antitumor activity in both dMMR/MSI-H (ORR 43.5%) and MMRp/MSS EC (ORR 14.1%) with a manageable safety profile.Trial registration numberNCT02715284.
Most patients with ovarian cancer will relapse after receiving frontline platinum-based chemotherapy and eventually develop platinum-resistant or platinum-refractory disease. We report results of ...avelumab alone or avelumab plus pegylated liposomal doxorubicin (PLD) compared with PLD alone in patients with platinum-resistant or platinum-refractory ovarian cancer.
JAVELIN Ovarian 200 was an open-label, parallel-group, three-arm, randomised, phase 3 trial, done at 149 hospitals and cancer treatment centres in 24 countries. Eligible patients were aged 18 years or older with epithelial ovarian, fallopian tube, or peritoneal cancer (maximum of three previous lines for platinum-sensitive disease, none for platinum-resistant disease) and an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients were randomly assigned (1:1:1) via interactive response technology to avelumab (10 mg/kg intravenously every 2 weeks), avelumab plus PLD (40 mg/m2 intravenously every 4 weeks), or PLD and stratified by disease platinum status, number of previous anticancer regimens, and bulky disease. Primary endpoints were progression-free survival by blinded independent central review and overall survival in all randomly assigned patients, with the objective to show whether avelumab alone or avelumab plus PLD is superior to PLD. Safety was assessed in all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT02580058. The trial is no longer enrolling patients and this is the final analysis of both primary endpoints.
Between Jan 5, 2016, and May 16, 2017, 566 patients were enrolled and randomly assigned (combination n=188; PLD n=190, avelumab n=188). At data cutoff (Sept 19, 2018), median duration of follow-up for overall survival was 18·4 months (IQR 15·6–21·9) for the combination group, 17·4 months (15·2–21·3) for the PLD group, and 18·2 months (15·8–21·2) for the avelumab group. Median progression-free survival by blinded independent central review was 3·7 months (95% CI 3·3–5·1) in the combination group, 3·5 months (2·1–4·0) in the PLD group, and 1·9 months (1·8–1·9) in the avelumab group (combination vs PLD: stratified HR 0·78 repeated 93·1% CI 0·59–1·24, one-sided p=0·030; avelumab vs PLD: 1·68 1·32–2·60, one-sided p>0·99). Median overall survival was 15·7 months (95% CI 12·7–18·7) in the combination group, 13·1 months (11·8–15·5) in the PLD group, and 11·8 months (8·9–14·1) in the avelumab group (combination vs PLD: stratified HR 0·89 repeated 88·85% CI 0·74–1·24, one-sided p=0·21; avelumab vs PLD: 1·14 0·95–1·58, one-sided p=0·83). The most common grade 3 or worse treatment-related adverse events were palmar-plantar erythrodysesthesia syndrome (18 10% in the combination group vs nine 5% in the PLD group vs none in the avelumab group), rash (11 6% vs three 2% vs none), fatigue (ten 5% vs three 2% vs none), stomatitis (ten 5% vs five 3% vs none), anaemia (six 3% vs nine 5% vs three 2%), neutropenia (nine 5% vs nine 5% vs none), and neutrophil count decreased (eight 5% vs seven 4% vs none). Serious treatment-related adverse events occurred in 32 (18%) patients in the combination group, 19 (11%) in the PLD group, and 14 (7%) in the avelumab group. Treatment-related adverse events resulted in death in one patient each in the PLD group (sepsis) and avelumab group (intestinal obstruction).
Neither avelumab plus PLD nor avelumab alone significantly improved progression-free survival or overall survival versus PLD. These results provide insights for patient selection in future studies of immune checkpoint inhibitors in platinum-resistant or platinum-refractory ovarian cancer.
Pfizer and Merck KGaA, Darmstadt, Germany.
A key resistance mechanism to platinum-based chemotherapies and PARP inhibitors in
-mutant cancers is the acquisition of
reversion mutations that restore protein function. To estimate the prevalence ...of
reversion mutations in high-grade ovarian carcinoma (HGOC), we performed targeted next-generation sequencing of circulating cell-free DNA (cfDNA) extracted from pretreatment and postprogression plasma in patients with deleterious germline or somatic
mutations treated with the PARP inhibitor rucaparib.
reversion mutations were identified in pretreatment cfDNA from 18% (2/11) of platinum-refractory and 13% (5/38) of platinum-resistant cancers, compared with 2% (1/48) of platinum-sensitive cancers (
= 0.049). Patients without
reversion mutations detected in pretreatment cfDNA had significantly longer rucaparib progression-free survival than those with reversion mutations (median, 9.0 vs. 1.8 months; HR, 0.12;
< 0.0001). To study acquired resistance, we sequenced 78 postprogression cfDNA, identifying eight additional patients with
reversion mutations not found in pretreatment cfDNA. SIGNIFICANCE:
reversion mutations are detected in cfDNA from platinum-resistant or platinum-refractory HGOC and are associated with decreased clinical benefit from rucaparib treatment. Sequencing of cfDNA can detect multiple
reversion mutations, highlighting the ability to capture multiclonal heterogeneity.
.
ARIEL2 (NCT01891344) is a single-arm, open-label phase 2 study of the PARP inhibitor (PARPi) rucaparib in relapsed high-grade ovarian carcinoma. In this post hoc exploratory biomarker analysis of ...pre- and post-platinum ARIEL2 samples, RAD51C and RAD51D mutations and high-level BRCA1 promoter methylation predict response to rucaparib, similar to BRCA1/BRCA2 mutations. BRCA1 methylation loss may be a major cross-resistance mechanism to platinum and PARPi. Genomic scars associated with homologous recombination deficiency are irreversible, persisting even as platinum resistance develops, and therefore are predictive of rucaparib response only in platinum-sensitive disease. The RAS, AKT, and cell cycle pathways may be additional modulators of PARPi sensitivity.
To develop and validate a histopathologic scoring system for measuring response to neoadjuvant chemotherapy in interval debulking surgery specimens of stage IIIC to IV tubo-ovarian high-grade serous ...carcinoma.
A six-tier histopathologic scoring system was proposed and applied to a test cohort (TC) of 62 patients treated with neoadjuvant chemotherapy and interval debulking surgery. Adnexal and omental sections were independently scored by three pathologists. On the basis of TC results, a three-tier chemotherapy response score (CRS) system was developed and applied to an independent validation cohort of 71 patients.
The initial system showed moderate interobserver reproducibility and prognostic stratification of TC patients when applied to the omentum but not to the adnexa. Condensed to a three-tier score, the system was highly reproducible (kappa, 0.75). When adjusted for age, stage, and debulking status, the score predicted progression-free survival (PFS; score 2 v 3; median PFS, 11.3 v 32.1 months; adjusted hazard ratio, 6.13; 95% CI, 2.13 to 17.68; P < .001). The three-tier CRS system applied to omental samples from the validation cohort showed high reproducibility (kappa, 0.67) and predicted PFS (CRS 1 and 2 v 3: median, 12 v 18 months; adjusted hazard ratio, 3.60; 95% CI, 1.69 to 7.66; P < .001). CRS 3 also predicted sensitivity to first-line platinum therapy (94.3% negative predictive value for progression < 6 months). A Web site was established to train pathologists to use the CRS system.
The CRS system is reproducible and shows prognostic significance for high-grade serous carcinoma. Implementation in international pathology reporting has been proposed by the International Collaboration on Cancer Reporting, and the system could potentially have an impact on patient care and research.
The study aim to identify novel molecular subtypes of ovarian cancer by gene expression profiling with linkage to clinical and pathologic features.
Microarray gene expression profiling was done on ...285 serous and endometrioid tumors of the ovary, peritoneum, and fallopian tube. K-means clustering was applied to identify robust molecular subtypes. Statistical analysis identified differentially expressed genes, pathways, and gene ontologies. Laser capture microdissection, pathology review, and immunohistochemistry validated the array-based findings. Patient survival within k-means groups was evaluated using Cox proportional hazards models. Class prediction validated k-means groups in an independent dataset. A semisupervised survival analysis of the array data was used to compare against unsupervised clustering results.
Optimal clustering of array data identified six molecular subtypes. Two subtypes represented predominantly serous low malignant potential and low-grade endometrioid subtypes, respectively. The remaining four subtypes represented higher grade and advanced stage cancers of serous and endometrioid morphology. A novel subtype of high-grade serous cancers reflected a mesenchymal cell type, characterized by overexpression of N-cadherin and P-cadherin and low expression of differentiation markers, including CA125 and MUC1. A poor prognosis subtype was defined by a reactive stroma gene expression signature, correlating with extensive desmoplasia in such samples. A similar poor prognosis signature could be found using a semisupervised analysis. Each subtype displayed distinct levels and patterns of immune cell infiltration. Class prediction identified similar subtypes in an independent ovarian dataset with similar prognostic trends.
Gene expression profiling identified molecular subtypes of ovarian cancer of biological and clinical importance.
Abstract
CX-5461 is a G-quadruplex stabilizer that exhibits synthetic lethality in homologous recombination-deficient models. In this multicentre phase I trial in patients with solid tumors, 40 ...patients are treated across 10 dose levels (50–650 mg/m
2
) to determine the recommended phase II dose (primary outcome), and evaluate safety, tolerability, pharmacokinetics (secondary outcomes). Defective homologous recombination is explored as a predictive biomarker of response. CX-5461 is generally well tolerated, with a recommended phase II dose of 475 mg/m
2
days 1, 8 and 15 every 4 weeks, and dose limiting phototoxicity. Responses are observed in 14% of patients, primarily in patients with defective homologous recombination. Reversion mutations in PALB2 and BRCA2 are detected on progression following initial response in germline carriers, confirming the underlying synthetic lethal mechanism. In vitro characterization of UV sensitization shows this toxicity is related to the CX-5461 chemotype, independent of G-quadruplex synthetic lethality. These results establish clinical proof-of-concept for this G-quadruplex stabilizer. Clinicaltrials.gov NCT02719977.
Deficient mismatch mutation repair mechanisms may sensitize endometrial cancers to anti-programmed death 1 (PD-1) therapies. Dostarlimab (TSR-042) is an investigational anti-PD-1 antibody that binds ...with high affinity to the PD-1 receptor.
To assess the antitumor activity and safety of dostarlimab for patients with deficient mismatch repair endometrial cancer.
This ongoing, open-label, single-group, multicenter study began part 1 on March 7, 2016, and began enrolling patients with deficient mismatch mutation repair endometrial cancer on May 8, 2017. Median follow-up was 11.2 months (range, 0.03 ongoing to 22.11 ongoing months; based on radiological assessments). Statistical analysis was performed July 8 to August 9, 2019.
Patients received 500 mg of dostarlimab intravenously every 3 weeks for 4 doses, then 1000 mg every 6 weeks until disease progression, treatment discontinuation, or withdrawal.
The primary end point was objective response rate and duration of response by blinded independent central review using Response Evaluation Criteria in Solid Tumors, version 1.1.
As of the data cutoff, 104 women (median age, 64.0 years range, 38-80 years) with deficient mismatch mutation repair endometrial cancers were enrolled and treated with dostarlimab. Of these, 71 had measurable disease at baseline and at 6 months or more of follow-up and were included in the analysis. There was a confirmed response in 30 patients (objective response rate, 42.3%; 95% CI, 30.6%-54.6%); 9 patients (12.7%) had a confirmed complete response, and 21 patients (29.6%) had a confirmed partial response. Responses were durable; the median duration of response was not reached (median follow-up was 11.2 months). The estimated likelihood of maintaining a response was 96.4% at 6 months and 76.8% at 12 months. Anemia (3 of 104 2.9%), colitis (2 of 104 1.9%), and diarrhea (2 of 104 1.9%) were the most common grade 3 or higher treatment-related adverse events.
In this nonrandomized trial, dostarlimab was associated with clinically meaningful and durable antitumor activity with an acceptable safety profile for patients with deficient mismatch mutation repair endometrial cancers after prior platinum-based chemotherapy.
ClinicalTrials.gov identifier: NCT02715284.
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