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.

FBXW7-loss Sensitizes Cells to ATR Inhibition Through Induced Mitotic Catastrophe

FBXW7 is a commonly mutated tumor suppressor gene that functions to regulate numerous oncogenes involved in cell-cycle regulation. Genome-wide CRISPR fitness screens identified a signature of DNA repair and DNA damage response genes as required for the growth of FBXW7-knockout cells. Guided by these findings, we show that FBXW7-mutant cells have high levels of replication stress, which results in a genotype-specific vulnerability to inhibition of the ATR signaling pathway, as these mutant cells become heavily reliant on a robust S-G2 checkpoint. ATR inhibition induces an accelerated S-phase, leading to mitotic catastrophe and cell death caused by the high replication stress present in FBXW7-/- cells. In addition, we provide evidence in cell and organoid studies, and mining of publicly available high-throughput drug screening efforts, that this genotype-specific vulnerability extends to multiple types of cancer, providing a rational means of identifying responsive patients for targeted therapy.

SIGNIFICANCE

We have elucidated the synthetic lethal interactions between FBXW7 mutation and DNA damage response genes, and highlighted the potential of ATR inhibitors as targeted therapies for cancers harboring FBXW7 alterations.

Rerouting the GPS Directing Immunotherapy in Endometrial Cancer

Mismatch repair (MMR) status alone is insufficient to guide the use of PD-(L)1 monotherapy in patients with endometrial cancer. Additional biomarkers, including tumor mutational burden and combined positive score, may help to identify patients with MMR-proficient tumors with a high probability of benefit from PD-(L)1 monotherapy, and those with MMR-deficient tumors who might require combination strategies. See related article by Oaknin et al., p. 4564.

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.

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.

A rapidly evolving landscape: immune checkpoint inhibitors in pretreated metastatic endometrial cancer

Background and objectives

Endometrial cancer is a common malignancy and recurrences can be fatal. Although platinum-pretreated endometrial tumors are commonly treated with anthracyclines and taxanes, there is no current standard of care. Both immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors (TKIs) have been extensively assessed in this setting, including tumors selected for DNA mismatch repair (MMR)/microsatellite instability (MSI) and programmed death-ligand 1 expression status. This review will provide evidence-based guidance on use of ICIs alone or in combination with TKIs in patients with pretreated advanced, persistent, or recurrent metastatic endometrial cancer.

Data sources and methods

Randomized phase II-III trials in unselected populations pretreated, recurrent, or metastatic endometrial cancer and phase I-II trials in biomarker selected populations were identified from PubMed as well as conference proceedings using the key search terms 'immune checkpoint inhibitors', 'endometrial cancer', and 'advanced'.

Results

A total of nine eligible studies were identified assessing ICI monotherapy for biomarker-selected or ICI plus TKI combinations and a dual ICI regimen for biomarker-unselected patients with pretreated recurrent or metastatic endometrial cancer. In MMR/MSI-selected tumors, five phase I/II studies evaluated ICI monotherapy indicating benefit in these patients. Only the phase III KEYNOTE-775 trial reported a statistically significant overall survival improvement for the combination of pembrolizumab plus lenvatinib compared with docetaxel or paclitaxel regardless of MMR/MSI status.

Conclusions

Pembrolizumab plus lenvatinib is indicated for patients with unselected pretreated metastatic endometrial cancer and pembrolizumab monotherapy is a preferred option for patients with MMRd/MSI-H tumors.

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.

Digital quantitative tissue image analysis of hypoxia in resected pancreatic ductal adenocarcinomas

Background

Tumor hypoxia is theorized to contribute to the aggressive biology of pancreatic ductal adenocarcinoma (PDAC). We previously reported that hypoxia correlated with rapid tumor growth and metastasis in patient-derived xenografts. Anticipating a prognostic relevance of hypoxia in patient tumors, we developed protocols for automated semi-quantitative image analysis to provide an objective, observer-independent measure of hypoxia. We further validated this method which can reproducibly estimate pimonidazole-detectable hypoxia in a high-through put manner.

Methods

We studied the performance of three automated image analysis platforms in scoring pimonidazole-detectable hypoxia in resected PDAC (n = 10) in a cohort of patients enrolled in PIMO-PANC. Multiple stained tumor sections were analyzed on three independent image-analysis platforms, Aperio Genie (AG), Definiens Tissue Studio (TS), and Definiens Developer (DD), which comprised of a customized rule set.

Results

The output from Aperio Genie (AG) had good concordance with manual scoring, but the workflow was resource-intensive and not suited for high-throughput analysis. TS analysis had high levels of variability related to misclassification of cells class, while the customized rule set of DD had a high level of reliability with an intraclass coefficient of more than 85%.

Discussion

This work demonstrates the feasibility of developing a robust, high-performance pipeline for an automated, quantitative scoring of pimonidazole-detectable hypoxia in patient tumors.

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]

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.

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.

Research biopsies in patients with gynecologic cancers: patient-reported outcomes, perceptions, and preferences

BACKGROUND

Despite the growing integration of mandatory biopsies for correlative endpoints within oncology clinical trials, there are sparse data on patient-reported outcomes, perceptions, and preferences.

OBJECTIVE

This study aimed to prospectively assess the impact of research biopsies on the quality of life in patients with gynecologic cancer, evaluate patient-reported outcomes, and determine factors associated with patients' willingness to undergo sequential biopsies.

STUDY DESIGN

We conducted a prospective study in patients with gynecologic malignancies undergoing research biopsies between 2015 and 2019 at Princess Margaret Cancer Centre (ClinicalTrials.gov Identifier: NCT02334761). Here, we report the results of the paper-based surveys performed before and 1 week after biopsy. Although the questionnaires each assessed the impact of anxiety using a modified version of the Hospital Anxiety and Depression Scale, the postbiopsy questionnaire specifically assessed the likelihood of future biopsies, postbiopsy symptoms, complications, and perceptions.

RESULTS

A total of 129 patients were enrolled, of which 91 (70.5%) completed at least 1 questionnaire. These patients had either ovarian (89%; 81 of 91) or endometrial cancer (11%; 10 of 91). Of all biopsies taken, 75% were from the abdomen or pelvis (67 of 89). There was 1 clinician-reported complication, a perihepatic hematoma (1%). Pain during the biopsy and physical discomfort were experienced by 60.3% (41 of 68) and 61.8% (42 of 68), respectively. Embarrassment and loss of dignity were experienced by 13.2% (9 of 68) and 11.8% (8 of 68), respectively. Although the mean Hospital Anxiety and Depression Scale score was in the normal range before and after biopsy, there was a significant decline in the total score after the biopsy (prebiopsy, 5.3 [standard deviation, 4.7] vs postbiopsy, 3.7 [standard deviation, 4.5]; P=.005); 84% of subjects (58 of 69) stated that they would definitely or likely consent to another biopsy. There was no impact on patients' willingness for future biopsies based on Eastern Cooperative Oncology Group status, biopsy site, age, number of cores, and pain during the biopsy; however, subjects who reported feeling physically uncomfortable (odds ratio, 0.14; P=.005), embarrassed (odds ratio, 0.03; P=.004) or experienced loss of dignity (odds ratio, 0.05; P=.01) during the biopsy and those who experienced flu-like symptoms (odds ratio, 0.2; P=.018) or felt feverish (odds ratio, 0.2; P=.035) 1 week after biopsy, were less likely to undergo a sequential biopsy. Similarly, those with higher Hospital Anxiety and Depression Scale scores before biopsy (odds ratio, 0.83; P=.008) and after biopsy (odds ratio, 0.8; P=.003) were less likely to consent for another biopsy.

CONCLUSION

Research biopsies were generally well accepted. Most patients (83%) were willing to undergo serial biopsies if necessary. Addressing the potentially modifiable psychosocial aspects of the procedure may improve the experience with research biopsies for patients with gynecologic cancers.

Safety and Antitumor Activity of α-PD-L1 Antibody as Monotherapy or in Combination with α-TIM-3 Antibody in Patients with Microsatellite Instability-High/Mismatch Repair-Deficient Tumors

PURPOSE

Immune checkpoint inhibitors show high response rates and durable clinical benefit in microsatellite instability-high/mismatch repair-deficient (MSI-H/dMMR) tumors. However, 50%-60% do not respond to single-agent anti-programmed death-1/programmed death ligand 1 (PD-1/PD-L1) antibodies, and approximately 50% of responders relapse within 6-12 months. This phase Ib trial evaluated safety and antitumor activity of anti-PD-L1 antibody LY3300054 monotherapy or in combination with anti-TIM-3 antibody LY3321367 in patients with MSI-H/dMMR advanced solid tumors.

PATIENTS AND METHODS

Eligible patients ≥18 years without prior anti-PD-1/PD-L1 therapy received LY3300054 monotherapy (N = 40) or combination (N = 20); patients with PD-1/PD-L1 inhibitor-resistant/refractory tumors received the combination (N = 22). LY3300054 (700 mg) and anti-TIM-3 antibody (cycles 1-2: 1,200 mg, cycle 3 onward: 600 mg) were administered intravenously every 2 weeks. Primary endpoints were safety and tolerability.

RESULTS

Eighty-two patients were enrolled. Most had colorectal (n = 39, 47.6%) or endometrial (n = 14, 17.1%) tumors. More than 70% of patients in the PD-1/PD-L1 inhibitor-resistant/refractory combination cohort had received ≥3 treatment lines. Treatment-related adverse events (TRAE) occurred in 22 patients (55.0%) receiving monotherapy, 13 (65.0%) in the PD-1/PD-L1 inhibitor-naïve combination cohort, and 6 (27.3%) in the PD-1/PD-L1 inhibitor-resistant/refractory combination cohort. A total of 2 patients (5.0%) receiving monotherapy and 3 (7.1%) receiving the combination experienced grade ≥3 TRAEs. Objective responses occurred in 13 patients (32.5%) with monotherapy, 9 (45.0%) in the PD-1/PD-L1 inhibitor-naïve combination cohort, and 1 patient (4.5%) in the PD-1/PD-L1 inhibitor-resistant/refractory combination cohort.

CONCLUSIONS

LY3300054 monotherapy and combined LY3300054/anti-TIM-3 had manageable safety profiles. Both regimens showed promising clinical activity against PD-1/PD-L1 inhibitor-naïve MSI-H/dMMR tumors. The combination had limited clinical benefit in patients with PD-1/PD-L1 inhibitor-resistant/refractory MSI-H/dMMR tumors.

Phase II trial assessing niraparib with or without dostarlimab (anti-PD-1) in recurrent endometrial carcinoma

5574

Background: Treatment options in recurrent endometrial carcinoma (EC) are limited. Endometrioid EC shows alterations in PTEN, a possible biomarker of response to PARP inhibitors (PARPi). Similarly, homologous recombination deficiency (HRd), a biomarker of response to PARPi in ovarian cancer, is associated with serous EC harbouring TP53 mutations. Preclinical EC models have shown synergy between combining a PARPi and immune checkpoint inhibitor (ICI). Methods: A pilot multi-centre, non-randomized, phase II trial enrolled patients (pts) with recurrent serous or endometrioid EC in two consecutive cohorts (NCT03016338). In the first cohort (C1) pts received niraparib 200 or 300 mg qd, based on baseline body weight and platelet count, in 4 week (w) cycles. In the second cohort (C2) niraparib was given with dostarlimab 500 mg q 3 w for 4 cycles, followed by 1000 mg q 6 w thereafter. There was no limit on prior lines of therapy. Prior ICI was not allowed in C2. Primary endpoint was clinical benefit rate (CBR; complete, partial response or stable disease ≥16w). Secondary endpoints included toxicity assessment and ORR. CT scans were performed q 8 w. Potential biomarkers were assessed in archival tissue by IHC (PTEN, p53, MMR, PDL-1 [threshold 1%]) and a NGS panel (including TP53, PTEN, POLE and other HRd genes). Tumour mutational burden-high (TMBh) was defined as top 20% mutation load. Results: In C1, 25 pts were enrolled (23 evaluable for response). Median age was 69 years old, 64% had serous EC, 72% were platinum resistant (PlatR) and median prior therapies was 2 (range 1-4). Median number of cycles was 3. The CBR was 20% (95% CI: 9-39) and median clinical benefit (CB) duration was 5.3 (1.8-7.2) months. The ORR was 1/23 (4%; 0-20). Related grade (g) ≥3 AEs ≥10% were anemia (24%), fatigue (16%) and thrombocytopenia (16%). In C2, 22 pts were enrolled (all evaluable) and two continue on-treatment. Median age was 64 years old, 46% had serous EC, 68% were PlatR and median prior therapies was 2 (1-6). Three pts had MMR deficient (MMRd) tumors (14%) and one pt a POLE mutation (5%). Median number of cycles was 3. The CBR was 31.8% (16-53) and median CB duration was 6.8 months (3.7-9.5). The ORR was 3/22 (14%; 3-35), out of the three responders one had MMRd and one a POLE mutation. Related g≥3 AEs ≥10% were anemia (27%) and neutropenia (14%). No significant correlation was detected between CB and IHC markers (PTEN, p53, MMR, PDL-1), or NGS ( PTEN, TP53, HRd TMBh) in C1 and C2. Conclusions: Niraparib as single agent for treatment in a PlatR enriched recurrent EC population showed modest activity with clinical benefit rate at 16w of 20%. The combination of niraparib and dostarlimab showed a clinical benefit rate at 16w of 31.8% in a predominantly PlatR recurrent EC. PTEN loss by IHC or NGS, and alterations in HRd genes did not correlate with clinical benefit. Clinical trial information: NCT03016338.

Patient self-reporting of tolerability using PRO-CTCAE: A randomized double-blind placebo controlled phase II trial comparing gemcitabine in combination with adavosertib or placebo in women with platinum resistant epithelial ovarian cancer

5541

Background: A 4 month improvement in OS was demonstrated when Wee1 inhibitor adavosertib (Ad) and gemcitabine (G; arm A) was compared to G and placebo (P; arm B) in a phase 2 trial in recurrent ovarian cancer (NCT02151292). The patient reported outcome version of the CTCAE (PRO-CTCAE) was used to capture self-report of the frequency, severity and/or interference (scored 0-4; higher scores indicating worse symptomatic adverse events [syAEs]). Methods: Ad/P was given orally on D1-2, D8-9, D15-16 with G D1, D8, D15 in a 28-day cycle. English speaking pts in 2 centres completed PRO-CTCAE items electronically in clinic at baseline, D1 and D15 of each cycle and off treatment. An exploratory objective was to characterize syAEs in the first 3 months of therapy. We calculated 12-week area under the curve (AUC12w) as a measure of syAE over time and incremental AUC12w (iAUC12w) for adjustment to baseline syAEs and compared arms A and B using an independent samples t-test. We assessed proportion of scores 3-4 at 6 time-points and compared them using Fisher’s Exact Test at each survey. Results: 51 pts were enrolled and completed ≥1 survey, 47 were evaluable for primary outcome (arm A: 28, B: 19). ECOG status was ≤1 in 44/47 pts. Median number of cycles of therapy were 5 (1-16) in arm A, and 2 (1-16) in B. Survey completion rates were high (arm A 93%, B 95%). Mean AUC12w fatigue severity (A 152 [standard error 9] vs B 112 [10]; p = 0.005) and interference (A 144 [11] vs 98 [15]; p = 0.018), diarrhea frequency (A 70 [12] vs B 33 [9]; p = 0.014), mucositis (A 23 [6] vs B 6 [3]; p = 0.012) and difficulty swallowing severity (A 10 [3] vs B 2 [2]; p = 0.023) were higher in arm A (any grade). There were no statistically significant between-arm differences in abdominal pain, bloating, nausea, vomiting and anxiety. The iAUC12w was significantly higher in arm A vs B for difficulty swallowing severity (A 10.1 [3] vs B -2.7 [4.7]; p = 0.02), mucositis severity (A 19.9 [6.6] vs B -3.1 [6.9]; p = 0.02) and fatigue severity (A 35.2 [8.2] vs B -3.1 [9.8]; p = 0.005). Proportions with high scores (3-4) were only significantly higher at C1D15 for fatigue severity in arm A (A 55% vs B 19%, p = 0.044). No significant differences were seen in other 3-4 scores per survey time. Conclusions: This is the first study evaluating pts self-reported toxicity with adavosertib in a randomized setting, allowing pts self-evaluation of toxicity in the context of improved PFS and OS. Greater fatigue, diarrhea, mucositis and difficulty swallowing were experienced by pts receiving adavosertib and gemcitabine, but score 3-4 reached significance on C1D15 fatigue only. No significant differences were detected in syAE profile for nausea, vomiting, abdominal pain, bloating and anxiety. This approach allows objective assessment of pts perception of toxicity with complex therapy. Clinical trial information: NCT02151292.

Amplifying the Voice of the Whispering Cancer

Nontargeted circulating tumor DNA (ctDNA) whole-genome sequencing is a novel strategy for genomic characterization of high-grade serous ovarian cancer. Changes in ctDNA levels are a sensitive indicator of disease burden with an average lead time of 6 months to clinical progression. This presents a unique opportunity to identify pathways driving progression as molecular vulnerabilities for clinical drug development.See related article by Paracchini et al., p. 2549.

Adavosertib plus gemcitabine for platinum-resistant or platinum-refractory recurrent ovarian cancer: a double-blind, randomised, placebo-controlled, phase 2 trial

BACKGROUND

The Wee1 (WEE1hu) inhibitor adavosertib and gemcitabine have shown preclinical synergy and promising activity in early phase clinical trials. We aimed to determine the efficacy of this combination in patients with ovarian cancer.

METHODS

In this double-blind, randomised, placebo-controlled, phase 2 trial, women with measurable recurrent platinum-resistant or platinum-refractory high-grade serous ovarian cancer were recruited from 11 academic centres in the USA and Canada. Women were eligible if they were aged 18 years or older, had an Eastern Cooperative Oncology Group performance status of 0-2, a life expectancy of more than 3 months, and normal organ and marrow function. Women with ovarian cancer of non-high-grade serous histology were eligible for enrolment in a non-randomised exploratory cohort. Eligible participants with high-grade serous ovarian cancer were randomly assigned (2:1), using block randomisation (block size of three and six) and no stratification, to receive intravenous gemcitabine (1000 mg/m2 on days 1, 8, and 15) with either oral adavosertib (175 mg) or identical placebo once daily on days 1, 2, 8, 9, 15, and 16, in 28-day cycles until disease progression or unacceptable toxicity. Patients and the team caring for each patient were masked to treatment assignment. The primary endpoint was progression-free survival. The safety and efficacy analysis population comprised all patients who received at least one dose of treatment. The trial is registered with ClinicalTrials.gov, NCT02151292, and is closed to accrual.

FINDINGS

Between Sept 22, 2014, and May 30, 2018, 124 women were enrolled, of whom 99 had high-grade serous ovarian cancer and were randomly assigned to adavosertib plus gemcitabine (65 [66%]) or placebo plus gemcitabine (34 [34%]). 25 women with non-high-grade serous ovarian cancer were enrolled in the exploratory cohort. After randomisation, five patients with high-grade serous ovarian cancer were found to be ineligible (four in the experimental group and one in the control group) and did not receive treatment. Median age for all treated patients (n=119) was 62 years (IQR 54-67). Progression-free survival was longer with adavosertib plus gemcitabine (median 4·6 months [95% CI 3·6-6·4] with adavosertib plus gemcitabine vs 3·0 months [1·8-3·8] with placebo plus gemcitabine; hazard ratio 0·55 [95% CI 0·35-0·90]; log-rank p=0·015). The most frequent grade 3 or worse adverse events were haematological (neutropenia in 38 [62%] of 61 participants in the adavosertib plus gemcitabine group vs ten [30%] of 33 in the placebo plus gemcitabine group; thrombocytopenia in 19 [31%] of 61 in the adavosertib plus gemcitabine group vs two [6%] of 33 in the placebo plus gemcitabine group). There were no treatment-related deaths; two patients (one in each group in the high-grade serous ovarian cancer cohort) died while on study medication (from sepsis in the experimental group and from disease progression in the control group).

INTERPRETATION

The observed clinical efficacy of a Wee1 inhibitor combined with gemcitabine supports ongoing assessment of DNA damage response drugs in high-grade serous ovarian cancer, a TP53-mutated tumour type with high replication stress. This therapeutic approach might be applicable to other tumour types with high replication stress; larger confirmatory studies are required.

FUNDING

US National Cancer Institute Cancer Therapy Evaluation Program, Ontario Institute for Cancer Research, US Department of Defense, Princess Margaret Cancer Foundation, and AstraZeneca.

Biomarkers of outcome to weekly paclitaxel in epithelial ovarian cancer

OBJECTIVE

We sought to evaluate the role of intrinsic chromosomal aberrations in determining favorable outcome to weekly paclitaxel (WP) in patients with epithelial ovarian cancer (EOC).

METHODS

We evaluated the common genomic aberrations of two patients with EOC and exceptional WP response in the GENIUS study (NCT03740503). We then searched for potential markers of unusual outcomes to WP in a validation cohort. We performed shallow whole genome sequencing (sWGS) in the tumor tissue of women with EOC considered as short-responders (SR; progression with ≤3 cycles) and long-responders (LR; response at ≥8 cycles) to WP monotherapy.

RESULTS

We identified two women with exceptional response to WP, lasting over four years, who shared chromosome 8 gain as a common genomic aberration. In order to validate our findings, we reviewed 188 patients with EOC treated with WP and selected 61 women (39 SR, 22 LR) with unusual responses. By sWGS, there was no differential alterations in the copy number changes in chromosome 8, or in genes related to angiogenesis, tubulin superfamily, cell-cycle, apoptosis and paclitaxel metabolism or transportation pathways. Amongst the LR group, we identified six exceptionally long responders (ExLR), with responses lasting over a year. In an exploratory analysis, there was increased amplification of angiogenesis (VEGFB, MMP9), tubulin superfamily (TSC2) and apoptosis related genes (BCL2L1, BAD) in ExLR compared to SR. We identified one patient with a complete response to WP for over 7 years. Molecular profiling identified unique amplifications in interleukin related genes (CXCR1, CXCR2, IL1A, IL1B), not detected in other patients.

CONCLUSION

Intrinsic tumor pathways may impact outcome with weekly paclitaxel monotherapy and further investigations are required.

Phase I/II trial assessing hydroxychloroquine and itraconazole in women with advanced platinum-resistant epithelial ovarian cancer (EOC) (HYDRA-01)

6049

Background: Autophagy is a mechanism of resistance to platinum chemotherapy. Itraconazole (Itr), an antifungal agent, can alter cholesterol-trafficking, leading to accumulation of cholesterol in endosomes/lysosomes and resulting in cancer cell death. Itr is also involved in regulation of angiogenesis, mTOR and Hedgehog pathways. In preclinical studies the Itr effect can be enhanced by combining it with the autophagy inhibitor hydroxychloroquine (H). Drug repurposing studies with Itr have shown a signal of activity in prostate, lung and basal cell carcinoma. Methods: A rolling-6 phase I design was used to enroll patients (pts) with platinum-resistant/refractory EOC. Pts received Itr 300mg twice daily (BID) with H as per dose escalation schedule (range 200mg BID- 600mg BID), continuously in a 28-day cycle. Primary objective was establishment of MTD; secondary objective was objective response rate, progression free survival (PFS). Pre- and on-treatment biopsies were mandatory to evaluate exploratory objectives assessing effect on apoptosis/proliferation, angiogenesis, cholesterol metabolism and mechanism of cytotoxicity. RNAseq and IHC was performed in the sequential biopsies. Results: 11 pts were enrolled, 9 evaluable for efficacy. Histology was high 91% and low-grade serous 9%. Median lines of prior therapy was 7. RP2D was Itr 300mg BID and H 600mg BID. 1 DLT was seen in dose-level 2 was grade 3 hypertension. Other grade ≥3 related toxicity were grade 3 hypokalemia and grade 4 QTc prolongation (1 pt, dose-level 3). No objective responses were observed and 1 pt had stable disease. Median PFS was 1.6 months (1-1.7). Pre- and on-treatment biopsy was available for 10 pts. Increase in autophagy related protein, LC3, P62 and lysosomal marker, LAMP1, expression by IHC was identified in 3 pts. RNAseq revealed no differences between pre and on treatment samples in cholesterol homeostasis, angiogenesis, lysosomal-autophagy, PI3K-mTOR pathways. Conclusions: The combination of Itr and H was feasible but did not show antitumour activity in this heavily pre-treated platinum resistant EOC population. Increase of IHC expression in autophagy related proteins was detected in 30% of pts but did not correlate with patient benefit. Clinical trial information: NCT03081702. [Table: see text]

Bridging the gap between micro- and macro-scales in medical imaging with textural analysis - A biological basis for CT radiomics classifiers?

INTRODUCTION

Studies suggest there is utility in computed tomography (CT) radiomics for pancreatic disease; however, the precise biological interpretation of its features is unclear. In this manuscript, we present a novel approach towards this interpretation by investigating sub-micron tissue structure using digital pathology.

METHODS

A classification-to attenuation (CAT) function was developed and applied to digital pathology images to create sub-micron linear attenuation maps. From these maps, grey level co-occurrence matrix (GLCM) features were extracted and compared to pathology features. To simulate the spatial frequency loss in a CT scanner, the attenuation maps were convolved with a point spread function (PSF) and subsequently down-sampled. GLCM features were extracted from these down-sampled maps to assess feature stability as a function of spatial frequency loss.

RESULTS

Two GLCM features were shown to be strongly and positively correlated (r = 0.8) with underlying characteristics of the tumor microenvironment, namely percent pimonidazole staining in the tumor. All features underwent marked change as a function of spatial frequency loss; progressively larger spatial frequency losses resulted in progressively larger inter-tumor standard deviations; two GLCM features exhibited stability up to a 100 µm pixel size.

CONCLUSION

This work represents a necessary step towards understanding the biological significance of radiomics. Our preliminary results suggest that cellular metrics of pimonidazole-detectable hypoxia correlate with sub-micron attenuation coefficient texture; however, the consistency of these textures in face of spatial frequency loss is detrimental for robust radiomics. Further study in larger data sets may elucidate additional, potentially more robust features of biologic and clinical relevance.

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1-3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10-18.

A randomized, multicenter, phase II trial of gemcitabine (G), cisplatin (C) +/- veliparib (V) in patients with pancreas adenocarcinoma (PDAC) and a known germline (g)BRCA/ PALB2 mutation

639

Background: gBRCA 1,2 mutations occur in 5-8% PDAC. Platinum and poly-ADP ribose polymerase inhibitors (PARPi) effective in BRCA-mut cancers. Phase I GC + V high RR 78%; combination may delay resistance in PDAC (O’Reilly, Cancer, 2018). Herein, we evaluate GC +/- V in a multi-national, randomized phase II trial. Methods: Eligibility: Untreated germline (g)BRCA, PALB2 mut PDAC; measurable stage III/IV; ECOG 0-1. Randomized 1:1 Arm A or B. Treatment: Arm A: G 600 mg/m2 IV, C 25 mg/m2 IV, d3 and 10, V 80 mg PO BID day 1-12, all q 3 weeks or Arm B: GC only. Primary endpoint: RECIST 1.1 response rate (RR). Simon 2-stage per arm: null hypothesis 10% vs promising 28%; type I, II error 10%. Secondary endpoints: progression-free survival (PFS), OS (m), disease control rate (CR+PR+SD), safety and correlative analyses. PFS, OS compared between arms using log-rank test and RR, DCR using Fisher’s exact test between arms. Results: N = 52 enrolled 01/14- 11/18. N = 2 withdrew Arm B. N = 50 for ITT. Male = 22 (44%), Female = 28. Median age = 64 years (range 37-82). BRCA1 N = 12, BRCA2 N = 35, PALB2 N = 3. Stage III N = 8; Stage IV N = 42. Hematologic Toxicity: Arm A vs Arm B: Gd 3-4 neutropenia 13 (48%) vs 7 (30%); Gd 3-4 platelets 15 (55%) vs 2 (9%); Gd 3-4 anemia 14 (52%) vs 8 (35%). Non-hematologic toxicity similar Arm A vs B. Exploratory analyses (combined Arms): Med OS if > 4 m platinum → PARPi: 23 m (95%CI 6.5- 53.9). Med OS by BRCA: BRCA1: 14 m (8.1- 18.5); BRCA2: 20.2 m (12.3- 24.4). Med OS by ECOG: ECOG 0: 23 m (13.8- 24.5); ECOG 1: 14.3 (8.1 vs 16.4). Two-year OS rate for entire cohort: 30.6% and 3-year OS: 17.8%. Conclusions: GC +/- V very active in gBRCA/PALB2 mut PDAC with high RR, PFS, OS with both A, B significantly exceeding threshold RR. Improved DCR arm A vs B, but with greater heme toxicity A vs B. Study confirms GC as reference treatment in gBRCA/PALB2 with durable survival in subset. Funding: National Cancer Institute, CTEP, Lustgarten Foundation, AbbVie. Clinical trial information: NCT01585805 . [Table: see text]

Phase II Trial of Cabozantinib in Recurrent/Metastatic Endometrial Cancer: A Study of the Princess Margaret, Chicago, and California Consortia (NCI9322/PHL86)

PURPOSE

The relevance of the MET/hepatocyte growth factor pathway in endometrial cancer tumor biology supports the clinical evaluation of cabozantinib in this disease.

PATIENTS AND METHODS

PHL86/NCI#9322 (NCT01935934) is a single arm study that evaluated cabozantinib (60 mg once daily) in women with endometrial cancer with progression after chemotherapy. Coprimary endpoints were response rate and 12-week progression-free-survival (PFS). Patients with uncommon histology endometrial cancer (eg, carcinosarcoma and clear cell) were enrolled in a parallel exploratory cohort.

RESULTS

A total of 102 patients were accrued. Among 36 endometrioid histology patients, response rate was 14%, 12-week PFS rate was 67%, and median PFS was 4.8 months. In serous cohort of 34 patients, response rate was 12%, 12-week PFS was 56%, and median PFS was 4.0 months. In a separate cohort of 32 patients with uncommon histology endometrial cancer (including carcinosarcoma), response rate was 6% and 12-week PFS was 47%. Six patients were on treatment for >12 months, including two for >30 months. Common cabozantinib-related toxicities (>30% patients) included hypertension, fatigue, diarrhea, nausea, and hand-foot syndrome. Gastrointestinal fistula/perforation occurred in four of 70 (6%) patients with serous/endometrioid cancer and five of 32 (16%) patients in exploratory cohort. We observed increased frequency of responses with somatic CTNNB1 mutation [four partial responses (PRs) in 10 patients, median PFS 7.6 months] and concurrent KRAS and PTEN/PIK3CA mutations (three PRs in 12 patients, median PFS 5.9 months).

CONCLUSIONS

Cabozantinib has activity in serous and endometrioid histology endometrial cancer. These results support further evaluation in genomically characterized patient cohorts.

Implementation of malignant bowel obstruction multidisciplinary case conferences (MCCs) to improve clinical decision making in malignant bowel obstruction (MBO) in gynecologic oncology

e18322

Background: Though patients (pts) with gynecological cancer are at higher risk of MBO, clinical management is not well defined. We implemented a coordinated team approach to evaluate MBO at Princess Margaret Cancer Centre. The Princess Margaret Cancer Centre inter-professional MBO management program includes nurse led ambulatory symptom management, inpatient treatment algorithm, patient directed bowel management education & MCCs. This study evaluates the utility of MBO MCC on clinical decision making in gynecologic oncology. Methods: Monthly MBO MCCs are conducted to discuss complex clinical management issues. A clinical summary is presented prior to the discussion with each case incorporating radiology review followed by interdisciplinary discussion. In this study, the initial management plan was compared to post-MCC consensus. A change in plan was defined as a consensus plan different from the pre-MCC plan or no definite plan prior to MCC. Barriers to implementation of the consensus were analyzed. Results: From December 2016 to November 2018, 90 pts were discussed in 22 MCCs. Of these, 60 had high grade serous ovarian carcinoma (67%) & 64 had small bowel obstruction (71%). Discussion in MCCs lead to a change in management plan in 49 cases(54%). These changes included recommendations for palliative surgery (25%) or radiation (10%), interventional radiology (23%), pharmacologic management alone (14%), imaging studies (4%) & total parenteral nutrition (TPN) (4%). Chemotherapy continuation, break or regimen changes were recommended in 20%. MCC consensus plan could not be implemented in 11 cases (23%). The barriers were refusal of surgery (8%), interventional radiology procedures (2%), TPN (4%) by patients, functional decline (6%) & inability to create a colostomy due to dense adhesions (2%). During MCC referrals to the dietitian & palliative care team were planned for 16 (18%) & 22 (24%) pts respectively. Conclusions: Interdisciplinary MBO MCCs have a significant impact on decision making in complex MBO cases. Radiology review & group discussion facilitates greater clarity in formulation of a management plan.

Clinical outcome of sequential chemotherapy after immune checkpoint inhibitors in advanced ovarian cancer

5580

Background: Immunomodulation through check point inhibition is an important treatment strategy in many cancers. In ovarian cancer (OC) response rates with immune checkpoint inhibitors (ICI) alone are around 10%. Chemotherapy antitumoural effect is driven by cytotoxicity and immunomodulatory effect. ICI treatment reduces tumour induced immune-tolerance improving immunocompetence, essential for chemotherapy effect. We chose to investigate clinical outcomes of chemotherapy post ICI in women with OC. Methods: The Tumor Immunotherapy Program (TIP) database at the Princess Margaret Cancer Centre identified patients with OC treated with chemotherapy after ICI from 2011 to 2018. Evaluation of clinical outcomes including response rate (RR), progression free survival (PFS) and overall survival (OS) was assessed for pre ICI, ICI and post ICI. Results: 40 women with OC were treated with chemotherapy after ICI. 90% had high grade serous histology, 7.5% carcinosarcoma and 2.5% low grade serous. Median number of pre ICI treatment lines was 3 (1-8) and 2 (1-6) in the post ICI setting. Median time of ICI initiation from diagnosis was 3 years. At ICI all patients had PS 0-1 and treated in clinical trials. 2% of the patients had platinum refractory disease, 88% had platinum resistant disease and 10% platinum sensitive disease. 50% were treated with ICI single agent, 16% were treated with ICI combined with chemotherapy, 14% ICI combo and 17% ICI in combination with other agents. Patients were treated for a median of 3 cycles (1-26). 8% experienced PR, 18% SD, no CR were seen. 67% of the patients discontinued treatment due to PD, 25% due to toxicity. Last treatment in pre ICI RR was 35%. First treatment in post ICI RR was 30%. RR for each treatment used in post ICI was 9% for liposomal doxorubicin, 25% for single agent platinum, 29% for weekly paclitaxel and 67% for chemotherapy with bevacizumab. Median PFS in the last pre ICI treatment was 6.5m and 5m in the first post ICI treatment. Median PFS and OS for all the population was 53m and 54m respectively. Conclusions: ICI are associated with modest activity in OC, planned clinical trials exploring systematic sequential therapy integrating ICI, targeted agents and chemotherapy are needed.

Evolve: A post PARP inhibitor clinical translational phase II trial of cediranib-olaparib in ovarian cancer—A Princess Margaret Consortium – GCIG Phase II Trial

5521

Background: PARP inhibitors (PARPi) are approved therapies in high grade serous ovarian cancer (HGSOC). There are few studies after PARPi progression and correlation with dynamic changes in resistance. We hypothesized that PARPi resistance could be overcome by adding an anti-angiogenic. Methods: We report the first phase 2 trial assessing the combination of olaparib and cediranib after PARPi failure in HGSOC. This investigator initiated study included three cohorts of 10 evaluable patients (pts): i) platinum sensitive post PARPi (PS), ii) platinum resistant post PARPi (PR) and iii) exploratory cohort of pts re-challenged with chemotherapy post PARPi progression (PE) (NCT02681237). The primary objective was to determine objective response rate by RECIST v1.1 and progression free survival (PFS) at 16 weeks. Secondary objectives were to evaluate safety, PFS, overall survival (OS) and mechanisms of PARPi resistance. Pts who had radiographic progression on any PARPi were eligible. Archival tumor at initial diagnosis and baseline tumor biopsy at PARPi progression were mandatory. Pts received olaparib tablets 150mg BID with cediranib 20mg QD until progression or unacceptable toxicity. CT scans were performed every 8 weeks. Whole exome and RNA sequencing were performed on paired tumors tissues. Results: Thirty-four pts were enrolled. BRCA1/2 mutations were found in 9/11 PS, 8/10 PR and 7/13 PE pts. By RECIST1.1, four partial responses were observed (2 in PR and 2 in PE cohorts) and 18 stable disease. The 16−week PFS was 54.5% (31.8−93.6) in PS, 50% (26.9−92.9) in PR and 36% (15.6−82.8) in PE, respectively. OS at 1 year was 81.8% (61.9−100) in PS, 64.8% (39.3−100) in PR and 39.1% (14.7−100) in PE. Main related adverse events were anemia, hypertension, diarrhea and fatigue, grade 3 < 10%. Molecular analyses identified different mechanisms of PARPi resistance in ~77% of evaluable pts with matched pre-post PARPi progression biopsies such as reversion mutations in BRCA1/2 and other homologous repair (HR) genes; BRCA, HR and MDR upregulation, CCNE amplification and RIG-I like receptor downregulation. Conclusions: Treatment with olaparib-cediranib after PARPi failure was feasible and met the predefined bar for efficacy in each cohort. This is the largest clinical trial prospectively evaluating PARPi failure and correlating tissue genomic mechanisms of resistance. Clinical trial information: NCT02681237.

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

5518

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

Impact of somatic molecular profiling on clinical trial outcomes in rare epithelial gynecologic cancer patients

OBJECTIVES

Conducting clinical trials in rare malignancies is challenging due to the limited number of patients and differences in biologic behavior. We investigated the feasibility and clinical utility of using genomic profiling for rare gynecologic malignancies.

METHODS

Rare epithelial gynecologic cancer patients were analyzed for somatic variants through an institutional molecular profiling program using the Sequenom MassArray platform or the TruSeq Amplicon Cancer Panel on the MiSeq platform. Clinical trial outcomes by RECIST 1.1, and time on treatment were evaluated.

RESULTS

From March 2012 to November 2015, 767 gynecologic patients were enrolled and 194 (27%) were classified as rare epithelial malignancies. At least one somatic mutation was identified in 72% of patients, most commonly in TP53 (39%), KRAS (28%) and PIK3CA (27%). A total of 14% of patients were treated on genotype-matched trials. There were no significant differences in overall response rate between genotype-matched versus unmatched trials, nor in median time on treatment between genotype trials and the immediate prior systemic standard treatment. Among 13 evaluable Low Grade Serous ovarian cancer patients treated on genotype-matched trials with MEK inhibitor-based targeted combinations, there were four partial responses.

CONCLUSIONS

Somatic molecular profiling is feasible and enables the identification of patients with rare gynecologic cancers who are candidates for genotype-matched clinical trials. Genotype-matched trials, predominantly MEK-based combinations in KRAS and/or NRAS mutant Low Grade Serous ovarian cancer patients, and genotype-unmatched trials, have shown potential clinical activity. Prospective trials with integrated genotyping are warranted to assess the clinical utility of next generation sequencing tests as a standard clinical application in rare malignancies.

Impact of an inter-professional clinic on pancreatic cancer outcomes: The Princess Margaret Cancer Centre (PM) experience

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Background: Patients with pancreatic ductal adenocarcinoma (PDAC) have limited treatment options. Management of complex symptoms and psychosocial implications requires an interprofessional approach as prognosis is often measured in months. A multidisciplinary approach has been associated with improvement in clinical outcomes including survival. We aimed to evaluate the impact of an inter-professional approach for PDAC patients at the Wallace McCain Centre for Pancreatic Cancer (WMCPC) at PM on their management and clinical outcomes. Methods: We undertook retrospective review of all patients with PDAC seen at PM two years before (July ‘12 – June ‘14) and two years after (July ‘14 – June ‘16) establishment of the WMCPC. Standard therapies (surgical approach, chemotherapy, radiation therapy) were the same during both time periods. Comparison of overall survival (OS), stage at diagnosis, surgical outcomes, waiting times, and proportion seen by social worker, dietician and clinical nurse specialist (CNS) was explored with descriptive statistic and survival analysis. Results: A total of 993 patients were reviewed; 482 patients pre- and 511 patients post-WMCPC. Age (median 67 yrs), sex (54% men) and stage III/IV (52%) were similar in both groups. There was a trend to improved OS in the post-WMCPC group (9.6 vs. 10.9 m; p = 0.055); multivariable analysis found a significant improvement in OS after adjustment for performance status and stage (p = 0.023; HR 0.84, 95% CI 0.72-0.98). Rate of R0 versus R1/R2 resection for curative surgery (n = 264, 28%) was similar in both groups. Time from referral to first clinic visit significantly decreased from 13.4 to 8.8 days in the post-WMCPC group (p < 0.001) as did time from first clinic appointment to diagnostic biopsy (25.9 vs. 16.9 days, p = 0.022). Patients in the post-WMCPC were more frequently seen by a social worker, dietician or CNS (8% vs. 38%, 9% vs. 35% and 31% vs. 50% respectively, p < 0.001). Conclusions: Establishment of an interprofessional clinic for the treatment of PDAC patients at PM has streamlined diagnosis, aided symptom management and improved overall survival. This has implications for planning care delivery models and proves the value of this intervention.

An updated retrospective review of the safety and efficacy of sorafenib for recurrent hepatocellular carcinoma post-liver transplantation

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Background: Orthotopic liver transplantation (OLT) is a potentially curative treatment for hepatocellular carcinoma (HCC). Despite an estimated recurrence rate between 15%-20%, there is currently no proven systemic therapy for the treatment of HCC relapse post OLT. Sorafenib has been a standard therapy for advanced HCC however data is lacking for the safety and efficacy of sorafenib in the setting of concurrent immunosuppressive agents. Methods: A retrospective review was performed of patients who received sorafenib for HCC relapse after OLT. Data on patient characteristics, treatment toxicity and efficacy was collected. The primary objectives were to evaluate toxicity and safety of sorafenib when used in combination with immunosuppressive therapies such as calcineurin and mTOR inhibitors. Secondary objectives were objective response rate, progression free survival (PFS), and time on therapy. Results: 35 patients over the last 11 years received sorafenib for HCC recurrence following OLT. 54.3% of patients received concurrent immunosuppression with tacrolimus. Toxicity from sorafenib was as expected, with no cases of acute or chronic organ rejection whilst on treatment. The median maximum tolerated dose was 400 mg a day with 40% of patients requiring dose reductions. The incidence of any adverse events (AEs) was 88.6%, with 17.1% having Grade 3-4 toxicity. Incidence of Grade 3-4 liver dysfunction was higher than historical studies at 6%. The overall response rate was 2.8% with a median PFS of 2.8 months. Median time on sorafenib was 3.1 months. Conclusions: There is a paucity of evidence guiding treatment of HCC recurrence following OLT. This retrospective review is one of the largest in the literature and shows that sorafenib used concurrently with immunosuppressive therapy for organ transplant is safe, with no precipitation of acute or chronic rejection, although liver function should be monitored closely. The median PFS in our cohort was shorter than expected. The efficacy of other agents should be explored in this population.[Table: see text]

TP53 mutations in high grade serous ovarian cancer and impact on clinical outcomes: a comparison of next generation sequencing and bioinformatics analyses

Objective

Mutations in TP53 are found in the majority of high grade serous ovarian cancers, leading to gain of function or loss of function of its protein product, p53, involved in oncogenesis. There have been conflicting reports as to the impact of the type of these on prognosis. We aim to further elucidate this relationship in our cohort of patients.

Methods

229 patients with high grade serous ovarian cancer underwent tumor profiling through an institutional molecular screening program with targeted next generation sequencing. TP53 mutations were classified using methods previously described in the literature. Immunohistochemistry on formalin-fixed paraffin embedded tissue was used to assess for TP53 mutation. Using divisive hierarchal clustering, we generated patient clusters with similar clinicopathologic characteristics to investigate differences in outcomes.

Results

Six different classification schemes of TP53 mutations were studied. These did not show an association with first platinum-free interval or overall survival. Next generation sequencing reliably predicted mutation in 80% of cases, similar to the proportion detected by immunohistochemistry. Divisive hierarchical clustering generated four main clusters, with cluster 3 having a significantly worse prognosis (p<0.0001; log-rank test). This cluster had a higher concentration of gain of function mutations and these patients were less likely to have undergone optimal debulking surgery.

Conclusions

Different classifications of TP53 mutations did not show an impact on outcomes in this study. Immunohistochemistry was a good predictor for TP53 mutation. Cluster analysis showed that a subgroup of patients with gain of function mutations (cluster 3) had a worse prognosis.

A Clinical and Molecular Phase II Trial of Oral ENMD-2076 in Ovarian Clear Cell Carcinoma (OCCC): A Study of the Princess Margaret Phase II Consortium

PURPOSE

Patients with recurrent ovarian clear cell carcinoma (OCCC) have limited effective options due to chemoresistance. A phase II study was designed to assess the activity of ENMD-2076, an oral multitarget kinase selective against Aurora A and VEGFR.

PATIENTS AND METHODS

This multicenter phase II study included patients with recurrent OCCC who received prior platinum-based chemotherapy. Primary endpoints were objective response and 6-month progression-free survival (PFS) rates. Correlative analyses include ARID1A and PTEN expression by IHC and gene sequencing with a targeted custom capture next-generation sequencing panel.

RESULTS

Forty patients were enrolled with a median age of 54, of which 38 patients were evaluable. ENMD-2076 was well tolerated with main related grade 3 toxicities being hypertension (28%), proteinuria (10%), and diarrhea (10%). Best response was partial response for 3 patients (1 unconfirmed) and stable disease for 26 patients. The overall 6-month PFS rate was 22% and differed according to ARID1A expression (ARIDIA^- vs. ARID1A⁺; 33% vs. 12%, P = 0.023). PTEN-positive expression was observed in 20 of 36 patients, and there was no correlation with outcome. Median PFS in patients with PI3KCA wild-type versus PI3KCA-mutated group was 5 versus 3.7 months (P = 0.049). Molecular profiling showed variants in PI3KCA (27%), ARID1A (26%), and TP53 (7%). The patient with the longest treatment duration (22 months) was PTEN wild-type, diploid PTEN with putative biallelic inactivation of ARID1A.

CONCLUSIONS

Single-agent ENMD-2076 did not meet the preset bar for efficacy. Loss of ARID1A correlated with better PFS on ENMD-2076 and warrants further investigation as a potential predictive biomarker.

Association of Ipilimumab With Safety and Antitumor Activity in Women With Metastatic or Recurrent Human Papillomavirus-Related Cervical Carcinoma

Importance

Based on evidence of human papillomavirus (HPV)-induced immune evasion, immunotherapy may be an attractive strategy in cervical cancer. Ipilimumab is a fully humanized monoclonal antibody that blocks cytotoxic T-lymphocyte antigen-4 (CTLA-4), which acts to downregulate the T-cell immune response.

Objective

To assess the safety and antitumor activity of ipilimumab in recurrent cervical cancer.

Design, Setting, and Participants

A multicenter trial was designed for patients with metastatic cervical cancer (squamous cell carcinoma or adenocarcinoma) with measurable disease and progression after at least 1 line of platinum chemotherapy. A run-in safety cohort using ipilimumab, 3 mg/kg, every 21 days for 4 cycles in 6 patients was followed by a phase II cohort of ipilimumab, 10 mg/kg, every 21 days for 4 cycles and then 4 cycles of maintenance therapy every 12 weeks for patients demonstrating radiologic response or stabilization. Immune correlative studies were performed on peripheral blood before and after therapy on archival tissue and fresh tumor obtained prior to registration and 7 days after cycle 2. The study was conducted from December 3, 2012, to September 15, 2014. The data were analyzed from April 2016 to June 2016 and in July 2017.

Main Outcomes and Measures

The primary end points were safety and objective response rate. Immune analyses were performed on blood and tumor tissue.

Results

A total of 42 women (median age, 49 years; range, 23-78 years) were enrolled (29 [69%] squamous cell cervical cancer and 13 [31%] adenocarcinoma; 37 [93%] of 40 patients with tissue available for analysis had HPV-positive confirmation; there was no archival tissue for 2 women). Grade 3 toxic effects included diarrhea in 4 patients, 3 of whom had colitis. Of 34 patients evaluated for best response (Response Evaluation Criteria in Solid Tumors, version 1.1), 1 patient had partial response and 10 had stable disease. The median progression-free survival and overall survival were 2.5 months (95% CI, 2.1-3.2 months) and 8.5 months (95% CI, 3.6-not reached; 1 patient was still alive), respectively. Intratumoral pretreatment CD3, CD4, CD8, FoxP3, indoleamine 2,3-dioxygenase, and programmed cell death ligand 1 (PD-L1) expression was not predictive of benefit and did not significantly change with treatment. Multicolor flow cytometry on peripheral lymphocytes revealed a treatment-dependent increase of inducible T-cell costimulator, human leukocyte antigen-antigen D related, and PD-1 during initial treatment, which returned to baseline during maintenance.

Conclusions and Relevance

Ipilimumab was tolerable in this population but did not show significant single-agent activity. Immune changes were induced by anti-CTLA-4 therapy but did not correlate with clinical activity. Changes in these markers may guide further treatment strategies.

Comparison of Practice Guidelines, BRCAPRO, and Genetic Counselor Estimates to Identify Germline BRCA1 and BRCA2 Mutations in Pancreatic Cancer

Germline BRCA1 and BRCA2 (BRCA) mutation carriers with pancreatic ductal adenocarcinoma (PDAC) may benefit from precision therapies and their relatives should undergo tailored cancer prevention. In this study, we compared strategies to identify BRCA carriers with PDAC. Incident cases of PDAC were prospectively recruited for BRCA sequencing. Probands were evaluated using the National Comprehensive Cancer Network (NCCN) and the Ontario Ministry of Health and Long-Term Care (MOHLTC) guidelines. The probability of each proband carrying a mutation was estimated by surveying genetic counselors and using BRCAPRO. BRCA mutations were detected in 22/484 (4.5%) probands. 152/484 (31.2%) and 16/484 (3.3%) probands met the NCCN and MOHLTC guidelines, respectively. The NCCN guidelines had higher sensitivity than the MOHLTC guidelines (0.864 versus 0.227, P < 0.001) but lower specificity (0.712 versus 0.976, P < 0.001). One hundred and nineteen genetic counselors completed the survey. Discrimination was similar between genetic counselors and BRCAPRO (area-under-the-curve: 0.755 and 0.775, respectively, P = 0.702). Genetic counselors generally overestimated (P = 0.008), whereas BRCAPRO severely underestimated (P < 0.001), the probability that each proband carried a mutation. Our results indicate that the NCCN guidelines and genetic counselors accurately identify BRCA mutations in PDAC, while the MOHLTC guidelines and BRCAPRO should be updated to account for the association between BRCA and PDAC.

The Canadian Cancer Trials Group PA.7 trial: Results from the safety run in of a randomized phase II study of gemcitabine (GEM) and nab-paclitaxel (Nab-P) versus GEM, nab-P, durvalumab (D), and tremelimumab (T) as first-line therapy in metastatic pancreatic ductal adenocarcinoma (mPDAC)

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Background: GEM and Nab-P is a standard first line therapy for mPDAC based on the MPACT Trial. D is a human monoclonal antibody (mAb) that inhibits binding of programmed cell death ligand 1 (PD-L1) to its receptor. T is a mAb directed against the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). PA.7 is designed to evaluate whether combining PD-L1 and CTLA-4 inhibition with GEM and Nab-P increases treatment efficacy. Methods: This randomized phase II study (ClinicalTrials.gov NCT02879318) is assessing the efficacy and safety of GEM and Nab-P vs. GEM, Nab-P, D, and T in patients (pts) with mPDAC (n = 190). Pts with untreated mPDAC and good performance status (ECOG PS 0-1) are eligible. A safety run in was planned for 10 pts receiving GEM, Nab-P, D and T. The study is then planned to randomize pts in a 2:1 ratio to receive GEM (1000mg/m2 D1, 8, 15); Nab-P (125mg/m2 D1, 8, 15); D (1500 mg) D1 q 28 days and T (75 mg) D1 for first 4 cycles vs. GEM and Nab-P alone. The primary endpoint is overall survival (OS); secondary endpoints include progression free survival (PFS), safety, overall response rate and quality of life. Results: 11 pts were enrolled in the safety run in (2 final pts enrolled on the same day). Median (Med) age = 59; 9 male/ 2 female; 2 ECOG 0/ 9 ECOG 1; no pts had prior adjuvant therapy. Med follow-up was 8.3 months at the time of data lock. Med number of treatment cycles was 6 (3-10). The most common Grade 3 or greater adverse events included fatigue (27%), anemia (36%), abnormal WBC (27%), hyponatremia (27%), hypoalbuminemia (45%), and abnormal lipase (45%). 1 pt (9.1%) experienced grade 3 colitis. 8/11 pts (73%) had a partial response, with the med duration of 7.4 months. Disease control rate was 100%. Med PFS was 7.9 months (95% C.I. 3.5-9.2 months). 6-month survival rate was 80% (95% C.I 40.9%-94.6%). Med OS has not been reached. Conclusions: The combination of GEM, Nab-P, D and T was well tolerated and promising efficacy signals were noted. The originally designed randomized phase II study is ongoing, and an international randomized phase III trial is planned. Clinical trial information: NCT02879318.

A phase II trial of GSK2256098 and trametinib in patients with advanced pancreatic ductal adenocarcinoma (PDAC) (MOBILITY-002 Trial, NCT02428270)

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Background: MEK (mitogen-activated protein kinase kinase) is activated through mutated KRAS in > 90% of PDAC. Focal adhesion kinase (FAK) integrates signals from integrins and growth factor receptors. MEK and FAK are frequently co-activated in PDAC providing a rationale for dual inhibition with GSK2256098, an oral FAK inhibitor, and trametinib, an oral allosteric MEK1/2 inhibitor. Methods: Patients with advanced PDAC patients who progressed after first line chemotherapy were treated with GSK2256098 250mg twice daily and trametinib 0.5mg once daily in 28 day cycles. The primary endpoint was antitumor activity measured by clinical benefit (CB; complete response, partial response, or stable disease ≥24 weeks) by RECIST 1.1. We planned to enrol 24 patients using a 2-stage minimax design (p0 = 0.15, p1 = 0.40; alpha = 0.05, power 0.86). The combination would be considered active if > 7/24 response-evaluable patients achieved CB; and inactive if 2/12 or fewer patients achieved CB at the end of stage 1. Response assessment was performed every 2 cycles. Results: Between June/16 and June/17, 16 patients were enrolled. Five were not evaluable for response. Of 11 evaluable patients, 10 had PD as best tumor response and one had SD for 4 months. One response unevaluable patient who had rapidly progressed on 1st line FOLFIRINOX chemotherapy with a basal-like tumor by RNA-sequencing and KRAS amplification achieved clinical stability for 5 months with a > 50% decline in serum CA19-9 after 3 months of treatment and symptomatic improvement. No treatment related Grade≥3 adverse events (AEs) were observed. The most common treatment related grade 2 AEs were acneiform rash (19%), diarrhea (13%), nausea (6%), fatigue (6%), proteinuria (6%), paronychia (6%), and retinal detachment (6%). The median progression free survival was 1.6 (95% CI 1.5-1.8) months and the median overall survival was 3.6 (95% CI 2.7-not reached) months. Conclusions: GSK2256098 and trametinib was well tolerated but was not active in unselected advanced PDAC. Correlative studies are ongoing to evaluate RNA-expression subtypes and dynamic markers of pathway inhibition from serial tumor biopsies and cell free DNA. Clinical trial information: NCT02428270.

Genomics-driven precision medicine for advanced pancreatic ductal carcinoma (PDAC): Early results from the COMPASS trial (NCT02750657)

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Background: COMPASS is a prospective study with the primary aim to identify predictive mutational and transcriptional features in advanced PDAC for improved patient stratification and treatment selection. Methods: Patients with advanced PDAC were prospectively recruited prior to first-line combination chemotherapy for whole genome sequencing (WGS) and RNA sequencing (RNASeq). Fresh tumor tissue was acquired by image guided percutaneous core needle biopsy of locally advanced primary or metastatic tumors. Laser capture microdissection was performed for all cases to ensure high-resolution genomic analyses. Primary endpoint was feasibility to report WGS results prior to first disease assessment CT scan at 8 weeks. The main secondary endpoint was discovery of patient subsets with predictive mutational and transcriptional signatures. Results: Of 63 patients who underwent a tumor biopsy between December 2015 and June 2017, WGS and RNASeq were successful in 62 (98%) and 60 (95%), respectively. Genomic results were reported at a median of 35 days (range 19-52 days) from biopsy, meeting the primary feasibility endpoint. Three patients with an ‘unstable’ genomic subtype, including two with a novel ‘duplicator’ phenotype, responded well to m-FOLFIRINOX. Of two cases with the same germline BRCA2 mutation, only the chemotherapy responder had loss of heterozygosity and genomic hallmarks of double stranded break repair deficiency. Approximately 25% of tumors displayed the basal-like RNA expression signature and these were chemotherapy resistant, with tumor shrinkage mainly observed in those with the classical RNA subtype (P = 0.003). Thirty percent of patients had potentially actionable genetic alterations. Conclusions: Prospective comprehensive genomic profiling of advanced PDAC is feasible and our early data indicate that chemotherapy response differs among patients with different genomic/transcriptomic subtypes providing the impetus for further studies. Clinical trial information: NCT02750657.

Major arterial resection for stage 3 adenocarcinoma of the pancreas

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Background: Stage 3 pancreas ductal adenocarcinoma (PDAC) is defined by arterial involvement, and its resection remains controversial. The objective of this study was to evaluate clinical and oncologic outcomes for patients with stage 3 PDAC who entered a treatment program of neoadjuvant therapy (NAT) and pancreatic resection, with comparison between those who underwent arterial (AR) vs. standard resection (SR). Methods: This cohort study included patients from 2009-2016 in a single academic institution, with biopsy-proven potentially resectable stage 3 PDAC who entered a treatment program of NAT followed by surgical exploration if non-progressive disease on imaging. AR was performed if required to achieve R0 resection. Oncological outcomes were analyzed as intention to treat from diagnosis date. Results: Eighty-nine patients met inclusion criteria, of whom 87 (97.8%) received chemotherapy and 50 (56.2%) received radiotherapy. 46/89 (51.7%) underwent surgical exploration; 31 underwent pancreas resection (AR n = 20, SR n = 11), and 15 were found to have metastatic or unresectable disease. The AR group had a longer operative time (681 vs. 563 minutes, p = 0.0059) and more blood loss (1600 vs. 575 mL, p = 0.0004) compared with SR, with no difference between groups for blood transfusion, overall complications, pancreatic fistula, length of stay, reoperation, readmission or mortality. R0 rate was 100% for resected patients. Post-operative 90-day mortality was 1.1%. Median overall survival of resected patients was longer than in non-resected patients (25.9 vs. 14.8 months, p = 0.01), while AR had comparable overall survival to SR (19.7 vs. 28.4 months, p = 0.41). Conclusions: Patients with non-progressive stage 3 PDAC after NAT should be considered for pancreas resection. AR had comparable clinical and oncologic outcomes to SR. Resection may offer a survival advantage over non-surgical therapy alone, and AR should be considered if required to obtain a negative resection margin.

Baseline anemia in patients with biliary tract cancer (BTC) and its association with survival: A retrospective cohort study

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Background: The prognostic significance of anemia in BTC is unknown, but is common and may be multifactorial; data regarding its causes are limited. This study interrogated a large institutional database to examine the effect of anemia on overall survival (OS) in BTC, and explore factors associated with anemia. Methods: This Princess Margaret Cancer Centre cohort study included patients with BTC with available baseline hemoglobin (Hb) (1987-2016). Anemia was defined as Hb < 132 mg/dL for men > 60 years, < 137mg/dL for men aged 20-59, and < 122mg/dL in women. Additional relevant covariates were included in multivariable Cox regression for OS, and linear regression for association with Hb. Results: Of 1398 patients included, 711 (51%) were anemic at baseline (mean Hb 112 mg/dL). Anemic versus non-anemic patients were older (median age 66 vs 64 yrs, p = 0.006), had worse ECOG PS (12% ECOG 2-3 vs 6%, p < .001), BMI < 20 (31% vs 27%, p = 0.006) and elevated neutrophil:lymphocyte ratio (NLR), (64% vs 47%, p < .001), but cancer staging was not significantly different. Anemia was associated with shorter OS on univariate (HR 1.35, p < .001) and multivariable (HR 1.39, p < .001) regression (Table). Factors associated with lower Hb included older age, male gender, worse ECOG PS, tumor site, thrombocytopenia, elevated NLR. Conclusions: Baseline anemia was associated with shorter survival following diagnosis of BTC, independent of tumor stage or ECOG PS. Clinicians should be aware of this prognostic marker; validation in prospective datasets is warranted. [Table: see text]

Impact of tissue transport on PET hypoxia quantification in pancreatic tumours

Background

The clinical impact of hypoxia in solid tumours is indisputable and yet questions about the sensitivity of hypoxia-PET imaging have impeded its uptake into routine clinical practice. Notably, the binding rate of hypoxia-sensitive PET tracers is slow, comparable to the rate of diffusive equilibration in some tissue types, including mucinous and necrotic tissue. This means that tracer uptake on the scale of a PET imaging voxel—large enough to include such tissue and hypoxic cells—can be as much determined by tissue transport properties as it is by hypoxia. Dynamic PET imaging of 20 patients with pancreatic ductal adenocarcinoma was used to assess the impact of transport on surrogate metrics of hypoxia: the tumour-to-blood ratio [TBR(t)] at time t post-tracer injection and the trapping rate k₃ inferred from a two-tissue compartment model. Transport quantities obtained from this model included the vascular influx and efflux rate coefficients, k₁ and k₂, and the distribution volume v_d≡k₁/(k₂+k₃).

Results

Correlations between voxel- and whole tumour-scale k₃ and TBR values were weak to modest: the population average of the Pearson correlation coefficients (r) between voxel-scale k₃ and TBR (1 h) [TBR(2 h)] values was 0.10 [0.01] in the 20 patients, while the correlation between tumour-scale k₃ and TBR(2 h) values was 0.58. Using Patlak’s formula to correct uptake for the distribution volume, correlations became strong (r=0.80[0.52] and r=0.93, respectively). The distribution volume was substantially below unity for a large fraction of tumours studied, with v_d ranging from 0.68 to 1 (population average, 0.85). Surprisingly, k₃ values were strongly correlated with v_d in all patients. A model was proposed to explain this in which k₃ is a combination of the hypoxia-sensitive tracer binding rate k_b and the rate k_eq of equilibration in slow-equilibrating regions occupying a volume fraction 1−v_d of the imaged tissue. This model was used to calculate the proposed hypoxia surrogate marker k_b.

Conclusions

Hypoxia-sensitive PET tracers are slow to reach diffusive equilibrium in a substantial fraction of pancreatic tumours, confounding quantification of hypoxia using both static (TBR) and dynamic (k₃) PET imaging. TBR is reduced by distribution volume effects and k₃ is enhanced by slow equilibration. We proposed a novel model to quantify tissue transport properties and hypoxia-sensitive tracer binding in order to improve the sensitivity of hypoxia-PET imaging.

Electronic supplementary material

The online version of this article (doi:10.1186/s13550-017-0347-3) contains supplementary material, which is available to authorized users.

Novel malignant bowel obstruction (MBO) management program for women with advanced gynecological cancer

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Background: Malignant bowel obstruction (MBO) is a common and challenging clinical predicament in women with advanced gynecological cancers. However, there is a lack of evidence-based guidelines or innovative approaches to improve patient care and quality of life. We implemented an inter-professional MBO management program incorporating a nurse-led ambulatory symptom management algorithm and multidisciplinary care conferences (MCC) as hallmarks of this program. Methods: Princess Margaret Cancer Centre has piloted an inter-professional MBO management program that supports women with advanced gynecological cancers who are at risk of/have developed MBO. The MBO team includes oncologists (medical, surgical, gynecologic and radiation), palliative care physicians, diagnostic and interventional radiologists, home parenteral nutrition physicians, specialized oncology nurses, dietitians, pharmacists and social workers. Complex MBO cases are discussed at regular MCC to derive treatment consensus. A symptom-driven MBO management algorithm has been devised and all patients are educated with a personalized bowel symptom management and dietary plan. For outpatient care, patients with MBO are proactively monitored by our specialized oncology nurses via phone or an eHealth bowel application to facilitate communication of symptoms and early intervention. Access to community services and home palliative care services are utilized to support care at home. All patients are enrolled into a prospective database to assess care impact and quality. Results: A total of 145 patients have been followed through the MBO management program over 12 months. At time of data cutoff, 14 had MBO (3 inpatients and 11 outpatients) and 22 were deemed at risk of MBO. Majority patients are managed as an outpatient and avoided unnecessary emergency department episodes. Detailed methodology and data analyses will be presented. Conclusions: A successful novel MBO program incorporating inter-professional care model and nurse-led ambulatory symptom management algorithm optimizes patient care in this vulnerable population and foster collaboration in implementing best practice clinical processes.