Safety and preliminary efficacy of pembrolizumab following trans-arterial chemoembolization for hepatocellular carcinoma: the PETAL phase Ib study

BACKGROUND

TACE may prime adaptive immunity and enhance immunotherapy efficacy. PETAL evaluated safety, preliminary activity of TACE plus pembrolizumab and explored mechanisms of efficacy.

METHODS

Patients with liver-confined HCC were planned to receive up to 2 rounds of TACE followed by pembrolizumab 200 mg every 21 days commencing 30-days post-TACE until disease progression or unacceptable toxicity for up to 1 year. Primary endpoint was safety, 21-days dose-limiting toxicities (DLT) from pembrolizumab initiation. Secondary endpoints included progression-free survival (PFS) and evaluation of tumour and host determinants of response.

RESULTS

Fifteen patients were included in the safety and efficacy population: 73% had non-viral cirrhosis, median age was 72 years. Child-Pugh (CP) class was A in 14 patients. Median tumour size was 4 cm. Ten patients (67%) received pembrolizumab after 1 TACE, 5 patients after 2 (33%). Pembrolizumab yielded no synergistic toxicity nor DLTs post-TACE. Treatment-related adverse events occurred in 93% of patients most commonly skin rash (40%), fatigue and diarrhoea (27%). After a median follow-up of 38.5 months, objective response rate (ORR) 12 weeks post-TACE was 53%. PFS rate at 12 weeks was 93% and median PFS was 8.95 months (95%CI 7.30-NA). Median duration of response was 7.3 months (95%CI: 6.3-8.3). Median OS was 33.5 months (95%CI: 11.6-NA). Dynamic changes in peripheral T-cell subsets, circulating tumour DNA, serum metabolites and in stool bacterial profiles highlight potential mechanisms of action of multi-modal therapy.

CONCLUSIONS

TACE plus pembrolizumab was tolerable with no evidence of synergistic toxicity, encouraging further clinical development of immunotherapy alongside TACE.

Review: Embryonic stem cells as tools for in vitro gamete production in livestock

The goal of in vitro gametogenesis is to reproduce the events of sperm and oocyte development in the laboratory. Significant advances have been made in the mouse in the last decade, but evolutionary divergence from the murine developmental program has prevented the replication of these advances in large mammals. In recent years, intensive work has been done in humans, non-human primates and livestock to elucidate species-specific differences that regulate germ cell development, due to the number of potential applications. One of the most promising applications is the use of in vitro gametes to optimize the spread of elite genetics in cattle. In this context, embryonic stem cells have been posed as excellent candidates for germ cell platforms. Here, we present the most relevant advances in in vitro gametogenesis of interest to livestock science, including new types of pluripotent stem cells with potential for germline derivation, characterization of the signaling environment in the gonadal niche, and experimental systems used to reproduce different stages of germ cell development in the laboratory.

A phase I/II study of the CXCR2 inhibitor, AZD5069, in combination with durvalumab, in patients (pts) with advanced hepatocellular carcinoma (HCC)

TPS631

Background: HCC is increasing rapidly in incidence worldwide driven by a rise in chronic liver disease including non-alcoholic steato-hepatitis (NASH). Most pts are not suitable for curative or loco-regional treatments and may be candidates for systemic therapies. Immune checkpoint inhibitors combined with VEGF inhibition is a standard of care in HCC. However, a meta-analysis of 3 phase III randomised trials of PD-1 or PDL-1 inhibitors (n > 1,600 pts) with HCC suggests that pts with NASH-related HCC treated with PD-1/PDL-1 inhibitors had reduced overall survival compared with other aetiologies. Neutrophils expressing the chemokine receptor CXCR2, crucial to neutrophil recruitment in acute-injury, are highly represented in NASH-HCC. In NASH-HCC murine models, lacking response to immune-checkpoint inhibitors, AZD5069 (CXCR2 inhibitor) in combination with anti-PDL-1 suppressed tumor burden and extended survival, accompanied by an increase in tumor-associated neutrophils which switched from a pro-tumor to anti-tumor progenitor-like neutrophil phenotype. We propose that inhibition of CXCR2 may potentiate the efficacy of anti-PDL-1 inhibition in pts with HCC. Methods: In this multi-centre (n = 10) study, pts with biopsy-confirmed HCC, PS ECOG < 1, Child-Pugh A, < 1 prior systemic therapies, receive 1 of escalating doses of AZD5069 (bid, po daily) with Durvalumab (1.5 gm iv on day 1) in 28-day cycles for up to 2 years to determine the recommended phase II dose using a Keyboard design, followed by an additional cohort of pts to determine the anti-tumor efficacy of this combination using a Simon’s two-stage design (min 18, max 35 pts; target objective response rate > 30%; unacceptable response rate < 10%). Dose limiting toxicities (DLTs) are assessed during cycle 1. Disease assessments are performed 8-weekly (12-weekly after 1 year). The 1st dose cohort has been completed with no DLTs. The 2nd dose cohort opened to recruitment in September 2022. Exploratory studies (blood; pre- & on-treatment tumor and non-malignant liver biopsies) include biomarkers of CXCR2 inhibition (blood); proof-of-mechanism (tumor: expression of CXCR2, PD-L1, PD-1, CD8, CD4, CD66b, CD69); proof-of-mechanism (blood: ctDNA); drug-induced changes of mRNA expression, CXCR2 ligands & signalling pathway genes, T-cell and myeloid cell pathways, neutrophil-associated genes; predictive biomarkers (blood and tumour) include biomarkers of the CXCR2/PD-L1 immune axis; aberrant CXCR2 signalling pathways; proliferation biomarkers and CD10 (neutrophils), CD68 (macrophages), CD103 (T-regs); tumour mutational status. This study is funded by a grant from Cancer Research UK (A29287) and is co-sponsored by University of Glasgow and NHS Greater Glasgow & Clyde. Study sites are supported by the Experimental Cancer Medicine Centre Network. AZD5069 and Durvalumab are provided by Astra Zeneca. Clinical trial information: 2020-003346-36 .

Significance of alterations in DNA damage repair (DDR) genes in advanced biliary cancers (ABCs) treated with second-line active-symptom-control (ASC) alone or ASC with oxaliplatin/5-FU chemotherapy (ASC+FOLFOX) in the randomised phase III, multicentre, open-label ABC-06 trial

593

Background: The ABC-06 clinical trial established ASC+mFOLFOX as the standard of care treatment after Cisplatin and Gemcitabine (CisGem) for ABC. Translational research explored the role of alterations in DDR-related genes in the context of the ABC-06 clinical trial. Methods: Translational research using samples collected from the ABC-06 trial included all recruited patients with tissue sample containing >20% tumour cellularity with sufficient DNA extracted for analysis. Primary objective: assess the prevalence of somatic mutations within DDR genes in ABC. Secondary objectives: explore the impact of somatic mutations in DDR genes on: A) Patient’s response to platinum-based chemotherapy (predictive biomarker): 1) Retrospectively, using progression-free survival (PFS) data from 1st-line chemotherapy and 2) Prospectively, by assessing the impact on PFS/radiological response to 2nd-line FOLFOX (vs. control) and B) Overall survival (prognostic biomarker). Survival analysis was performed with Kaplan-Meier and Cox Regression. Results: Of 162 pts randomised, 83 had a sample available for analysis; of these, analysis failed in 24 despite >20% tumour content. Thus, a total of 59 patients (30 ASC arm, 29 ASC+FOLFOX arm) were eligible for this translational analysis: male 50.85%, metastatic 77.97%, intrahepatic cholangiocarcinoma 47.46%, adenocarcinoma 91.53%, median age 65.84 years (95% CI 63.36-68.91). Pathogenic mutations in DDR genes were identified in 22 patients (37.29%). PFS did not vary depending on the DDR-gene alterations either in the first-line setting with CisGem (n=59; 8.73 months vs 8.18 months; p-value 0.155) or with second-line FOLFOX (n=29; 3.19 months vs 3.45 months; p-value 0.098). Median OS for DDR-altered patients was 4.59 months (95% CI 2.17-5.88) (vs 7.23 months (95% CI 5.45-8.28) for DDR-wild-type); HR 2.63 (95% CI 1.48-4.67); p-value 0.001. This prognostic impact was confirmed when the prognostic model was adjusted for treatment arm and stratification factors (HR 3.75 (95% CI 1.99-7.09); p-value <0.001). Conclusions: For ABC patients, the presence of DDR-related gene pathogenic mutations are present in around one third of patients. Despite presence of DDR-mutations having a negative prognostic impact, their predictive role is not confirmed either for first-line CisGem or second-line FOLFOX. Clinical trial information: NCT01926236 .

bESC from cloned embryos do not retain transcriptomic or epigenetic memory from somatic donor cells

In brief

Epigenetic reprogramming after mammalian somatic cell nuclear transfer is often incomplete, resulting in low efficiency of cloning. However, gene expression and histone modification analysis indicated high similarities in transcriptome and epigenomes of bovine embryonic stem cells from in vitro fertilized and somatic cell nuclear transfer embryos.

Abstract

Embryonic stem cells (ESC) indefinitely maintain the pluripotent state of the blastocyst epiblast. Stem cells are invaluable for studying development and lineage commitment, and in livestock, they constitute a useful tool for genomic improvement and in vitro breeding programs. Although these cells have been recently derived from bovine blastocysts, a detailed characterization of their molecular state is lacking. Here, we apply cutting-edge technologies to analyze the transcriptomic and epigenomic landscape of bovine ESC (bESC) obtained from in vitro fertilized (IVF) and somatic cell nuclear transfer (SCNT) embryos. bESC were efficiently derived from SCNT and IVF embryos and expressed pluripotency markers while retaining genome stability. Transcriptome analysis revealed that only 46 genes were differentially expressed between IVF- and SCNT-derived bESC, which did not reflect significant deviation in cellular function. Interrogating histone 3 lysine 4 trimethylation, histone 3 lysine 9 trimethylation, and histone 3 lysine 27 trimethylation with cleavage under targets and tagmentation, we found that the epigenomes of both bESC groups were virtually indistinguishable. Minor epigenetic differences were randomly distributed throughout the genome and were not associated with differentially expressed or developmentally important genes. Finally, the categorization of genomic regions according to their combined histone mark signal demonstrated that all bESC shared the same epigenomic signatures, especially at gene promoters. Overall, we conclude that bESC derived from SCNT and IVF embryos are transcriptomically and epigenetically analogous, allowing for the production of an unlimited source of pluripotent cells from high genetic merit organisms without resorting to transgene-based techniques.

A phase Ib study of pembrolizumab following trans-arterial chemoembolization (TACE) in hepatocellular carcinoma (HCC): PETAL

e16195

Background: Trans-arterial chemoembolization (TACE) is the gold-standard for intermediate stage HCC. We hypothesised the ischemic and cytotoxic effect of TACE to boost anti-cancer immunity and to synergise with the anti PD-1 pembrolizumab (pembro). We designed a phase Ib study to test the safety and preliminary efficacy of pembro after TACE in intermediate HCC. Methods: PETAL study will enroll up to 32 patients with intermediate HCC to receive pembro 200 mg every 3 weeks for up to 1 year or until disease progression or unacceptable toxicity. The first safety-run-in phase includes 6 patients: if no dose limiting toxicities (DLTs) emerge over a 21-day window after first pembro, the others are enrolled in the expansion phase. Pembro is given within 30 days after 1 or 2 TACEs. The first phase includes 1 patient scoring Child-Pugh (CP)-B7 and the remaining have to be CP-A. Safety is the primary endpoint and is measured as the incidence of treatment-related adverse events (TRAEs), graded according to NCI CTCAEv4. Efficacy is the secondary endpoint and is evaluated as progression free survival (PFS) from first TACE, according to mRECIST criteria. Survival is estimated using Kaplan-Meier method. All the patients who have received at least one dose of pembro are evaluable for safety. Results: At the time of data cut-off, on the 14th of January 2022, 14 patients had received at least one dose of pembro. The median age was 72 (IQR: 63.3-74.6), 79% were male, 71% were cirrhotic, 29% had viral hepatis and 43% ECOG PS 1. One patient had Child-Pugh (CP) class B7 and 13 had A. The median number of nodules was 1.5 (IQR:1-2.8), and 4.1 cm (IQR: 3.7-4.5) the median diameter. Overall, 5 patients received 2 TACEs and 9 had 1. Patients received a median of 4.5 cycles (IQR: 2.3-6.5) of pembro. No DLTs emerged in the first phase. Treatment-related adverse events (TRAE) of any grade (G) were reported in 86% of participants, 21% of participants experienced G3 TRAEs, and there were no G4 or G5 TRAEs. Specific skin-related toxicity was the most frequently reported (35%) TRAE. No patients had treatment-related liver toxicity. Causes of treatment discontinuation were PD (n=7), TRAEs (n=1), clinical deterioration in the CP B patient (n=1), COVID pandemic (n=2) and withdrawal of consent (n=1); at the time of data cut-off, mPFS from first TACE was 10.8 months (95%CI: 6.63-14.97). Conclusions: Adjuvant pembro following TACE is manageable and tolerable with signs of activity. These results prompt the investigation in larger trials. Clinical trial information: NCT03397654. [Table: see text]

Clinical outcomes associated with tislelizumab in patients (pts) with advanced hepatocellular carcinoma (HCC) who have been previously treated with sorafenib (SOR) or lenvatinib (LEN) in RATIONALE-208

4072

Background: Tislelizumab, an anti-PD-1 monoclonal antibody, demonstrated clinical activity and was well tolerated in pts with previously treated advanced HCC in the Phase 2 RATIONALE-208 study (NCT03419897). At the time of this study, SOR and LEN were recommended first-line treatments for pts with advanced HCC and continue to have an important role in the first-line treatment of HCC despite the recent approval of new immuno-oncology-based combinations (atezolizumab and bevacizumab) in some regions. We report the clinical outcomes of pts with advanced HCC who were previously treated with SOR/LEN. Methods: Pts who had received ≥ 1 prior line of systemic therapy for advanced HCC received tislelizumab 200 mg intravenously once every three weeks. Objective response rate (ORR) by independent review committee (IRC) (ORRIRC), duration of response by IRC (DORIRC), progression-free survival by IRC (PFSIRC), overall survival (OS), and safety were evaluated in pts who had been previously treated with SOR/LEN. Results: As of February 2020, 249 pts were enrolled and 235 pts had received prior treatment with SOR/LEN, of whom 126 and 109 pts had received 1 or ≥ 2 prior lines of systemic therapy, respectively. At study entry, 211 (89.8%) pts had BCLC stage C and 187 (79.6%) pts had extrahepatic spread. Median follow-up duration for pts previously treated with SOR/LEN was 12.5 months and ORRIRC was 13.6% (95% CI: 9.5, 18.7), including 2 complete responses and 30 partial responses. Median DORIRC was not reached. Median PFSIRC and OS of pts previously treated with SOR/LEN was 2.7 months (95% CI: 1.6, 2.8) and 13.5 months (95% CI: 10.9, 15.8), respectively. Tislelizumab was generally well tolerated in pts previously treated with SOR/LEN (Table), and the most common treatment-emergent adverse events were increased aspartate aminotransferase (n=70; 28.1%) and alanine aminotransferase (n=52; 20.9%). Conclusions: Tislelizumab was investigated beyond the first-line setting, as effective second- and third-line treatment options are limited for pts with advanced HCC and there is an unmet medical need. This analysis indicates that tislelizumab is clinically active and well tolerated in pts with advanced HCC who have received prior systemic treatment with SOR/LEN. Clinical trial information: NCT03419897. [Table: see text]

Clinical outcomes associated with tislelizumab in patients (pts) with advanced hepatocellular carcinoma (HCC) who have been previously treated with sorafenib (SOR) or lenvatinib (LEN) in RATIONALE-208

420

Background: Tislelizumab, an anti-PD-1 monoclonal antibody, demonstrated clinical activity and was well tolerated in pts with previously treated advanced HCC in the phase 2 RATIONALE-208 study (NCT03419897). At the time of this study, SOR and LEN were recommended first-line treatments for pts with advanced HCC and continue to have an important role in the first-line treatment of HCC despite the recent approval of new immuno-oncology-based combinations (atezolizumab and bevacizumab) in some regions. We report the clinical outcomes of pts with advanced HCC who were previously treated with SOR/LEN. Methods: Pts who had received ≥1 prior line of systemic therapy for advanced HCC received tislelizumab 200 mg intravenously once every three weeks. Objective response rate (ORR) by independent review committee (IRC) (ORRIRC), duration of response by IRC (DORIRC), progression-free survival by IRC (PFSIRC), overall survival (OS), and safety were evaluated in pts who had been previously treated with SOR/LEN. Results: As of February 2020, 249 pts were enrolled and 235 pts had received prior treatment with SOR/LEN, of whom 126 and 109 pts had received 1 or ≥ 2 prior lines of systemic therapy, respectively. At study entry, 211 (89.8%) pts had BCLC stage C and 187 (79.6%) pts had extrahepatic spread. Median follow-up duration for pts previously treated with SOR/LEN was 12.5 months and ORRIRC was 13.6% (95% CI: 9.5, 18.7), including 2 complete responses and 30 partial responses. Median DORIRC was not reached. Median PFSIRC and OS of pts previously treated with SOR/LEN was 2.7 months (95% CI: 1.6, 2.8) and 13.5 months (95% CI: 10.9, 15.8), respectively. Tislelizumab was generally well tolerated in pts previously treated with SOR/LEN (Table), and the most common treatment-emergent adverse events were increased aspartate aminotransferase (n=70; 28.1%) and alanine aminotransferase (n=52; 20.9%). Conclusions: Tislelizumab was investigated beyond the first-line setting, as effective second- and third-line treatment options are limited for pts with advanced HCC and there is an unmet medical need. This analysis indicates that tislelizumab is clinically active and well tolerated in pts with advanced HCC who have received prior systemic treatment with SOR/LEN. Clinical trial information: NCT03419897. [Table: see text]

Results of a single-arm pilot study of 32P microparticles in unresectable locally advanced pancreatic adenocarcinoma with gemcitabine/nab-paclitaxel or FOLFIRINOX chemotherapy

Background

Unresectable locally advanced pancreatic cancer (LAPC) is generally managed with chemotherapy or chemoradiotherapy, but prognosis is poor with a median survival of ∼13 months (or up to 19 months in some studies). We assessed a novel brachytherapy device, using phosphorous-32 (³²P) microparticles, combined with standard-of-care chemotherapy.

Patients and methods

In this international, multicentre, single-arm, open-label pilot study, adult patients with histologically or cytologically proven unresectable LAPC received ³²P microparticles, via endoscopic ultrasound-guided fine-needle implantation, planned for week 4 of 5-fluorouracil, leucovorin, irinotecan and oxaliplatin (FOLFIRINOX) or gemcitabine/nab-paclitaxel chemotherapy, per investigator’s choice. The primary endpoint was safety and tolerability measured using Common Terminology Criteria for Adverse Events version 4.0. The lead efficacy endpoint was local disease control rate at 16 weeks.

Results

Fifty patients were enrolled and received chemotherapy [intention-to-treat (ITT) population]. Forty-two patients received ³²P microparticle implantation [per protocol (PP) population]. A total of 1102 treatment-emergent adverse events (TEAEs) were reported in the ITT/safety population (956 PP), of which 167 (139 PP) were grade ≥3. In the PP population, 41 TEAEs in 16 (38.1%) patients were possibly or probably related to ³²P microparticles or implantation procedure, including 8 grade ≥3 in 3 (7.1%) patients, compared with 609 TEAEs in 42 (100%) patients attributed to chemotherapy, including 67 grade ≥3 in 28 patients (66.7%). The local disease control rate at 16 weeks was 82.0% (95% confidence interval: 68.6% to 90.9%) (ITT) and 90.5% (95% confidence interval: 77.4% to 97.3%) (PP). Tumour volume, carbohydrate antigen 19-9 levels, and metabolic tumour response at week 12 improved significantly. Ten patients (20.0% ITT; 23.8% PP) had surgical resection and median overall survival was 15.2 and 15.5 months for ITT and PP populations, respectively.

Conclusions

Endoscopic ultrasound-guided ³²P microparticle implantation has an acceptable safety profile. This study also suggests clinically relevant benefits of combining ³²P microparticles with standard-of-care systemic chemotherapy for patients with unresectable LAPC.

•

PanCO is the first prospective study of intratumoural ³²P microparticles for locally advanced pancreatic cancer (LAPC).

•

This single-arm study assessed a novel brachytherapy (³²P microparticles) combined with standard-of-care chemotherapy.

•

Treatment-emergent adverse events attributable to ³²P microparticle implantation were relatively infrequent.

•

Local disease control rate at 16 weeks (82%) and resection rate (20%) suggest a clinical benefit of ³²P microparticles.

•

The results suggest that ³²P microparticles may address a significant unmet need in patients with unresectable LAPC.

Trifluridine/Tipiracil in Metastatic Colorectal Cancer: A UK Multicenter Real-world Analysis on Efficacy, Safety, Predictive and Prognostic Factors

BACKGROUND

The orally administered combination trifluridine/tipiracil has been approved as third line treatment in mCRC, demonstrating survival benefit and acceptable toxicity profile in the phase III RECOURSE study.

PATIENT AND METHODS

We performed a multicenter retrospective real-world analysis of patients with mCRC receiving trifluridine/tipiracil between 2016 and 2019 in eight cancer centers across the United Kingdom.

RESULTS

A total of 236 patients were included with median age of 69 years. All patients had received at least 2 lines of fluoropyrimidine-based chemotherapy doublet with oxaliplatin or irinotecan. About 10% of patients had ECOG ≥ 2. Median duration of trifluridine/tipiracil treatment was 3 months with an ORR of 2.1% and disease control rate of 21.6%. Median OS was 7.6 and median PFS 3.3 months. A dose reduction was required in 27% of patients, while 7.6% discontinued treatment due to toxicity. The most common grade 3 toxicities were neutropenia (34%), fatigue (10%), anemia (9%) and febrile neutropenia (5%). Baseline NLR <5 and CEA <200 had favorable prognostic (HR: 0.52 and 0.39, P≤ .001) and predictive value (OR: 4.1 and 6.7, P< .05). Development of grade 3 neutropenia predicted treatment response (OR: 0.32, P< .001). Following treatment with trifluridine/tipiracil 41% were referred for phase I trial or rechallenged with chemotherapy.

CONCLUSION

Trifluridine/tipiracil is well tolerated in refractory mCRC patients with comparable efficacy and toxicity profile to that of the phase III RECOURSE. Pretreatment NLR and CEA could serve as potential markers for patient selection, while treatment-induced grade 3 neutropenia predicted response. Prospective validation is needed.

Genome activation in equine in vitro-produced embryos

Embryonic genome activation is a critical event in embryo development, in which the transcriptional program of the embryo is initiated. The timing and regulation of this process are species-specific. In vitro embryo production is becoming an important clinical and research tool in the horse; however, very little is known about genome activation in this species. The objective of this work was to identify the timing of genome activation, and the transcriptional networks involved, in in vitro-produced horse embryos. RNA-Seq was performed on oocytes and embryos at eight stages of development (MII, zygote, 2-cell, 4-cell, 8-cell, 16-cell, morula, blastocyst; n = 6 per stage, 2 from each of 3 mares). Transcription of seven genes was initiated at the 2-cell stage. The first substantial increase in gene expression occurred at the 4-cell stage (minor activation), followed by massive gene upregulation and downregulation at the 8-cell stage (major activation). An increase in intronic nucleotides, indicative of transcription initiation, was also observed at the 4-cell stage. Co-expression network analyses identified groups of genes that appeared to be regulated by common mechanisms. Investigation of hub genes and binding motifs enriched in the promoters of co-expressed genes implicated several transcription factors. This work represents, to the best of our knowledge, the first genomic evaluation of embryonic genome activation in horse embryos.

Allele-specific expression analysis reveals conserved and unique features of preimplantation development in equine ICSI embryos

Embryonic genome activation and dosage compensation are major genetic events in early development. Combined analysis of single embryo RNA-seq data and parental genome sequencing was used to evaluate parental contributions to early development and investigate X-chromosome dynamics. In addition, we evaluated dimorphism in gene expression between male and female embryos. Evaluation of parent-specific gene expression revealed a minor increase in paternal expression at the 4-cell stage that increased at the 8-cell stage. We also detected eight genes with allelic expression bias that may have an important role in early development, notably NANOGNB. The main actor in X-chromosome inactivation, XIST, was significantly upregulated at the 8-cell, morula, and blastocyst stages in female embryos, with high expression at the latter. Sexual dimorphism in gene expression was identified at all stages, with strong representation of the X-chromosome in females from the 16-cell to the blastocyst stage. Female embryos showed biparental X-chromosome expression at all stages after the 4-cell stage, demonstrating the absence of imprinted X-inactivation at the embryo level. The analysis of gene dosage showed incomplete dosage compensation (0.5 < X:A < 1) in MII oocytes and embryos up to the 4-cell stage, an increase of the X:A ratio at the 16-cell and morula stages after genome activation, and a decrease of the X:A ratio at the blastocyst stage, which might be associated with the beginning of X-chromosome inactivation. This study represents the first critical analysis of parent- and sex-specific gene expression in early equine embryos produced in vitro.

Effects of sodium salicylate and time postpartum on mammary tissue proliferation, gene transcript profile, and DNA methylation

Previous studies have demonstrated nonsteroidal antiinflammatory drug treatment in early lactation had a positive impact on whole-lactation milk production in older cows. The objective of this study was to evaluate proliferative, transcriptional, and epigenetic changes in the mammary gland that could explain increased production responses due to nonsteroidal antiinflammatory drug treatment. Sodium salicylate (SAL; 125 g/d) or water (CON) were administered via oral drench to multiparous Holstein cows (n = 8/treatment) once daily for 3 d beginning approximately 24 h after parturition, and mammary tissue was collected on d 1, 4, and 45 postpartum. Day 1 tissue was collected immediately preceding the initial drench, and d 4 tissue was collected 24 h following the final drench. Blood was collected twice weekly and analyzed for plasma glucose, insulin, β-hydroxybutyrate, free fatty acids, and prolactin. Cows were milked twice daily until d 7 of lactation, and thrice daily for the remainder of the study. Total RNA extracted from tissue was deep-sequenced and analyzed for differential gene expression using DESeq2. We detected no treatment effect on milk yield or plasma metabolites through 45 d of lactation; additionally, no change in mammary epithelial cell proliferation was detected when assessed by Ki67 labeling. Comparison of SAL versus CON revealed that only 16 of 18,286 genes were differentially expressed (false discovery rate <0.1) in mammary tissue collected on d 45, whereas no differentially expressed genes due to treatment were detected on d 1 or 4. Analysis of transcriptional differences over time showed downregulation of pathways related to immune cell recruitment and differentiation, and extensive overlap with pathways related to cholesterol synthesis and liver X receptor signaling. Global DNA methylation of mammary tissue was decreased for CON compared with SAL. Transcriptome analysis emphasized extensive involvement of immune-related signaling pathways in the switch from lactogenesis to galactopoiesis, and changes in methylation with SAL treatment merit future investigation into epigenetic effects on milk production.

Phase III study of NUC-1031 + cisplatin versus gemcitabine + cisplatin for first-line treatment of patients with advanced biliary tract cancer (NuTide:121)

TPS4164

Background: Biliary tract cancer (BTC) is an aggressive disease with a poor prognosis. Gemcitabine + cisplatin (GemCis) is the accepted global standard of care (SoC), however key cancer resistance mechanisms associated with the transport, activation and breakdown of gemcitabine are known to limit its clinical activity across a range of tumor types, including BTC. NUC-1031 is a phosphoramidate transformation of gemcitabine designed to overcome these key resistance mechanisms and generate much higher levels of the active anti-cancer metabolite, dFdCTP, in cells. Promising efficacy has been observed with single-agent NUC-1031 in a phase I study in advanced solid tumors and in the phase Ib ABC-08 study of NUC-1031 + cisplatin for first-line treatment of advanced BTC. Of 21 patients enrolled in 2 dose cohorts (NUC-1031 625 mg/m2 or 725 mg/m2 + cisplatin 25 mg/m2 on Days 1 and 8 of 21-day cycle), 16 were considered to be efficacy evaluable. In this population, 1 patient had a CR and 6 patients had PRs, resulting in an ORR of 44% (7/16). This compares favorably to the 26% ORR reported for the SoC regimen. In addition, 6 patients had SD, resulting in a DCR of 81% (13/16). The combination was well tolerated with no unexpected AEs or DLTs. The recommended dose of NUC-1031 with cisplatin was 725 mg/m2. The tolerability profile, together with encouraging efficacy led to initiation of a global registrational study. Methods: NuTide:121 is a phase III, open-label, randomized study of NUC-1031 + cisplatin vs GemCis for first-line treatment of advanced BTC. Patients ≥18 years with histologically- or cytologically-confirmed BTC (including cholangiocarcinoma, gallbladder, or ampullary cancer), who have had no prior systemic chemotherapy for locally advanced/metastatic disease, are eligible. A total of 828 patients are being randomized (1:1) to either 725 mg/m2 NUC-1031 or 1000 mg/m2 gemcitabine, both with 25 mg/m2 cisplatin, administered on Days 1 and 8 of 21-day cycles. Primary endpoints are OS and ORR. Secondary endpoints include PFS, safety, PK and patient-reported quality of life. In addition to the final analysis, three interim analyses are planned. The study has passed an initial safety analysis, with no protocol changes required. NuTide:121 is being conducted at approximately 130 sites across North America, Europe and Asia Pacific. Clinical trial information: NCT04163900.

Impact of the COVID-19 pandemic in treating gastrointestinal (GI) cancer patients receiving systemic anticancer treatment (SACT): The Guy's Cancer Centre experience

3612

Background: The COVID-19 pandemic has hugely affected the spectrum of cancer care. Worldwide healthcare systems have rapidly reorganized cancer services to ensure patients continue to receive essential care whilst optimizing the use of systemic anti-cancer treatments (SACT) and minimizing exposure to SARS-CoV-2 infection. Our study aimed to identify the outcome of patients with gastrointestinal (GI) cancers in our Cancer Centre during the pandemic compared to the same period in 2019. Methods: Retrospective analysis of all GI patients receiving any SACT at Guy’s Cancer Centre from the 1 March-31 May 2020 and 2019. Demographic data (age, ethnicity, socio-economic status (SES), Performance status, cancer and SACT characteristics (type, intent and treatment-line) were collected during both periods. Also we collated the number of COVID-19 infections confirmed by PCR and severity defined by the WHO classification. Patients with clinical or radiological diagnosis were excluded. Results: 567 patients received SACT in 2019 and 417 patients in 2020 (26.4% less). No differences were observed in the demographic or tumour type characteristics. Commonest cancers in both periods were similar: colorectal (47.1, 47%), oesophago-gastric (29, 27.6%), pancreatic-biliary and NET tumours (23.8, 25.4%). However, there were a higher proportion of patients with advanced disease treated in 2020 (70.3% versus 55.2%). Treatment intent was similar in both years: radical (3.5 vs 3.8%), adjuvant (18.2% vs 17.3%), neoadjuvant (15.3% vs 12.7%) and palliative (63% vs 66.2%). There was an increase in the proportion of patients treated in the palliative first line setting (63.8% in 2020 vs 47.6% in 2019) and a reduction in the proportion of third or more treatment (8.7% versus 16.2%) mainly in the colorectal patients. Of 417 GI patients receiving SACT, 14 (3.35%) were diagnosed with COVID-19 infection. Of these, 64.3% were male, 92.9% were low SES and 35.7% were of Caucasian ethnicity. Colorectal cancer was the commonest (57.1%) tumour-type in the COVID-positive group and 57.1% had advanced disease. All the patients that died from COVID-19 were male. 13 patients were on chemotherapy and 1 was on targeted/biological treatment . None was in immunotherapy (n=4). Only one patient was neutropenic (grade 1). 8 patients (57.1%) had severe infection and there were 3 (21.4%) COVID-related deaths. Conclusions: Our study shows the delivery of SACT through the COVID-19 pandemic is relatively safe with low COVID-related mortality rate. It also reflects how we tailored the delivery of anti-cancer treatments to reduce the possible detrimental myelo-suppressive toxicities that could potentially put GI patients at higher risk of severe SARS-CoV-2 infection. This is crucial data that can inform anti-cancer treatment decision making during the protracted COVID-19 pandemic.

Second-line FOLFOX chemotherapy versus active symptom control for advanced biliary tract cancer (ABC-06): a phase 3, open-label, randomised, controlled trial

BACKGROUND

Advanced biliary tract cancer has a poor prognosis. Cisplatin and gemcitabine is the standard first-line chemotherapy regimen, but no robust evidence is available for second-line chemotherapy. The aim of this study was to determine the benefit derived from second-line FOLFOX (folinic acid, fluorouracil, and oxaliplatin) chemotherapy in advanced biliary tract cancer.

METHODS

The ABC-06 clinical trial was a phase 3, open-label, randomised trial done in 20 sites with expertise in managing biliary tract cancer across the UK. Adult patients (aged ≥18 years) who had histologically or cytologically verified locally advanced or metastatic biliary tract cancer (including cholangiocarcinoma and gallbladder or ampullary carcinoma) with documented radiological disease progression to first-line cisplatin and gemcitabine chemotherapy and an Eastern Cooperative Oncology Group performance status of 0-1 were randomly assigned (1:1) centrally to active symptom control (ASC) and FOLFOX or ASC alone. FOLFOX chemotherapy was administered intravenously every 2 weeks for a maximum of 12 cycles (oxaliplatin 85 mg/m2, L-folinic acid 175 mg [or folinic acid 350 mg], fluorouracil 400 mg/m2 [bolus], and fluorouracil 2400 mg/m2 as a 46-h continuous intravenous infusion). Randomisation was done following a minimisation algorithm using platinum sensitivity, serum albumin concentration, and stage as stratification factors. The primary endpoint was overall survival, assessed in the intention-to-treat population. Safety was also assessed in the intention-to-treat population. The study is complete and the final results are reported. This trial is registered with ClinicalTrials.gov, NCT01926236, and EudraCT, 2013-001812-30.

FINDINGS

Between March 27, 2014, and Jan 4, 2018, 162 patients were enrolled and randomly assigned to ASC plus FOLFOX (n=81) or ASC alone (n=81). Median follow-up was 21·7 months (IQR 17·2-30·8). Overall survival was significantly longer in the ASC plus FOLFOX group than in the ASC alone group, with a median overall survival of 6·2 months (95% CI 5·4-7·6) in the ASC plus FOLFOX group versus 5·3 months (4·1-5·8) in the ASC alone group (adjusted hazard ratio 0·69 [95% CI 0·50-0·97]; p=0·031). The overall survival rate in the ASC alone group was 35·5% (95% CI 25·2-46·0) at 6 months and 11·4% (5·6-19·5) at 12 months, compared with 50·6% (39·3-60·9) at 6 months and 25·9% (17·0-35·8) at 12 months in the ASC plus FOLFOX group. Grade 3-5 adverse events were reported in 42 (52%) of 81 patients in the ASC alone group and 56 (69%) of 81 patients in the ASC plus FOLFOX group, including three chemotherapy-related deaths (one each due to infection, acute kidney injury, and febrile neutropenia). The most frequently reported grade 3-5 FOLFOX-related adverse events were neutropenia (ten [12%] patients), fatigue or lethargy (nine [11%] patients), and infection (eight [10%] patients).

INTERPRETATION

The addition of FOLFOX to ASC improved median overall survival in patients with advanced biliary tract cancer after progression on cisplatin and gemcitabine, with a clinically meaningful increase in 6-month and 12-month overall survival rates. To our knowledge, this trial is the first prospective, randomised study providing reliable, high-quality evidence to allow an informed discussion with patients of the potential benefits and risks from second-line FOLFOX chemotherapy in advanced biliary tract cancer. Based on these findings, FOLFOX should become standard-of-care chemotherapy in second-line treatment for advanced biliary tract cancer and the reference regimen for further clinical trials.

FUNDING

Cancer Research UK, StandUpToCancer, AMMF (The UK Cholangiocarcinoma Charity), and The Christie Charity, with additional funding from The Cholangiocarcinoma Foundation and the Conquer Cancer Foundation Young Investigator Award for translational research.

COVID-19 infection in gastrointestinal (GI) cancer patients receiving systemic anticancer treatment (SACT) during the outbreak of the pandemic: The Guy's Cancer Centre experience

455

Background: The COVID-19 pandemic has prompted difficult decisions around the use of SACT. These were based on limited early data suggesting cancer patients receiving SACT were at an increased risk of COVID-19 severe infection and death. Our study aim was to identify the COVID-19 infection and mortality rates of GI cancer patients receiving SACT. Methods: All GI patients receiving SACT at Guy’s Cancer Centre between March, and May 31, 2020 were included. Demographic data (age, ethnicity, socio-economic status (SES)) and cancer characteristics (stage, SACT type, intent and treatment-line) were collected. COVID-19 infection was confirmed by PCR and severity defined by the World Health Organisation (WHO) classification. Patients with clinical or radiological diagnosis alone were excluded. Results: Of 417 GI patients receiving SACT during the study period, 345 (82.7%) received chemotherapy (alone or combined with targeted/biological treatment), 68 (16.3%) targeted/biological treatment alone and 4 (1%) immunotherapy. 14 (3.4%) patients were diagnosed with COVID-19, 13 were on chemotherapy and 1 on targeted/biological treatment. Commonest cancers in the COVID-19 positive group were colorectal (57.1%) and hepatobiliary (21.4%), followed by oesophago-gastric (14.3%) and neuroendocrine tumours (7.1%); 57.1% had stage IV disease. 64.3% of the positive patients were male (compared to 57.3% in the COVID-19 negative population), mean age was 57.7 years (63.1 years) and 85.7% had low SES (79.7%). 8 (57.1%) patients had severe infection and there were 3 (21.4%) COVID-19 related deaths. All the patients who died from COVID-19 were male and were receiving palliative chemotherapy. Only one patient was neutropenic (grade 1) when diagnosed with COVID-19. Conclusions: The rate of COVID-19 infection in our population was relatively low (3.4 %). Of the 14 COVID-19 positive patients, 57.1% had severe infection, 21.4% died (compared to 3.7% mortality in the non-infected group) and all but one were on chemotherapy. This prospective data, from a large UK comprehensive Cancer Centre, provides some evidence that continuing SACT through the pandemic is relatively safe. The risk of COVID-19 related infection and death must be off-set against the cancer-related morbidity and mortality associated with treatment delays.

Phase III study of NUC-1031 + cisplatin vs gemcitabine + cisplatin for first-line treatment of patients with advanced biliary tract cancer (NuTide:121)

TPS351

Background: Biliary tract cancer (BTC) carries a poor prognosis and no first-line treatments are approved. The accepted global standard of care is gemcitabine + cisplatin (GemCis). NUC-1031 is a phosphoramidate transformation of gemcitabine designed to overcome key cancer resistance mechanisms that are associated with gemcitabine. Promising efficacy has been observed with single-agent NUC-1031 in a phase I study in advanced solid tumors and in the phase Ib ABC-08 study of NUC-1031 + cisplatin for first-line treatment of advanced BTC. Of 14 patients enrolled in 2 cohorts (NUC-1031 625 mg/m2 or 725 mg/m2 + cisplatin 25 mg/m2 on Days 1 and 8 of 21-day cycle), 1 had a CR and 6 had PRs, resulting in an unconfirmed ORR of 50%. This represents an approximate doubling of ORR over SoC. The combination was well-tolerated with no unexpected AEs or DLTs. The RP2D of NUC-1031 with cisplatin was 725 mg/m2. The tolerability profile, together with encouraging efficacy, suggested NUC-1031 + cisplatin may represent a more effective therapy than GemCis for BTC and led to initiation of a global registrational study. Methods: NuTide:121 is a Phase III, open-label, randomized study of NUC-1031 + cisplatin vs GemCis for first-line treatment of advanced BTC. Patients ≥18 years with histologically- or cytologically-confirmed BTC (including cholangiocarcinoma, gallbladder, or ampullary cancer), who have had no prior systemic chemotherapy for locally advanced/metastatic disease, are eligible. A total of 828 patients are being randomized (1:1) to either 725 mg/m2 NUC-1031 or 1000 mg/m2 gemcitabine, both with 25 mg/m2 cisplatin, administered on days 1 and 8 of 21-day cycles. Primary objectives are OS and ORR. Secondary objectives include PFS, safety, PK and patient-reported quality of life. In addition to the final analysis, three interim analyses, including two designed to support accelerated approval, are planned. The study has passed an initial safety analysis, with no protocol changes required. NuTide:121 is being conducted at approximately 130 sites across North America, Europe and Asia Pacific countries. Clinical trial information: NCT04163900.

Cost-utility analysis of selective internal radiation therapy with Y-90 resin microspheres in hepatocellular carcinoma

Background: The study assessed the cost-utility of selective internal radiation therapy (SIRT) with Y-90 resin microspheres versus sorafenib in UK patients with unresectable hepatocellular carcinoma ineligible for transarterial chemoembolization. Materials & methods: A lifetime partitioned survival model was developed for patients with low tumor burden (≤25%) and good liver function (albumin-bilirubin grade 1). Efficacy, safety and quality of life data were from a European Phase III randomized controlled trial and published studies. Resource use was from registries and clinical surveys. Results: Discounted quality-adjusted life-years were 1.982 and 1.381, and discounted total costs were £29,143 and 30,927, for SIRT and sorafenib, respectively. Conclusion: SIRT has the potential to be a dominant (more efficacious/less costly) or cost-effective alternative to sorafenib in patients with unresectable hepatocellular carcinoma.

Systematic review and network meta-analyses of third-line treatments for metastatic colorectal cancer

BACKGROUND

Limited treatment options are available in chemotherapy-refractory metastatic colorectal cancer (mCRC). The objective was to conduct a systematic literature review (SLR) and exploratory network meta-analysis (NMA) to compare the tolerability and effectiveness of SIRT with Y-90 resin microspheres, regorafenib, TAS-102 (trifluridine/tipiracil), and best supportive care (BSC) as third-line treatment in patients with mCRC.

METHODS

An SLR was conducted to identify studies comparing two or more of the treatments and reporting overall survival (OS), progression-free survival, tumor response, or adverse event (AE) incidence. An exploratory NMA was conducted to compare hazard ratios (HRs) for OS using Markov chain Monte Carlo (MCMC) techniques.

RESULTS

Seven studies were identified in the SLR: two double-blind randomized-controlled trials (RCT) for each drug, one open-label RCT, and two non-randomized comparative studies for SIRT. Patient selection criteria differed between studies, with SIRT studies including patients with liver-dominant colorectal metastases. Nausea and vomiting were more frequent with TAS-102 than regorafenib or SIRT; diarrhea was more common with TAS-102 and regorafenib than SIRT. The exploratory NMA suggested that all active treatments improved OS, with HRs of 0.48 (95% CrI 0.30-0.78) for SIRT with Y-90 resin microspheres, 0.63 (0.38-1.03) for TAS-102, and 0.67 (0.40-1.08) for regorafenib each compared to BSC.

CONCLUSIONS

Regorafenib, TAS-102 and SIRT using Y-90 resin microspheres are more effective than BSC in third-line treatment of mCRC; however, study heterogeneity made comparisons between active treatments challenging. SIRT is a viable treatment for third-line mCRC and its favorable AE profile should be considered in the therapeutic decision-making process.

NUC-1031/cisplatin versus gemcitabine/cisplatin in untreated locally advanced/metastatic biliary tract cancer (NuTide:121)

Gemcitabine/cisplatin is standard of care for first-line treatment of patients with advanced biliary tract cancer (aBTC); new treatments are needed. NUC-1031 is designed to overcome key cancer resistance mechanisms associated with gemcitabine. The tolerability/efficacy signal of NUC-1031/cisplatin in the Phase Ib ABC-08 study suggested that this combination may represent a more efficacious therapy than gemcitabine/cisplatin for patients with aBTC, leading to initiation of the global NuTide:121 study which will include 828 patients ≥18 years with untreated histologically/cytologically-confirmed aBTC (including cholangiocarcinoma, gallbladder or ampullary cancer); randomized (1:1) to NUC-1031 (725 mg/m2)/cisplatin (25 mg/m2) or gemcitabine (1000 mg/m2)/cisplatin (25 mg/m2), on days 1/8, Q21-days. Primary objectives are overall survival and objective response rate. Secondary objectives: progression-free survival, safety, pharmacokinetics, patient-reported quality of life and correlative studies. (Investigational new drug (IND) number: 139058, European Clinical Trials database: EudraCT Number 2019-001025-28, ClinicalTrials.gov identifier: NCT04163900).

ESPAC-4: A multicenter, international, open-label randomized controlled phase III trial of adjuvant combination chemotherapy of gemcitabine (GEM) and capecitabine (CAP) versus monotherapy gemcitabine in patients with resected pancreatic ductal adenocarcinoma: Five year follow-up

4516

Background: The ESPAC-4 trial demonstrated that adjuvant GEM/CAP for pancreatic cancer significantly improved survival compared to GEM monotherapy. The aim of this study is to evaluate the long-term outcomes in the ESPAC-4 trial. Methods: Patients with pancreatic ductal adenocarcinoma were randomized within 12 weeks of surgery (stratified for R0/R1 resection margin status and country) to have either six 4-week cycles of IV GEM alone or GEM with oral CAP. The primary endpoint was five-year survival; secondary endpoints were toxicity and relapse free survival. 722 patients (480 expected events), 361 in each arm, were needed to detect a 10% difference in 2-year survival rates with 90% power (log-rank test with 5% two-sided alpha). Results: Between Nov 10 2008 and Sep 11 2014, 732 patients were randomized with 730 included in the full analysis set (366 GEM, 364 GEM/CAP). Median age was 65 years, 57% were men. WHO performance status was 0, 1 or 2 in 42% 55% and 3% respectively. Postoperative median CA19-9 was 19 kU/L. Median maximum tumor size was 30 mm, 61% were R1 resections, 80% were node positive and 40% were poorly differentiated. The data freeze was on 24 February 2020; median follow up was 60 months with 531 overall deaths, 280 in GEM, and 251 in GEM/CAP. Median (95% CI) survival (months) for patients treated with GEM/CAP was 27.7 23.3 – 31.2) and 26.0 (22.7 – 28.4) for GEM. Five-year (95% CI) survival rates were 20 (16 – 25) % for GEM and 28 (23 – 33) % for GEM/CAP. Stratified log-rank analysis revealed an HR=0.84 [95% CI, 0.70 – 0.99]; χ2 (1) = 3.87, P=0.049. 70 out of 366 GEM patients in the safety set reported 101 grade 3/4 serious adverse events, while 65 out of 359 GEM/CAP patients reported 97 grade 3/4 serious adverse events ( P=0.724). Conclusions: Adjuvant GEM/CAP for pancreatic cancer had a statistically significant improvement in survival compared to GEM monotherapy. Clinical trial information: 96397434 .

Systematic alteration of ATAC-seq for profiling open chromatin in cryopreserved nuclei preparations from livestock tissues

The use of Assay for Transposase-Accessible Chromatin (ATAC-seq) to profile chromatin accessibility has surged over the past years, but its applicability to tissues has been very limited. With the intent of preserving nuclear architecture during long-term storage, cryopreserved nuclei preparations from chicken lung were used to optimize ATAC-seq. Sequencing data were compared with existing DNase-seq, ChIP-seq, and RNA-seq data to evaluate library quality, ultimately resulting in a modified ATAC-seq method capable of generating high quality chromatin accessibility data from cryopreserved nuclei preparations. Using this method, nucleosome-free regions (NFR) identified in chicken lung overlapped half of DNase-I hypersensitive sites, coincided with active histone modifications, and specifically marked actively expressed genes. Notably, sequencing only the subnucleosomal fraction dramatically improved signal, while separation of subnucleosomal reads post-sequencing did not improve signal or peak calling. The broader applicability of this modified ATAC-seq technique was tested using cryopreserved nuclei preparations from pig tissues, resulting in NFR that were highly consistent among biological replicates. Furthermore, tissue-specific NFR were enriched for binding motifs of transcription factors related to tissue-specific functions, and marked genes functionally enriched for tissue-specific processes. Overall, these results provide insights into the optimization of ATAC-seq and a platform for profiling open chromatin in animal tissues.

Real-world experience of regorafenib in patients with hepatocellular carcinoma: A multicenter United Kingdom study

499

Background: Regorafenib was the first treatment to demonstrate a survival benefit in patients with HCC after progression on sorafenib. The RESORCE trial found that regorafenib improved overall survival with acceptable toxicity, in patients with disease progression on sorafenib who tolerated ≥400mg sorafenib daily and had Child-Pugh A liver function. Methods: We performed a multicentre, retrospective, observational study of patients with HCC receiving regorafenib in the UK, following its availability in April 2018. Results: Data on a total of 104 patients were included from April 2018–August 2019, and 80.8% were male. Age was collected in 85 patients, with a median of 68 years (range 22–86). 23.5% had NAFLD, 21.2% had ALD, 12.9% had HBV, and 3.5% had HCV. Prior management included sorafenib (100%), TACE (30.8%), resection (12.9%). Duration of sorafenib treatment was evaluable in 99/104 patients, and reported a median of 8.7 months (range 1.8–76.6). Duration of regorafenib treatment was evaluable in 92/104 patients, and reported a median of 3.9 months (range 0.0–15.7). Following treatment with regorafenib, 6 patients (5.8%) achieved partial response, 37 (35.6%) achieved stable disease and 45 (43.3%) had progressive disease as the best response. 15 (14.4%) were not assessed and 1 (1.1%) had mixed response. Survival data is immature with 62/101 (61.4%) patients alive at the time of census with median survival currently 6.5 months. Fatigue was the most frequent AE, with 69/88 patients (85.2%) for all grades. 12/88 patients (14.8%) had Grade 3 fatigue. Other significant AEs include hand-foot syndrome (6/85 patients [7.3%] had Grade 3) and diarrhoea (4/83 patients [4.9%] had Grade 3). Conclusions: The population in our real-world experience of regorafenib for HCC had a similar duration of prior sorafenib to those in the RESORCE trial. However, there was different balance of aetiologies with a lower proportion of patients with HBV and HCV. The rate of partial response is similar to the RESORCE trial with fewer patients achieving stable disease. The incidence of fatigue was higher, but the incidence of hand-foot syndrome and diarrhoea were lower. Further expansion and follow-up of this population is warranted.

NUC-1031 in combination with cisplatin for first-line treatment of patients with advanced biliary tract cancer (NuTide:121)

TPS602

Background: Biliary tract cancer (BTC) carries a poor prognosis and has no approved treatments. Although gemcitabine + cisplatin (GemCis) is accepted as the global standard of care (SoC) for 1st-line treatment, the reported unconfirmed ORR and OS from randomized studies of this combination are low at 18.5-26.1% and 11.2-11.7 months, respectively. NUC-1031, a phosphoramidate transformation of gemcitabine, is designed to overcome key cancer resistance mechanisms associated with gemcitabine. Promising signs of efficacy have been observed with single-agent NUC-1031 in a Phase I study in advanced solid tumors (Blagden et al 2018) and in the Phase Ib ABC-08 study of NUC-1031 + cisplatin 25 mg/m2 on days 1 and 8 of a 21-day cycle for the 1st-line treatment of advanced BTC. Of 14 patients (pts) enrolled in 2 cohorts (NUC-1031: 625 mg/m2 and 725 mg/m2), 1 pt achieved a CR and 6 pts achieved PR, giving an unconfirmed ORR of 50% and representing an approximate doubling of ORR over SoC. The combination was well-tolerated with no unexpected adverse events or dose-limiting toxicities. The RP2D of NUC-1031 in combination with cisplatin is 725 mg/m2. The tolerability profile together with robust efficacy signals suggested NUC-1031 + cisplatin may represent a more effective therapy than GemCis for BTC and led to initiation of a global Phase III study. Methods: A Phase III, open-label, randomized head-to-head study of NUC-1031 + cisplatin versus GemCis for 1st-line treatment of advanced BTC will include pts ≥18 years with histologically- or cytologically-proven BTC (including cholangiocarcinoma, gallbladder, or ampullary cancer), who have had no prior systemic chemotherapy for locally advanced/metastatic disease. A total of 828 pts will be randomized (1:1) to either 725 mg/m2 NUC-1031 + 25 mg/m2 cisplatin or 1000 mg/m2 gemcitabine + 25 mg/m2 cisplatin, administered on days 1 and 8 of a 21-day cycle. Primary objectives are OS and ORR. Secondary objectives include further measurements of efficacy, safety, pharmacokinetics, and patient-reported quality of life. The study will be conducted at approximately 120 sites across North America, Europe and Asia Pacific countries. Clinical trial information: NCT04163900.

Tumor burden and liver function in HCC patient selection for selective internal radiation therapy: SARAH post-hoc study

Aim: To determine whether a liver tumor burden ≤25% and well-preserved liver function (albumin-bilirubin grade 1) are appropriate criteria for identifying patients with unresectable hepatocellular carcinoma who may benefit from selective internal radiation therapy (SIRT) using ⁹⁰yttrium resin microspheres versus sorafenib. Patients & methods: Post-hoc analysis of patients in the intention-to-treat population of the SARAH trial (SIRT vs sorafenib) with ≤25% tumor burden and albumin-bilirubin grade 1. Primary end point: overall survival. Results: Median overall survival was 21.9 months (95% CI: 15.2-32.5, n = 37) with SIRT and 17.0 months (11.6-20.8, n = 48) with sorafenib (hazard ratios: 0.73; 95% CI: 0.44-1.21; p = 0.22). Conclusion: A combination of good liver function and low tumor burden may be relevant for selection of hepatocellular carcinoma patients for SIRT.

Patterns of Recurrence After Resection of Pancreatic Ductal Adenocarcinoma: A Secondary Analysis of the ESPAC-4 Randomized Adjuvant Chemotherapy Trial

Importance

The patterns of disease recurrence after resection of pancreatic ductal adenocarcinoma with adjuvant chemotherapy remain unclear.

Objective

To define patterns of recurrence after adjuvant chemotherapy and the association with survival.

Design, Setting, and Participants

Prospectively collected data from the phase 3 European Study Group for Pancreatic Cancer 4 adjuvant clinical trial, an international multicenter study. The study included 730 patients who had resection and adjuvant chemotherapy for pancreatic cancer. Data were analyzed between July 2017 and May 2019.

Interventions

Randomization to adjuvant gemcitabine or gemcitabine plus capecitabine.

Main Outcomes and Measures

Overall survival, recurrence, and sites of recurrence.

Results

Of the 730 patients, median age was 65 years (range 37-81 years), 414 were men (57%), and 316 were women (43%). The median follow-up time from randomization was 43.2 months (95% CI, 39.7-45.5 months), with overall survival from time of surgery of 27.9 months (95% CI, 24.8-29.9 months) with gemcitabine and 30.2 months (95% CI, 25.8-33.5 months) with the combination (HR, 0.81; 95% CI, 0.68-0.98; P = .03). The 5-year survival estimates were 17.1% (95% CI, 11.6%-23.5%) and 28.0% (22.0%-34.3%), respectively. Recurrence occurred in 479 patients (65.6%); another 78 patients (10.7%) died without recurrence. Local recurrence occurred at a median of 11.63 months (95% CI, 10.05-12.19 months), significantly different from those with distant recurrence with a median of 9.49 months (95% CI, 8.44-10.71 months) (HR, 1.21; 95% CI, 1.01-1.45; P = .04). Following recurrence, the median survival was 9.36 months (95% CI, 8.08-10.48 months) for local recurrence and 8.94 months (95% CI, 7.82-11.17 months) with distant recurrence (HR, 0.89; 95% CI, 0.73-1.09; P = .27). The median overall survival of patients with distant-only recurrence (23.03 months; 95% CI, 19.55-25.85 months) or local with distant recurrence (23.82 months; 95% CI, 17.48-28.32 months) was not significantly different from those with only local recurrence (24.83 months; 95% CI, 22.96-27.63 months) (P = .85 and P = .35, respectively). Gemcitabine plus capecitabine had a 21% reduction of death following recurrence compared with monotherapy (HR, 0.79; 95% CI, 0.64-0.98; P = .03).

Conclusions and Relevance

There were no significant differences between the time to recurrence and subsequent and overall survival between local and distant recurrence. Pancreatic cancer behaves as a systemic disease requiring effective systemic therapy after resection.

Trial Registration

ClinicalTrials.gov identifier: NCT00058201, EudraCT 2007-004299-38, and ISRCTN 96397434.

4324Fast-field cycling magnetic resonance detection of intracellular iron in the nanomolar range - A pre-requisite for in-vivo study of inflammation

Background

Ultra-small superparamagnetic iron oxide (USPIO) nanoparticles are phagocytosed by macrophages and when subjected to magnetic resonance imaging (MRI) detect inflammation. We describe a novel MR technique where the magnetic field is rapidly cycled (Fast field-cycling MR, FFC-MR), assessing T1 dispersion over a range of low (100μT-0.2T) fields and offering superior T1-based iron quantification.

AIM

To quantify iron using the FFC-MR R1 (1/T1) dispersion profile and flow cytometry features of USPIO-laden cells, in comparison to colorimetric assays.

Methods

Murine J774 macrophage-like cells were incubated with 0–200μg/ml Fe as USPIO (ferumoxytol) for 16 hours, washed and suspended in 500μl PBS/2mM EDTA. Prussian blue staining confirmed USPIO phagocytosis. Relaxation was measured using a clinical, in-house built prototype 0.2T FFC-MR system with a custom test tube coil. R1 dispersion was derived from a saturation recovery sequence (Fig. 1A). R1 (s–1) values were calculated with a monoexponential curve fitting algorithm, R2 of fits were ≥0.999. R1 dispersion profiles were generated plotting R1 against the magnetic field (T). Quantification of side scatter (SCC) intensity and the USPIO-occupied fraction of total cell area was performed with imaging flow cytometry. A colorimetric assay provided validation of cell iron content. All data are mean±SEM, analysed with t-tests, Pearson correlation and linear regression; statistical significance set at p<0.05.

Results

Table 1 shows quantitative data derived by all 3 modalities with increasing USPIO exposure. FFC-MR detection of intracellular iron was excellent (p≤0.001 vs. control for all), with separation of average R1 dispersion profiles (Fig. 1B), strong correlation with colorimetry (r=0.993 p<0.001) and good fit on linear regression model (R2=0.9222, Fig 1C). Flow cytometry quantification of SCC was comparable (p≤0.001 for all), whereas USPIO-occupied area was only sensitive at exposures ≥10μg/ml USPIO (r=0.967 p<0.001 & r=0.983 p<0.001 vs. colorimetric respectively). FFC-MR detected iron at ≥1.12ng/μg protein.

USPIO exposure (μg/ml medium) 0 5 10 40 80 100 200 FFC-MR Mean R1 1x106 cell suspension (s–1) 0.308±0.014 0.356±0.013** 0.432±0.016** 0.706±0.021** 1.174±0.031** 1.239±0.033** 1.599±0.041** Flow cytometry USPIO area/cell area 0.034±0.001 0.036±0.001 0.037±0.001* 0.069±0.001** 0.085±0.001** 0.090±0.001** 0.097±0.001** Flow cytometry SSC intensity 26860 32815** 39573** 69285** 80967** 82693** 86373** Colorimetric assay Iron concentration 1x106 cells (ng/μg protein) 0.115±0.118 1.121±0.045** 2.074±0.084** 5.496±0.134** 8.421±0.269** 9.771±0.100** 12.398±0.233** SSC = side-scattered light; *p<0.05 vs. control; **p<0.001 vs. control.

Conclusion

Field-cycling MR is capable of highly accurate intracellular USPIO quantification, which has potential to non-invasively detect clinically relevant amounts of iron in inflammatory cardiovascular diseases.

Acknowledgement/Funding

NHS Grampian Endowment Fund

Evaluation of protective and immune responses following vaccination with recombinant MIP and CPAF from Chlamydia abortus as novel vaccines for enzootic abortion of ewes

MIP and CPAF from Chlamydia have been shown to be effective in inducing immune responses important in clearing chlamydial infections. This study evaluates the protection conferred by MIP and CPAF as novel vaccines in pregnant C. abortus challenged ewes. Fifty C. abortus sero-negative sheep were randomly allocated into 5 groups of 10 according to the treatment they were to receive (1) 100 µg of MBP-MIP (2) 100 µg CPAF (3) 50 µg MBP-MIP and 50 µg CPAF (4) Tris-buffer (negative control) (5) Enzovax (positive control). Booster inoculations were administered 3 weeks after primary inoculations. Blood samples were taken pre-vaccination and weekly for 5 weeks. Five months after vaccination the ewes were mated. Pregnant ewes were then challenged on day 90 of gestation. Blood samples taken at four time-points post challenge were analysed for IFNγ levels, TNFα and IL-10 expression and anti-chlamydial antibody levels. Vaginal swabs, placental and foetal tissue and bacterial shedding were analysed using qPCR to quantify levels of C. abortus. Enzovax was 100% effective with no abortions occurring. The MIP/CPAF combined vaccine offered the greatest protection of the novel vaccines with 67% of ewes giving birth to one or more live lambs equating to a 50% vaccine efficacy rate. MIP and CPAF administered singly did not confer protection. Enzovax and MIP/CPAF vaccinated ewes had longer gestations and lambs with higher birth weights than negative control ewes. Aborting ewes shed higher numbers of C. abortus than ewes that had live lambs, all vaccinated ewes demonstrated lower levels of bacterial shedding than negative control ewes with Enzovax ewes shedding significantly fewer bacteria. Ewes that went on to abort had significantly higher levels of IFNγ and IL-10 at day 35 post challenge and significantly higher levels of anti-chlamydial antibodies at 24 h post lambing compared to ewes that had live lambs.

ABC-06 | A randomised phase III, multi-centre, open-label study of active symptom control (ASC) alone or ASC with oxaliplatin / 5-FU chemotherapy (ASC+mFOLFOX) for patients (pts) with locally advanced / metastatic biliary tract cancers (ABC) previously-treated with cisplatin/gemcitabine (CisGem) chemotherapy

4003

Background: Level A evidence supports use of CisGem as first-line chemotherapy for ABC; no robust evidence is available for second-line chemotherapy. Methods: Pts diagnosed with ABC with disease progression after prior CisGem were randomised (1:1) to either ASC+mFOLFOX or ASC. Randomisation was stratified by serum albumin levels ( < 35 vs ≥35 g/L), platinum sensitivity (determined from first-line CisGem) and disease extent (locally advanced vs metastatic). Pts with ECOG PS0-1, adequate haematological, renal and liver function, and adequate biliary drainage were eligible. Primary end-point was overall survival (OS) (multivariable Cox regression adjusted for stratification factors); sample size: 162 pts delivering 148 events were required (80% power; 5% two-sided alpha) for a hypothesised hazard ratio (HR) of 0.63. Assumed median survival for ASC was 4 months. Results: 162 pts (81 in each arm) were randomised (27 March ‘14 - 04 Jan ‘18); median age 65 yrs (range 26-84); sex: 80 (49%) male, 82 (51%) female; primary site: intrahepatic 72 (44%), extrahepatic 45 (28%), gallbladder 34 (21%) and ampullary 11 (7%). Baseline characteristics were balanced between arms except platinum sensitivity (ASC+mFOLFOX 27 pts (33%); ASC 34 pts (42%)). After 150 OS events, the adjusted HR was 0.69 (95% CI 0.50-0.97; p = 0.031; ASC+mFOLFOX vs ASC). Median OS (months (m)), 6m and 12m OS-rate (%) were 6.2m, 50.6% and 25.9% for the ASC+mFOLFOX and 5.3m, 35.5%, 11.4% for the ASC arm, respectively. Grade 3/4 toxicities were reported in 48 (59%) and 32 (39%) pts in the ASC+mFOLFOX and ASC arm, respectively; these were balanced between arms except for fatigue and neutropenia (more frequent in ASC+mFOLFOX arm); data cleaning is ongoing. No chemotherapy-related deaths were reported. Conclusion: Survival with ASC was greater than assumed; ASC+mFOLFOX improved OS after progression to CisGem with a clinically meaningful increase in 6m and 12m OS rate. ASC+mFOLFOX should become standard of care in second-line for ABC. Clinical trial information: NCT01926236.

PanCO: An open-label, single-arm pilot study of phosphorus-32 (P-32; Oncosil) microparticles in patients with unresectable locally advanced pancreatic adenocarcinoma (LAPC) in combination with FOLFIRINOX or gemcitabine + nab-paclitaxel (GNP) chemotherapies

4125

Background: LAPC is associated with a poor prognosis. Current standard treatment is limited to chemotherapy or chemo-radiotherapy. P-32 Microparticles is a brachytherapy device that implants a predetermined dose of P-32 into pancreatic tumours via endoscopic ultrasound (EUS) guidance. This reports the initial results of a pilot study in combination with chemotherapy. Methods: Eligible patients were permitted to receive either GNP or FOLFIRINOX. P-32 was implanted at week 4 or 5. The dose of P-32 was calculated from tumour volume to deliver an absorbed dose of 100 Gy. Diffusion pattern of the P-32 suspension was assessed by EUS and bremsstrahlung SPECT/CT imaging. Safety data was graded using CTCAE v4.0 criteria. Response was assessed according to RECIST 1.1 with CT scans every 8 weeks and FDG-PET scans at baseline and week 12. Results: 50 patients were enrolled (Intent-to-Treat population (ITT)) of which 42 were implanted with the device (Per Protocol population (PP)). 10 received FOLFIRINOX and 40 GNP. Median age was 65, 28 were male and all had a PS 0/1. 1070 adverse events (ITT) were reported; 153 (80% of patients) were ≥ Grade 3. The most common AEs of ≥ Grade 3 were haematological (39, 46%) and gastrointestinal disorders (30, 34%). No serious device- or radiation-related toxicities have been reported. PP Local Disease Control Rate at Week 16 was 90%; 95% CI: 77-97% and at Week 24 was 71%; 95% CI: 55-84%. Overall Response Rate (ORR) was 31%; 95% CI: 18-47%. Median change in tumour volume from Baseline to Week 16 and to Week 24 was -38% (range +89% to -90%) and -27.5% (range +139% to -79%). Ten (24%) patients underwent surgical resection following repeat staging. Eight patients had R0 margin. Conclusions: The use of EUS-guided implantation of P-32 is feasible, with an acceptable safety profile in combination with first-line chemotherapy for LAPC patients. Encouraging OR and DCR are observed. Further follow-up to inform results of local progression free survival and progression free survival is warranted. Acknowledgement: Nab-paclitaxel was supported by Specialised Therapeutics Australia Pty Ltd. Clinical trial information: NCT03003078.

Real-world experience of trifluridine/tipiracil in patients with metastatic colorectal cancer: A multicenter United Kingdom study

668

Background: TAS-102 is an orally administered combination of the thymidine-based nucleic acid analogue, trifluridine and the thymidine phosphorylase inhibitor, tipiracil hydrochloride. Following the phase III RECOURSE study, it received approval as third line treatment for metastatic colorectal cancer showing significant improvement in overall and progression free survival and an acceptable toxicity profile. Methods: We performed a multicenter retrospective observational study of patients with metastatic colorectal cancer receiving TAS-102 as third line treatment between 2016 and 2018 in Cancer centers across the UK. Results: A total of 143 patients were included (94 men, 49 women). Median age was 68 years (35-82). All patients had received at least 2 lines of fluoropyrimidine-based chemotherapy doublet with oxaliplatin or irinotecan. About 90% of patients had ECOG ≥ 1. Median duration of treatment was 2.9 months (0.5-22.9), with a response rate of 1.6% and stable disease achieved in 24%. Median OS was 7 months (95% CI 5.84-8.15) and median PFS 2.6 months (95% CI 2.2-3.36). A dose reduction was required in 28% of patients, while 8% discontinued treatment due to toxicity. AEs reported included fatigue 81.3% (G3 16.8%), nausea 34.5% (G3 4.5%) and diarrhoea 25.5% (G3 1.8%). Neutropenia was common 50.4%, (≥ G3: 25.4%) with 4.2% cases of neutropenic fever while thrombocytopenia was less frequent 8.7% (≥ G3 1.8%). Conclusions: The OS, PFS and ORR observed in our real-world experience were consistent with the RECOURSE trial, though we noted a lower disease control rate. Overall, TAS-102 was well tolerated and the most prevalent adverse events seen in our patients were in keeping with those reported in the trial. Although severe toxicities were less frequent than the trial, we experienced higher rates of toxicity induced dose reductions and treatment cessations, which could reflect the differences between trial and real world populations. Further validation is warranted.

Circulating biomarkers during treatment in patients with advanced biliary tract cancer receiving cediranib in the UK ABC-03 trial

BACKGROUND

Advanced biliary tract cancer (ABC) has a poor prognosis. Cediranib, in addition to cisplatin/gemcitabine [CisGem], improved the response rate, but did not improve the progression-free survival (PFS) in the ABC-03 study. Minimally invasive biomarkers predictive of cediranib benefit may improve patient outcomes.

METHODS

Changes in 15 circulating plasma angiogenesis or inflammatory-related proteins and cytokeratin-18 (CK18), measured at baseline and during therapy until disease progression, were correlated with overall survival (OS) using time-varying covariate Cox models (TVC).

RESULTS

Samples were available from n = 117/124 (94%) patients. Circulating Ang1&2, FGFb, PDGFbb, VEGFC, VEGFR1 and CK18 decreased as a result of the therapy, independent of treatment with cediranib. Circulating VEGFR2 and Tie2 were preferentially reduced by cediranib. Patients with increasing levels of VEGFA at any time had a worse PFS and OS; this detrimental effect was attenuated in patients receiving cediranib. TVC analysis revealed CK18 and VEGFR2 increases correlated with poorer OS in all patients (P < 0.001 and P = 0.02, respectively).

CONCLUSIONS

Rising circulating VEGFA levels in patients with ABC, treated with CisGem, are associated with worse PFS and OS, not seen in patients receiving cediranib. Rising levels of markers of tumour burden (CK18) and potential resistance (VEGFR2) are associated with worse outcomes and warrant validation.

Differing molecular response of young and advanced maternal age human oocytes to IVM

STUDY QUESTION

What effect does maternal age have on the human oocyte's molecular response to in vitro oocyte maturation?

SUMMARY ANSWER

Although polyadenylated transcript abundance is similar between young and advanced maternal age (AMA) germinal vesicle (GV) oocytes, metaphase II (MII) oocytes exhibit a divergent transcriptome resulting from a differential response to in vitro oocyte maturation.

WHAT IS KNOWN ALREADY

Microarray studies considering maternal age or maturation stage have shown that either of these factors will affect oocyte polyadenylated transcript abundance in human oocytes. However, studies considering both human oocyte age and multiple stages simultaneously are limited to a single study that examined transcript levels for two genes by qPCR. Thus, polyadenylated RNA sequencing (RNA-Seq) could provide novel insight into age-associated aberrations in gene expression in GV and MII oocytes.

STUDY DESIGN, SIZE, DURATION

The effect of maternal age (longitudinal analysis) on polyadenylated transcript abundance at different stages was analyzed by examining single GV and single in vitro matured MII oocytes derived from five young (YNG; < 30 years; average age 26.8; range 20-29) and five advanced maternal age (AMA; ≥40 years; average age 41.6 years; range 40-43 years) patients. Thus, a total of 10 YNG (5 GV and 5 MII) and 10 AMA (5 GV and 5 MII) oocytes were individually processed for RNA-Seq analysis.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Patients undergoing infertility treatment at the Colorado Center for Reproductive Medicine (Lone Tree, CO, USA) underwent ovarian stimulation with FSH and received hCG for final follicular maturation prior to ultrasound guided oocyte retrieval. Unused GV oocytes obtained at retrieval were donated for transcriptome analysis. Single oocytes were stored (at -80°C in PicoPure RNA Extraction Buffer; Thermo Fisher Scientific, USA) immediately upon verification of immaturity or after undergoing in vitro oocyte maturation (24 h incubation), representing GV and MII samples, respectively. After isolating RNA and generating single oocyte RNA-Seq libraries (SMARTer Ultra Low Input RNA HV kit; Clontech, USA), Illumina sequencing (100 bp paired-end reads on HiSeq 2500) and bioinformatics analysis (CLC Genomics Workbench, DESeq2, weighted gene correlation network analysis (WGCNA), Ingenuity Pathway Analysis) were performed.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 12 770 genes were determined to be expressed in human oocytes (reads per kilobase per million mapped reads (RPKM) > 0.4 in at least three of five replicates for a minimum of one sample type). Differential gene expression analysis between YNG and AMA oocytes (within stage) identified 1 and 255 genes that significantly differed (adjusted P < 0.1 and log2 fold change >1) in polyadenylated transcript abundance for GV and MII oocytes, respectively. These genes included CDK1, NLRP5 and PRDX1, which have been reported to affect oocyte developmental potential. Despite the similarity in transcript abundance between GV oocytes irrespective of age, divergent expression patterns emerged during oocyte maturation. These age-specific differentially expressed genes were enriched (FDR < 0.05) for functions and pathways associated with mitochondria, cell cycle and cytoskeleton. Gene modules generated by WGCNA (based on gene expression) and patient traits related to oocyte quality (e.g. age and blastocyst development) were correlated (P < 0.05) and enriched (FDR < 0.05) for functions and pathways associated with oocyte maturation.

LARGE SCALE DATA

Raw data from this study can be accessed through GSE95477.

LIMITATIONS, REASONS FOR CAUTION

The human oocytes used in the current study were obtained from patients with varying causes of infertility (e.g. decreased oocyte quality and oocyte quality-independent factors), possibly affecting oocyte gene expression. Oocytes in this study were retrieved at the GV stage following hCG administration and the MII oocytes were derived by IVM of patient oocytes. Although the approach has the benefit of identifying intrinsic differences between samples, it may not be completely representative of in vivo matured oocytes.

WIDER IMPLICATIONS OF THE FINDINGS

Transcriptome profiles of YNG and AMA oocytes, particularly at the MII stage, suggest that aberrant transcript abundance may contribute to the age-associated decline in fertility.

STUDY FUNDING/COMPETING INTEREST(S)

J.M.R. was supported by an Austin Eugene Lyons Fellowship awarded by the University of California, Davis. The Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (awarded to P.J.R.; R01HD070044) and the Fertility Laboratories of Colorado partly supported the research presented in this manuscript.

Exome array analysis of adverse reactions to fluoropyrimidine-based therapy for gastrointestinal cancer

Fluoropyrimidines, including 5-fluororacil (5FU) and its pro-drug Capecitabine, are the common treatment for colorectal, breast, neck and head cancers—either as monotherapy or in combination therapy. Adverse reactions (ADRs) to the treatment are common and often result in treatment discontinuation or dose reduction. Factors contributing to ADRs, including genetic variation, are poorly characterized. We performed exome array analysis to identify genetic variants that contribute to adverse reactions. Our final dataset consisted of 504 European ancestry individuals undergoing fluoropyrimidine-based therapy for gastrointestinal cancer. A subset of 254 of these were treated with Capecitabine. All individuals were genotyped on the Illumina HumanExome Array. Firstly, we performed SNP and gene-level analyses of protein-altering variants on the array to identify novel associations the following ADRs, which were grouped into four phenotypes based on symptoms of diarrhea, mucositis, and neutropenia and hand-and-foot syndrome. Secondly, we performed detailed analyses of the HLA region on the same phenotypes after imputing the HLA alleles and amino acids. No protein-altering variants, or sets of protein-altering variants collapsed into genes, were associated with the main outcomes after Bonferroni correction. We found evidence that the HLA region was enriched for associations with Hand-and-Foot syndrome (p = 0.023), but no specific SNPs or HLA alleles were significant after Bonferroni correction. Larger studies will be required to characterize the genetic contribution to ADRs to 5FU. Future studies that focus on the HLA region are likely to be fruitful.

ACELARATE: A phase III, open label, multicentre randomised clinical study comparing Acelarin (NUC-1031) with gemcitabine in patients with metastatic pancreatic carcinoma

TPS537

Background: Single agent gemcitabine still remains an appropriate choice for patients with metastatic pancreatic adenocarcinoma who are not suitable for combination therapy. Known resistance factors, such as low hENT1 and dCK, and CDA overexpression limit gemcitabine’s efficacy. NUC-1031 (Acelarin), is designed to overcome this resistance and deliver significantly higher intracellular levels of the active agent, dFdCTP, than gemcitabine. In Phase I studies Acelarin has shown activity in a range of metastatic cancers, including pancreatic, biliary and ovarian cancers. This Phase III study is designed to show superiority of Acelarin over gemcitabine in patients unsuitable for combination chemotherapy. Methods: To date, 85 patients have been randomised in this multicentre, Phase III study comparing Acelarin with gemcitabine first-line in patients with metastatic pancreatic adenocarcinoma. Patients must have a Performance Status of 0-2 and be unsuitable for combination chemotherapy. To detect a hazard ratio of 0.705 between the two arms, 270 events must be obtained from 328 patients, assuming a median survival of 6 months in the control arm. Currently, pts are being recruited at 27 centres. Patients receive either 825mg/m2 Acelarin or 1000mg/m2 gemcitabine on Day 1, 8 and 15 of a 28-day cycle until disease progression. The primary outcome measure is Overall Survival. Secondary outcome measures include Progression Free Survival, Response Rate, Disease Control Rate and Toxicity. Translational research will explore the use of biomarkers for predictive benefit of Acelarin over gemcitabine. Clinical trial information: ISRCTN16765355.

Hand-foot skin reaction (HFSR) and overall survival (OS) in the phase 3 RESORCE trial of regorafenib for treatment of hepatocellular carcinoma (HCC) progressing on sorafenib

412

Background: Skin toxicity is a known adverse effect of multikinase inhibitors, and was shown to be a predictor of OS in patients (pts) with HCC treated with sorafenib (Reig M, 2014). In the RESORCE trial, regorafenib improved OS versus placebo in pts with HCC progressing on sorafenib (HR 0.62, 95% CI 0.50, 0.78; Bruix J, 2017). This retrospective analysis explored whether HFSR with regorafenib was associated with OS in RESORCE. Methods: Pts in RESORCE who were randomized to regorafenib 160 mg/day during the first 3 weeks of each 4-week cycle were divided into subgroups based on whether or not they had HFSR. Estimates of OS (95% CI) were calculated using the Kaplan–Meier method. Pts who were randomized, but not treated, were included in the no HFSR group for the analysis of survival. Results: Of 379 pts randomized, 374 received at least one dose of regorafenib. Of the treated pts, 53% (n = 199) had HFSR of any grade and 13% (n = 47) had grade 3 HFSR. Among pts with HFSR at any time during the study, 77% (n = 153) had the first HFSR event (any grade) during Cycle 1. Subgroups of pts with and without HFSR at any time had some imbalances in baseline characteristics (Table). OS was improved in pts who had HFSR at any time versus those who did not (Table). Pts who had a HFSR event during Cycle 1 also had improved OS versus those who did not (median OS 13.2 vs 8.5 months; HR 0.66, 95% CI 0.51, 0.86). Conclusions: In this post-hoc exploratory analysis, HFSR with regorafenib was associated with improved OS, as was previously shown for sorafenib. The potential confounding influence of baseline factors requires further investigation. Clinical trial information: NCT01774344. [Table: see text]

Effect of different mini-volume colloid centrifugation configurations on flow cytometrically sorted sperm recovery efficiency and quality using a computer-assisted semen analyzer

Straws of sex-sorted sperm are usually packaged at a low concentration (e.g., ~2.1 × 10⁶  sperm/ml) and cost significantly more than unsorted conventional semen from the same sire. In order to maximize the efficiency of using sex-sorted sperm under in vitro fertilization conditions, the selection of an appropriate sperm separation technique is essential. In this study, the effect of using different silane-coated silica colloid dilutions and layering configurations during centrifugation of sex-sorted sperm was examined over an extended period of incubation time. Sperm recovery and viability after centrifugation using the colloid separation technique were measured along with several sperm motility parameters using CASA. For this purpose, frozen and thawed sex-sorted sperm samples were centrifuged using mini-volume single-layer (40%, 60% and 80%) and mini-volume two-layer (45%/90%, 40%/80% and 30%/60%) separation configurations using PureSperm^® . A single layer of 40% PureSperm^® recovered significantly more sex-sorted sperm (78.07% ± 2.28%) followed by a single layer of 80% PureSperm^® (68.43% ± 2.33%). The lowest sperm recovery was obtained using a two-layer PureSperm^® dilution of 45%/90% (47.57% ± 2.33%). Single-layer centrifugation recovered more sorted sperm (68.67% ± 1.74%) than two layer (53.74% ± 1.74%) (p < .0001). A single layer of 80% PureSperm^® exhibited the highest sorted sperm viability (72.01% ± 2.90%) after centrifugation (p < .05). The mini-volume single layer of 80% PureSperm^® was determined to be an effective alternative to a two-layer centrifugation configuration for sex-sorted sperm selection. In addition, single-layer colloid dilution of 80% performed either as well as or significantly outperformed the other treatments, as well as the control, with regard to motility (MOT) for all time periods of analysis.

Sorafenib in combination with transarterial chemoembolisation in patients with unresectable hepatocellular carcinoma (TACE 2): a randomised placebo-controlled, double-blind, phase 3 trial

BACKGROUND

Transarterial chemoembolisation (TACE) is the standard of care for patients with intermediate stage hepatocellular carcinoma, while the multikinase inhibitor sorafenib improves survival in patients with advanced disease. We aimed to determine whether TACE with sorafenib improves progression-free survival versus TACE with placebo.

METHODS

We did a multicentre, randomised, placebo-controlled, phase 3 trial (TACE 2) in 20 hospitals in the UK for patients with unresectable, liver-confined hepatocellular carcinoma. Patients were eligible if they were at least aged 18 years, had Eastern Cooperative Oncology Group performance status of 1 or less, and had Child-Pugh A liver disease. Patients were randomised 1:1 by computerised minimisation algorithm to continuous oral sorafenib (400 mg twice-daily) or matching placebo combined with TACE using drug-eluting beads (DEB-TACE), which was given via the hepatic artery 2-5 weeks after randomisation and according to radiological response and patient tolerance thereafter. Patients were stratified according to randomising centre and serum α-fetoprotein concentration (<400 ng/mL and ≥400 ng/mL). Only the trial coordinator was unmasked to treatment allocation before patient progression during the study. The primary endpoint was progression-free survival defined as the interval between randomisation and progression according to Response Evaluation Criteria In Solid Tumors version 1.1 (RECIST v1.1) or death due to any cause, and was analysed by intention-to-treat. Safety was analysed by intention-to-treat. The trial has been completed and the final results are reported. The trial is registered at EudraCT, number 2008-005073-36, and ISRCTN, number ISRCTN93375053.

FINDINGS

Between Nov 4, 2010, and Dec 7, 2015, the trial enrolled 399 patients and was terminated after a planned interim futility analysis. 86 patients failed screening and 313 remaining patients were randomly assigned: 157 to sorafenib and 156 to placebo. The median daily dose was 660 mg (IQR 389·2-800·0) sorafenib versus 800 mg (758·2-800·0) placebo, and median duration of therapy was 120·0 days (IQR 43·0-266·0) for sorafenib versus 162·0 days (70·0-323·5) for placebo. There was no evidence of difference in progression-free survival between the sorafenib group and the placebo group (hazard ratio [HR] 0·99 [95% CI 0·77-1·27], p=0·94); median progression-free survival was 238·0 days (95% CI 221·0-281·0) in the sorafenib group and 235·0 days (209·0-322·0) in the placebo group. The most common grade 3-4 adverse events were fatigue (29 [18%] of 157 patients in the sorafenib group vs 21 [13%] of 156 patients in the placebo group), abdominal pain (20 [13%] vs 12 [8%]), diarrhoea (16 [10%] vs four [3%]), gastrointestinal disorders (18 [11%] vs 12 [8%]), and hand-foot skin reaction (12 [8%] and none). At least one serious adverse event was reported in 65 (41%) of 157 patients in the sorafenib group and 50 (32%) of 156 in the placebo group, and 181 serious adverse events were reported in total, 95 (52%) in the sorafenib group and 86 (48%) in the placebo group. Three deaths occurred in each group that were attributed to DEB-TACE. Four deaths were attributed to study drug; three in the sorafenib group and one in the placebo group.

INTERPRETATION

The addition of sorafenib to DEB-TACE does not improve progression-free survival in European patients with hepatocellular carcinoma. Alternative systemic therapies need to be assessed in combination with TACE to improve patient outcomes.

FUNDING

Bayer PLC and BTG PLC.

Adjuvant capecitabine for biliary tract cancer: The BILCAP randomized study

4006

Background: Despite improvements in multidisciplinary management, BTC has a poor outcome. Approximately 20% of cases are suitable for surgical resection with a 5 year survival of < 10%. BILCAP aimed to determine whether capecitabine (Cape) improves overall survival (OS) compared to observation (Obs) following radical surgery. Methods: Patients with completely-resected cholangiocarcinoma (CCA) or gallbladder cancer (including liver and pancreatic resection, as appropriate), with adequate biliary drainage, no ongoing infection, adequate renal, haematological and liver function, and ECOG PS ≤2, were randomized 1:1 to Cape (1250 mg/m2 D1-14 every 21 days, for 8 cycles) or Obs. Randomization was minimized on tumor site, resection status, ECOG PS and surgical center. The primary outcome was OS in the intention to treat (ITT) population. 410 patients were needed to detect a hazard ratio (HR) of 0.69 (2-sided α = 0.05 and 80% power). HR was estimated by Cox survival model with adjustment for the minimization factors. Primary analysis performed with at least 24 months (m) follow-up. Results: 447 participants were randomized to Cape (n = 223) or Obs (n = 224) from 44 UK sites between 2006-2014. Median age was 63y (IQR 55, 69) and 201 (45%), 232 (52%), and 14 (3%) patients were ECOG PS 0, 1 and 2 respectively. Primary site: 84 (19%) intrahepatic, 128 (28%) hilar, 156 (35%) extrahepatic CCA and 79 (18%) muscle-invasive gallbladder cancers. Resection margins: R0 in 279 (62%) and R1 in 168 (38%); 207 (46%) were node-negative. Follow up was at least 36m in > 80% of surviving patients. By ITT analysis (n = 447), median OS was 51m (95%CI 35, 59) for Cape and 36m (95%CI 30, 45) for Obs, HR 0.80 (95%CI 0.63, 1.04; p = 0.097). Sensitivity analyses with adjustment for nodal status, grade of disease and gender indicated HR 0.71 (95%CI 0.55, 0.92 p < 0.01). In the per-protocol analysis (Cape n = 210, Obs n = 220) median OS was 53m (95%CI 40, NR) for Cape and 36m (95%CI 30, 44) for Obs, HR 0.75 (95%CI 0.58, 0.97; p = 0.028). Median RFS (ITT) was 25m (95%CI 19, 37) for Cape and 18m (95%CI 13, 28) for Obs. Grade 3-4 toxicity was less than anticipated. Conclusions: Cape improves OS in BTC when used as adjuvant and should become standard of care. Clinical trial information: ISRCTN72785446.

Biomarker prediction of efficacy to vandetanib plus gemcitabine in a phase II double blind multicenter randomized placebo-controlled trial in locally advanced or metastatic pancreatic carcinoma

4104

Background: We investigated the potential of biomarkers to predict efficacy of vandetanib and gemcitabine in patients with locally advanced (N = 41) or metastatic (N = 101) pancreatic cancer in a phase II double-blind multicentre randomised placebo-controlled trial. Methods: All patients were 18y or above, (ECOG = 0-2), with at least 3 mths life expectancy had gemcitabine (1000mg/m2 30min iv wkly for 7 wks, followed by a 1wk break, then cycles of wkly treatment for 3wks with a 1-wk break) and randomly assigned to 300mg/d vandetanib or placebo once daily until disease progression. The primary outcome was overall survival (OS) by intention to treat. A panel of potential biomarkers was tested to predict best survival with vandetanib and gemcitabine. Results: 142 patients were randomised, median FU = 24·9 mths with 131 deaths. The median (95% CI) OS in the 70 gemcitabine-placebo patients was 8·95 (6·55-11·7) mths and 8·83 (7·11-11·6) mths in the 72 gemcitabine-vandetanib patients (HR = 1·21, 95% CI = 0·85, 1·73; log rank X21df = 1·1; P = 0·303). A CTCAE V.4.02 rash grade 2 or above occurred in 4 (6 %) of 70 placebo patients versus 14 (19%) of 72 vandetanib patients. The median OS for the 14 vandetanib patients and with rash was 11·92 (10·89 – NA) mths, 7·76 (4·34 – 11·5) mths for the 58 vandetanib patients and without rash and 8·95 (6·55 – 11·7) mths for the gemcitabine-placebo patients (log rank Χ2 2df = 7·23; P = 0·03). We identified two biomarkers that could select patients for response to vandetanib (JN101, JN102). The biomarker combination was present in 26 patients with median OS of 12.1 (10.9, 16.0) mths versus 8.15 (6.67, 11.7) mths for 23 patients with the same biomarker profile in the placebo group (HR = 0.53 [0.29, 0.97], p = 0.0396). A logistic regression model showed that patients with JN102 were more likely to develop a rash (OR =0.81 [0.713, 0.925] p = 0.002). Conclusions: A two biomarker combination and a rash grade 2 or above may predict response to vandetanib and gemcitabine. This requires prospective evaluation. Clinical trial information: 96397434.

Comparison of adjuvant gemcitabine and capecitabine with gemcitabine monotherapy in patients with resected pancreatic cancer (ESPAC-4): a multicentre, open-label, randomised, phase 3 trial

BACKGROUND

The ESPAC-3 trial showed that adjuvant gemcitabine is the standard of care based on similar survival to and less toxicity than adjuvant 5-fluorouracil/folinic acid in patients with resected pancreatic cancer. Other clinical trials have shown better survival and tumour response with gemcitabine and capecitabine than with gemcitabine alone in advanced or metastatic pancreatic cancer. We aimed to determine the efficacy and safety of gemcitabine and capecitabine compared with gemcitabine monotherapy for resected pancreatic cancer.

METHODS

We did a phase 3, two-group, open-label, multicentre, randomised clinical trial at 92 hospitals in England, Scotland, Wales, Germany, France, and Sweden. Eligible patients were aged 18 years or older and had undergone complete macroscopic resection for ductal adenocarcinoma of the pancreas (R0 or R1 resection). We randomly assigned patients (1:1) within 12 weeks of surgery to receive six cycles of either 1000 mg/m2 gemcitabine alone administered once a week for three of every 4 weeks (one cycle) or with 1660 mg/m2 oral capecitabine administered for 21 days followed by 7 days' rest (one cycle). Randomisation was based on a minimisation routine, and country was used as a stratification factor. The primary endpoint was overall survival, measured as the time from randomisation until death from any cause, and assessed in the intention-to-treat population. Toxicity was analysed in all patients who received trial treatment. This trial was registered with the EudraCT, number 2007-004299-38, and ISRCTN, number ISRCTN96397434.

FINDINGS

Of 732 patients enrolled, 730 were included in the final analysis. Of these, 366 were randomly assigned to receive gemcitabine and 364 to gemcitabine plus capecitabine. The Independent Data and Safety Monitoring Committee requested reporting of the results after there were 458 (95%) of a target of 480 deaths. The median overall survival for patients in the gemcitabine plus capecitabine group was 28·0 months (95% CI 23·5-31·5) compared with 25·5 months (22·7-27·9) in the gemcitabine group (hazard ratio 0·82 [95% CI 0·68-0·98], p=0·032). 608 grade 3-4 adverse events were reported by 226 of 359 patients in the gemcitabine plus capecitabine group compared with 481 grade 3-4 adverse events in 196 of 366 patients in the gemcitabine group.

INTERPRETATION

The adjuvant combination of gemcitabine and capecitabine should be the new standard of care following resection for pancreatic ductal adenocarcinoma.

FUNDING

Cancer Research UK.

Application of ALBI and PALBI score as prognostic variables in hepatocellular carcinoma patients treated with transarterial-chemoembolization

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Background: Albumin-Bilirubin Score(ALBI) is simple prognostic tool to stratify HCC patients on liver function. It is proposed as more accurate predicting score of hepatic dysfunction compared with Child-Pugh (CP) grading. Platelet-Albumin-Bilirubin Score (PALBI) incorporating platelet count may offer further prognostic sensitivity. We sought to correlate ALBI, PALBI and CP grade with overall survival in HCC patients who underwent transarterial-chemoembolization (TACE). Methods: 431 HCC patients who received TACE between 2006 and 2012 at a Liver Centre, UK was included. Serum albumin, bilirubin and platelet were used to calculate ALBI and PALBI scores. Patients were classified into three groups using previously described formulas. Survival outcomes (Median OS) were measured using Kaplan-Meier method. Results: Median age of study population was 62 years. Patients classified by ALBI score, Group 1 was 208 patients (48%), 2 was 196 (45.4%) and 3 was 27 (6.3%). Median OS for Group 1 was 26.1 months (m) (95% CI 19.5-32.6), 2 was 18.6m (95% CI 14.9-21.5) and 3 was 11.7m (95% CI 6.1-17.3) (p < 0.001). PALBI Group 1 was 179 (41.5%), 2 was 150 (34.8%) and 3 was102 (23.7%). PALBI group 1 had median OS 25.5m (95% CI 17.9-33.1), 2 had 22.3m (95% CI 18.3-26.3), 3 had 10m (95% CI 5.9-14.3) (p < 0.001). Majority were class CP-A. (A = 365, B = 63, C = 2). CP-A patients were re-stratified on ALBI and PALBI status. ALBI Group 1 (N = 204) OS 26.0m (95% CI 19.5-32.6), 2 (N = 151) OS 19.1m (95% CI 14.7-23.5), 3 (N = 7) OS 7.6m (95% CI2.27-12.9) (p = 0.04). Survival of CP-A patients by PALBI was significantly different - Group1 (N = 175) OS 28.8m (95%CI 20.79-36.74), 2 (N = 140) OS 22.6m (95%CI 18.89-26.25) and 3 (N = 50) OS 8.9m (95%CI 6.25-11.5) (p < 0.001). Conclusions: Significant comparable survival difference was seen in ALBI and PALBI groups. CP-A patients with group 3 ALBI or PALBI had significantly poorer survival than groups 1 and 2 suggesting increased sensitivity determining hepatic dysfunction compared with CP status. Our results suggest ALBI and PALBI scores likely more accurate stratifying method for mild liver disease and guide treatment. Further prospective studies using both scores are warranted.

Survival by pattern of tumor progression during prior sorafenib (SOR) treatment in patients with hepatocellular carcinoma (HCC) in the phase III RESORCE trial comparing second-line treatment with regorafenib (REG) or placebo

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Background: HCC progression may be due to tumor growth or new intrahepatic or extrahepatic lesions. RECIST does not discriminate between progression patterns even though the prognosis may differ (Reig, Hepatology 2013). REG improves overall survival (OS) in patients with HCC who progress during SOR treatment (HR 0.63; 95% CI 0.50, 0.79; P < 0.001). This exploratory analysis aimed to validate the pattern of progression concept in a global cohort treated with prior SOR and to assess the impact of REG on survival by prior progression. Methods: Adults with HCC who tolerated SOR and had radiologic progression during SOR, Child–Pugh A liver function, and ECOG PS 0–1 were randomized 2:1 to REG 160 mg/day or placebo during weeks 1–3 of each 4-week cycle. Progression during SOR was due to tumor growth or new lesions. Post-progression survival (PPS) was the time from progression on SOR until death. Results: Baseline characteristics of the 573 randomized patients (REG = 379; placebo = 194) were balanced; median age was 63 years, 88% were male, 87% were BCLC stage C, 29% had macrovascular invasion, and 72% had extrahepatic disease. Hazard ratios favored REG irrespective of pattern of progression during prior SOR, but differed according to progression pattern (Table). Conclusions: The development of new extrahepatic lesions is associated with worse survival irrespective of treatment. REG provided an OS benefit, regardless of progression pattern. Progression pattern may be a key prognostic parameter and should be considered in future trial design and analysis. Clinical trial information: NCT01774344. [Table: see text]