Comprehensive Examination of Cholangiocarcinoma Patients Treated with Novel Targeted Therapies after Extended Molecular Profiling on Liquid Biopsies.

BACKGROUND: Cholangiocarcinoma (CCA) is associated with poor outcomes and limited treatment options, leading to increased use of targeted therapies for its management. Here, we performed one of the largest single-centre reviews evaluating outcomes following personalised targeted agents in CCA patients. METHODS: All consecutive CCA patients receiving systemic therapy between January 2010 and April 2023 at UCLH were included. The primary objective of this study was to evaluate treatment response, survival outcomes and predictors of clinical benefit in CCA patients treated with molecularly guided therapies. Patient demographic factors, disease characteristics and survival outcomes were evaluated using the Kaplan-Meier method and Cox proportional-hazards models. RESULTS: Of the 227 consecutive CCA patients, 162 (71%) had molecular profiling, of whom 56 (35%) were eligible and 55 received molecular-targeted treatment. CCA histological classifications comprised intrahepatic (N = 32), extrahepatic (N = 11), hilar (N = 4) and unknown (N = 9) subtypes. Most patients received targeted agents based on genomic profiling in a second treatment line setting (N = 34). Frequently observed genomic alterations occurred in the FGFR2 (N = 21), IDH1 (N = 7) and BRCA2 (N = 6) genes. Median progression-free survival (PFS) following first-, second- and third-line systemic therapy and overall survival (OS) were 8.44 (95% CI, 7.49-12.78), 5.65 (95% CI, 3.71-7.13), 5.55 (2.79-12.58) and 29.01 (24.21-42.91) months, respectively. CCA subtype and FGFR/BRCA molecular aberration status were not associated with PFS or OS. However, a prior CCA-related surgical history was predictive of OS (p = 0.02). Stratification by best overall response to second-line targeted agents demonstrated an association with PFS (p = 0.002) and OS (p = 0.02). Duration of treatment with second-line targeted therapy was associated with OS (p < 0.001). CONCLUSIONS: Patients receiving targeted therapeutics achieved promising outcomes, especially those attaining a favourable treatment response and those receiving targeted agents for longer periods. Liquid biopsies can reliably provide information on extended molecular profiling to aid patient selection for personalised therapies.

Trellis tree-based analysis reveals stromal regulation of patient-derived organoid drug responses.

Patient-derived organoids (PDOs) can model personalized therapy responses; however, current screening technologies cannot reveal drug response mechanisms or how tumor microenvironment cells alter therapeutic performance. To address this, we developed a highly multiplexed mass cytometry platform to measure post-translational modification (PTM) signaling, DNA damage, cell-cycle activity, and apoptosis in >2,500 colorectal cancer (CRC) PDOs and cancer-associated fibroblasts (CAFs) in response to clinical therapies at single-cell resolution. To compare patient- and microenvironment-specific drug responses in thousands of single-cell datasets, we developed "Trellis"-a highly scalable, tree-based treatment effect analysis method. Trellis single-cell screening revealed that on-target cell-cycle blockage and DNA-damage drug effects are common, even in chemorefractory PDOs. However, drug-induced apoptosis is rarer, patient-specific, and aligns with cancer cell PTM signaling. We find that CAFs can regulate PDO plasticity-shifting proliferative colonic stem cells (proCSCs) to slow-cycling revival colonic stem cells (revCSCs) to protect cancer cells from chemotherapy.

PANTHER: AZD8931, inhibitor of EGFR, ERBB2 and ERBB3 signalling, combined with FOLFIRI: a Phase I/II study to determine the importance of schedule and activity in colorectal cancer.

BACKGROUND: Epidermal growth factor receptor (EGFR) is a therapeutic target to which HER2/HER3 activation may contribute resistance. This Phase I/II study examined the toxicity and efficacy of high-dose pulsed AZD8931, an EGFR/HER2/HER3 inhibitor, combined with chemotherapy, in metastatic colorectal cancer (CRC). METHODS: Treatment-naive patients received 4-day pulses of AZD8931 with irinotecan/5-FU (FOLFIRI) in a Phase I/II single-arm trial. Primary endpoint for Phase I was dose limiting toxicity (DLT); for Phase II best overall response. Samples were analysed for pharmacokinetics, EGFR dimers in circulating exosomes and Comet assay quantitating DNA damage. RESULTS: Eighteen patients received FOLFIRI and AZD8931. At 160 mg bd, 1 patient experienced G3 DLT; 160 mg bd was used for cohort expansion. No grade 5 adverse events (AE) reported. Seven (39%) and 1 (6%) patients experienced grade 3 and grade 4 AEs, respectively. Of 12 patients receiving 160 mg bd, best overall response rate was 25%, median PFS and OS were 8.7 and 21.2 months, respectively. A reduction in circulating HER2/3 dimer in the two responding patients after 12 weeks treatment was observed. CONCLUSIONS: The combination of pulsed high-dose AZD8931 with FOLFIRI has acceptable toxicity. Further studies of TKI sequencing may establish a role for pulsed use of such agents rather than continuous exposure. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov number: NCT01862003.

T cell-inflamed gene expression profile and PD-L1 expression and pembrolizumab efficacy in advanced esophageal cancer.

Aim: Investigate the relationship between response to pembrolizumab and expression of the 18-gene T cell-inflamed gene expression profile (TcellinfGEP) or PD-L1 combined positive score (CPS) in esophageal cancer. Materials & methods: This analysis included heavily pretreated patients with advanced/metastatic esophageal/gastroesophageal junction adenocarcinoma or squamous cell carcinoma who received pembrolizumab in the single-arm, phase II study KEYNOTE-180. PD-L1 CPS was evaluated with PD-L1 IHC 22C3 pharmDx. Results: In patients with squamous cell carcinoma, trends toward enrichment for responders were observed for patients with PD-L1 CPS ≥10 tumors. In patients with adenocarcinoma, a trend was observed for TcellinfGEP but not for PD-L1. Conclusion: TcellinfGEP and PD-L1 CPS may enrich for responders to pembrolizumab in patients with esophageal cancer. Clinical trial registration: NCT02559687 (ClinicalTrials.gov).

Overall Survival Results From the POLO Trial: A Phase III Study of Active Maintenance Olaparib Versus Placebo for Germline BRCA-Mutated Metastatic Pancreatic Cancer.

PURPOSE: The phase III POLO study demonstrated significant progression-free survival (PFS) benefit for active olaparib maintenance therapy versus placebo for patients with metastatic pancreatic adenocarcinoma and a germline BRCA mutation. Here, we report the final analysis of overall survival (OS) and other secondary end points. PATIENTS AND METHODS: Patients with a deleterious or suspected deleterious germline BRCA mutation whose disease had not progressed after ≥ 16 weeks of first-line platinum-based chemotherapy were randomly assigned 3:2 to active maintenance olaparib (300 mg twice daily) or placebo. The primary end point was PFS; secondary end points included OS, time to second disease progression or death, time to first and second subsequent cancer therapies or death, time to discontinuation of study treatment or death, and safety and tolerability. RESULTS: In total, 154 patients were randomly assigned (olaparib, n = 92; placebo, n = 62). No statistically significant OS benefit was observed (median 19.0 v 19.2 months; hazard ratio [HR], 0.83; 95% CI, 0.56 to 1.22; P = .3487). Kaplan-Meier OS curves separated at approximately 24 months, and the estimated 3-year survival after random assignment was 33.9% versus 17.8%, respectively. Median time to first subsequent cancer therapy or death (HR, 0.44; 95% CI, 0.30 to 0.66; P < .0001), time to second subsequent cancer therapy or death (HR, 0.61; 95% CI, 0.42 to 0.89; P = .0111), and time to discontinuation of study treatment or death (HR, 0.43; 95% CI, 0.29 to 0.63; P < .0001) significantly favored olaparib. The HR for second disease progression or death favored olaparib without reaching statistical significance (HR, 0.66; 95% CI, 0.43 to 1.02; P = .0613). Olaparib was well tolerated with no new safety signals. CONCLUSION: Although no statistically significant OS benefit was observed, the HR numerically favored olaparib, which also conferred clinically meaningful benefits including increased time off chemotherapy and long-term survival in a subset of patients.

The role of PARP inhibitors in gastrointestinal cancers.

The use of BReast CAncer (BRCA) mutations as biomarkers for sensitivity to DNA damage response (DDR) targeted drugs and platinum agents is well documented in breast and gynaecological cancers. More recently the successful use DDR targeted therapies including poly (ADP-ribose) polymerases (PARP) inhibitors has been shown to extend to other germline and somatic deficiencies within the homologous recombination (HR) pathway (Farmer et al., 2005; Turner et al., 2019; Li and Heyer, 2008). Gastrointestinal (GI) cancers are lagging behind other tumour types when it comes to personalising treatment with targeted therapies. Current methods of identifying PARP-inhibitor sensitivity in gastrointestinal cancers are based on analogies from other cancer types despite there being a lack of uniformity in determining HR status between tumour types. There is an urgent clinical need to better understand the treatment implications of DDR alterations in gastrointestinal cancers. We have reviewed PARP-inhibitor use in pancreatic, gastroesophageal, hepatobiliary and colorectal cancers and explored HRD as a biomarker for sensitivity to PARP-inhibitors.

Drug delivery, biodistribution and anti-EGFR activity: theragnostic nanoparticles for simultaneous in vivo delivery of tyrosine kinase inhibitors and kinase activity biosensors.

In vivo delivery of small molecule therapeutics to cancer cells, assessment of the selectivity of administration, and measuring the efficacity of the drug in question at the molecule level, are important ongoing challenges in developing new classes of cancer chemotherapeutics. One approach that has the potential to provide targeted delivery, tracking of biodistribution and readout of efficacy, is to use multimodal theragnostic nanoparticles to deliver the small molecule therapeutic. In this paper, we report the development of targeted theragnostic lipid/peptide/DNA lipopolyplexes. These simultaneously deliver an inhibitor of the EGFR tyrosine kinase, and plasmid DNA coding for a Crk-based biosensor, Picchu-X, which when expressed in the target cells can be used to quantify the inhibition of EGFR in vivo in a mouse colorectal cancer xenograft model. Reversible bioconjugation of a known analogue of the tyrosine kinase inhibitor Mo-IPQA to a cationic peptide, and co-formulation with peptides containing both EGFR-binding and cationic sequences, allowed for good levels of inhibitor encapsulation with targeted delivery to LIM1215 colon cancer cells. Furthermore, high levels of expression of the Picchu-X biosensor in the LIM1215 cells in vivo allowed us to demonstrate, using fluorescence lifetime microscopy (FLIM)-based biosensing, that EGFR activity can be successfully suppressed by the tyrosine kinase inhibitor, released from the lipopolyplexes. Finally, we measured the biodistribution of lipopolyplexes containing 125I-labelled inhibitors and were able to demonstrate that the lipopolyplexes gave significantly higher drug delivery to the tumors compared with free drug.

Effects of N-terminus modified Hx-amides on DNA binding affinity, sequence specificity, cellular uptake, and gene expression.

Five X-HxIP (Hx-amides) 6a-e, in which the N-terminus p-anisyl moiety is modified, were designed and synthesised with the purpose of optimising DNA binding, improving cellular uptake/nuclear penetration, and enhancing the modulation of the topoisomerase IIα (TOP2A) gene expression. The modifications include a fluorophenyl group and other heterocycles bearing different molecular shapes, size, and polarity. Like their parent compound HxIP 3, all five X-HxIP analogues bind preferentially to their cognate sequence 5'-TACGAT-3', which is found embedded on the 5' flank of the inverted CCAAT box-2 (ICB2) site in the TOP2A gene promoter, and inhibit protein complex binding. Interestingly, the 4-pyridyl analog 6a exhibits greater binding affinity for the target DNA sequence and abolishes the protein:ICB2 interaction in vitro, at a lower concentration, compared to the prototypical compound HxIP 3. Analogues 6b-e, display improved DNA sequence specificity, but reduced binding affinity for the cognate sequence, relative to the unmodified HxIP 3, with polyamides 6b and 6e being the most sequence selective. However, unlike 3 and 6b, 6a was unable to enter cells, access the nucleus and thereby affect TOP2A gene expression in confluent human lung cancer cells. These results show that while DNA binding affinity and sequence selectivity are important, consideration of cellular uptake and concentration in the nucleus are critical when exerting biological activity is the desired outcome. By characterising the DNA binding, cellular uptake and gene regulatory properties of these small molecules, we can elucidate the determinants of the elicited biological activity, which can be impacted by even small structural modifications in the polyamide molecular design.

Efficacy of Pembrolizumab Monotherapy for Advanced Gastric/Gastroesophageal Junction Cancer with Programmed Death Ligand 1 Combined Positive Score ≥10.

PURPOSE: Pembrolizumab demonstrated efficacy in PD-L1-positive [combined positive score (CPS) ≥1] advanced gastric/gastroesophageal junction (G/GEJ) cancer in the first-, second-, and third-line setting in KEYNOTE-062, KEYNOTE-061, and KEYNOTE-059, respectively. To better delineate the specificity of CPS as a predictor of clinical outcomes, we analyzed pembrolizumab efficacy in patients with CPS ≥ 10 in these trials. PATIENTS AND METHODS: Included were patients with CPS ≥ 10 tumors from KEYNOTE-059 cohort 1 (pembrolizumab, n = 46; post hoc), KEYNOTE-061 (pembrolizumab, n = 53; chemotherapy, n = 55; post hoc), and KEYNOTE-062 (pembrolizumab, n = 92; chemotherapy, n = 90; primary). Efficacy outcomes were overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and duration of response (DOR). RESULTS: In KEYNOTE-059, median follow-up was 6 months, median OS was 8 months [95% confidence interval (CI), 5.8-11.1], ORR was 17%, and median (range) DOR was 21 months (3+ to 35+). In KEYNOTE-061, median follow-up was 9 months, median OS (pembrolizumab vs. chemotherapy) was 10 versus 8 months (HR, 0.64; 95% CI, 0.41-1.02), median PFS was 3 months versus 3 months (HR, 0.86; 95% CI, 0.56-1.33), ORR was 25% versus 9%, and median (range) DOR was not reached (4 to 26+ months) versus 7 months (3-7). In KEYNOTE-062, median follow-up was 11 months, median OS (pembrolizumab vs. chemotherapy) was 17 months versus 11 months (HR, 0.69; 95% CI, 0.49-0.97), median PFS was 3 months versus 6 months (HR, 1.09, 95% CI; 0.79-1.49), ORR was 25% versus 38%, and median (range) DOR was 19 months (1+ to 34+) versus 7 months (2+ to 30+). CONCLUSIONS: This comprehensive analysis showed consistent improvements toward more favorable clinical outcomes with pembrolizumab across lines of therapy in patients with CPS ≥ 10 G/GEJ cancer.

Multimodal Treatment in Metastatic Colorectal Cancer (mCRC) Improves Outcomes-The University College London Hospital (UCLH) Experience.

BACKGROUND: Despite notable advances in the management of metastatic colorectal cancer (mCRC) over the last two decades, treatment intent in the vast majority of patients remains palliative due to technically unresectable disease, extensive disease, or co-morbidities precluding major surgery. Up to 30% of individuals with mCRC are considered potentially suitable for primary or metastasis-directed multimodal therapy, including surgical resection, ablative techniques, or stereotactic radiotherapy (RT), with the aim of improving survival outcomes. We reviewed the potential benefits of multimodal therapy on the survival of patients with mCRC treated at the UCLH. METHODS: Clinical data on baseline characteristics, multimodal treatments, and survival outcomes were retrospectively collected from all patients with mCRC receiving systemic chemotherapy between January 2013 and April 2017. Primary outcome was the impact of multimodal therapy on overall survival, compared to systemic therapy alone, and the effect of different types of multimodal therapy on survival outcome, and was assessed using the Kaplan-Meier approach. All analyses were adjusted for age, gender, and side of primary tumour. RESULTS: One-hundred and twenty-five patients with mCRC were treated during the study period (median age: 62 years (range 19-89). The liver was the most frequent metastatic site (78%; 97/125). A total of 52% (65/125) had ≥2 lines of systemic chemotherapy. Of the 125 patients having systemic chemotherapy, 74 (59%) underwent multimodal treatment to the primary tumour or metastasis. Median overall survival (OS) was 25.7 months [95% Confidence Interval (CI) 21.5-29.0], and 3-year survival, 26%. Univariate analysis demonstrated that patients who had additional procedures (surgery/ablation/RT) were significantly less likely to die (Hazard Ratio (HR) 0.18, 95% CI 0.12-0.29, p < 0.0001) compared to those receiving systemic chemotherapy alone. Increasing number of multimodal procedures was associated with an incremental increase in survival-with median OS 28.4 m, 35.7 m, and 64.8 m, respectively, for 1, 2, or ≥3 procedures (log-rank p < 0.0001). After exclusion of those who received systemic chemotherapy only (n = 51), metastatic resections were associated with improved survival (adjusted HR 0.36, 95% CI 0.20-0.63, p < 0.0001), confirmed in multivariate analysis. Multiple single-organ procedures did not improve survival. CONCLUSION: Multimodal therapy for metastatic bowel cancer is associated with significant survival benefit. Resection/radical RT of the primary and resection of metastatic disease should be considered to improve survival outcomes following multidisciplinary team (MDT) discussion and individual assessment of fitness.

COVID-19 in cancer patients on systemic anti-cancer therapies: outcomes from the CAPITOL (COVID-19 Cancer PatIenT Outcomes in North London) cohort study.

BACKGROUND: Patients with cancer are hypothesised to be at increased risk of contracting COVID-19, leading to changes in treatment pathways in those treated with systemic anti-cancer treatments (SACT). This study investigated the outcomes of patients receiving SACT to assess whether they were at greater risk of contracting COVID-19 or having more severe outcomes. METHODS: Data was collected from all patients receiving SACT in two cancer centres as part of CAPITOL (COVID-19 Cancer PatIenT Outcomes in North London). The primary outcome was the effect of clinical characteristics on the incidence and severity of COVID-19 infection in patients on SACT. We used univariable and multivariable models to analyse outcomes, adjusting for age, gender and comorbidities. RESULTS: A total of 2871 patients receiving SACT from 2 March to 31 May 2020 were analysed; 68 (2.4%) were diagnosed with COVID-19. Cancer patients receiving SACT were more likely to die if they contracted COVID-19 than those who did not [adjusted (adj.) odds ratio (OR) 9.84; 95% confidence interval (CI) 5.73-16.9]. Receiving chemotherapy increased the risk of developing COVID-19 (adj. OR 2.99; 95% CI = 1.72-5.21), with high dose chemotherapy significantly increasing risk (adj. OR 2.36, 95% CI 1.35-6.48), as did the presence of comorbidities (adj. OR 2.29; 95% CI 1.19-4.38), and having a respiratory or intrathoracic neoplasm (adj. OR 2.12; 95% CI 1.04-4.36). Receiving targeted treatment had a protective effect (adj. OR 0.53; 95% CI 0.30-0.95). Treatment intent (curative versus palliative), hormonal- or immunotherapy and solid versus haematological cancers had no significant effect on risk. CONCLUSION: Patients on SACT are more likely to die if they contract COVID-19. Those on chemotherapy, particularly high dose chemotherapy, are more likely to contract COVID-19, while targeted treatment appears to be protective.

Outcomes of the 2019 novel coronavirus in patients with or without a history of cancer: a multi-centre North London experience.

BACKGROUND: This study aims to compare the outcomes of COVID-19-positive disease in patients with a history of cancer to those without. METHODS: We retrospectively collected clinical data and outcomes of COVID-19 positive cancer patients treated consecutively in five North London hospitals (cohort A). Outcomes recorded included time interval between most recent anti-cancer treatment and admission, severe outcome [a composite endpoint of intensive care unit (ITU) admission, ventilation and/or death] and mortality. Outcomes were compared with consecutively admitted COVID-19 positive patients, without a history of cancer (cohort B), treated at the primary centre during the same time period (1 March-30 April 2020). Patients were matched for age, gender and comorbidity. RESULTS: The median age in both cohorts was 74 years, with 67% male, and comprised of 30 patients with cancer, and 90 without (1:3 ratio). For cohort B, 579 patients without a history of cancer and consecutively admitted were screened from the primary London hospital, 105 were COVID-19 positive and 90 were matched and included. Excluding cancer, both cohorts had a median of two comorbidities. The odds ratio (OR) for mortality, comparing patients with cancer to those without, was 1.05 [95% confidence interval (CI) 0.4-2.5], and severe outcome (OR 0.89, 95% CI 0.4-2.0) suggesting no increased risk of death or a severe outcome in patients with cancer. Cancer patients who received systemic treatment within 28 days had an OR for mortality of 4.05 (95% CI 0.68-23.95), p = 0.12. On presentation anaemia, hypokalaemia, hypoalbuminaemia and hypoproteinaemia were identified predominantly in cohort A. Median duration of admission was 8 days for cancer patients and 7 days for non-cancer. CONCLUSION: A diagnosis of cancer does not appear to increase the risk of death or a severe outcome in COVID-19 patients with cancer compared with those without cancer. If a second spike of virus strikes, rational decision making is required to ensure optimal cancer care.

Liver resection surgery compared with thermal ablation in high surgical risk patients with colorectal liver metastases: the LAVA international RCT.

BACKGROUND: Although surgical resection has been considered the only curative option for colorectal liver metastases, thermal ablation has recently been suggested as an alternative curative treatment. There have been no adequately powered trials comparing surgery with thermal ablation. OBJECTIVES: Main objective - to compare the clinical effectiveness and cost-effectiveness of thermal ablation versus liver resection surgery in high surgical risk patients who would be eligible for liver resection. Pilot study objectives - to assess the feasibility of recruitment (through qualitative study), to assess the quality of ablations and liver resection surgery to determine acceptable standards for the main trial and to centrally review the reporting of computed tomography scan findings relating to ablation and outcomes and recurrence rate in both arms. DESIGN: A prospective, international (UK and the Netherlands), multicentre, open, pragmatic, parallel-group, randomised controlled non-inferiority trial with a 1-year internal pilot study. SETTING: Tertiary liver, pancreatic and gallbladder (hepatopancreatobiliary) centres in the UK and the Netherlands. PARTICIPANTS: Adults with a specialist multidisciplinary team diagnosis of colorectal liver metastases who are at high surgical risk because of their age, comorbidities or tumour burden and who would be suitable for liver resection or thermal ablation. INTERVENTIONS: Thermal ablation conducted as per local policy (but centres were encouraged to recruit within Cardiovascular and Interventional Radiological Society of Europe guidelines) versus surgical liver resection performed as per centre protocol. MAIN OUTCOME MEASURES: Pilot study - patients' and clinicians' acceptability of the trial to assist in optimisation of recruitment. Primary outcome - disease-free survival at 2 years post randomisation. Secondary outcomes - overall survival, timing and site of recurrence, additional therapy after treatment failure, quality of life, complications, length of hospital stay, costs, trial acceptability, and disease-free survival measured from end of intervention. It was planned that 5-year survival data would be documented through record linkage. Randomisation was performed by minimisation incorporating a random element, and this was a non-blinded study. RESULTS: In the pilot study over 1 year, a total of 366 patients with colorectal liver metastases were screened and 59 were considered eligible. Only nine participants were randomised. The trial was stopped early and none of the planned statistical analyses was performed. The key issues inhibiting recruitment included fewer than anticipated patients eligible for both treatments, misconceptions about the eligibility criteria for the trial, surgeons' preference for one of the treatments ('lack of clinical equipoise' among some of the surgeons in the centre) with unconscious bias towards surgery, patients' preference for one of the treatments, and lack of dedicated research nurses for the trial. CONCLUSIONS: Recruitment feasibility was not demonstrated during the pilot stage of the trial; therefore, the trial closed early. In future, comparisons involving two very different treatments may benefit from an initial feasibility study or a longer period of internal pilot study to resolve these difficulties. Sufficient time should be allowed to set up arrangements through National Institute for Health Research (NIHR) Research Networks. TRIAL REGISTRATION: Current Controlled Trials ISRCTN52040363. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 21. See the NIHR Journals Library website for further project information.

In about 50% of people with bowel cancer, cancer spreads to the liver (colorectal liver metastases) within 5 years of detection and treatment. Liver resection (i.e. surgical removal of a portion of the liver) is the standard treatment in people below 70 years of age who are otherwise well, provided that the liver cancer is confined to a limited part of the liver. Such patients are considered 'low-risk' patients. Older patients and those with major medical problems or extensive cancers are considered 'high-risk' patients, as they are at a higher risk of developing complications following liver resection. Thermal ablation destroys the liver cancers using a needle that heats the cancer deposits until they are destroyed. There is significant uncertainty as to whether or not ablation can offer equivalent survival compared with surgery for 'high-risk' patients. We planned and conducted a randomised controlled trial comparing ablation with surgery to resolve this uncertainty. In this trial, some patients received ablation and others received surgery. The treatment was allocated at random with neither patients nor the study organisers choosing the treatment. The trial had an internal pilot (i.e. a smaller version of the full trial to resolve any 'teething problems' and ensure that a sufficient number of participants can be included in the full trial). Only nine patients were recruited in the 1-year internal pilot, compared with the anticipated recruitment of 45 patients. Therefore, the trial closed early as a result of poor recruitment, and the uncertainty about the best treatment for high-risk patients with colorectal liver metastases continues. The main reasons for the poor recruitment included fewer than anticipated eligible participants, clinicians' unconscious bias towards surgery, and patients' preference for one treatment or the other. In the future, comparisons involving two very different treatments may benefit from a feasibility study or a longer period of pilot study to resolve any difficulties.

Geographic and Ethnic Heterogeneity of Germline BRCA1 or BRCA2 Mutation Prevalence Among Patients With Metastatic Pancreatic Cancer Screened for Entry Into the POLO Trial.

PURPOSE: Germline BRCA1 and/or BRCA2 mutations (gBRCAms) are risk factors for pancreatic cancer. The extent to which demographic and geographic factors affect the uptake of gBRCAm testing in pancreatic cancer (PC) is unknown. METHODS: We conducted a retrospective, descriptive analysis of demographic/geographic data from the first 2,206 patients with metastatic PC (mPC) screened for eligibility to enter the phase III POLO trial of maintenance olaparib. No formal statistical tests were performed. RESULTS: Of 2,167 patients with previously unknown gBRCAm status, 128 (5.9%) had a newly identified gBRCAm; rates were highest in the United States, France, and Israel (9.5%, 7.6%, and 7.4%, respectively). When including patients with a previously known gBRCAm, prevalence rose to 7.2% (or 5.8% after excluding populations enriched in Ashkenazi Jews, who are known to have a high rate of BRCA1 and BRCA2 founder mutations). Patients with a gBRCAm were slightly younger (57.9 v 61.1 years) and more likely to have early-onset mPC than those without. Higher newly identified gBRCAm prevalence was observed among African American (n = 28) versus white (n = 1,808), Asian (n = 218), and other (n = 61) patients (10.7% v 6.1%, 5.0%, and 1.6%, respectively). Of 139 white patients with a gBRCAm, 110 were newly identified during screening; the majority of gBRCAms in African American, Asian, and Hispanic patients (n = 3, n = 11, and n = 5, respectively) were newly identified. CONCLUSION: We identified substantial geographic and some racial variability in gBRCAm prevalence among patients with mPC, an important consideration given the increased use of familial screening and possible future use of targeted therapies in this setting. Although our study included small numbers of nonwhite patients, prior knowledge of their gBRCAm status was limited compared with their white counterparts, which suggests disparities in genetic testing uptake.

Targeting of EGFR by a combination of antibodies mediates unconventional EGFR trafficking and degradation.

Antibody combinations targeting cell surface receptors are a new modality of cancer therapy. The trafficking and signalling mechanisms regulated by such therapeutics are not fully understood but could underlie differential tumour responses. We explored EGFR trafficking upon treatment with the antibody combination Sym004 which has shown promise clinically. Sym004 promoted EGFR endocytosis distinctly from EGF: it was asynchronous, not accompanied by canonical signalling events and involved EGFR clustering within detergent-insoluble plasma mebrane-associated tubules. Sym004 induced lysosomal degradation independently of EGFR ubiquitylation but dependent upon Hrs/Tsg101 that are required for the formation of intraluminal vesicles (ILVs) within late endosomes. We propose Sym004 cross-links EGFR physically triggering EGFR endocytosis and incorporation onto ILVs and so Sym004 sensitivity correlates with EGFR numbers available for binding, rather than specific signalling events. Consistently Sym004 efficacy and potentiation of cisplatin responses correlated with EGFR surface expression in head and neck cancer cells. These findings will have implications in understanding the mode of action of this new class of cancer therapeutics.

HER2-HER3 Heterodimer Quantification by FRET-FLIM and Patient Subclass Analysis of the COIN Colorectal Trial.

BACKGROUND: The phase III MRC COIN trial showed no statistically significant benefit from adding the EGFR-target cetuximab to oxaliplatin-based chemotherapy in first-line treatment of advanced colorectal cancer. This study exploits additional information on HER2-HER3 dimerization to achieve patient stratification and reveal previously hidden subgroups of patients who had differing disease progression and treatment response. METHODS: HER2-HER3 dimerization was quantified by fluorescence lifetime imaging microscopy in primary tumor samples from 550 COIN trial patients receiving oxaliplatin and fluoropyrimidine chemotherapy with or without cetuximab. Bayesian latent class analysis and covariate reduction was performed to analyze the effects of HER2-HER3 dimer, RAS mutation, and cetuximab on progression-free survival and overall survival (OS). All statistical tests were two-sided. RESULTS: Latent class analysis on a cohort of 398 patients revealed two patient subclasses with differing prognoses (median OS = 1624 days [95% confidence interval [CI] = 1466 to 1816 days] vs 461 days [95% CI = 431 to 504 days]): Class 1 (15.6%) showed a benefit from cetuximab in OS (hazard ratio = 0.43, 95% CI = 0.25 to 0.76, P = .004). Class 2 showed an association of increased HER2-HER3 with better OS (hazard ratio = 0.64, 95% CI = 0.44 to 0.94, P = .02). A class prediction signature was formed and tested on an independent validation cohort (n = 152) validating the prognostic utility of the dimer assay. Similar subclasses were also discovered in full trial dataset (n = 1630) based on 10 baseline clinicopathological and genetic covariates. CONCLUSIONS: Our work suggests that the combined use of HER dimer imaging and conventional mutation analyses will be able to identify a small subclass of patients (>10%) who will have better prognosis following chemotherapy. A larger prospective cohort will be required to confirm its utility in predicting the outcome of anti-EGFR treatment.

Maintenance Olaparib for Germline BRCA-Mutated Metastatic Pancreatic Cancer.

BACKGROUND: Patients with a germline BRCA1 or BRCA2 mutation make up a small subgroup of those with metastatic pancreatic cancer. The poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitor olaparib has had antitumor activity in this population. METHODS: We conducted a randomized, double-blind, placebo-controlled, phase 3 trial to evaluate the efficacy of olaparib as maintenance therapy in patients who had a germline BRCA1 or BRCA2 mutation and metastatic pancreatic cancer and disease that had not progressed during first-line platinum-based chemotherapy. Patients were randomly assigned, in a 3:2 ratio, to receive maintenance olaparib tablets (300 mg twice daily) or placebo. The primary end point was progression-free survival, which was assessed by blinded independent central review. RESULTS: Of the 3315 patients who underwent screening, 154 underwent randomization and were assigned to a trial intervention (92 to receive olaparib and 62 to receive placebo). The median progression-free survival was significantly longer in the olaparib group than in the placebo group (7.4 months vs. 3.8 months; hazard ratio for disease progression or death, 0.53; 95% confidence interval [CI], 0.35 to 0.82; P = 0.004). An interim analysis of overall survival, at a data maturity of 46%, showed no difference between the olaparib and placebo groups (median, 18.9 months vs. 18.1 months; hazard ratio for death, 0.91; 95% CI, 0.56 to 1.46; P = 0.68). There was no significant between-group difference in health-related quality of life, as indicated by the overall change from baseline in the global quality-of-life score (on a 100-point scale, with higher scores indicating better quality of life) based on the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (between-group difference, -2.47 points; 95% CI, -7.27 to 2.33). The incidence of grade 3 or higher adverse events was 40% in the olaparib group and 23% in the placebo group (between-group difference, 16 percentage points; 95% CI, -0.02 to 31); 5% and 2% of the patients, respectively, discontinued the trial intervention because of an adverse event. CONCLUSIONS: Among patients with a germline BRCA mutation and metastatic pancreatic cancer, progression-free survival was longer with maintenance olaparib than with placebo. (Funded by AstraZeneca and others; POLO ClinicalTrials.gov number, NCT02184195.).

Measurement of Tumor Antioxidant Capacity and Prediction of Chemotherapy Resistance in Preclinical Models of Ovarian Cancer by Positron Emission Tomography.

PURPOSE: Drug resistance is a major obstacle for the effective treatment of patients with high-grade serous ovarian cancer (HGSOC). Currently, there is no satisfactory way to identify patients with HGSOC that are refractive to the standard of care. Here, we propose the system xc - radiotracer (4S)-4-(3-[18F]fluoropropyl)-l-glutamate ([18F]FSPG) as a non-invasive method to measure upregulated antioxidant pathways present in drug-resistant HGSOC. EXPERIMENTAL DESIGN: Using matched chemotherapy sensitive and resistant ovarian cancer cell lines, we assessed their antioxidant capacity and its relation to [18F]FSPG uptake, both in cells and in animal models of human ovarian cancer. We identified the mechanisms driving differential [18F]FSPG cell accumulation and evaluated [18F]FSPG tumor uptake as predictive marker of treatment response in drug-resistant tumors. RESULTS: High intracellular glutathione (GSH) and low reactive oxygen species corresponded to decreased [18F]FSPG cell accumulation in drug-resistant versus drug-sensitive cells. Decreased [18F]FSPG uptake in drug-resistant cells was a consequence of changes in intracellular cystine, a key precursor in GSH biosynthesis. In vivo, [18F]FSPG uptake was decreased nearly 80% in chemotherapy-resistant A2780 tumors compared with parental drug-sensitive tumors, with nonresponding tumors displaying high levels of oxidized-to-reduced GSH. Treatment of drug-resistant A2780 tumors with doxorubicin resulted in no detectable change in tumor volume, GSH, or [18F]FSPG uptake. CONCLUSIONS: This study demonstrates the ability of [18F]FSPG to detect upregulated antioxidant pathways present in drug-resistant cancer. [18F]FSPG may therefore enable the identification of patients with HGSOC that are refractory to standard of care, allowing the transferal of drug-resistant patients to alternative therapies, thereby improving outcomes in this disease.

Efficacy and Safety of Pembrolizumab for Heavily Pretreated Patients With Advanced, Metastatic Adenocarcinoma or Squamous Cell Carcinoma of the Esophagus: The Phase 2 KEYNOTE-180 Study.

IMPORTANCE: Effective treatment options are limited for patients with advanced, metastatic esophageal cancer progressing after 2 or more lines of systemic therapy. OBJECTIVE: To evaluate the efficacy and safety of pembrolizumab for patients with advanced, metastatic esophageal squamous cell carcinoma (ESCC) or advanced, metastatic adenocarcinoma of the esophagus and gastroesophageal junction that progressed after 2 or more lines of systemic therapy. DESIGN, SETTING, AND PARTICIPANTS: This phase 2, open-label, interventional, single-arm study, KEYNOTE-180, enrolled 121 patients from January 12, 2016, to March 21, 2017, from 57 sites in 10 countries. Patients had advanced, metastatic esophageal cancer that progressed after 2 or more lines of therapy and had evaluable tumor samples for biomarkers. INTERVENTIONS: Pembrolizumab, 200 mg, was administered intravenously every 3 weeks until disease progression, unacceptable toxic effects, or study withdrawal, for up to 2 years. MAIN OUTCOMES AND MEASURES: Primary end point was objective response rate per the Response Evaluation Criteria in Solid Tumors by central imaging review for all patients. RESULTS: As of September 18, 2017, of 121 enrolled patients (100 men and 21 women; median age, 65 years [range, 33-87 years]), 18 (14.9%) had undergone 3 or more prior therapies, 63 (52.1%) had ESCC, and 58 (47.9%) had tumors positive for programmed death ligand-1 (PD-L1), defined as a combined positive score of 10 or higher assessed by immunohistochemistry. Median duration of follow-up was 5.8 months (range, 0.2-18.3 months). Objective response rate was 9.9% (95% CI, 5.2%-16.7%) among all patients (12 of 121), and median duration of response was not reached (range, 1.9-14.4 months). Objective response rate was 14.3% (95% CI, 6.7%-25.4%) among patients with ESCC (9 of 63), 5.2% (95% CI, 1.1%-14.4%) among patients with adenocarcinoma (3 of 58), 13.8% (95% CI, 6.1%-25.4%) among patients with PD-L1-positive tumors (8 of 58), and 6.3% (95% CI, 1.8%-15.5%) among patients with PD-L1-negative tumors (4 of 63). Overall, 15 patients (12.4%) had treatment-related grade 3 to 5 adverse events. Only 5 patients (4.1%) discontinued treatment because of adverse events. There was 1 treatment-related death from pneumonitis. CONCLUSIONS AND RELEVANCE: Where effective treatment options are an unmet need, pembrolizumab provided durable antitumor activity with manageable safety in patients with heavily pretreated esophageal cancer. Phase 3 studies evaluating pembrolizumab vs standard therapy for patients with esophageal cancer progressing after first-line therapy or in combination with chemotherapy as first-line therapy for patients with locally advanced unresectable or metastatic esophageal cancer are ongoing. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02559687.

MEK inhibition leads to BRCA2 downregulation and sensitization to DNA damaging agents in pancreas and ovarian cancer models.

Targeting the DNA damage response (DDR) in tumors with defective DNA repair is a clinically successful strategy. The RAS/RAF/MEK/ERK signalling pathway is frequently deregulated in human cancers. In this study, we explored the effects of MEK inhibition on the homologous recombination pathway and explored the potential for combination therapy of MEK inhibitors with DDR inhibitors and a hypoxia-activated prodrug. We studied effects of combining pimasertib, a selective allosteric inhibitor of MEK1/2, with olaparib, a small molecule inhibitor of poly (adenosine diphosphate [ADP]-ribose) polymerases (PARP), and with the hypoxia-activated prodrug evofosfamide in ovarian and pancreatic cancer cell lines. Apoptosis was assessed by Caspase 3/7 assay and protein expression was detected by immunoblotting. DNA damage response was monitored with γH2AX and RAD51 immunofluorescence staining. In vivo antitumor activity of pimasertib with evofosfamide were assessed in pancreatic cancer xenografts. We found that BRCA2 protein expression was downregulated following pimasertib treatment under hypoxic conditions. This translated into reduced homologous recombination repair demonstrated by levels of RAD51 foci. MEK inhibition was sufficient to induce formation of γH2AX foci, suggesting that inhibition of this pathway would impair DNA repair. When combined with olaparib or evofosfamide, pimasertib treatment enhanced DNA damage and increased apoptosis. The combination of pimasertib with evofosfamide demonstrated increased anti-tumor activity in BRCA wild-type Mia-PaCa-2 xenograft model, but not in the BRCA mutated BxPC3 model. Our data suggest that targeted MEK inhibition leads to impaired homologous recombination DNA damage repair and increased PARP inhibition sensitivity in BRCA-2 proficient cancers.