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.

Genetic and immune landscape evolution in MMR-deficient colorectal cancer

Mismatch repair-deficient (MMRd) colorectal cancers (CRCs) have high mutation burdens, which make these tumours immunogenic and many respond to immune checkpoint inhibitors. The MMRd hypermutator phenotype may also promote intratumour heterogeneity (ITH) and cancer evolution. We applied multiregion sequencing and CD8 and programmed death ligand 1 (PD-L1) immunostaining to systematically investigate ITH and how genetic and immune landscapes coevolve. All cases had high truncal mutation burdens. Despite pervasive ITH, driver aberrations showed a clear hierarchy. Those in WNT/β-catenin, mitogen-activated protein kinase, and TGF-β receptor family genes were almost always truncal. Immune evasion (IE) drivers, such as inactivation of genes involved in antigen presentation or IFN-γ signalling, were predominantly subclonal and showed parallel evolution. These IE drivers have been implicated in immune checkpoint inhibitor resistance or sensitivity. Clonality assessments are therefore important for the development of predictive immunotherapy biomarkers in MMRd CRCs. Phylogenetic analysis identified three distinct patterns of IE driver evolution: pan-tumour evolution, subclonal evolution, and evolutionary stasis. These, but neither mutation burdens nor heterogeneity metrics, significantly correlated with T-cell densities, which were used as a surrogate marker of tumour immunogenicity. Furthermore, this revealed that genetic and T-cell infiltrates coevolve in MMRd CRCs. Low T-cell densities in the subgroup without any known IE drivers may indicate an, as yet unknown, IE mechanism. PD-L1 was expressed in the tumour microenvironment in most samples and correlated with T-cell densities. However, PD-L1 expression in cancer cells was independent of T-cell densities but strongly associated with loss of the intestinal homeobox transcription factor CDX2. This explains infrequent PD-L1 expression by cancer cells and may contribute to a higher recurrence risk of MMRd CRCs with impaired CDX2 expression. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Pembrolizumab plus chemotherapy versus placebo plus chemotherapy for HER2-negative advanced gastric cancer (KEYNOTE-859): a multicentre, randomised, double-blind, phase 3 trial

BACKGROUND

PD-1 inhibitors combined with chemotherapy have shown efficacy in gastric or gastro-esophageal junction cancer. We compared the efficacy and safety of pembrolizumab plus chemotherapy with placebo plus chemotherapy in participants with locally advanced or metastatic HER2-negative gastric or gastro-esophageal junction adenocarcinoma.

METHODS

KEYNOTE-859 is a multicentre, double-blind, placebo-controlled, randomised, phase 3 trial, done at 207 medical centres across 33 countries. Eligible participants were aged 18 years and older with previously untreated histologically or cytologically confirmed locally advanced or metastatic HER2-negative gastric or gastro-esophageal junction adenocarcinoma and an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients were randomly assigned (1:1) to receive pembrolizumab or placebo 200 mg, administered intravenously every 3 weeks for up to 35 cycles. All participants received investigator's choice of fluorouracil (intravenous, 800 mg/m2 per day) administered continuously on days 1-5 of each 3-week cycle plus cisplatin (intravenous, 80 mg/m2) administered on day 1 of each 3-week cycle or capecitabine (oral, 1000 mg/m2) administered twice daily on days 1-14 of each 3-week cycle plus oxaliplatin (intravenous, 130 mg/m2) administered on day 1 of each 3-week cycle. Randomisation was done using a central interactive voice-response system and stratified by geographical region, PD-L1 status, and chemotherapy in permuted block sizes of four. The primary endpoint was overall survival, assessed in the intention-to-treat (ITT) population, and the populations with a PD-L1 combined positive score (CPS) of 1 or higher, and PD-L1 CPS of 10 or higher. Safety was assessed in the as-treated population, which included all randomly assigned participants who received at least one dose of study intervention. Here, we report the results of the interim analysis. This study is registered with ClinicalTrials.gov, NCT03675737, and recruitment is complete.

FINDINGS

Between Nov 8, 2018, and June 11, 2021, 1579 (66%) of 2409 screened participants were randomly assigned to receive pembrolizumab plus chemotherapy (pembrolizumab group; n=790) or placebo plus chemotherapy (placebo group; n=789). Most participants were male (527 [67%] of 790 participants in the pembrolizumab plus chemotherapy group; 544 [69%] of 789 participants in the placebo plus chemotherapy group) and White (426 [54%]; 435 [55%]). Median follow-up at the data cutoff was 31·0 months (IQR 23·0-38·3). Median overall survival was longer in the pembrolizumab group than in the placebo group in the ITT population (12·9 months [95% CI 11·9-14·0] vs 11·5 months [10·6-12·1]; hazard ratio [HR] 0·78 [95% CI 0·70-0·87]; p<0·0001), in participants with a PD-L1 CPS of 1 or higher (13·0 months [11·6-14·2] vs 11·4 months [10·5-12·0]; 0·74 [0·65-0·84]; p<0·0001), and in participants with a PD-L1 CPS of 10 or higher (15·7 months [13·8-19·3] vs 11·8 months [10·3-12·7]; 0·65 [0·53-0·79]; p<0·0001). The most common grade 3-5 adverse events of any cause were anaemia (95 [12%] of 785 participants in the pembrolizumab group vs 76 [10%] of 787 participants in the placebo group) and decreased neutrophil count (77 [10%] vs 64 [8%]). Serious treatment-related adverse events occurred in 184 (23%) participants in the pembrolizumab group and 146 (19%) participants in the placebo group. Treatment-related deaths occurred in eight (1%) participants in the pembrolizumab group and 16 (2%) participants in the placebo group. No new safety signals were identified.

INTERPRETATION

Participants in the pembrolizumab plus chemotherapy group had a significant and clinically meaningful improvement in overall survival with manageable toxicity compared with participants in the placebo plus chemotherapy group. Therefore, pembrolizumab with chemotherapy might be a first-line treatment option for patients with locally advanced or metastatic HER2-negative gastric or gastro-esophageal junction adenocarcinoma.

FUNDING

Merck Sharp and Dohme.

The immunomodulatory role of IDO1-Kynurenine-NAD+ pathway in switching cold tumor microenvironment in PDAC

Pancreatic ductal adenocarcinoma (PDAC) is the most common exocrine tumor of the pancreas characterized by late diagnosis, adverse overall 5-year survival, a higher propensity for metastatic disease, and lack of efficacy of systemic therapy options. These adverse outcomes can be partly attributed to complex tumor microenvironment (TME). Over the past decade, immunotherapy has revolutionized the management of certain cancers; thus far, the immunologically 'non-inflamed' tumor microenvironment in PDACs has proven to be challenging. Indolamine 2,3-dioxygenase 1 (IDO1) is the rate-limiting enzyme in the catabolic pathway of L-Tryptophan, an essential amino acid, that gives rise to the immunosuppressive metabolite Kynurenine. IDO1, Indolamine 2,3-dioxygenase 2 (IDO2), and Tryptophan 2,3-dioxygenase (TDO) are the key enzymes in the tryptophan catabolic pathway but we focus on the role of the predominant enzyme form IDO1 in this review. Nicotinamide phosphoribosyl transferase (iNAMPT) regulates the intracellular concentration of NAD and is upregulated in the tumor. In light of the potential role of IDO1 as a driver of hostile TME in PDAC and NAD⁺ as a key coenzyme in anti-tumor immune response, this review urges focus on extensive research and initiation of clinical trials using IDO1 and NAMPT inhibitors in pancreatic cancer in the future.

Pembrolizumab in Asian patients with microsatellite-instability-high/mismatch-repair-deficient colorectal cancer

The phase 3 KEYNOTE-177 study evaluated pembrolizumab versus chemotherapy with or without bevacizumab or cetuximab in patients with newly diagnosed, microsatellite-instability-high (MSI-H)/mismatch-repair-deficient (dMMR) metastatic colorectal cancer (mCRC). Primary endpoints were progression-free survival (PFS) per RECIST v1.1 by blinded independent central review (BICR) and overall survival (OS). Secondary endpoints were overall response rate (ORR) per RECIST v1.1 by BICR and safety. Here, we report results from the post hoc analysis of patients who were enrolled in Asia from the final analysis (FA) of KEYNOTE-177. A total of 48 patients from Japan, Korea, Singapore, and Taiwan (pembrolizumab, n = 22; chemotherapy, n = 26) were included. At FA, median time from randomization to data cutoff (February 19, 2021) was 45.3 (range 38.1-57.8) months with pembrolizumab and 43.9 (range 36.6-55.1) months with chemotherapy. Median PFS was not reached (NR; 95% confidence interval [CI] 1.9 months-NR) with pembrolizumab versus 10.4 (95% CI 6.3-22.0) months with chemotherapy (hazard ratio [HR] 0.56, 95% CI 0.26-1.20). Median OS was NR (range 13.8 months-NR) versus 30.0 (14.7-NR) months (HR 0.65, 95% CI 0.27-1.55) and ORR was 50% (95% CI 28-72) versus 46% (95% CI 27-67). Grade 3/4 treatment-related adverse events (TRAEs) were reported by two patients (9%) in the pembrolizumab arm and 20 (80%) in the chemotherapy arm. Immune-mediated adverse events or infusion reactions were reported by six patients (27%) and 10 patients (40%), respectively. No deaths due to TRAEs occurred. These data support first-line pembrolizumab as a standard of care for patients from Asia with MSI-H/dMMR mCRC. ClinicalTrials.gov identifier: NCT02563002.

NEOPRISM-CRC: Neoadjuvant pembrolizumab stratified to tumor mutation burden for high-risk stage 2 or stage 3 deficient-MMR/MSI-high colorectal cancer

TPS3645

Background: The prognostic advantage of early stage deficient-MMR/MSI-High CRC is lost after relapse, so there is a pressing clinical need to maximize the chance of cure in the early stages where prevalence of dMMR is higher comprising approximately 12% of Stage 3 and 20% of Stage 2 CRC. The efficacy of adjuvant checkpoint inhibition in this patient group has yet to be demonstrated in the context of micrometastatic disease without a supporting immune-competent microenvironment. Longitudinal studies especially in the neoadjuvant setting would optimally interrogate post-immunotherapy changes both in time and space. The NEOPRISM-CRC (NEOadjuvant PembRolizumab In Stratified Medicine – ColoReCtal) study is a Phase II Trial to determine whether neoadjuvant Pembrolizumab stratified to tumour mutation burden (TMB) is efficacious and safe. It will also be a platform to explore the relationships between possible predictive novel biomarkers and response to Pembrolizumab in blood, tumour tissue and microbiome. Methods: The study population consists of subjects with newly diagnosed operable dMMR/MSI-H CRC. Patients must be fit and eligible for planned curative surgery based on a) radiological node positive T1-4 CRC or b) high risk T3 defined as EITHER ≥ 5mm of extramural depth of invasion or unequivocal EMVI on imaging (regardless of depth), or T4 disease. They will receive one of two pre-operative regimens depending upon their TMB based on the FoundationOne®CDx test (FM1CDx). All patients will have one 21 day cycle of Pembrolizumab 200 mg IV. Prior to cycle 2 and with the result of the FM1CDx test, patients will continue their treatment as follows: A) TMB-high (defined as ≥20 mutations per Mb) or TMB-medium (defined as 6-19 mutations per Mb), or MSI-H on PCR if FM1CDx test is not evaluable: A further 2 cycles of Pembrolizumab 200 mg IV every 21 days. B) TMB-low (defined as ≤5 mutations per Mb), or if FM1CDx and PCR tests are not evaluable: No further Pembrolizumab given. Surgery to remove the CRC will be performed 4-6 weeks after the last dose of Pembrolizumab in both arms. Following resection patients may receive adjuvant chemotherapy in accordance with local institutional guidelines. The primary end point is pathological complete response rate (pCR). Secondary endpoints include 3 year RFS, OS, safety and health-related quality of life. Up to 32 patients will be registered over a 18-24 month period assuming that the pCR with 3 cycles of Pembrolizumab will be ≥ 33% for patients with high or medium TMB based on the FM1CDx profile, and intend to rule out a percentage ≤10%. To reach 80% power with 5% statistical significance, 19 patients are required in the high/medium TMB arm. The trial will be considered a success if at least 5/19 patients have a pCR after 3 cycles of Pembrolizumab. Enrolment will commence in March 2022. Clinical trial information: NCT05197322.

Pembrolizumab versus chemotherapy for microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer (KEYNOTE-177): final analysis of a randomised, open-label, phase 3 study

BACKGROUND

Pembrolizumab has shown improved progression-free survival versus chemotherapy in patients with newly diagnosed microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer. However, the treatment's effect on overall survival in this cohort of patients was unknown. Here, we present the final overall survival analysis of the KEYNOTE-177 study.

METHODS

This randomised, open-label, phase 3 study was done in 193 academic medical centres and hospitals in 23 countries. We recruited patients aged at least 18 years, with an Eastern Cooperative Oncology Group performance status of 0 or 1, and who had previously untreated microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer. Patients were randomly assigned (1:1) in blocks of four using an interactive voice response system or integrated web response system to intravenous pembrolizumab 200 mg every 3 weeks or to the investigator's choice of intravenous mFOLFOX6 (oxaliplatin 85 mg/m2 on day 1, leucovorin 400 mg/m2 on day 1, and fluorouracil 400 mg/m2 bolus on day 1 followed by a continuous infusion of 1200 mg/m2 per day for 2 days on days 1-2) or intravenous FOLFIRI (irinotecan 180 mg/m2 on day 1, leucovorin 400 mg/m2 on day 1, and fluorouracil 400 mg/m2 bolus on day 1 followed by a continuous infusion of 1200 mg/m2 per day for 2 days on days 1-2), every 2 weeks with or without intravenous bevacizumab 5 mg/kg every 2 weeks or intravenous weekly cetuximab (first dose 400 mg/m2, then 250 mg/m2 for every subsequent dose). Patients receiving chemotherapy could cross over to pembrolizumab for up to 35 treatment cycles after progression. The co-primary endpoints were overall survival and progression-free survival in the intention-to-treat population. KEYNOTE-177 is registered at ClinicalTrials.gov, NCT02563002, and is no longer enrolling patients.

FINDINGS

Between Feb 11, 2016, and Feb 19, 2018, 852 patients were screened, of whom 307 (36%) were randomly assigned to pembrolizumab (n=153) or chemotherapy (n=154). 93 (60%) patients crossed over from chemotherapy to anti-PD-1 or anti-PD-L1 therapy (56 patients to on-study pembrolizumab and 37 patients to off-study therapy). At final analysis (median follow-up of 44·5 months [IQR 39·7-49·8]), median overall survival was not reached (NR; 95% CI 49·2-NR) with pembrolizumab vs 36·7 months (27·6-NR) with chemotherapy (hazard ratio [HR] 0·74; 95% CI 0·53-1·03; p=0·036). Superiority of pembrolizumab versus chemotherapy for overall survival was not demonstrated because the prespecified α of 0·025 needed for statistical significance was not achieved. At this updated analysis, median progression-free survival was 16·5 months (95% CI 5·4-38·1) with pembrolizumab versus 8·2 months (6·1-10·2) with chemotherapy (HR 0·59, 95% CI 0·45-0·79). Treatment-related adverse events of grade 3 or worse occurred in 33 (22%) of 153 patients in the pembrolizumab group versus 95 (66%) of 143 patients in the chemotherapy group. Common adverse events of grade 3 or worse that were attributed to pembrolizumab were increased alanine aminotransferase, colitis, diarrhoea, and fatigue in three (2%) patients each, and those attributed to chemotherapy were decreased neutrophil count (in 24 [17%] patients), neutropenia (22 [15%]), diarrhoea (14 [10%]), and fatigue (13 [9%]). Serious adverse events attributed to study treatment occurred in 25 (16%) patients in the pembrolizumab group and in 41 (29%) patients in the chemotherapy group. No deaths attributed to pembrolizumab occurred; one death due to intestinal perforation was attributed to chemotherapy.

INTERPRETATION

In this updated analysis, although pembrolizumab continued to show durable antitumour activity and fewer treatment-related adverse events compared with chemotherapy, there was no significant difference in overall survival between the two treatment groups. These findings support pembrolizumab as an efficacious first-line therapy in patients with microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer.

FUNDING

MSD.

Capecitabine Versus Active Monitoring in Stable or Responding Metastatic Colorectal Cancer After 16 Weeks of First-Line Therapy: Results of the Randomized FOCUS4-N Trial

PURPOSE

Despite extensive randomized evidence supporting the use of treatment breaks in metastatic colorectal cancer (mCRC), they are not universally offered to patients despite improvements in quality of life without detriment to overall survival (OS). FOCUS4-N was set up to explore the impact of oral maintenance therapy in patients who are responding to first-line therapy.

METHODS

FOCUS4 was a molecularly stratified trial program that registered patients with newly diagnosed mCRC. The FOCUS4-N trial was offered to patients in whom a targeted subtrial was unavailable or biomarker tests failed. Patients were randomly assigned using a 1:1 ratio between maintenance capecitabine and active monitoring (AM). The primary outcome was progression-free survival (PFS) with secondary outcomes including OS toxicity and tolerability.

RESULTS

Between March 2014 and March 2020, 254 patients were randomly assigned (127 to capecitabine and 127 to AM) across 88 UK sites. Baseline characteristics were balanced. There was strong evidence of efficacy for PFS (hazard ratio = 0.40; 95% CI, 0.21 to 0.75; P < .0001), but no significant improvement in OS (hazard ratio, 0.93; 95% CI, 0.69 to 1.27; P = .66) was observed. Compliance with treatment was good, and toxicity from capecitabine versus AM was as expected with grade ≥ 2 fatigue (25% v 12%), diarrhea (23% v 13%), and hand-foot syndrome (26% v 3%). Quality of life showed little difference between the groups.

CONCLUSION

Despite strong evidence of disease control with maintenance therapy, OS remains unaffected and FOCUS4-N provides additional evidence to support the use of treatment breaks as safe management alternatives for patients who are stable or responding to first-line treatment for mCRC. Capecitabine without bevacizumab may be used to extend PFS in the interval after 16 weeks of first-line therapy.

Immunogenomics of Colorectal Cancer Response to Checkpoint Blockade: Analysis of the KEYNOTE 177 Trial and Validation Cohorts

BACKGROUND & AIMS

Colorectal cancer (CRC) shows variable response to immune checkpoint blockade, which can only partially be explained by high tumor mutational burden (TMB). We conducted an integrated study of the cancer tissue and associated tumor microenvironment (TME) from patients treated with pembrolizumab (KEYNOTE 177 clinical trial) or nivolumab to dissect the cellular and molecular determinants of response to anti- programmed cell death 1 (PD1) immunotherapy.

METHODS

We selected multiple regions per tumor showing variable T-cell infiltration for a total of 738 regions from 29 patients, divided into discovery and validation cohorts. We performed multiregional whole-exome and RNA sequencing of the tumor cells and integrated these with T-cell receptor sequencing, high-dimensional imaging mass cytometry, detection of programmed death-ligand 1 (PDL1) interaction in situ, multiplexed immunofluorescence, and computational spatial analysis of the TME.

RESULTS

In hypermutated CRCs, response to anti-PD1 immunotherapy was not associated with TMB but with high clonality of immunogenic mutations, clonally expanded T cells, low activation of Wnt signaling, deregulation of the interferon gamma pathway, and active immune escape mechanisms. Responsive hypermutated CRCs were also rich in cytotoxic and proliferating PD1+CD8 T cells interacting with PDL1+ antigen-presenting macrophages.

CONCLUSIONS

Our study clarified the limits of TMB as a predictor of response of CRC to anti-PD1 immunotherapy. It identified a population of antigen-presenting macrophages interacting with CD8 T cells that consistently segregate with response. We therefore concluded that anti-PD1 agents release the PD1-PDL1 interaction between CD8 T cells and macrophages to promote cytotoxic antitumor activity.

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.

Final overall survival for the phase III KN177 study: Pembrolizumab versus chemotherapy in microsatellite instability-high/mismatch repair deficient (MSI-H/dMMR) metastatic colorectal cancer (mCRC)

3500

Background: In the phase III, randomized open-label KEYNOTE-177 (NCT02563002) study 1L pembrolizumab (pembro) versus chemotherapy (chemo) provided superior progression-free survival (PFS) at second interim analysis (IA2) in patients (pts) with MSI-H/dMMR mCRC. The study continued to final analysis of overall survival (OS), planned after 190 OS events or 12 months after IA2, whichever occurred first. We present results of the final analysis of OS, 12 months after IA2. Methods: A total of 307 pts with MSI-H/dMMR mCRC and ECOG PS 0 or 1 were randomized 1:1 to 1L pembro 200 mg Q3W for up to 2y or investigator’s choice of mFOLFOX6 or FOLFIRI Q2W ± bevacizumab or cetuximab. Treatment continued until PD, unacceptable toxicity, pt/investigator decision to withdraw, or completion of 35 cycles (pembro only). Pts receiving chemo could crossover to pembro for up to 35 cycles after confirmed PD. Primary end points were OS and PFS (RECIST v1.1, central review). Secondary end points included ORR, duration of response (DOR) (RECIST v1.1, central review), and safety. For OS significance, the p-value had to meet a prespecified α of 0.0246 (one-sided). Sensitivity analyses to adjust for crossover effect were performed. Data cut-off for final analysis was Feb 19, 2021. Results: Median (range) study follow-up was 44.5 mo (36.0-60.3) with pembro vs 44.4 mo (36.2-58.6) with chemo. 56 (36%) pts crossed over from chemo to pembro, with 37 more receiving anti-PD-1/PD-L1 therapies off study (60% effective crossover rate in the ITT). The HR for OS favored pembro vs chemo with a trend toward reduction in the risk of death (HR 0.74; 95% CI, 0.53-1.03; P=0.0359; median not reached [NR] vs 36.7 mo); this difference did not reach statistical significance. Sensitivity analysis by the rank-preserving structure failure time model and inverse probability of censoring weighting showed OS HRs of 0.66 (95% CI 0.42-1.04) and 0.77 (95% CI 0.44-1.38), respectively. Pembro vs chemo met the prespecified criteria for PFS superiority at IA2. At final analysis, median PFS was 16.5 mo vs 8.2 mo (HR 0.59; 95% CI, 0.45-0.79), but was not formally tested per analysis plan. Confirmed ORR was 45.1% (20 CR, 49 PR) vs 33.1% (6 CR, 45 PR). Median (range) DOR was NR (2.3+ to 53.5+) vs 10.6 mo (2.8 to 48.3+), respectively. Treatment-related adverse events (TRAEs) occurred in 79.7% vs 98.6% of pts; 21.6% vs 66.4%, respectively, had grade ≥3 TRAEs. Conclusions: As 1L therapy for pts with MSI-H/dMMR mCRC, pembro vs chemo provides statistically superior PFS with fewer TRAEs, and is associated with a trend toward reduced mortality that did not meet statistical significance likely due to the high crossover rate from chemo to anti-PD1/PD-L1 therapies. Together these data confirm pembro as a new standard-of-care in the 1L for pts with MSI-H/dMMR mCRC. Clinical trial information: NCT02563002.

Outcomes for cancer patients on systemic anti-cancer therapies during the COVID-19 pandemic from the CAPITOL (COVID-19 Cancer PatIenT Outcomes in North London) cohort study

10567

Background: One of the major challenges with COVID-19 has been the changes to cancer services, including changes to the type of systemic anti-cancer treatment being delivered to patients. There needs to be a better understanding of which cancer patients are at the greatest amount of risk to make informed decisions on how cancer treatment can be altered to protect patients from COVID-19 infection. The CAPITOL (COVID-19 CAncer PatIenT Outcomes in North London) study investigated the outcomes of patients receiving systemic anti-cancer therapies (SACT) with regards to COVID-19 infection, as patients with cancer are hypothesised to be at higher risk. Methods: CAPITOL collected data from all patients receiving SACT at two cancer centres. The effect of clinical characteristics on the incidence and severity of COVID-19 infection in patients on SACT was the primary outcome, and we used univariable and multivariable models in our analysis, adjusting for age, gender and comorbidities. Results: 2871 patients were analysed from 2nd March to 31st May 2020, all of whom received SACT; during this time period 68 (2.4%) were diagnosed with COVID-19. Receiving SACT increased the risk of death when contracting COVID-19 (adjusted (adj.) OR 9.84; 95% CI 5.73 – 16.9). The risk of contracting COVID-19 was increased by receiving chemotherapy (adj. OR 2.99; 95% CI = 1.72 - 5.21), with the risk significantly increased by high dose chemotherapy (adj. OR 2.36, 95% CI 1.35 – 6.48). Patients with comorbidities (adjusted OR 2.29; 95% CI 1.19 - 4.38), or with a respiratory or intrathoracic neoplasm (adj. OR 2.12; 95% CI 1.04 - 4.36) were also at increased risk of contracting COVID-19. Cancer patients who received targeted treatment had a reduced risk of contracting COVID-19 (adj. OR 0.53; 95% CI 0.30 – 0.95), while there was no significant change in risk caused by treatment intent (curative versus palliative), hormonal- or immunotherapy and solid versus haematological cancers. Conclusions: To the best of our knowledge, this is one of the first investigations into the risk of contracting COVID-19 in a cohort of all cancer patients on SACT. We found that patients on SACT are more likely to die if they contract COVID-19. The type of SACT received by cancer patients can affect their likelihood of contacting COVID-19, with chemotherapy increasing risk, targeted therapy decreasing risk and a potential protective effect for hormonal and immunotherapy.

Health-related quality of life in patients with microsatellite instability-high or mismatch repair deficient metastatic colorectal cancer treated with first-line pembrolizumab versus chemotherapy (KEYNOTE-177): an open-label, randomised, phase 3 trial

BACKGROUND

In the KEYNOTE-177 study, pembrolizumab monotherapy provided statistically significant and clinically meaningful improvements in progression-free survival versus chemotherapy as first-line treatment in patients with microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer. To further support the efficacy and safety findings of the KEYNOTE-177 study, results of the health-related quality of life (HRQOL) analyses are reported here.

METHODS

KEYNOTE-177 is an open-label, randomised, phase 3 trial being done at 192 cancer centres in 23 countries, in patients aged 18 years and older with microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer, with an Eastern Cooperative Oncology Group performance status of 0 or 1, and who had not received previous systemic therapy for metastatic disease. Eligible patients were randomly assigned (1:1) centrally by use of interactive voice response or integrated web response technology to receive pembrolizumab 200 mg intravenously every 3 weeks or investigator's choice chemotherapy (mFOLFOX6 [leucovorin, fluorouracil, and oxaliplatin] or FOLFIRI [leucovorin, fluorouracil, and irinotecan] intravenously every 2 weeks with or without intravenous bevacizumab or cetuximab). Patients and investigators were not masked to treatment assignment. The primary endpoints were progression-free survival (previously reported) and overall survival (data to be reported at the time of the final analysis). HRQOL outcomes were evaluated as prespecified exploratory endpoints. The analysis population comprised all randomly assigned patients who received at least one dose of study treatment and completed at least one HRQOL assessment. HRQOL outcomes were mean change from baseline to prespecified week 18 in European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and EORTC Quality of Life Questionnaire-Colorectal 29 (EORTC QLQ-CR29) scale and item scores, and in the EuroQoL 5 Dimensions 3 Levels (EQ-5D-3L) visual analogue scale and health utility scores; the proportion of patients with improved, stable, or deteriorated scores from baseline to prespecified week 18 in EORTC QLQ-C30 scales and items; and time to deterioration in EORTC QLQ-C30 global health status/quality of life (GHS/QOL), physical functioning, social functioning, and fatigue scores and EORTC QLQ-CR29 urinary incontinence scores. The threshold for a small and clinically meaningful mean difference in EORTC QLQ-C30 score was 5-8 points. This study is registered with ClinicalTrials.gov, NCT02563002 and is ongoing; recruitment is closed.

FINDINGS

Between Feb 11, 2016, and Feb 19, 2018, 307 patients were enrolled and randomly assigned to receive pembrolizumab (n=153) or chemotherapy (n=154). The HRQOL analysis population comprised 294 patients (152 receiving pembrolizumab and 142 receiving chemotherapy). As of Feb 19, 2020, median time from randomisation to data cutoff was 32·4 months (IQR 27·7-37·8). Least squares mean (LSM) change from baseline to prespecified week 18 showed a clinically meaningful improvement in EORTC QLQ-C30 GHS/QOL scores with pembrolizumab versus chemotherapy (between-group LSM difference 8·96 [95% CI 4·24-13·69]; two-sided nominal p=0·0002). Median time to deterioration was longer with pembrolizumab versus chemotherapy for GHS/QOL (hazard ratio 0·61 [95% CI 0·38-0·98]; one-sided nominal p=0·019), physical functioning (0·50 [95% CI 0·32-0·81]; one-sided nominal p=0·0016), social functioning (0·53 [95% CI 0·32-0·87]; one-sided nominal p=0·0050), and fatigue scores (0·48 [95% CI 0·33-0·69]; one-sided nominal p<0·0001).

INTERPRETATION

Pembrolizumab monotherapy led to clinically meaningful improvements in HRQOL compared with chemotherapy in patients with previously untreated microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer. These data, along with the previously reported clinical benefits, support pembrolizumab as a first-line treatment option for this population.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co, Kenilworth, NJ, USA.

KEYNOTE-177: Phase III randomized study of pembrolizumab versus chemotherapy for microsatellite instability-high advanced colorectal cancer

6

Background: KEYNOTE-177 (NCT02563002) evaluated the antitumor activity of pembrolizumab (pembro) vs chemotherapy ± bevacizumab or cetuximab (chemo) as first-line therapy for patients with microsatellite-instability high/mismatch repair deficient (MSI-H/dMMR) metastatic colorectal cancer (mCRC). We present results of the final PFS analysis and analysis of PFS2. Methods: Patients with locally-determined MSI-H/dMMR mCRC and ECOG PS 0 or 1 were randomized 1:1 to first-line pembro 200 mg Q3W for up to 2 years or investigator’s choice of mFOLFOX6 or FOLFIRI Q2W ± bevacizumab or cetuximab (chosen before randomization). Treatment continued until progression, unacceptable toxicity, patient/investigator decision to withdraw, or completion of 35 cycles (pembro only). Patients receiving chemo could crossover to pembro for up to 35 cycles after confirmed PD. Primary end points were PFS (RECIST v1.1, central review) and OS. Secondary end points included ORR (RECIST v1.1, central review) and safety. Exploratory endpoints included duration of response (DOR), PFS2 (time from randomization to progression on next line of therapy or any cause death), and health-related quality of life (HRQoL). Data cutoff was Feb 19, 2020. Results: At data cutoff a total of 307 patients were randomized (153 to pembro, 154 to chemo). Median (range) study follow-up was 32.4 mo (24.0-48.3). Pembro was superior to chemo for PFS (median 16.5 mo vs 8.2 mo; HR 0.60; 95% CI, 0.45-0.80; P= 0.0002). The 12- and 24-mo PFS rates were 55.3% and 48.3% with pembro vs 37.3% and 18.6% with chemo. Confirmed ORR was 43.8% vs 33.1%; median (range) DOR was not reached (2.3+ to 41.4+) with pembro vs 10.6 mo (2.8 to 37.5+) with chemo. PFS2 was longer with pembro vs chemo (median not reached vs 23.5 mo [HR 0.63; 95% CI, 0.45-0.88]). OS analysis is ongoing. Grade ≥3 treatment related adverse event (TRAE) rates were 22% vs 66% for pembro vs chemo. There were no grade 5 TRAEs in the pembro arm and 1 grade 5 intestinal perforation in the chemo arm. HRQoL scores were improved with pembro vs chemo. Conclusions: Pembro provided a statistically significant improvement in PFS vs chemo as first-line therapy for patients with MSI-H/dMMR mCRC, with fewer TRAEs observed. Furthermore, pembro provided a clinically meaningful improvement in PFS2 for patients with MSI-H/dMMR mCRC. Clinical trial information: NCT02563002.

A systematic review and meta-analysis of PD-1/PD-L1 inhibitors in specific patient subgroups with advanced gastro-oesophageal junction and gastric adenocarcinoma

BACKGROUND

immune checkpoint inhibitors(ICIs) have shown contradictory results in patients with advanced gastro-oesophageal junction/gastric cancer(GOJ/GC).

AIM

to identify specific patient subgroups that would derive survival benefit from ICIs.

METHODS

a subgroup meta-analysis of randomised clinical trials(RCTs) was carried out.

RESULTS

four phase-III-RCTs were identified with data on the following variables: primary location(Gastric vs GOJ); age(≤ 65 vs >65); gender(male vs female); ECOG PS(0 vs 1); ethnicity (Asian vs non-Asian), histology(intestinal vs diffuse), PD-L1 expression(≥ 1% vs < 1%). PD-L1 positivity was significantly associated with survival benefit from ICIs (HR: 0.82, p 0.047), with a significant interaction between PD-L1 expression and ICI efficacy (interaction HR: 1.41, p 0.02). Numerically, the second most relevant interaction was ICI efficacy and gender, with ICI being more effective in males.

CONCLUSION

The PD-L1 positive patient subgroup derives significant survival benefit from ICI in GOJ/GC, however other predictors are eagerly needed to further refine patient selection.

Pembrolizumab in Microsatellite-Instability-High Advanced Colorectal Cancer

BACKGROUND

Programmed death 1 (PD-1) blockade has clinical benefit in microsatellite-instability-high (MSI-H) or mismatch-repair-deficient (dMMR) tumors after previous therapy. The efficacy of PD-1 blockade as compared with chemotherapy as first-line therapy for MSI-H-dMMR advanced or metastatic colorectal cancer is unknown.

METHODS

In this phase 3, open-label trial, 307 patients with metastatic MSI-H-dMMR colorectal cancer who had not previously received treatment were randomly assigned, in a 1:1 ratio, to receive pembrolizumab at a dose of 200 mg every 3 weeks or chemotherapy (5-fluorouracil-based therapy with or without bevacizumab or cetuximab) every 2 weeks. Patients receiving chemotherapy could cross over to pembrolizumab therapy after disease progression. The two primary end points were progression-free survival and overall survival.

RESULTS

At the second interim analysis, after a median follow-up (from randomization to data cutoff) of 32.4 months (range, 24.0 to 48.3), pembrolizumab was superior to chemotherapy with respect to progression-free survival (median, 16.5 vs. 8.2 months; hazard ratio, 0.60; 95% confidence interval [CI], 0.45 to 0.80; P = 0.0002). The estimated restricted mean survival after 24 months of follow-up was 13.7 months (range, 12.0 to 15.4) as compared with 10.8 months (range, 9.4 to 12.2). As of the data cutoff date, 56 patients in the pembrolizumab group and 69 in the chemotherapy group had died. Data on overall survival were still evolving (66% of required events had occurred) and remain blinded until the final analysis. An overall response (complete or partial response), as evaluated with Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, was observed in 43.8% of the patients in the pembrolizumab group and 33.1% in the chemotherapy group. Among patients with an overall response, 83% in the pembrolizumab group, as compared with 35% of patients in the chemotherapy group, had ongoing responses at 24 months. Treatment-related adverse events of grade 3 or higher occurred in 22% of the patients in the pembrolizumab group, as compared with 66% (including one patient who died) in the chemotherapy group.

CONCLUSIONS

Pembrolizumab led to significantly longer progression-free survival than chemotherapy when received as first-line therapy for MSI-H-dMMR metastatic colorectal cancer, with fewer treatment-related adverse events. (Funded by Merck Sharp and Dohme and by Stand Up to Cancer; KEYNOTE-177 ClinicalTrials.gov number, NCT02563002.).

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.

Pembrolizumab versus chemotherapy for microsatellite instability-high/mismatch repair deficient metastatic colorectal cancer: The phase 3 KEYNOTE-177 Study

LBA4

Background: KEYNOTE-177 (NCT02563002) is a phase 3, randomized open-label study evaluating the efficacy and safety of pembrolizumab (pembro) versus standard of care chemotherapy ± bevacizumab or cetuximab (chemo) as first-line therapy for patients (pts) with microsatellite-instability high/mismatch repair deficient (MSI-H/dMMR) metastatic colorectal cancer (mCRC). We present results of the final PFS analysis. Methods: A total of 307 pts with MSI-H/dMMR mCRC as determined locally and ECOG PS 0 or 1 were randomly assigned 1:1 to first-line pembro 200 mg Q3W for up to 2 years or investigator’s choice of mFOLFOX6 or FOLFIRI Q2W ± bevacizumab or cetuximab (chemo chosen prior to randomization). Treatment continued until PD, unacceptable toxicity, pt/investigator decision to withdraw, or completion of 35 cycles (pembro only). Patients receiving chemo could crossover to pembro for up to 35 cycles after confirmed PD. Primary end points were PFS (RECIST v1.1, central review) and OS. Key secondary end points included ORR (RECIST v1.1, central review), and safety. The data cutoff date for this interim analysis was Feb 19, 2020. The study will continue without changes to evaluate OS. Results: At data cutoff, 153 pts were randomized to pembro and 154 to chemo. Median (range) study follow-up was 28.4 mo (0.2-48.3) with pembro vs 27.2 mo (0.8-46.6) with chemo. Pembro was superior to chemo for PFS (median 16.5 mo vs 8.2 mo; HR 0.60; 95% CI, 0.45-0.80; P=0.0002). The 12- and 24-mo PFS rates were 55.3% and 48.3% with pembro vs 37.3% and 18.6% with chemo. Confirmed ORR was 43.8% vs 33.1%; median (range) duration of response was not reached (2.3+ to 41.4+) with pembro vs 10.6 mo (2.8 to 37.5+) with chemo. Grade 3-5 treatment related adverse event (AE) rates were 22% vs 66% for pembro vs chemo. One pt in the chemo arm died due to a treatment-related AE. Conclusions: Pembro provided a clinically meaningful and statistically significant improvement in PFS versus chemo as first-line therapy for pts with MSI-H/dMMR mCRC, with fewer treatment-related AEs observed and should be the new standard of care for these pts. Clinical trial information: NCT02563002 .

Gastric inflammatory prognostic index (GIPI) to predict efficacy of PD-1/PD-L1 immune checkpoint inhibitors in metastatic gastroesophageal junction (GOJ)/gastric cancer (GC) patients

4530

Background: ICIs demonstrated improved overall survival (OS) in heavily pre-treated mGOJ/GC pts. Pts selection exclusively based on PD-L1 tissue expression appears to be suboptimal, despite data from subgroup analyses of KEYNOTE trials. Strong rationale suggests a potential predictive role of inflammatory biomarkers in ICIs treated mGOJ/GC pts. Methods: Ten systemic inflammatory markers [platelets, monocytes, neutrophil/lymphocyte ratio (NLR), platelets-lymphocyte ratio, lymphocytes, sum of mononuclear cells, albumin, lactate dehydrogenase, c-reactive protein (CRP) and serum globulin] were retrospectively analyzed at baseline in 57 mGOJ/GC pts with unknown PD-L1 status treated in second-line with ICIs, and correlated with OS. Least Absolute Shrinkage and Selection Operator (LASSO) method was used to select variables (preliminarily subject to optimal coding using HR smoothed curves for OS) with the highest prognostic value. Selected variables were then analyzed in a multivariate Cox Regression Model and used to build a GIPI nomogram. Results: NLR and CRP taken as continuous variables and albumin categorized as < vs > 30 g/dL were found as the most meaningful independent predictors of OS and used to build the GIPI nomogram. Nomogram-based lowest (l), mid-low, mid-high and highest (h) risk quartiles were associated with median(m)OS of 14.9, 7.1, 5.6 and 2.1 months (mos), respectively [HR of l vs h 4.94, p 0.0002]. By optimally dichotomizing CRP and NLR, pts with one or more of the following risk factors: NLR >6, CRP >15 mg/L, albumin <30 g/dL (n: 29) had a mOS of 3.9 mos vs 14.2 mos of pts with no risk factor (n: 28) (HR 2.48, p 0.001). Conclusions: GIPI, combining NLR, CRP and Albumin, is the first inflammatory index with a significant prognostic value in mOGJ/GC pts receiving second-line ICIs. Its implementation in correlation with PD-L1 expression in the present cohort is ongoing. GIPI merits validation in independent cohorts and prospective clinical trials.

Review of metastatic colorectal cancer treatment pathways and early clinical experience of trifluridine/tipiracil in the UK named patient programme

Background

The standard first- and second- line chemotherapy backbone regimens for metastatic colorectal cancer (mCRC) are 5-fluorouracil (5-FU)/capecitabine-based with addition of irinotecan or oxaliplatin. Until recently, evidence for optimal sequencing post second-line was sparse. Trifluridine/tipiracil (indicated for mCRC and gastric cancer after standard chemotherapies) was made available to UK patients via a named patient programme (NPP) before receiving marketing authorisation in Europe in 2016, allowing characterisation of UK treatment pathways, and evaluation of trifluridine/tipiracil in a UK non-trial population.

Methods

Data collected routinely for the NPP were analysed to describe the patient demographics, clinical characteristics and treatment pathways. Patients eligible for the programme were adults (≥18 years) with histologically or cytologically confirmed mCRC who had previously received chemotherapy treatment(s).

Results

Of the 250 eligible patients enrolled in the NPP, 194 patients received ≥1 dose of trifluridine/tipiracil and 56 patients did not receive trifluridine/tipiracil. The following results are reported first for patients who received trifluridine/tipiracil and second for those who did not receive trifluridine/tipiracil: median (IQR) age was 63.0 (54.0–69.0) and 62.0 (54.8–69.0) years; Eastern Cooperative Oncology Group performance status score was 0 for 28 and 14%, 1 for 65 and 70%, 2 for 7 and 16%. In terms of previous systemic treatments 47 and 43% had 2 prior lines of therapy. FOLFOX-, FOLFIRI- and CAPOX-based therapies were the most common first-line regimens in patients receiving trifluridine/tipiracil (37, 35 and 21%, respectively), and in patients not receiving trifluridine/tipiracil (41, 30 and 20%, respectively). Second-line treatment regimens in patients receiving and not receiving trifluridine/tipiracil were most commonly FOLFIRI-based (48 and 41%, respectively) and FOLFOX-based (19 and 21%, respectively). Patients received a median of 2 cycles of trifluridine/tipiracil with a median treatment duration of 1.8 (95% CI: 1.8–2.4) months. In patients who discontinued treatment due to disease progression, the median progression-free duration was 2.8 (95% CI: 2.4–2.9) months.

Conclusions

The results highlight the number of treatment pathways used to treat mCRC in routine UK clinical practice prior to the marketing authorisation and National Institute for Health and Care Excellence approval of trifluridine/tipiracil and highlight the lack of clinical guidelines for mCRC.

Gastric Immune Prognostic Index (GIPI) in metastatic (m) gastro-oesophageal junction (GOJ)/gastric cancer (GC) patients (pts) treated with PD-1/PD-L1 immune checkpoint inhibitors (ICIs)

417

Background: ICIs demonstrated improved overall survival (OS) in heavily pre-treated mGOJ/GC pts. Pts selection exclusively based on PD-L1 tissue expression appears to be suboptimal, despite data from subgroup analyses of KEYNOTE trials. Strong rationale suggests a potential predictive role of inflammatory biomarkers in ICIs treated mGOJ/GC pts. Methods: 11 systemic inflammatory markers [platelets, monocytes, neutrophil/lymphocyte ratio (NLR), platelets-lymphocyte ratio, lymphocytes, sum of mononuclear cells, albumin, lactate dehydrogenase, alkaline phosphatase (ALP), c-reactive protein (CRP) and serum globulin] were retrospectively analyzed at baseline in 57 mGOJ/GC pts with unknown PD-L1 status treated in second-line with ICIs, and correlated with OS. Least Absolute Shrinkage and Selection Operator (LASSO) method was used to select variables (preliminarily subject to optimal coding using HR smoothed curves for OS) with the highest prognostic value.Selected variables were then analysed in a multivariate Cox Regression Model and used to build a GIPI nomogram. Results: NLR and CRP taken as continuous variables and ALP categorized as < vs > 150 IU/L were found as the most meaningful independent predictors of OS [(HR 1.30 (95%CI 1.02-1.65), 2.00 (95%CI 1.09-3.66), 2.82 (95%CI 1.29-6.20) and p values 0.04, 0.01, 0.02, respectively)] and used to build the GIPI nomogram. Nomogram-based lowest(l), mid and highest(h) risk tertiles were associated with median(m)OS of 14.5,10.6 and 2.4 months(mos), respectively [HR of l vs h 0.26 (95%CI 0.12-0.53), p 0.0002]. By optimally dichotomizing CRP and NLR, pts with one or more of the following risk factors: NLR > 6, CRP > 15 mg/L, ALP < 150 IU/L (n: 31) had a mOS of 3.9mos vs 14.5mos of pts with no risk factor (n: 26) (HR 2.72, p 0.0005). Conclusions: GIPI, combining NLR, CRP and ALP, is the first inflammatory index with a significant prognostic value in mOGJ/GC pts receiving second line ICIs. Its implementation with analysis of PD-L1 expression in the present cohort is ongoing. GIPI merits validation in external cohorts and prospective clinical trials.

A phase II, open-label, randomized study to evaluate the efficacy and safety of andecaliximab combined with nivolumab versus nivolumab alone in subjects with unresectable or recurrent gastric or gastroesophageal junction adenocarcinoma

75

Background: Andecaliximab (ADX) is a monoclonal antibody that inhibits matrix metalloproteinase 9 (MMP9). Preclinical studies suggest that MMP9 inhibition relieves immune suppression and promotes T-cell infiltration to potentiate checkpoint blockade. Methods: Phase 2, open-label, randomized study of the efficacy and safety of ADX + nivolumab (NIVO) vs. NIVO alone in patients with pre-treated metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma. Patients were randomized to either ADX 800 mg IV + NIVO 3 mg/kg IV, or NIVO 3 mg/kg IV alone, and stratified by tumor PD-L1 status. Treatment was administered every 2 weeks. Re-staging CT scans were performed every 8 weeks to evaluate response. Primary endpoint: objective response rate (ORR). Secondary endpoints: progression-free survival (PFS), overall survival (OS), and adverse events (AEs). Results: Of the 144 patients randomized, 141 were treated, 109 (76%) completed tumor assessment. 81% of patients were white, with 69% male and a mean (SD) age of 59 (12) years. ORR (95% CI) was 11.1% (4.9–20.7%) in patients receiving ADX + NIVO, and 6.9% (2.3–15.5%) in those receiving NIVO alone, p = 0.6. Kaplan-Meier estimated median (95% CI) PFS was 1.8 (1.8–2.0) months in patients receiving ADX + NIVO, and 1.9 (1.7–1.9) months in those receiving NIVO alone, p = 0.2. Kaplan-Meier estimated median (95% CI) OS was 7.2 (5.2–9.1) months in patients receiving ADX + NIVO, and 5.9 (3.5–8.6) months in those receiving NIVO alone, p = 0.4. AEs leading to treatment discontinuation occurred in 1 patient in the ADX + NIVO group, and in 1 patient in NIVO-only group. PD-L1 and mismatch repair deficient subgroup analyses will be presented. Exploratory biomarker analyses will be submitted separately. Conclusions: Addition of ADX to NIVO did not improve ORR, PFS, or OS compared with NIVO alone in patients with pre-treated metastatic gastric or GEJ adenocarcinoma. Combination of ADX with NIVO had a favorable safety and tolerability profile. Clinical trial information: NCT02864381.

FOCUS4: A prospective molecularly stratified, adaptive multicenter program of randomized controlled trials for patients with colorectal cancer (CRC)

TPS3645

Background: Targeted therapies based on somatic gene mutations or activated pathways have inhibited progression of some cancers. However, although various targets are identifiable in CRC, KRAS mutation is currently the only validated predictive biomarker for selection of a targeted therapy. FOCUS4 is a rolling phase II-III trial for testing in a staged way both the utility of molecular stratification and the efficacy of novel agents in subpopulations of mCRC patients. It is also a trial of a new strategy for testing stratified approaches to therapy in any biologically complex tumour type using a Multi-Arm, Multi-Stage design. Methods: The study population consists of subjects with newly diagnosed inoperable mCRC. Subjects receive first-line chemotherapy for 16 weeks. During this time the tumour is tested for BRAF/PIK3CA/KRAS/NRAS mutations and PTEN loss. Subjects with responding or stable disease on CT, who would normally be candidates for a treatment break, are then randomised to four coherent biomarker-based subgroups: FOCUS4-A: BRAF mutant, FOCUS4-B: PIK3CA mutant or complete loss of PTEN on IHC, FOCUS4-C: KRAS or NRAS mutant, FOCUS4-D: All wild type (no mutations of BRAF, PIK3CA, KRAS or NRAS). For each subgroup, a relevant novel agent or combination is to be tested in an adaptive double-blind placebo controlled randomised trial design with multiple interim analyses for early termination if there is no strong evidence of worthwhile activity. There will also be a 5thsubgroup FOCUS4-N testing maintenance capecitabine for unclassifiable tumours or for patients whose marker defined cohort is temporarily suspended. The primary endpoint is progression free survival. Promising results in any biomarker defined cohort will then be tested for response in cohorts without the biomarker. Within the overall trial, biomarker developments can be accommodated with changes in the distribution of the cohorts or testing of new targeted agents. Enrolment will commence in May 2013. Upto 3400 patients will be registered over a 4-5 year period depending on which cohorts pass their staged interim analyses and proceed to later stages, including an overall survival endpoint. Clinical trial information: 2012-005111-12.

Functional characterization of the 19q12 amplicon in grade III breast cancers

INTRODUCTION

The 19q12 locus is amplified in a subgroup of oestrogen receptor (ER)-negative grade III breast cancers. This amplicon comprises nine genes, including cyclin E1 (CCNE1), which has been proposed as its 'driver'. The aim of this study was to identify the genes within the 19q12 amplicon whose expression is required for the survival of cancer cells harbouring their amplification.

METHODS

We investigated the presence of 19q12 amplification in a series of 313 frozen primary breast cancers and 56 breast cancer cell lines using microarray comparative genomic hybridisation (aCGH). The nine genes mapping to the smallest region of amplification on 19q12 were silenced using RNA interference in phenotypically matched breast cancer cell lines with (MDA-MB-157 and HCC1569) and without (Hs578T, MCF7, MDA-MB-231, ZR75.1, JIMT1 and BT474) amplification of this locus. Genes whose silencing was selectively lethal in amplified cells were taken forward for further validation. The effects of cyclin-dependent kinase 2 (CDK2) silencing and chemical inhibition were tested in cancer cells with and without CCNE1 amplification.

RESULTS

19q12 amplification was identified in 7.8% of ER-negative grade III breast cancer. Of the nine genes mapping to this amplicon, UQCRFS1, POP4, PLEKHF1, C19ORF12, CCNE1 and C19ORF2 were significantly over-expressed when amplified in primary breast cancers and/or breast cancer cell lines. Silencing of POP4, PLEKHF1, CCNE1 and TSZH3 selectively reduced cell viability in cancer cells harbouring their amplification. Cancer cells with CCNE1 amplification were shown to be dependent on CDK2 expression and kinase activity for their survival.

CONCLUSIONS

The 19q12 amplicon may harbour more than a single 'driver', given that expression of POP4, PLEKHF1, CCNE1 and TSZH3 is required for the survival of cancer cells displaying their amplification. The observation that cancer cells harbouring CCNE1 gene amplification are sensitive to CDK2 inhibitors provides a rationale for the testing of these chemical inhibitors in a subgroup of patients with ER-negative grade III breast cancers.

Adenoid cystic carcinomas constitute a genomically distinct subgroup of triple-negative and basal-like breast cancers

Adenoid cystic carcinoma (AdCC) is a rare form of triple-negative and basal-like breast cancer that has an indolent clinical behaviour. Four breast AdCCs were recently shown to harbour the recurrent chromosomal translocation t(6;9)(q22-23;p23-24), which leads to the formation of the MYB-NFIB fusion gene. Our aims were (i) to determine the prevalence of the MYB-NFIB fusion gene in AdCCs of the breast; (ii) to characterize the gene copy number aberrations found in AdCCs; and (iii) to determine whether AdCCs are genomically distinct from histological grade-matched or triple-negative and basal-like invasive ductal carcinomas of no special type (IDC-NSTs). The presence of the MYB-NFIB fusion gene was investigated in 13 AdCCs of the breast by fluorescence in situ hybridization (FISH) and reverse transcriptase-PCR (RT-PCR), and MYB and BRCA1 RNA expression was determined by quantitative RT-PCR. Fourteen AdCCs, 14 histological grade-matched IDC-NSTs, and 14 IDC-NSTs of triple-negative and basal-like phenotype were microdissected and subjected to high-resolution microarray-based comparative genomic hybridization (aCGH). The MYB-NFIB fusion gene was detected in all but one AdCC. aCGH analysis demonstrated a relatively low number of copy number aberrations and a lack of recurrent amplifications in breast AdCCs. Contrary to grade-matched IDC-NSTs, AdCCs lacked 1q gains and 16q losses, and in contrast with basal-like IDC-NSTs, AdCCs displayed fewer gene copy number aberrations and expressed MYB and BRCA1 at significantly higher levels. Breast AdCCs constitute an entity distinct from grade-matched and triple-negative and basal-like IDC-NSTs, emphasizing the importance of histological subtyping of triple-negative and basal-like breast carcinomas.

Functional viability profiles of breast cancer

The design of targeted therapeutic strategies for cancer has largely been driven by the identification of tumor-specific genetic changes. However, the large number of genetic alterations present in tumor cells means that it is difficult to discriminate between genes that are critical for maintaining the disease state and those that are merely coincidental. Even when critical genes can be identified, directly targeting these is often challenging, meaning that alternative strategies such as exploiting synthetic lethality may be beneficial. To address these issues, we have carried out a functional genetic screen in >30 commonly used models of breast cancer to identify genes critical to the growth of specific breast cancer subtypes. In particular, we describe potential new therapeutic targets for PTEN-mutated cancers and for estrogen receptor-positive breast cancers. We also show that large-scale functional profiling allows the classification of breast cancers into subgroups distinct from established subtypes.

SIGNIFICANCE

Despite the wealth of molecular profiling data that describe breast tumors and breast tumor cell models, our understanding of the fundamental genetic dependencies in this disease is relatively poor. Using high-throughput RNA interference screening of a series of pharmacologically tractable genes, we have generated comprehensive functional viability profiles for a wide panel of commonly used breast tumor cell models. Analysis of these profiles identifies a series of novel genetic dependencies, including that of PTEN-null breast tumor cells upon mitotic checkpoint kinases, and provides a framework upon which additional dependencies and candidate therapeutic targets may be identified.

Abstract 4987: Identification of novel genes and pathways involved in resistance to HER2-targeting agents in breast cancer

The HER2 gene ERBB2 is amplified and/ or overexpressed in up to 15% of all invasive breast cancers. These cancers are characterised by an aggressive phenotype and poor clinical outcome. HER2 positive tumours often display multiple high level amplifications of genes in addition to HER2. Although targeted therapies to HER2 have proven clinical benefit, a substantial number of patients have tumours that are either de novo resistant or acquire resistance over time to these agents. Reasons for this are still largely unknown. By using a high throughput siRNA screen we sought to determine whether genes recurrently amplified and overexpressed in HER2-amplified breast cancer mediate resistance to HER2-targeting agents. We profiled 45 HER2-amplified primary breast cancers and 13 HER2-amplified cell lines with high resolution microarray-based comparative genomic hybridisation (aCGH) and Illumina WG6 v2 arrays. Overlaying of aCGH and gene expression data led to the identification of 369 genes recurrently amplified and overexpressed when amplified. Lapatinib-resistant HER2-amplified breast cancer cell lines were treated with lapatinib, a HER2 small molecule inhibitor, and screened with an RNA interference (RNAi) library targeting these 369 genes and controls. This RNAi screen and subsequent validation screens identified eight genes that when silenced lead to a significant sensitization to lapatinib. The mechanisms of resistance conferred by the identified genes were further investigated and pointed to the involvement of NF-kappaB-signalling, Wnt-signalling and reactive oxygen species scavenging. Our results indicate that specific amplified and overexpressed genes found in HER2 positive breast cancers mediate resistance to anti-HER2 agents. These findings might be used to identify patients likely to be de novo resistant to lapatinib and provide new targets for combined targeted therapies to overcome resistance to anti-HER2 therapies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4987. doi:10.1158/1538-7445.AM2011-4987

Abstract 3039: Identification of a novel biomarker of resistance to lapatinib common to both breast and oesophagogastric cancer

HER2 is amplified and/or overexpressed in 15% and 20% of breast and oesophagogastric (OG) cancers, respectively. Results from the recently published ToGA trial reveal that trastuzumab plus standard chemotherapy improves survival in patients with advanced HER2-positive OG cancer compared with chemotherapy alone, which mirrors the survival benefit shown with trastuzumab plus chemotherapy in metastatic breast cancer. The clinical value of lapatinib, already confirmed in advanced trastuzumab-resistant breast cancer, is currently being evaluated in prospective phase III trials for HER2-positive OG cancer in the metastatic setting. Despite improvements in outcome with anti-HER2 therapy, less than half of patients respond to treatment, and predictive biomarkers to lapatinib for breast and OG cancer have not yet been identified.

We sought to identify predictive biomarkers of resistance to lapatinib treatment, common to both breast and OG cancer, by using a siRNA screen of genes identified in a primary siRNA screen to sensitise lapatinib-resistant breast cancer cell lines to lapatinib. These genes are found recurrently amplified and overexpressed in 45 HER2-amplified primary breast cancers and 13 HER2-amplified breast cancer cell lines. OG junction cell lines were treated with lapatinib and screened using the siRNA library. We found that silencing of TP53INP1, a gene target of TP53 which is known to be a reactive oxygen species scavenger, resulted in significant sensitisation to lapatinib in two of the most lapatinib-resistant HER2-positive cell lines derived from the OG junction. TP53INP1 was over-expressed, but not amplified, in the sensitised OG junction cell lines.

Our results suggest that genes which mediate resistance to anti-HER2 therapy in breast cancer may be relevant to OG cancer. We are currently developing assays for TP53INP1 in tumours for validation within the context of prospective randomised controlled clinical trials for OG cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3039. doi:10.1158/1538-7445.AM2011-3039

DNA amplifications in breast cancer: genotypic-phenotypic correlations

DNA copy number changes in cancer cells, in particular, amplifications, occur frequently, have prognostic impact and are associated with subtypes of breast cancer. Some amplicons contain well-characterized oncogenes, including 11q13 (CCND1) and 17q12 (HER2). HER2 amplification and overexpression defines the HER2+ subgroup of breast cancer patients and is both a prognostic marker for poor outcome and a predictive marker for response to anti-HER2 targeted therapies. Therefore, there is considerable interest in documenting the locations of other recurring amplifications in breast cancers as they may also provide a rich source of new biomarkers and novel therapeutic targets for these subgroups. This article focuses on the genomic profiling of breast cancer, with an emphasis on the characteristics of the amplifications found in subtypes of breast cancer, including luminal (ER+)/HER2(-)), HER2+ and basal-like (ER(-)/HER2(-)), and discusses their known or potential roles in cancer biology and their clinical implications.

Loss of 16q in high grade breast cancer is associated with estrogen receptor status: Evidence for progression in tumors with a luminal phenotype?

Loss of the long arm of chromosome 16 (16q) is observed in the vast majority of low grade/grade I (GI) invasive ductal carcinomas of no special type (IDC-NSTs), whereas this event is uncommonly seen in high grade/grade III (GIII) IDC-NSTs. Together with data on the pathology and genetics of breast cancer recurrences, this has led to the proposal that GI and GIII breast cancers evolve through distinct genetic pathways and that progression from GI to GIII is an unlikely biological phenomenon. We compared the genomic profiles of GIII-IDC-NSTs with 16q whole arm loss (16qWL) according to estrogen receptor (ER) status. 16qWL was found in 36.5% of cases and was significantly associated with ER expression and luminal phenotype. ER+ GIII-IDC-NSTs with 16qWL displayed significantly higher levels of genomic instability than ER+ IDC-NSTs without 16qWL. Furthermore, ER+ and ER- IDC-NSTs stratified according to the presence of 16qWL harbored distinct patterns of genetic aberrations. Interestingly, ER+/16qWL tumors displayed genetic features usually found in tumors with homologous DNA repair defects and significantly more frequently harbored heterozygous loss of BRCA2 than the remaining ER+ cancers. Our results demonstrate that approximately one third of GIII tumors harbor 16qWL, confirming that progression from low to high grade breast cancer is not found in the majority of breast cancers. 16qWL was significantly more prevalent in ER+/luminal GIII-IDC-NSTs. Given that GI breast cancers harbor a luminal phenotype, our results suggest that if progression from GI to GIII breast cancer does happen, it may preferentially occur in breast cancers of luminal phenotype.

Development of therapeutic approaches to 'triple negative' phenotype breast cancer

BACKGROUND

Triple negative phenotype (TNP) breast cancers are characterised by the lack of expression of oestrogen and progesterone receptors and of human EGF receptor 2 (HER2) overexpression/amplification. This subgroup of cancers has an aggressive clinical behaviour and is associated with poorer overall survival compared with other subtypes. Given the lack of targets for current tailored therapies in TNP tumours, chemotherapy is the only systemic treatment available; however, overall outcomes remain poor. Therefore, optimal treatment regimens and targeted therapies are urgently needed.

OBJECTIVE

We discuss characteristics of TNP cancers that underpin the rationale of current and novel therapeutic strategies, and an approach for finding and validating new therapeutic targets.

RESULTS/CONCLUSION

The results of large prospective randomised controlled trials are currently awaited. Efforts to unravel the heterogeneity and complexity of TNP cancers using the latest high-throughput molecular techniques and integrating these findings with biology-driven therapeutic strategies in clinical trials will be of paramount importance for the development of treatment approaches for this breast cancer subtype.