Best Practices for Managing Patients with Unresectable Metastatic Gastric and Gastroesophageal Junction Cancer in Canada

Gastric cancer (GC) is one of the most common types of cancer and is associated with relatively low survival rates. Despite its considerable burden, there is limited guidance for Canadian clinicians on the management of unresectable metastatic GC and gastroesophageal junction cancer (GEJC). Therefore, we aimed to discuss best practices and provide expert recommendations for patient management within the current Canadian unresectable GC and GEJC landscape. A multidisciplinary group of Canadian healthcare practitioners was assembled to develop expert recommendations via a working group. The often-rapid progression of unresectable GC and GEJC and the associated malnutrition have a significant impact on the patient's quality of life and ability to tolerate treatment. Hence, recommendations include early diagnosis, identification of relevant biomarkers to improve personalized treatment, and relevant support to manage comorbidities. A multidisciplinary approach including early access to registered dietitians, personal support networks, and palliative care services, is needed to optimize possible outcomes for patients. Where possible, patients with unresectable GC and GEJC would benefit from access to clinical trials and innovative treatments.

Pembrolizumab Plus Binimetinib With or Without Chemotherapy for MSS/pMMR Metastatic Colorectal Cancer: Outcomes From KEYNOTE-651 Cohorts A, C, and E

BACKGROUND

Cohorts A, C, and E of the phase Ib KEYNOTE-651 study evaluated pembrolizumab + binimetinib ± chemotherapy in microsatellite stable/mismatch repair-proficient metastatic colorectal cancer.

PATIENTS AND METHODS

Patients received pembrolizumab 200 mg every 3 weeks plus binimetinib 30 mg twice daily alone (cohort A; previously treated with any chemotherapy) or with 5-fluorouracil, leucovorin, oxaliplatin (cohort C; previously untreated) or 5-fluorouracil, leucovorin, irinotecan (cohort E; previously treated with 1 line of therapy including fluoropyrimidine + oxaliplatin-based regimen) every 2 weeks. Binimetinib dose-escalation to 45 mg twice daily was planned in all cohorts using a modified toxicity probability interval design (target dose-limiting toxicity [DLT], 30%). The primary endpoint was safety; investigator-assessed objective response rate was secondary.

RESULTS

In cohort A, 1/6 patients (17%) had DLTs with binimetinib 30 mg; none occurred in 14 patients with 45 mg. In cohort C, 3/9 patients (33%) had DLTs with binimetinib 30 mg; dose was not escalated to 45 mg. In cohort E, 1/5 patients (20%) had DLTs with binimetinib 30 mg; 5/10 patients (50%) had DLTs with 45 mg. Enrollment was stopped in cohort E binimetinib 45 mg and deescalated to 30 mg; 2/4 additional patients (50%) had DLTs with binimetinib 30 mg (total 3/9 [33%] had DLTs with binimetinib 30 mg). Objective response rate was 0% in cohort A, 9% in cohort C, and 15% in cohort E.

CONCLUSION

Per DLT criteria, binimetinib + pembrolizumab (cohort A) was tolerable, binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, oxaliplatin (cohort C) did not qualify for binimetinib dose escalation to 45 mg, and binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, irinotecan (cohort E) required binimetinib dose reduction from 45 to 30 mg. No new safety findings were observed across cohorts. There was no apparent additive efficacy when binimetinib + pembrolizumab was added to chemotherapy. Data did not support continued enrollment in cohorts C and E.

Pembrolizumab Plus mFOLFOX7 or FOLFIRI for Microsatellite Stable/Mismatch Repair-Proficient Metastatic Colorectal Cancer: KEYNOTE-651 Cohorts B and D

BACKGROUND

The phase 1b KEYNOTE-651 study evaluated pembrolizumab plus chemotherapy in microsatellite stable or mismatch repair-proficient metastatic colorectal cancer.

PATIENTS AND METHODS

Patients with microsatellite stable or mismatch repair-proficient metastatic colorectal cancer received pembrolizumab 200 mg every 3 weeks plus 5-fluorouracil, leucovorin, oxaliplatin (previously untreated; cohort B) or 5-fluorouracil, leucovorin, irinotecan (previously treated with fluoropyrimidine plus oxaliplatin; cohort D) every 2 weeks. Primary end point was safety; investigator-assessed objective response rate per RECIST v1.1 was secondary and biomarker analysis was exploratory.

RESULTS

Thirty-one patients were enrolled in cohort B and 32 in cohort D; median follow-up was 30.2 and 33.5 months, respectively. One dose-limiting toxicity (grade 3 small intestine obstruction) occurred in cohort D. In cohort B, grade 3 or 4 treatment-related adverse events (AEs) occurred in 18 patients (58%), most commonly neutropenia and decreased neutrophil count (n = 5 each). In cohort D, grade 3 or 4 treatment-related AEs occurred in 17 patients (53%), most commonly neutropenia (n = 7). No grade 5 treatment-related AEs occurred. Objective response rate was 61% in cohort B (KRAS wildtype: 71%; KRAS mutant: 53%) and 25% in cohort D (KRAS wildtype: 47%; KRAS mutant: 6%). In both cohorts, PD-L1 combined positive score and T-cell-inflamed gene expression profiles were higher and HER2 expression was lower in responders than nonresponders. No association between tumor mutational burden and response was observed.

CONCLUSION

Pembrolizumab plus 5-fluorouracil, leucovorin, oxaliplatin/5-fluorouracil, leucovorin, irinotecan demonstrated an acceptable AE profile. Efficacy data appeared comparable with current standard of care (including by KRAS mutation status). Biomarker analyses were hypothesis-generating, warranting further exploration.

CLINICALTRIALS

GOV IDENTIFIER

ClinicalTrials.gov; NCT03374254.

First-Line Nivolumab Plus Chemotherapy for Advanced Gastric, Gastroesophageal Junction, and Esophageal Adenocarcinoma: 3-Year Follow-Up of the Phase III CheckMate 649 Trial

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We report 3-year efficacy and safety results from the phase III CheckMate 649 trial. Patients with previously untreated advanced or metastatic gastroesophageal adenocarcinoma were randomly assigned to nivolumab plus chemotherapy or chemotherapy. Primary end points were overall survival (OS) and progression-free survival (PFS) by blinded independent central review (BICR) in patients whose tumors expressed PD-L1 combined positive score (CPS) ≥5. With 36.2-month minimum follow-up, for patients with PD-L1 CPS ≥5, the OS hazard ratio (HR) for nivolumab plus chemotherapy versus chemotherapy was 0.70 (95% CI, 0.61 to 0.81); 21% versus 10% of patients were alive at 36 months, respectively; the PFS HR was 0.70 (95% CI, 0.60 to 0.81); 36-month PFS rates were 13% versus 8%, respectively. The objective response rate (ORR) per BICR was 60% (95% CI, 55 to 65) with nivolumab plus chemotherapy versus 45% (95% CI, 40 to 50) with chemotherapy; median duration of response was 9.6 months (95% CI, 8.2 to 12.4) versus 7.0 months (95% CI, 5.6 to 7.9), respectively. Nivolumab plus chemotherapy also continued to show improvement in OS, PFS, and ORR versus chemotherapy in the overall population. Adding nivolumab to chemotherapy maintained clinically meaningful long-term survival benefit versus chemotherapy alone, with an acceptable safety profile, supporting the continued use of nivolumab plus chemotherapy as standard first-line treatment for advanced gastroesophageal adenocarcinoma.

A Phase II Exploratory Study to Identify Biomarkers Predictive of Clinical Response to Regorafenib in Patients with Metastatic Colorectal Cancer Who Have Failed First-Line Therapy

Single-agent regorafenib is approved in Canada for metastatic colorectal cancer (mCRC) patients who have failed previous lines of therapy. Identifying prognostic biomarkers is key to optimizing therapeutic strategies for these patients. In this clinical study (NCT01949194), we evaluated the safety and efficacy of single-agent regorafenib as a second-line therapy for mCRC patients who received it after failing first-line therapy with an oxaliplatin or irinotecan regimen with or without bevacizumab. Using various omics approaches, we also investigated putative biomarkers of response and resistance to regorafenib in metastatic lesions and blood samples in the same cohort. Overall, the safety profile of regorafenib seemed similar to the CORRECT trial, where regorafenib was administered as ≥ 2 lines of therapy. While the mutational landscape showed typical mutation rates for the top five driver genes (APC, KRAS, BRAF, PIK3CA, and TP53), KRAS mutations were enriched in intrinsically resistant lesions. Additional exploration of genomic-phenotype associations revealed several biomarker candidates linked to unfavorable prognoses in patients with mCRC using various approaches, including pathway analysis, cfDNA profiling, and copy number analysis. However, further research endeavors are necessary to validate the potential utility of these promising genes in understanding patients' responses to regorafenib treatment.

Current and Emerging Role of Monoclonal Antibody-Based First-Line Treatment in Advanced Gastro-Esophageal and Gastric Cancer

Gastric cancer is the fifth most common malignancy worldwide and one of the main causes of cancer-related death. While surgical treatment is the only curative option for early disease, many have inoperable or advanced disease at diagnosis. Treatment in this case would be a combination of chemotherapy and immunotherapy. Gastro-esophageal (GEJ) and gastric cancer (GC) genetic profiling with current molecular diagnostic techniques has significantly changed the therapeutic landscape in advanced cancers. The identification of key players in GEJ and GC survival and proliferation, such as human epidermal growth factor 2 (HER2), vascular endothelial growth factor (VEGF), and programmed cell death protein 1 (PD-1)/programmed cell death ligand-1 (PD-L1), has allowed for the individualization of advanced cancer treatment and significant improvement in overall survival and progression-free survival of patients. This review comprehensively examines the current and emerging role of monoclonal antibody-based first-line treatments in advanced GEJ and GC. We explore the impact of monoclonal antibodies targeting HER2, VEGF, PD-1/PD-L1, and Claudin 18.2 (CLDN18.2) on the first-line treatment landscape by talking about key clinical trials. This review emphasizes the importance of biomarker testing for optimal treatment selection and provides practical recommendations based on ASCO guidelines.

The prognostic impact of KRAS, TP53, STK11 and KEAP1 mutations and their influence on the NLR in NSCLC patients treated with immunotherapy

BACKGROUND

PD-L1 expression is used to predict NSCLC response to ICIs, but its performance is suboptimal. The impact of KRAS mutations in these patients is unclear. Studies evaluating co-mutations in TP53, STK11 and KEAP1 as well as the NLR showed that they may predict the benefit of ICIs.

PATIENTS & METHODS

This is a retrospective study of patients with NSCLC treated with ICIs at the CHUM between July 2015 and June 2020. OS and PFS were compared using Kaplan-Meier and logrank methods. Co-mutations in TP53, STK11 and KEAP1 as well as the NLR were accounted for. ORR and safety were compared using Wald method.

RESULTS

From 100 patients with known KRAS status, 50 were mutated (KRASMut). Mutation in TP53, STK11 and KEAP1 were present, and their status known in, respectively, 19/40 (47.5 %), 8/39 (20.5 %) and 4/38 (10.5 %) patients. STK11Mut and KEAP1Mut were associated with shorter overall survival when compared with wild type tumors (respectively median OS of 3.3 vs 20.4, p = 0.0001 and 10.1 vs 17.7, p = 0.24). When KRAS status was compounded with STK11/KEAP1, KRASMut trended to a better prognosis in STK11+KEAP1WT tumors (median OS 21.1 vs 15.8 for KRASWT, p = 0.15), but not for STK11+/-KEAP1Mut tumors. The NLR was strongly impacted by STK11 (6.0Mutvs 3.6WT, p = 0.014) and TP53 (3.2Mutvs 4.8WT, p = 0.048), but not by KEAP1 or KRAS mutations.

CONCLUSION

STK11Mut and KEAP1Mut are adverse predictors of ICI therapy benefit. The NLR is strongly impacted by STK11Mut but not by KEAP1Mut, suggesting differences in their resistance mechanism. In STK11-KEAP1WT tumors, KRASMut seem associated with improved survival in NSCLC patients treated with ICIs.

MICROABSTRACT

Response of NSCLC to immunotherapy is not easily predictable. We conducted a retrospective study in 100 patients with NSCLC and a known KRAS status. By accounting for different co-mutations, KRAS mutation was found to be associated with a better median overall survival in STK11 and KEAP1 wild-type tumors (21.1 vs 15.8, p = 0.15). NLR was impacted by STK11, but not KEAP1 mutation, suggesting a difference in their resistance mechanism.

Systemic inflammatory prognostic scores in advanced pancreatic adenocarcinoma

BACKGROUND

Systemic inflammatory scores may aid prognostication and patient selection for trials. We compared five scores in advanced pancreatic adenocarcinoma (PDAC).

METHODS

Unresectable/metastatic PDAC patients enrolled in the Comprehensive Molecular Characterisation of Advanced Pancreatic Ductal Adenocarcinoma for Better Treatment Selection trial (NCT02750657) were included. Patients had pre-treatment biopsies for whole genome and RNA sequencing. CD8 immunohistochemistry was available in a subset. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, Prognostic Nutritional Index, Gustave Roussy Immune Score (GRIm-S), and Memorial Sloan Kettering Prognostic Score (MPS) were calculated. Overall survival (OS) was estimated using Kaplan-Meier methods. Associations between inflammatory scores, clinical/genomic characteristics, and OS were analysed.

RESULTS

We analysed 263 patients. High-risk NLR, GRIm-S and MPS were poorly prognostic. The GRIm-S had the highest predictive ability: median OS 6.4 vs. 10 months for high risk vs. low-risk (P < 0.001); HR 2.26 (P < 0.001). ECOG ≥ 1, the basal-like subtype, and low-HRDetect were additional poor prognostic factors (P < 0.01). Inflammatory scores did not associate with RNA-based classifiers or homologous recombination repair deficiency genotypes. High-risk MPS (P = 0.04) and GRIm-S (P = 0.02) patients had lower median CD8 + tumour-infiltrating lymphocytes.

CONCLUSIONS

Inflammatory scores incorporating NLR have prognostic value in advanced PDAC. Understanding immunophenotypes of poor-risk patients and using these scores in trials will advance the field.

A plain language summary of the CheckMate 649 study: nivolumab in combination with chemotherapy compared to chemotherapy alone for untreated advanced or metastatic cancer of the stomach or esophagus

WHAT IS THIS SUMMARY ABOUT?

This is a summary of the 1-year results of a clinical research study known as CheckMate 649 published in The Lancet in June 2021. The 2-year results on the participants' health and overall quality of life from the same study are in a second publication in Nature in March 2022. Until recently, chemotherapy was the only first treatment option for people with advanced or metastatic gastroesophageal adenocarcinoma who had not been treated before. Patients receiving chemotherapy lived on average for less than 1 year. Nivolumab is an immunotherapy that works by activating a person's immune system to fight back against cancer cells. The goal of CheckMate 649 was to find out if the combination of nivolumab and chemotherapy would help patients with advanced or metastatic gastroesophageal adenocarcinoma live longer and without their cancer getting worse.

WHAT WERE THE RESULTS?

Results from the final analysis are reported here. Of 1581 people who took part in the study, 789 received nivolumab and chemotherapy and 792 received chemotherapy. Researchers found that, on average, participants who received nivolumab and chemotherapy lived longer overall than those who received chemotherapy alone. The length of time participants lived without their cancer getting worse was also longer on average with nivolumab and chemotherapy than chemotherapy treatment alone. However, more participants in the nivolumab and chemotherapy group had side effects than those in the chemotherapy group. The three most common side effects in both types of treatment were nausea (urge to vomit), diarrhea and peripheral neuropathy. Participants who received nivolumab and chemotherapy had a lower risk of their cancer symptoms worsening and reported that they were 'less bothered' from side effects of treatment than those receiving chemotherapy alone.

WHAT DO THE RESULTS MEAN?

The nivolumab and chemotherapy combination is considered a new standard treatment option and is approved in several countries as a treatment for adults who have not been treated before for their advanced or metastatic gastroesophageal cancer based on results from CheckMate 649. Clinical Trial Registration: NCT02872116 (ClinicalTrials.gov).

Phase 2 multicenter trial combining nivolumab and radiosurgery for NSCLC and RCC brain metastases

Background

Anti-PD-1 has activity in brain metastases (BM). This phase 2 open labeled non-randomized single arm trial examined the safety and efficacy of combining nivolumab with radiosurgery (SRS) in the treatment of patients with BM from non-small cell lung cancer (NSCLC) and renal cell carcinoma (RCC).

Methods

This was a multicenter trial (NCT02978404) in which patients diagnosed with NSCLC or RCC, having ≤ 10 cc of un-irradiated BM and no prior immunotherapy were eligible. Nivolumab (240mg or 480mg IV) was administered for up to 2 years until progression. SRS (15-21Gy) to all un-irradiated BM was delivered within 14 days after the first dose of nivolumab. The primary endpoint was intracranial progression free survival (iPFS).

Results

Twenty-six patients (22 NSCLC and 4 RCC) were enrolled between August 2017 and January 2020. A median of 3 (1-9) BM were treated with SRS. Median follow-up was 16.0 months (0.43-25.9 months). Two patients developed nivolumab and SRS related grade 3 fatigue. One-year iPFS and OS were 45.2% (95%CI 29.3-69.6%) and 61.3% (95%CI 45.1%-83.3%), respectively. Overall response (partial or complete) of SRS treated BM was attained in 14 out of the 20 patients with ≥1 evaluable follow-up MRI. Mean FACT-Br total scores were 90.2 at baseline and improved to 146.2 within 2-4 months (p = 0.0007).

Conclusions

The adverse event profile and FACT-Br assessments suggested that SRS during nivolumab was well tolerated. Upfront SRS with the initiation of anti-PD-1 prolonged the 1-year iPFS and achieved high intracranial control. This combined approach merits validation randomized studies.

Use of positron emission tomography-computed tomography (PET-CT) scan in patients with gastrointestinal (GI) cancer at the University Hospital of Montreal (CHUM)

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Background: In the province of Quebec, Canada, PET-CT scan recommendations are published by the Institut national d’excellence en santé et en services sociaux (INESSS). These recommendations are based on evidence-based literature and publications from oncology societies (ASCO, NCCN...) Judicious use of PET-CT scans is particularly important in a public health system for appropriate allocation of resources. An analysis conducted by INESSS in 2017 demonstrated a remarkable use of 507 PET-CT scans per 100,000 persons in Quebec, an incidence more than twice as high as other provinces, and equivalent to that of the United States (510 per 100,000 person). Methods: We present a retrospective quality control study in which all PET-CT scans completed for oncologic purposes for patients of 18 years or older at CHUM between September 1st and November 30th, 2019, were included. Patients who had a PET-CT scan for non-oncologic purposes or weren’t followed at the CHUM were excluded. We reviewed disease characteristics of patients, and adherence to 2017 INESSS guidelines. All cancer types were analysed and classified according to imaging reason (staging, response to treatment, follow up). We herein report the use of PET-CT in GI cancers and how it compares to INESSS recommendation . Results: A total of 2331 PET-CT scans were completed in the studied period. Among them 975 PET-CT scans fit our inclusion criteria. 155 patients (16%) underwent PET-CT scans for GI cancers. Only 35% followed INESSS recommendations, 44% did not, and 21% had GI cancer types without revised clear recommendations from INESSS. Among specialists, surgeons requested most PET-CT scans (66%), but surgeons, oncologists, and gastroenterologist were equally non-adherent to guidelines (44, 45, and 43% respectively). Strikingly, 43% of PET-CT scans for GI cancers were prescribed for cancer follow up, yet 83% did not follow guidelines. Most PET-CT scans were used for colorectal (41%) or gastroesophageal cancers (28%), and only 40 and 53% followed guidelines, respectively. 49.7% of PET-CT scans did not result in treatment modification. Conclusions: In our university hospital, more than 40% of PET-CT scans prescribed don’t follow INESSS recommendations. In the interest of proper resource allocation in a public health care system, we recommend guideline adherence and discussion in multidisciplinary Tumour Boards prior to off-label use of PET-CT scans.

Reflex testing for RAS and BRAF mutations in metastatic colorectal cancer: A single Canadian academic oncology center experience

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Background: Patients with left-sided metastatic colorectal cancer (mCRC) without mutations in RAS or BRAF V600E are eligible to a combination treatment of an anti-EGFR monoclonal antibody in association with chemotherapy. This combination is associated with a survival benefit and is recommended by oncology guidelines as first line therapy for RAS/BRAF wild type left-sided mCRC patients. The CHUM (University of Montreal Hospital Center) has implemented reflex testing of RAS/BRAF mutations for mCRC since October 22nd 2019, and was one of the only hospitals in Canada to do so. With this study, we want to demonstrate that reflex testing of these mutations improves the quality of care received by patients. Methods: In this retrospective study, we reviewed pathological and clinical data of 101 patients with newly diagnosed mCRC that had their pathological diagnosis done at the CHUM. Patients diagnosed between July 1st 2017 and October 21st 2019, before implementation of reflex testing, (“Before reflex testing” group, n = 62 patients) were compared to patients diagnosed between October 22nd 2019 and December 31st 2021 (“After reflex testing” group, n = 39 patients). Results: The average delay between the mCRC biopsy and the result of the RAS/BRAF mutations was reduced to 25 days (CI95% 22.6 – 28.1) in the “After reflex testing” group, compared to 154 days (CI95% 111.2 – 202.5) in the “Before reflex testing” group. Respectively 66% (41/62) of patients in the “Before reflex testing” group and 69% (27/39) of patients in the “After reflex testing” received a systemic treatment. At initiation of systemic therapy, results of RAS/ BRAF mutations were available for 85% (35/41) of patients in the “After reflex testing” group, versus only 17% (7/41) of patients in the “Before reflex testing” group. Among patients eligible for an anti-EGFR monoclonal antibody and who received it, 100% of them (6/6) received it in the first line setting in the “After reflex testing” group, compared to 33% (3/9) in the “Before reflex testing” group. Conclusions: Our study shows that with reflex testing of RAS/ BRAF mutations, oncologists have quicker access to all relevant information to make the best treatment decision for their patients. It allows eligible patients to receive an anti-EGFR therapy in the first line setting, as recommended by oncology guidelines.

Nivolumab (NIVO) plus chemotherapy (chemo) vs chemo as first-line (1L) treatment for advanced gastric cancer/gastroesophageal junction cancer/esophageal adenocarcinoma (GC/GEJC/EAC): 3-year follow-up from CheckMate 649

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Background: NIVO + chemo demonstrated superior overall survival (OS) and clinically meaningful progression-free survival (PFS) benefit vs chemo and an acceptable safety profile in previously untreated patients (pts) with advanced GC/GEJC/EAC, leading to approvals in multiple countries including the US. NIVO + chemo continued to demonstrate clinically meaningful improvement in efficacy after 2 years of follow-up. We present efficacy and safety analyses from NIVO + chemo vs chemo from the 3-year follow-up of CheckMate 649. Methods: Adults with previously untreated, unresectable advanced, or metastatic GC/GEJC/EAC were enrolled, regardless of programmed death ligand 1 (PD-L1) expression. Pts with known HER2-positive status were excluded. Randomized pts received NIVO (360 mg Q3W or 240 mg Q2W) + chemo (XELOX Q3W or FOLFOX Q2W), NIVO + ipilimumab, or chemo. Dual primary endpoints for NIVO + chemo vs chemo were OS and PFS by blinded independent central review (BICR) in pts with PD-L1 combined positive score (CPS) ≥ 5. Results: 581 pts were concurrently randomized to NIVO + chemo or chemo. With 36-month (mo) minimum follow-up, NIVO + chemo continued to demonstrate OS and PFS benefit vs chemo in pts with PD-L1 CPS ≥ 5 and all randomized pts. The objective response rate (ORR) per BICR in pts with PD-L1 CPS ≥ 5 who had measurable lesions at baseline was 60% (95% CI 55–65) with NIVO + chemo vs 45% (95% CI 40–50) with chemo; in all randomized pts, ORR per BICR was 58% (95% CI 54–62) with NIVO + chemo vs 46% (95% CI 42–50) with chemo. Responses were more durable with NIVO + chemo vs chemo in pts with PD-L1 CPS ≥ 5 (median [m] duration of response [mDOR] 9.6 mo [95% CI 8.2–12.4] vs 7.0 mo [95% CI 5.6–7.9], respectively) and in all randomized pts (mDOR 8.5 mo [95% CI 7.7–9.9] vs 6.9 mo [95% CI 5.8–7.2], respectively). OS benefit with NIVO + chemo was observed across most prespecified subgroups. No new safety signals were identified. A summary of treatment-related adverse events (TRAEs) is shown here. Conclusions: After 3 years of follow-up, NIVO + chemo continued to demonstrate clinically meaningful long-term survival benefit with an acceptable safety profile, further supporting its use as a standard 1L treatment in previously untreated pts with advanced GC/GEJC/EAC. Clinical trial information: NCT02872116 . [Table: see text]

Successful Treatment with Brigatinib after Alectinib-Induced Hemolytic Anemia in Patients with Metastatic Lung Adenocarcinoma-A Case Series

Alectinib is a second-generation anaplastic lymphoma kinase (ALK) inhibitor used in the treatment of advanced ALK-rearrangement positive non-small-cell lung cancer (NSCLC). Many tolerable adverse events were reported with the use of Alectinib; nevertheless, hemolytic anemia was not mentioned in the safety analysis. In this case, series, we report four cases of Alectinib-induced oxidative hemolytic anemia and discuss different etiologic hypotheses on the underlying mechanism of such overlooked adverse event of the drug. Furthermore, we draw attention to the successful treatment with Brigatinib, an alternative second-generation ALK-inhibitor without recurrence of hemolytic anemia in three of our four cases, suggesting a probable class effect.

hENT1 Expression Predicts Response to Gemcitabine and Nab-Paclitaxel in Advanced Pancreatic Ductal Adenocarcinoma

PURPOSE

Modified FOLFIRINOX (mFFX) and gemcitabine/nab-paclitaxel (GnP) remain standard first-line options for patients with advanced pancreatic ductal adenocarcinoma (PDAC). Human equilibrative nucleoside transporter 1 (hENT1) was hypothesized to be a biomarker of gemcitabine in the adjuvant setting, with conflicting results. In this study, we explore hENT1 mRNA expression as a predictive biomarker in advanced PDAC.

EXPERIMENTAL DESIGN

COMPASS was a prospective observational trial of patients with advanced PDAC. A biopsy was required prior to initiating chemotherapy, as determined by treating physician. Biopsies underwent laser capture microdissection prior to whole genome and RNA sequencing. The cut-off thresholds for hENT1 expression were determined using the maximal χ2 statistic.

RESULTS

253 patients were included in the analyses with a median follow-up of 32 months, with 138 patients receiving mFFX and 92 receiving GnP. In the intention to treat population, median overall survival (OS) was 10.0 months in hENT1high versus 7.9 months in hENT1low (P = 0.02). In patients receiving mFFX, there was no difference in overall response rate (ORR; 35% vs. 28%, P = 0.56) or median OS (10.6 vs. 10.5 months, P = 0.45). However, in patients treated with GnP, the ORR was significantly higher in hENT1high compared with hENT1low tumors (43% vs. 21%, P = 0.038). Median OS in this GnP-treated cohort was 10.6 months in hENT1high versus 6.7 months hENT1low (P < 0.001). In an interaction analysis, hENT1 was predictive of treatment response to GnP (interaction P = 0.002).

CONCLUSIONS

In advanced PDAC, hENT1 mRNA expression predicts ORR and OS in patients receiving GnP.

Association between immune-related adverse events and microbiome composition in patients with advanced non–small cell lung cancer treated with immunotherapy

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Background: Despite immune-checkpoint inhibitors (ICI) achieving high response rates in patients (pts) with advanced non-small cell lung cancer (NSCLC), immune-related adverse events (irAE) remain an important therapeutic hurdle. The gut microbiome represents a novel prognostic marker of ICI response and early clinical evidence suggests that the microbiome may also regulate the development of irAE. We aimed to assess the association between irAE and the gut microbiome composition in advanced NSCLC pts amenable to ICI. Methods: In this study, we enrolled 464 pts from two independent cohorts (Montreal and Tokyo) with advanced NSCLC treated with ICI monotherapy or combination with chemotherapy. Fecal samples were collected prior to ICI initiation. Metagenomics microbiome profiling and 16S rRNA microbiome sequencing were performed for 81 pts and 133 pts respectively. The irAE were classified as CTCEA grade 0-1 (G0-1 irAE) and grade > 2 (G2-5 irAE). Microbiome composition of both groups was represented using alpha diversity, beta diversity indexes and LEfSe relative abundances. Results: Median follow-up was 28.3 months (mos) and the incidence of G2-5 irAE was 25.1% in the Montreal cohort. For the Tokyo cohort, the median follow-up was 19.6 mos and 30.8% pts developed G2-5 irAE. First, in both cohorts, overall survival (OS) and progression-free survival (PFS) were significantly improved for pts with G2-5 irAE compared to G0-1 irAE (OS: HR: 1.71, p = 0.008 and PFS: HR: 1.65, p < 0.001) and (OS: HR: 2.34, p = 0.001, and PFS: HR = 2.34, p = 0.006) respectively. Second, metagenomics analysis of 81 pts demonstrated a numerical decrease of the alpha diversity in terms of observed species in the G2-5 irAE. Dorea sp CAG 31, Anaerosporobacter mobilis, Butyricicococcus, and Enterococcus faecium were overrepresented in pts with G2-5 irAE. Conversely, Gordonibacter was increased in G0-1 irAE. Next, 16S rRNA profiling from the Tokyo cohort revealed an enrichment of Dorea, Butyricicococcus, and Eubacterium ventriosum in G2-5 irAE . Finally, we observed an enrichment in Dorea and Butyricicococcus in the pts with PFS > 6 months, as observed in the G2-5 irAE group. Conclusions: IrAE correlated with clinical outcome and microbiome composition in two independent cohorts of pts with advanced NSCLC. These results prompt further research on the potential mechanism underling the role of the microbiome in the development of irAE.

Comparison of systematic inflammatory prognostic scores in patients with advanced pancreatic adenocarcinoma

4149

Background: Systemic inflammatory scores have been developed as tools to aid clinicians in prognostication and patient (pt) selection for clinical trials. We compared the accuracy of five prognostic scores to predict overall survival (OS) in pts with advanced pancreatic adenocarcinoma (PDAC). Methods: Pts with advanced PDAC enrolled on the COMPASS trial (NCT02750657) from 2015 to 2020 were included. All pts had biopsies for whole genome and RNA sequencing prior to standard first-line chemotherapy in the advanced setting. Prognostic risk was calculated using: neutrophil-to-lymphocyte ratio (NLR; >5 = high), platelet-to-lymphocyte ratio (PLR; > 150 = high), Prognostic Nutritional Index (PNI = albumin + 5 x lymphocytes. PNI < 45 = high risk), Gustave Roussy Immune Score (GRIm-S; NLR>6 = 1 point, albumin <35 = 1 point, LDH > upper limit of normal [ULN] = 1 point. GRIm-S ≥2 = high risk), and Memorial Sloan Kettering Prognostic Score (MPS; NLR >4 and albumin < 40 = high risk). OS was estimated using the Kaplan-Meier method and compared between risk groups (high vs. not-high) for each scoring system using the log-rank test. Cox proportional hazards models were used to analyze the association between each prognostic score and OS, adjusting for baseline clinical and genomic factors. Results: In total, 263 pts with advanced PDAC cancer were included, with median follow up of 32.9 (95% CI 15.9-64.2) months. Median OS in the intention to treat population was 9.3 months (95% CI 8-10.2). PLR and PNI were not prognostic. High risk NLR (N=85, 32%), GRIm-S (N=47, 18%) and MPS (N=46, 17%) identified pts with poor prognosis. The GRIm-S and MPS were most significant: median OS in high vs low risk pts 6.4 vs. 10 months p<0.001 (GRIm-S) and 6.3 vs. 10 months p=0.002 (MPS). On multivariable analyses, high risk NLR, GRIm-Score and MPS were each associated with poor OS after adjusting for baseline clinical and genomic factors (Table). For all models, ECOG ≥1 (N=165, 63%); the basal-like Moffitt RNA subtype (N=49, 20% vs 80% classical) and low HRDetect scores (N=31, 13%) were significantly associated with poor OS. However these scores did not associate with RNA based classifiers or HRD scores and can therefore provide additional prognostic information. Conclusions: Both the GRIm-S and MPS are highly prognostic in PDAC and are scores easily used in the clinical setting and may help in clinical trial selection. Genotypic correlates are being explored.[Table: see text]

Pembrolizumab (pembro) plus mFOLFOX7 or FOLFIRI for metastatic colorectal cancer (CRC) in KEYNOTE-651: Long-term follow-up of cohorts B and D

3521

Background: Response to antiPD-1 monotherapy is poor in patients (pts) with advanced microsatellite stable (MSS)/mismatch-repair proficient (pMMR) CRC. Combination of chemotherapy with antiPD-1 pembro may potentiate the antitumor immune response and provide greater antitumor activity than either agent alone. Combination of pembro and mFOLFOX7 or FOLFIRI in the ongoing phase 1b multicohort KEYNOTE-651 (NCT03374254) study in metastatic MSS/pMMR CRC showed antitumor activity. We present results with approximately 20 mo of additional follow-up. Methods: Pts had metastatic MSS/pMMR CRC and were previously untreated (cohort B) or received 1 prior line including a fluoropyrimidine + oxaliplatin (cohort D). Pts received pembro 200 mg Q3W + mFOLFOX7 Q2W (cohort B) or pembro 200 mg Q3W + FOLFIRI Q2W (cohort D). Primary end points were safety (DLT) and RP2D. Secondary end point was ORR per RECIST v1.1 by investigator review. DOR, DCR, and PFS per RECIST v1.1, and OS were exploratory end points. Results: Median study follow-up (range) at data cutoff (Oct 15, 2021) was 30.2 mo (25.0-43.6) for cohort B (n = 31) and 33.5 mo (25.2-43.2) for cohort D (n = 32). Treatment was discontinued in 29 pts (94%) in cohort B and 28 pts (88%) in cohort D, mostly because of PD (61% and 66%, respectively). At prior analysis (Feb 10, 2020), RP2D was confirmed as the starting dose in both cohorts; no new DLT had occurred. In cohort B, gr 3/4 TRAEs occurred in 18 pts (58%), most commonly neutropenia and decreased neutrophil count (both n = 5; 16%); 19 pts (61%) discontinued drug because of a TRAE. In cohort D, gr 3/4 TRAEs occurred in 17 pts (53%), most commonly, neutropenia (n = 7; 22%), diarrhea and fatigue (both n = 4; 13%); 3 pts (9%) discontinued drug because of a TRAE. There were no gr 5 TRAEs in either cohort. Efficacy by cohort and KRAS mutation status are below (Table). PD-L1 data and DNA/RNA-based biomarker data including GEP, consensus signatures, TMB, and LoF mutations will be included in the presentation. Conclusions: After 2.5 y of follow-up, the combination of pembro with either mFOLFOX7 or FOLFIRI continued to demonstrate a manageable safety profile with no new safety signals. Efficacy data from these single-arm cohorts appear comparable to historical data for current SOC. Clinical trial information: NCT03374254. [Table: see text]

Pembrolizumab (pembro) plus binimetinib (bini) with or without chemotherapy (chemo) for metastatic colorectal cancer (mCRC): Results from KEYNOTE-651 cohorts A, C, and E

3573

Background: Response to antiPD-1 monotherapy is poor in microsatellite stable (MSS)/mismatch-repair proficient (pMMR) mCRC; the combination of antiPD-1 pembro + anti-MEK bini, with or without chemo, may improve upon this limited response. KEYNOTE-651 (NCT03374254) is an open-label phase 1b multicenter trial of pembro + bini (cohort A) or pembro + bini + chemo (mFOLFOX7 in cohort C, FOLFIRI in cohort E) in MSS/pMMR mCRC. Preliminary results from the dose-finding phase at 2 dose levels (DL) of bini are presented. Methods: Patients (pts) had MSS/pMMR mCRC and must have been previously treated with fluoropyrimidine, irinotecan, and oxaliplatin in cohort A, or with fluoropyrimidine + oxaliplatin-based regimen in cohort E; pts were previously untreated in cohort C. Pts received pembro 200 mg Q3W + bini 30 mg BID (cohort A, DL1), pembro 200 mg Q3W+ bini 30 mg BID + mFOLFOX7 Q2W (cohort C, DL1) or pembro 200 mg Q3W + bini 30 mg BID + FOLFIRI Q2W (cohort E, DL1). Bini dose escalation to 45 mg BID (DL2) was planned in cohorts A, C, and E, with a target dose-limiting toxicity (DLT) of 30%. Primary end point was safety (DLT). Secondary end point was ORR. DCR, PFS, and OS were exploratory. ORR, DCR, and PFS were assessed by investigator per RECIST v1.1. Results: Median study follow-up at data cutoff (Oct 15, 2021) was 36 mo (range, 32-43) for cohort A, 17 mo (2-24) for cohort C, and 11 mo (2-25) for cohort E. In cohort A, 1/6 pts (17%) had DLT at DL1; no DLT occurred in 14 pts (0%) at DL2. In cohort A, gr 3/4 TRAEs occurred in 3/6 pts (50%) at DL1 and 8/14 pts (57%) at DL2. In cohort C, 3/9 evaluable pts (33%) had DLT at DL1; thus, bini dose was not escalated to DL2. In cohort C, gr 3/4 TRAEs occurred in 9/11 total pts (82%). In cohort E, 1/5 evaluable pts (20%) had DLT at DL1 and 5/10 evaluable pts (50%) had DLT at DL2. Enrollment was stopped in cohort E, DL2 and bini dose was de-escalated to DL1; 2/4 additional pts (50%) had DLT at DL1 (total 3/9 pts [33%] had DLT in cohort E, DL1). In cohort E, gr 3/4 TRAEs occurred in 5/9 pts (56%) at DL1 and 10/11 total pts (91%) at DL2. No gr 5 TRAEs occurred in any cohort. ORR was 0% in cohort A; limited efficacy was seen in cohorts C and E (Table). Conclusions: Bini could be safely combined with pembro in cohort A. However, with bini + pembro + chemo, the 45-mg dose of bini was not well tolerated and required dose reduction to 30 mg. Addition of bini to pembro + chemo did not improve efficacy; therefore, enrollment was prematurely closed in cohorts C and E. Efficacy by KRAS mutation status will be shown. Clinical trial information: NCT03374254. [Table: see text]

COVID-19 impact on diagnosis and staging of colorectal cancer: A single tertiary Canadian oncology center experience

33

Background: COVID-19 pandemic urged public health to imposed drastic reduction on endoscopic activities and surgery, leading to delays that still not have been caught up today. The Ministry of Health and Social Services (MSSS) of Quebec conducted a study of the impact of those measures and reported a 66% reduction of colonoscopy and a 30% reduction of colorectal cancer (CRC) surgery activities during the first wave (March to May 2020). Whether those reduction had an impact on diagnosis and staging of CRC remains unknown. Methods: Demographic information of CRC diagnosed at Centre Hospitalier de l’Université de Montréal (CHUM) between January 1 2018 and March 12 2020 (pre-pandemic period), and March 13 2020 and June 30 2021 (pandemic period) were obtained from the SARDO registry and data regarding colonoscopy, surgery and staging at diagnosis (clinical or pathological as appropriate) were collected. Priority of elective colonoscopy was defined using the MSSS grading system ranging from P1 to P5. We compared delays to colonoscopy, delays to surgery and CRC staging of the pandemic period to the pre-pandemic period using one-way ANOVA, t tests and Chi-square tests as appropriate. Only delays in elective surgeries intended as first and curative treatment were analyzed. Results: 280 CRC diagnosis were made at the pre-pandemic period compared to 127 CRC diagnosis during the pandemic period. Mean diagnosis rates of the pandemic period tend to be lower (8.3 vs. 10.5 diagnosis/month, p=0.03) compared to the pre-pandemic period. 37.6% of patient in the pandemic period had a diagnosis of CRC during a hospitalization compared to 25.9% at the pre-pandemic period (p=0.048). 51.7% of elective colonoscopy leading to a diagnostic of CRC during the pandemic period did not meet required delays according to priority compared to 38.3% (p=0.049) during the pre-pandemic period. P3 colonoscopies (mostly indicated for a positive FIT and iron deficiency anemia) were the most affected (58.9 vs. 106.5 days, p˂0.001). P2 colonoscopy (indicated for suspected colorectal cancer) did not experienced an augmentation in delays (20.9 vs. 25.2 days, p=0.39). A mean of 3.5 elective curative surgeries per month were performed during the pandemic period compared to 3.4 at the pre-pandemic period (p=0.96), and mean delays for surgery were not affected (60.4 vs. 57 days, p=0.59). Stages at diagnosis did not differ (p=0.2). Most of the delayed colonoscopies led to a stage 0 or I CRC and did not lead to a higher stage at diagnosis (p=0.2). Conclusions: In our center, the COVID-19 pandemic led to overall less CRC diagnosis and increased diagnostic endoscopic delays without a higher rate of advanced stage disease. Delays for elective surgeries were quite similar once the CRC diagnostic established.

Prognostic ability of the Gustave Roussy Immune Score for patients with advanced pancreatic adenocarcinoma

469

Background: The Gustave Roussy Immune Score (GRIm-S) considers a composite of neutrophil to lymphocyte ratio (> 6 = 1), albumin (< 35 = 1) and LDH (> ULN = 1) and has been established as a prognostic score and may in aid in the selection of patients for phase 1 trials of immune checkpoint inhibitors. Methods: We explored the prognostic impact of the GRIm-S (high > 1) in patients enrolled on the COMPASS trial and correlated the score with genomic and clinical characteristics. Patients in this trial had biopsies for whole genomic and RNA sequencing prior to standard chemotherapy regimens in the advanced setting. Results: 252 patients were included in the analyses with a median follow-up time of 28 months. 16% of patients had a high GRIm-S with significantly shorter median overall survival (OS) of 4.1 months versus 10.0 months in those with a low score (HR 2.18, 95% CI 1.4-3.4, p < 0.0001). In the GRIm-S-high cohort, early progression with non-evaluable disease and disease progression were more common than in the GRIm-S low cohort (56% vs 31%, p = 0.003). In a multivariable analysis, a high GRIm-S was poorly prognostic (HR 1.6 95% CI 1.3-1.9, p < 0.001), whereas the classical RNA subtype (vs. basal-like) (HR 0.41, 95% CI 0.3-0.6, p < 0.001) and a high HRDetect score (HR 0.47 95% CI 0.3-0.7, p < 0.001) associated with superior OS. The GRIm-S did not correlate with RNA subtypes or with specific KRAS mutations. There were no differences in structural variant load or tumour mutational burden between groups. However those with a high GRIm-S did have a higher total target lesion diameter at baseline (p < 0.001). Conclusions: The GRIm-S identifies a subset of patients who have aggressive pancreas cancer and short life expectancy. This information may help clinicians in treatment decision making and selection for clinical trials.

Nivolumab (NIVO) plus chemotherapy (chemo) versus chemo as first-line (1L) treatment for advanced gastric cancer/gastroesophageal junction cancer/esophageal adenocarcinoma (GC/GEJC/EAC): Expanded efficacy, safety, and subgroup analyses from CheckMate 649

240

Background: CheckMate 649 is a randomized, global phase 3 study of 1L programmed death-1 (PD-1) inhibitor–based therapies in advanced non-HER2-positive GC/GEJC/EAC that demonstrated superior overall survival (OS) with NIVO + chemo vs chemo, leading to approvals in the US and other countries. Clinically meaningful long-term survival benefit with NIVO + chemo vs chemo was observed with 24 months (mo) of minimum follow-up in all randomized patients (pts) for both OS (HR 0.79 [95% CI 0.71–0.88]) and progression-free survival (PFS; HR 0.79 [95% CI 0.70–0.89]; Janjigian YY et al; ESMO 2021). We present expanded analyses of NIVO + chemo vs chemo with minimum follow-up of 24 mo. Methods: Adults with previously untreated, unresectable advanced or metastatic GC/GEJC/EAC were enrolled regardless of PD-ligand (L)1 expression. Pts with known HER2-positive status were excluded. Pts were randomized to NIVO (360 mg Q3W or 240 mg Q2W) + chemo (XELOX Q3W or FOLFOX Q2W), NIVO 1 mg/kg + IPI 3 mg/kg Q3W (4 doses, then NIVO 240 mg Q2W), or chemo. Dual primary endpoints were OS and PFS (per blinded independent central review) in pts with PD-L1 combined positive score (CPS) ≥ 5 for NIVO + chemo vs chemo. Hierarchically tested secondary endpoints included OS in NIVO + chemo vs chemo (PD-L1 CPS ≥ 1, then all randomized). Results: Of 2031 pts, 1581 were randomized to NIVO + chemo or chemo. In all randomized pts, 41% of pts (NIVO + chemo) and 44% of pts (chemo) received subsequent therapy. Median PFS2 (time from randomization to progression after subsequent systemic therapy, initiation of second subsequent systemic therapy, or death, whichever is earlier) was 12.2 (95% CI 11.3–13.5) mo with NIVO + chemo and 10.4 (95% CI 9.7–11.2) mo with chemo (HR 0.75 [95% CI 0.67–0.84]). 51% of pts (NIVO + chemo) and 43% of pts (chemo) had > 50% reduction from baseline in tumor burden, while 24% and 17% had > 80% reduction, respectively. The HR (95% CI) for OS was 0.66 (0.56–0.77) among pts with a PD-L1 CPS ≥ 10 (median OS for NIVO + chemo vs chemo: 15.0 [95% CI 13.7–16.7] vs 10.9 [95% CI 9.8–11.9] mo). OS benefit was observed with NIVO + chemo vs chemo across multiple additional subgroups, and these data will be presented. No new safety signals were identified. The majority of the treatment-related adverse events with potential immunologic etiology were grade 1 or 2 and grade 3 or 4 events were reported in ≤ 5% of pts in both treatment arms. Conclusions: NIVO + chemo continued to demonstrate clinically meaningful efficacy and an acceptable safety profile with longer follow-up, further supporting the use of NIVO + chemo as a standard 1L therapy in previously untreated pts with advanced GC/GEJC/EAC. Clinical trial information: NCT02872116.

First-line nivolumab plus chemotherapy versus chemotherapy alone for advanced gastric, gastro-oesophageal junction, and oesophageal adenocarcinoma (CheckMate 649): a randomised, open-label, phase 3 trial

BACKGROUND

First-line chemotherapy for advanced or metastatic human epidermal growth factor receptor 2 (HER2)-negative gastric or gastro-oesophageal junction adenocarcinoma has a median overall survival (OS) of less than 1 year. We aimed to evaluate first-line programmed cell death (PD)-1 inhibitor-based therapies in gastric, gastro-oesophageal junction, and oesophageal adenocarcinoma. We report the first results for nivolumab plus chemotherapy versus chemotherapy alone.

METHODS

In this multicentre, randomised, open-label, phase 3 trial (CheckMate 649), we enrolled adults (≥18 years) with previously untreated, unresectable, non-HER2-positive gastric, gastro-oesophageal junction, or oesophageal adenocarcinoma, regardless of PD-ligand 1 (PD-L1) expression from 175 hospitals and cancer centres in 29 countries. Patients were randomly assigned (1:1:1 while all three groups were open) via interactive web response technology (block sizes of six) to nivolumab (360 mg every 3 weeks or 240 mg every 2 weeks) plus chemotherapy (capecitabine and oxaliplatin every 3 weeks or leucovorin, fluorouracil, and oxaliplatin every 2 weeks), nivolumab plus ipilimumab, or chemotherapy alone. Primary endpoints for nivolumab plus chemotherapy versus chemotherapy alone were OS or progression-free survival (PFS) by blinded independent central review, in patients whose tumours had a PD-L1 combined positive score (CPS) of five or more. Safety was assessed in all patients who received at least one dose of the assigned treatment. This study is registered with ClinicalTrials.gov, NCT02872116.

FINDINGS

From March 27, 2017, to April 24, 2019, of 2687 patients assessed for eligibility, we concurrently randomly assigned 1581 patients to treatment (nivolumab plus chemotherapy [n=789, 50%] or chemotherapy alone [n=792, 50%]). The median follow-up for OS was 13·1 months (IQR 6·7-19·1) for nivolumab plus chemotherapy and 11·1 months (5·8-16·1) for chemotherapy alone. Nivolumab plus chemotherapy resulted in significant improvements in OS (hazard ratio [HR] 0·71 [98·4% CI 0·59-0·86]; p<0·0001) and PFS (HR 0·68 [98 % CI 0·56-0·81]; p<0·0001) versus chemotherapy alone in patients with a PD-L1 CPS of five or more (minimum follow-up 12·1 months). Additional results showed significant improvement in OS, along with PFS benefit, in patients with a PD-L1 CPS of one or more and all randomly assigned patients. Among all treated patients, 462 (59%) of 782 patients in the nivolumab plus chemotherapy group and 341 (44%) of 767 patients in the chemotherapy alone group had grade 3-4 treatment-related adverse events. The most common any-grade treatment-related adverse events (≥25%) were nausea, diarrhoea, and peripheral neuropathy across both groups. 16 (2%) deaths in the nivolumab plus chemotherapy group and four (1%) deaths in the chemotherapy alone group were considered to be treatment-related. No new safety signals were identified.

INTERPRETATION

Nivolumab is the first PD-1 inhibitor to show superior OS, along with PFS benefit and an acceptable safety profile, in combination with chemotherapy versus chemotherapy alone in previously untreated patients with advanced gastric, gastro-oesophageal junction, or oesophageal adenocarcinoma. Nivolumab plus chemotherapy represents a new standard first-line treatment for these patients.

FUNDING

Bristol Myers Squibb, in collaboration with Ono Pharmaceutical.

The prognostic impact of KRAS, TP53, STK11 and KEAP1 mutations and the influence of the NLR in NSCLC patients treated with immunotherapy

e21010

Background: ICIs changed the way NSCLC is treated, but not all patients benefit from it. PD-L1 level is used to predict response to therapy, but its performance is sub-optimal. KRAS is important in NSCLC tumorigenesis, but the impact of its mutations in patients treated with ICIs is unclear. Similarly, studies evaluating co-mutations in TP53, STK11 and KEAP1 as well as the NLR showed that they may predict the benefit of ICIs. Methods: We conducted a retrospective study including all consenting patients with NSCLC treated with ICIs at the CHUM between July 2015 and June 2020. OS and PFS were compared in co-mutation subgroups using Kaplan-Meier and logrank methods. Co-mutations in TP53, STK11 and KEAP1 as well as the NLR were accounted for. Overall response rate (ORR) and safety data was also compared in subgroups and will be detailed at the meeting. Results: We included 100 patients with known KRAS status. From these, 50 were wild-type ( KRASWT) and 50 were mutated ( KRASMut). The most frequent mutation was G12C (54%). Co-mutation status for TP53, STK11 and KEAP1 were known for, respectively, 40, 39 and 38 patients. Co-mutations for these genes were present in respectively 19 (47.5%), 8 (20.5%) and 4 (10.5%). Data comparing KRASMut and KRASWT showed non-significant differences in survival (median OS of respectively 21.1 vs. 17.7 months, p = 0.27). The presence of STK11 and/or KEAP1 mutations was associated with a negative impact on survival when compared with wild-type (median OS 7.4 vs 20.4 months, p = 0.001). When the presence of a KRAS mutation was compounded with STK11 and KEAP1, KRASMut (vs KRASWT) trended to a better prognosis in STK11+KEAP1WT tumors (median OS of 21.1 for KRASMut vs 15.8 for KRASWT, p = 0.15), but not in STK11+/-KEAP1Mut tumors (7.4 for KRASMut vs 7.0 for KRASWT). No influence on survival was seen in relationship to the TP53 co-mutation. Interestingly, the NLR was significantly higher with STK11 mutations (6.66Mut vs 3.59WT, p = 00012), slightly lower with TP53 mutations (3.23Mut vs 4.82WT, p = 0.047) but not impacted by KEAP1 (3.72Mut vs 4.20WT, p = 0.72) or KRAS mutations (4.32Mut vs 5.21WT, p = 0.34). Conclusions: The STK11 and KEAP1 mutations are significant adverse predictors of ICI therapy benefit. The NLR is strongly impacted by STK11 mutations but not by KEAP1 mutations suggesting marked differences in the resistance mechanism for both mutations. In STK11-KEAP1WT tumors, KRAS mutations seems to be associated with improved survival in NSCLC patient treated with ICIs.

A phase II trial combining nivolumab and stereotactic brain radiosurgery for treatment of brain metastases in patients with NSCLC

2023

Background: Previous studies suggested activity of anti-PD-1 in brain metastases from non-small cell lung cancer (NSCLC) and renal cell cancer (RCC). This investigator initiated phase 2 trial examined the safety and efficacy of combining nivolumab with radiosurgery (SRS) in the treatment of patients with brain metastases from NSCLC and RCC. Methods: This is a multicentre open-label trial (NCT02978404) in which patients diagnosed with NSCLC or RCC, having ≤ 10 cc of un-irradiated brain metastases, no whole brain radiotherapy and no prior immunotherapy were eligible. Study treatment commenced with a dose of nivolumab (240mg or 480mg IV), which was continued for up to 2 years at bi-weekly or monthly intervals until progression. SRS (15-21Gy) to all visible un-irradiated brain lesions was administered within 14 days after the first dose of nivolumab (cycle 1). Patients were followed by brain MRI, CT scan of the chest, abdomen and pelvis, neurocognitive and quality of life questionnaires (FACT-Br) every 3 months. The primary endpoint was intracranial progression free survival (icPFS), with death and disease progression within the brain as events. Results from NSCLC patients are presented here. Results: Of the 26 study patients, 22 NSCLC patients were enrolled between Aug 2017 and January 2020. Patients had a median of 2 (1-9) brain metastases. The median diagnosis-specific graded prognostic score was 2 (1-3). Median treatment and follow-up durations were 4.3 months (0-24.8 months) and 11 months (0-24.8 months), respectively. Forty-two percent of the patients had received prior cytotoxic chemotherapy, and 1 patient had received prior brain SRS. PD-L1 status was known for 21 of the 22 NSCLC (12 with ≥50% PD-L1 expression (DAKO 22C3). Median icPFS was 5.0 months (3 intracranial progression and 8 deaths without progression in the brain). Accounting for death as a competing risk, the 1-year cumulative incidence of intracranial relapse was 17.4%. Median extracranial PFS and overall survival were 2.9 months and 14 months, respectively. Four grade 3 adverse events in 2 patients were related to nivolumab or SRS. The rate of survival free of neurocognitive decline (Hopkins Verbal Learning Test total recall) was estimated to be 89% by 4 months. Mean FACT-Br total scores were 89.4 at baseline and improved (p = 0.01) to 139.3 within 2-4 months. Conclusions: Neurocognitive and quality of life assessments suggest that upfront SRS during nivolumab is well tolerated. High intracranial control was observed, but deaths from extracranial disease progression resulted in short icPFS. Studies evaluating the strategic addition of SRS combined with more efficacious systemic treatments are needed. Clinical trial information: 02978404.

Impact of KRAS mutational status on outcomes in patients with pancreatic cancer (PDAC)

4142

Background: KRAS mutations (m) (KRASm) are present in over 90% of pancreatic adenocarcinomas (PDAC) with a predominance of G12 substitutions. KRAS wildtype (WT) PDAC relies on alternate oncogenic drivers, and the prognostic impact of these remains unknown. We evaluated alterations in WT PDAC and explored the impact of specific KRASm and WT status on survival. Methods: WGS and RNAseq were performed on 570 patients (pts) ascertained through our translational research program from 2012-2021, of which 443 were included for overall survival (OS) analyses. This included 176 pts with resected and 267 pts with advanced PDAC enrolled on the COMPASS trial (NCT02750657). The latter cohort underwent biopsies prior to treatment with first line gemcitabine-nab-paclitaxel or mFOLFIRINOX as per physician choice. The Kaplan-Meier and Cox proportional hazards methods were used to estimate OS. Results: KRAS WT PDAC (n = 52) represented 9% of pts, and these cases trended to be younger than pts with KRASm (median age 61 vs 65 years p = 0.1). In resected cases, the most common alterations in WT PDAC (n = 23) included GNASm (n = 6) and BRAFm/fusions (n = 5). In advanced WT PDAC (n = 27), alterations in BRAF (n = 11) and ERBB2/3/4 (n = 6) were most prevalent. Oncogenic fusions (NTRK, NRG1, BRAF/RAF, ROS1, others) were identified in 9 pts. The BRAF in-frame deletion p.486_491del represented the most common single variant in WT PDAC, with organoid profiling revealing sensitivity to both 3rd generation BRAF inhibitors and MEK inhibition. In resected PDAC, multivariable analyses documented higher stage (p = 0.043), lack of adjuvant chemotherapy (p < 0.001), and the KRAS G12D variant (p = 0.004) as poor prognostic variables. In advanced disease, neither WT PDAC nor KRAS specific alleles had an impact on prognosis (median OS WT = 8.5 mths, G12D = 8.2, G12V = 10.0, G12R = 12.0, others = 9.2, p = 0.73); the basal-like RNA subtype conferred inferior OS (p < 0.001). A targeted therapeutic approach following first line chemotherapy was undertaken in 10% of pts with advanced PDAC: MMRd (n = 1), homologous recombination deficiency (HRD) (n = 19), KRASG12C (n = 1), CDK4/6 amplification (n = 3), ERBB family alterations (n = 2), BRAF variants (n = 2). OS in this group was superior (14.7 vs 8.8 mths, p = 0.04), mainly driven by HRD-PDAC where KRASm were present in 89%. Conclusions: In our dataset, KRAS G12D is associated with inferior OS in resected PDAC, however KRAS mutational status was not prognostic in advanced disease. This suggests that improved OS in the WT PDAC population can only be achieved if there is accelerated access to targeted drugs for pts.

Predictive value of germline ATM mutations in the CCTG PA.7 trial: Gemcitabine (GEM) and nab-paclitaxel (Nab-P) versus GEM, nab-P, durvalumab (D) and tremelimumab (T) as first-line therapy in metastatic pancreatic ductal adenocarcinoma (mPDAC)

4135

Background: PA.7 evaluated whether combining PD-L1 and CTLA-4 inhibition with GEM and Nab-P increases efficacy. A previous analysis of the PA.7 data demonstrated high plasma based TMB (≥9 mut/Mb) was associated with improved OS in the Gem, Nab-P, D+T arm. DNA repair pathway aberrations beyond mismatch repair have been associated with potential immune sensitivity. We assessed the predictive value of germline ATM mutations in the PA.7 trial. Methods: This randomized phase II study (ClinicalTrials.gov NCT02879318) assessed the efficacy and safety of GEM, Nab-P, D, and T (arm A) vs. GEM and Nab-P (arm B) in patients (pts) with mPDAC (n = 180). The primary endpoint was overall survival (OS). Pre-treatment plasma was sequenced with the Predicine ATLAS next generation assay (600 gene, 2.4 Mb panel). 2-sided alpha set at 0.1. Results: 180 pts were randomized (119 to arm A and 61 to arm B) There was no significant difference in OS (9.8 months in arm A vs. 8.8 months in arm B, p-value 0.72) or PFS (5.5 months and 5.4 months respectively, HR 0.98, p-value 0.91). Plasma analysis was performed on 174/180 pts with available samples. 16/174 (9.2%) pts had germline ATM mutations, 12 in arm A and 4 in arm B. GEM, Nab-P, D+T was associated with improved OS in patients with ATM mutations (HR 0.10, 90% CI 0.03-0.37; median OS 13.9 months vs. 4.9 months) while no activity was seen in pts with ATM Wild Type (HR 0.99, 90% CI 0.73-1.33; median OS 9.79 months vs. 10.2 months); interaction p = 0.014. Germline ATM mutation status was independent of plasma TMB levels (Wilcoxon p = 0.76). Conclusions: Germline ATM mutation appeared predictive of benefit from the addition of dual immune checkpoint inhibitors (D and T) to Gem and Nab-P, with a significant interaction p-value. In addition to previous data from this trial regarding the predictive value of high plasma TMB (≥9 mut/Mb), this data further supports that there may be independent subgroups of PDAC, beyond MSI-H, that may benefit from immunotherapy, and trials evaluating immunotherapy in subgroups of PDAC with these profiles are warranted. Clinical trial information: NCT02879318.

First-line (1L) nivolumab (NIVO) plus chemotherapy (chemo) versus chemo in advanced gastric cancer/gastroesophageal junction cancer/esophageal adenocarcinoma (GC/GEJC/EAC): Expanded efficacy and safety data from CheckMate 649

4002

Background: CheckMate 649 is the largest randomized, global phase 3 study of 1L programmed death (PD)-1 inhibitor–based therapy in GC/GEJC/EAC. 1L NIVO + chemo demonstrated superior overall survival (OS) vs chemo, with progression-free survival (PFS) benefit and an acceptable safety profile in pts whose tumors expressed PD-ligand (L)1 at combined positive score (CPS) ≥ 5 and ≥ 1, and in all randomized pts (Moehler et al. Ann Oncol 2020). We report additional data for all randomized pts. Methods: Eligible pts had previously untreated, unresectable advanced or metastatic GC/GEJC/EAC. Known HER2-positive pts were excluded. Pts were randomized to receive NIVO (360 mg Q3W or 240 mg Q2W) + chemo (XELOX Q3W or FOLFOX Q2W), NIVO + ipilimumab, or chemo. Dual primary endpoints for NIVO + chemo vs chemo were OS and PFS by blinded central review in PD-L1 CPS ≥ 5 pts. Hierarchically tested secondary endpoints were OS in PD-L1 CPS ≥ 1 and all randomized pts. Results: At 12-month minimum follow-up for 1581 randomized pts, NIVO + chemo had a statistically significant OS benefit vs chemo (HR 0.80 [99.3% CI 0.68–0.94; P = 0.0002]) in all randomized pts; PFS benefit was also seen (HR 0.77 [95% CI 0.68–0.87]). OS benefit was observed in multiple prespecified subgroups, consistent with the primary population. Grade 3–4 treatment-related adverse events (TRAEs) were reported in 59% (NIVO + chemo) and 44% (chemo) of pts. TRAEs with potential immunologic etiology (select TRAEs; sTRAEs) are shown in the table. Pts in the NIVO + chemo arm had decreased risk of symptom deterioration on treatment vs those in the chemo arm (HR 0.77 [95% CI 0.63–0.95; P = 0.0129]). Tolerability as measured by the FACT-Ga GP5 item was similar in both treatment groups. Conclusions: The addition of NIVO to chemo demonstrated improved OS and PFS benefit in all randomized pts, along with an acceptable safety profile and maintained tolerability as well as QoL, providing further support for NIVO + chemo as a standard 1L treatment for advanced GC/GEJC/EAC. Clinical trial information: NCT02872116. [Table: see text]

High intensity interval training safety and efficacy in patients with advanced NSCLC receiving systemic treatment: Results of a prospective trial

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Background: Patients with advanced NSCLC experience fatigue and physical deconditioning altering their quality of life. Safety and feasibility of high intensity exercise in advanced NSCLC has not been explored yet. Methods: We report the results of a single-center, prospective two-arm study. Patients with advanced NSCLC actively receiving systemic therapy or having completed treatment less than 2 months prior to enrollment were included. Patients were allocated to either an intervention arm consisting of kinesiologist supervised high intensity interval training (HIIT) at 2 sessions per week for a total of 12 weeks; or a control arm of home exercise guided by an informative pamphlet. All patients were evaluated at baseline, 6 and 12 weeks by a kinesiologist. Quality of life (QoL) exercise surveys and measurement of strength were measured. Results: Sixty patients were enrolled between January 2018 and March 2020. The study was interrupted due to COVID-19. Thirty-two patients were included in the exercise program and 28 patients in the control group. Both groups were balanced in respect to baseline characteristics. A total of 32 (53%) patients went off protocol, 13 (18%) patients stopped due to symptomatic disease progression which included 2 (3%) deaths, 2 (3%) stopped due to COVID-19 preoccupations and the remaining patients withdrew for other reasons. 42 (70%) patients were evaluated at 6-weeks and 28 (47%) completed the 12-week follow-up, with equal distribution in each group. There were no significant difference at 12 weeks in the physical assessment nor the overall QoL scores between both groups: FACT-L on 135 points (+4.1 vs +1.7, p = 0.342) and FACIT on 52 points (+3 vs -0.2, p = 0.832). Patients in the exercise group demonstrated a significant improvement at 12 weeks in the Lung Cancer Symptoms domain on 28 points (22.3 vs 19.8, p = 0.015) as well as the Physical Wellbeing domain on 28 points (23.6 vs 20.6, p = 0.056) compared to the control group, respectively. No significant exercise related complications were reported. After the study, 9 of the 14 patients (64%) who completed the HIIT program continued to exercise virtually with a kinesiologist in contrast to none in the control group. Conclusions: This study demonstrated the safety and potential benefit of a HIIT program on lung-specific and physical wellbeing in patients with advanced NSCLC on active treatment. This study provides further support on the role of supervised physical exercise in patients living with cancer. Clinical trial information: 16.229.

hENT1 gene expression as a predictor of response to gemcitabine and nab-paclitaxel in advanced pancreatic cancer

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Background: Human equilibrative nucleoside transporter 1 (hENT1) belongs to a family of nucleoside transporters critical to entry of gemcitabine into cells. The prognostic and predictive characteristics of this biomarker in pancreatic ductal adenocarcinoma (PDAC) have primarily been evaluated by immunohistochemistry, with conflicting results. We explored the impact of hENT1 gene expression in the Comprehensive Molecular Characterization of Advanced Ductal Pancreas Adenocarcinoma for Better Treatment Selection (COMPASS) trial. Methods: Patients were enrolled on COMPASS from December 2015 to June 2020 and underwent a biopsy for whole genome sequencing (WGS) and RNA sequencing prior to first chemotherapy in the advanced setting. Biopsies underwent laser capture microdissection to enrich for tumour epithelium. Chemotherapy regimen was determined based on clinician preference. The cut-off thresholds for hENT1 expression were determined using the maximal chi-squared statistic. Response rates and overall survival (OS) were computed based on hENT1 expression and chemotherapy regimen. Results: 254 patients were included in the analyses with a median follow-up time of 18 months. 146 patients were treated with modified FOLFIRINOX (FFX), 104 with gemcitabine and nab-paclitaxel (GnP), and 16 received no systemic therapy. Based on gene expression levels, 133 patients were classified as hENT1 high and 121 as hENT1 low. hENT1 expression was significantly associated with the modified Moffitt classifier with higher expression seen in classical tumours (p < 0.001). In the entire cohort, median OS was 10.0 months in hENT1 high vs. 8.3 months in hENT1 low (adjusted HR 0.78, 95% confidence interval 0.59 - 1.03, p = 0.08). In patients receiving modified FFX, there was no difference in response rates (32% vs. 31%, p = 1.00) or OS (10.6 vs. 10.6 months, p = 0.94) between the hENT1 high and hENT1 low groups, respectively. However, in patient treated with GnP, response rates were significantly higher in hENT1 high patients compared to those with hENT1 low tumors (45% vs. 21%, p = 0.035). Median OS in this GnP treated cohort was 9.8 months in hENT1 high vs. 6.1 months hENT1 low (p = 0.003). In an interaction analysis, hENT was predictive of treatment response to GnP (p = 0.0002). Conclusions: Biomarkers predictive of response to GnP and FFX are urgently needed. Here we demonstrate that hENT1 gene expression is a predictor of response to GnP in advanced PDAC.

Outcomes of Older Patients with Resectable Colorectal Liver Metastases Cancer (CRLM): Single Center Experience

Surgery is the only potential curative option of CRLM if resectable. The curative approach in patients over 70 years old is challenging mainly because of comorbidities and other geriatric syndromes. Herein, we report outcomes of older patients with resectable CRLM in our center. We retrospectively analyzed characteristics and outcomes of older patients with CRLM operated at "Centre Hospitalier de l'Université de Montréal" (CHUM) between 2010 and 2019. We identified 210 patients aged ≥70 years with a median age of 76 (range: 70-85). CRLM were synchronous in 56% of patients. Median disease-free survival (DFS) was 41.3 months. Median overall survival (OS) was 62.2 months and estimated 5-year survival rate was 51.5% similar to those of younger counterparts. Patients with metachronous CRLM had a trend to a higher OS compared to those with synchronous disease (67.2 vs. 58.7 months; p = 0.42). Factors associated with lower survival in the multivariate analysis were right-sided tumors and increased Charlson Comorbidity index (CCI). Survival outcomes of patients aged ≥70 years were comparable to those of younger patients and those reported in the literature. Age should not be a limiting factor in the curative management of older patients with resectable CRLM.

Predictive value of plasma tumor mutation burden (TMB) in the CCTG PA.7 trial: Gemcitabine (GEM) and nab-paclitaxel (Nab-P) vs. GEM, nab-P, durvalumab (D) and tremelimumab (T) as first line therapy in metastatic pancreatic ductal adenocarcinoma (mPDAC)

411

Background: PA.7 evaluated whether combining PD-L1 and CTLA-4 inhibition with GEM and Nab-P increases efficacy as first line therapy in mPDAC. High TMB is associated with immunotherapy sensitivity, with a threshold of ≥10 mut/Mb receiving FDA accelerated approved for pembrolizumab in a tissue agnostic setting. We assessed the predictive value of plasma TMB in the PA.7 trial. Methods: This randomized phase II study (ClinicalTrials.gov NCT02879318) assessed the efficacy and safety of GEM, Nab-P, D, and T (arm A) vs. GEM and Nab-P (arm B) in patients (pts) with mPDAC (n = 180). The primary endpoint was overall survival (OS). Pre-treatment plasma was sequenced with the CLIA-certified PredicineATLAS cfDNA next generation assay (600 genes, 2.4 Mb panel). A pre-specified cut point of 5 mut/MB was selected based on distribution of TMB in the trial. 2-sided alpha set at 0.1. Results: 180 pts were randomized (119 to arm A and 61 to arm B). There was no significant difference in OS (9.8 months in arm A vs. 8.8 months in arm B, p-value 0.72) or PFS (5.5 months and 5.4 months respectively, HR 0.98, p-value 0.91). Plasma TMB analysis was performed on 174/180 pts with available samples, and tumor derived variants were detected in 173/174 pts (99.4%). 172 pts were microsatellite stable and 1 pt was microsatellite high (MSI-H) (plasma TMB 52.9 muts/Mb). Using the pre-specified cut-point of 5 mut/Mb there was no significant predictive value from plasma TMB (interaction p = 0.91). Using a minimum p-value approach, a cut-point of 9 mut/MB appeared predictive (p-interaction = 0.064; significant at pre-specified p = 0.1). 8/174 (4.6%) pts had a plasma TMB ≥9 mut/Mb (5/115 (4.4%) in arm A and 3/59 (5%) in arm B). GEM, Nab-P, D+T was associated with improved OS in patients with plasma TMB ≥9 mut/Mb (HR 0.30, 90% CI 0.06-1.37) while no activity was seen in pts with < 9 mut/Mb, (HR 0.97, 90% CI 0.73-1.29). TMB cut-point analysis revealed a clear trend for a decreasing HR favoring the GEM, Nab-P, D and T arm above the selected cut point, with no benefit in the low TMB group. Conclusions: Plasma TMB analysis was successful in over 99% of pts with available samples. Plasma TMB ≥9 mut/Mb was predictive of benefit from the addition of dual immune checkpoint inhibitors (D and T) to Gem and Nab-P, with a significant interaction p-value. While only present in a subgroup of pts (4.6%), this data defines a group beyond MSI-H PDAC that may benefit from immunotherapy. The optimal cut-point for high TMB in this setting requires validation. A clinical trial specifically assessing the role of chemotherapy combined with immune checkpoint inhibition in high TMB mPDAC is warranted. Clinical trial information: NCT02879318.

Genomic characterization of ATM alterations in advanced pancreatic ductal adenocarcinoma (PDAC)

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Background: BRCA1/2 and PALB2 are genes critical to the faithful repair of double strand breaks through the homologous recombination repair (HRR) pathway. Alterations in these genes serve as predictive biomarkers to both platinum and PARP inhibitors. Ataxia-telangiectasia mutated ( ATM) is also indirectly involved in HRR; however, its role as a predictive biomarker to DNA damage response agents is debated. Herein we evaluated the genomic characteristics and clinical outcomes of patients with ATM alterations on the Comprehensive Molecular Characterization of Advanced Ductal Pancreas Adenocarcinoma for Better Treatment Selection (COMPASS) trial. Methods: Patients on this study undergo a biopsy for whole genome sequencing (WGS) and RNA sequencing prior to chemotherapy; those with germline variants in ATM were reviewed by a genetics counsellor and defined as pathogenic, likely pathogenic, variant of unknown significance (VUS) or benign/likely benign. Genomic characteristics were reviewed and published classifiers of homologous recombination deficiency (HRD) were applied to all cases and included the percentage of substitution base signature (SBS) 3, the HRDetect score, the computed algorithm of large scale transitions, telomeric allelic imbalances and loss of heterozygosity (LOH), otherwise known as the genomic instability score (GIS). Results: As of January 2020, 304 patients were enrolled and 245 patients had both WGS and clinical data available. 86 germline variants in ATM were present in 70 patients. The majority of these (80%) were classified as benign or likely benign. 10 VUS were detected and 4 patients (2%) had pathogenic/likely pathogenic variants (PV). Of these 4 patients, LOH or a second somatic hit was evident in 1 case. Upon review of the PVs and VUS, SBS were consistent with typical PDAC and tumour mutational burden was low. HRDetect scores were low ( < 0.1) for 13/14 cases with either a VUS or PV; one VUS without biallelic loss, had a high HRDetect score, with presence of SBS 3 and a high GIS. This particular case was also found to have a tandem duplicator phenotype. None of the 4 cases with PV had evidence of HRD. Furthermore all four were treated with platinum based regimens without evidence of response. Conclusions: In a large series of sequenced pancreatic cancers, the presence of pathogenic germline variants in ATM was rare, with none of the cases demonstrating evidence of HRD. This suggests that this population is unlikely to benefit from PARP inhibition.

Durvalumab therapy following chemoradiation compared with a historical cohort treated with chemoradiation alone in patients with stage III non-small cell lung cancer: A real-world multicentre study

BACKGROUND

The PACIFIC trial demonstrated that durvalumab therapy following chemoradiation (CRT) was associated with improved overall survival (OS) in patients with stage III non-small cell lung cancer (NSCLC). It is unclear whether the results obtained as part of randomised controlled trials are a reflection of real-world (RW) data. Several questions remain unanswered with regard to RW durvalumab use, such as optimal time to durvalumab initiation, incidence of pneumonitis and response in PD-L1 subgroups.

METHODS

In this multicentre retrospective analysis, 147 patients with stage III NSCLC treated with CRT followed by durvalumab were compared with a historical cohort of 121 patients treated with CRT alone. Survival curves were estimated using the Kaplan-Meier method and compared with the log-rank test in univariate analysis. Multivariate analysis was performed to evaluate the effect of standard prognostic factors for durvalumab use.

RESULTS

Median OS was not reached in the durvalumab group, compared with 26.9 months in the historical group (hazard ratio [HR]: 0.56, 95% confidence interval [CI]: 0.37-0.85, p = 0.001). In the durvalumab group, our data suggest improved 12-month OS in patients with PD-L1 expression ≥50% (100% vs 86%, HR: 0.25, 95% CI: 0.11-0.58, p = 0.007). There was no difference in OS between patients with a PD-L1 expression of 1-49% and patients with PD-L1 expression <1%. Delay in durvalumab initiation beyond 42 days did not impact OS. Incidence of pneumonitis was similar in the durvalumab and historical groups. In the durvalumab group, patients who experienced any-grade pneumonitis had a lower 12-month OS than patients without pneumonitis (85% vs 95%, respectively; HR: 3.3, 95% CI: 1.2-9.0, p = 0.006).

CONCLUSIONS

This multicentre analysis suggests that PD-L1 expression ≥50% was associated with favourable OS in patients with stage III NSCLC treated with durvalumab after CRT, whereas the presence of pneumonitis represented a negative prognostic factor.

Abstract 4325: A Phase II exploratory study to identify biomarkers prognostic of clinical response to regorafenib in patients with metastatic colorectal cancer who have failed first-line therapy

Single-agent regorafenib is approved in Canada and in the US for patients with metastatic colorectal cancer (mCRC) who have failed previous lines of therapy1. Identification of prognostic biomarkers is crucial to ensure the best therapeutic strategies for mCRC patients. The goal of this clinical study (NCT01949194) was to explore putative molecular signatures of response and resistance to regorafenib in metastatic tumors and serial blood samples. We used a multi-omics approach to profile metastatic tumor tissues and serial blood samples from 47 mCRC patients who received single-agent regorafenib as second-line therapy after failing first-line therapy with an oxaliplatin or irinotecan-containing regimen with or without bevacizumab. Whole exome sequencing was performed to assess both the mutational and copy number (CN) landscapes of metastatic tissues from 29 patients and the transcriptome was interrogated using RNA sequencing. A 14-gene panel was used to profile serial plasma samples. Molecular aberrations were then correlated with lesion-specific treatment response using RECIST 1.1 and progression free survival (PFS) to investigate potential associations.The copy number aberration (CNA) landscape of metastatic tumors was assessed using Nexus Copy Number Software and 20 significant focal aberrations were identified using Genomic Identification of Significant Target in Cancer (GISTIC) test (q-bound&lt;0.05). We interrogated all CNA regions across the genome using the log-rank statistic test and identified 38 CNA regions associated with PFS (permutated p-value &lt;0.05). Interestingly, CN gains targeting three genes, GPR52, PTGS2 and MYC, classified within the drug resistance gene category in the drug-interaction database (DGIdb), were associated with a shorter PFS (Kaplan Meier analysis). The mutational landscape showed typical mutation rates for the top 5 driver genes: APC, KRAS, BRAF, PIK3CA and TP53. However, KRAS mutations in exons 12 and 13 appeared enriched in intrinsically resistant lesions compared to stable and acquired resistance lesions (83% versus 41%). At the transcriptome level, three main pathways were associated with intrinsic resistance (TGF-β signaling activation and MAPK activation) and shorter PFS (adherens junction). The profiling of plasma samples showed a higher proportion of samples with non-detectable ctDNA in patients exhibiting longer PFS (PFS ≥ 9 months, 70%) compared to patients with shorter PFS (&lt; 9 months, 18%). This study allowed the identification of several candidate genes and regions at different molecular levels that warrant further validation in order to stratify patients who will likely respond, display intrinsic resistance or develop acquired resistance to regorafenib treatment. 1- Grothey A, Van Cutsem E, Sobrero A, Siena S, Falcone A, Ychou M, et al. Regorafenib monotherapy for previously treated metastatic colorectal cancer (CORRECT): an international, multicentre, randomized, placebo-controlled, phase 3 trial. Lancet. 2013 Jan 26;381(9863):303-12.

Citation Format: Karen Gambaro, Maud Marques, Suzan McNamara, Mathilde Couetoux du Tertre, Cyrla Hoffert, Archana Srivastava, Sophie Mathieu, Anna schab, Thierry Alcindor, Adrian Langleben, Lucas Sideris, Mahmoud Adbelsalam, Mustapha Tehfe, Gerald Batist, Petr Kavan. A Phase II exploratory study to identify biomarkers prognostic of clinical response to regorafenib in patients with metastatic colorectal cancer who have failed first-line therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4325.

Erratum: Therapeutic landscape of metastatic non-small-cell lung cancer in Canada in 2020

[This corrects the article DOI: 10.3747/co.27.5953.].

Outcomes and Immunogenicity of pancreatic cancer stratified by the HRDetect score

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Background: The HRDetect score uses whole genome sequencing (WGS) to incorporate patterns of substitution base signatures and structural variation to identify tumours deficient in homologous recombination repair (HRD). HRD-tumours, with a higher mutational burden, may be more immunogenic. Methods: We applied HRDetect to 182 resected pancreatic cancers (PDA) and 233 advanced PDA enrolled on the COMPASS trial; both cohorts underwent WGS after tumour enrichment. Patients were classified as high(hi) or low(lo) according to the published score threshold of 0.7; clinical characteristics and survival outcomes were determined. Immunogenicity of the cohorts was explored by analyzing cytolytic activity (CYT) as measured by RNA expression of perforin and granzyme A. Results: 14% of resected (25/182) and 14% of advanced cases (32/233) were considered HRDetecthi . The median age at PDA diagnosis was younger in HRDetecthi vs HRDetectlo (61 vs 66 years, p = 0.005), with no difference in sex between groups. Of the 57 cases identified, 37 (65%) were considered true HRD-PDA with inactivation of BRCA1, BRCA2, PALB2, RAD51C and XRCC2. The remaining 20 cases, were considered false positives for HRD; of these 7 had evidence of a tandem duplicator phenotype with duplications ranging from 10Kbp to 1Mbp in size and 13 had no defining genomic characteristics of the HRD-subtype. In resected PDA, the HRDetect score after adjusting for stage, was not prognostic. In contrast in a multivariable analysis of advanced cases, both HRDetect (HR 0.51, 95% CI 0.30-0.87, p = 0.01) and the Moffitt RNA classifier were highly prognostic (HR 1.99, 95% CI 1.32-3.00, p = 0.0001) with improved survival in HRDetecthi and classical PDA. Of patients receiving platinum in advanced disease (n = 128) HRDetecthi PDA had longer survival compared to the HRDetectlo (15.6 vs. 9.9 months, p = 0.02) although the interaction term between chemotherapy regimen (gemcitabine vs. platinum) and HRDetect score was not significant in this cohort. HRDetecthi tumours had increased cytolytic activity than HRDetectlo PDA; furthermore, within the cohort of HRDetecthi PDA, higher CYT scores were evident in primary lesions compared to metastatic sites sequenced. Conclusions: A high HRDetect score is prognostic in advanced PDA where patients treated with platinum have longest survival. HRDetecthi tumours have increased cytolytic activity with differences observed between primary and metastatic lesions.

Outcomes of elderly patients with resectable liver metastases from colorectal cancer (CRLM): Single center experience

34

Background: Half of patients with colorectal cancer develop liver metastases during the course of their disease. Surgery is the only potentially curative option for CRLM if resectable. Treatment of patients over 70 years old is challenging mainly because of comorbidities and other geriatric syndromes. Thus, we intended to report our experience with elderly patients with resectable CRLM. Methods: After approval by the Institutional Review Board (IRB), all records from a prospectively collected database at Centre Hospitalier de l’Université de Monréal (CHUM) were retrospectively analyzed. Clinicopathological characteristics, surgery and chemotherapy treatment modalities were reviewed. RFS and OS in patients ≥ 70y were calculated using the Kaplan Meier survival curve. Results: From 2010 to 2016, 101 patients older than 70 years were identified. Safety and surgical complications were previously reported. Median age was 75 years. CRLM were synchronous in 46.5% and metachronous in 53.5%. Relapse free survival (RFS) of patients ≥ 70 years was 33.7 months. Overall survival (OS) of patients ≥70 years was comparable to those of less than 65 years old (median OS: 56 vs 62 months; p = 0.15, respectively). Hepatic relapse showed worse survival when compared to extra-liver recurrence, mOS: 44 vs 33.2 vs 29.3 months for non-hepatic, hepatic only and hepatic with other sites respectively (trend p = 0.034). Although non-statistically significant, Patients with metachronous CRLM had superior mOS compared to those with synchronous disease (58.7 vs 44.7 months; p = 0.22). Conclusions: Survival Outcomes of patients with an age ≥ 70 years were comparable to those of younger patients and what is reported in literature. Age should not be a limiting factor in the management of elderly patients with resectable CRLM. Hepatic metastatectomies +/- chemotherapy should be offered with curative intents.

Therapeutic landscape of metastatic non-small-cell lung cancer in Canada in 2020

Lung cancer is the most commonly diagnosed cancer in Canada and remains associated with high mortality. Nevertheless, recent advances in the fields of immuno-oncology and precision medicine have led to significant improvements in clinical outcome in metastatic non-small-cell lung cancer (nsclc). Those improvements were facilitated by a greater understanding of the biologic classification of nsclc, which catalyzed discoveries of novel therapies. Here, we present a comprehensive review of the recent avalanche of practice-changing trials in metastatic nsclc, and we offer an approach to the management of this disease from a Canadian perspective. We begin with an overview of the pathologic and molecular characterization of metastatic nsclc. Next, we review the indications for currently approved immune checkpoint inhibitors, and we provide an approach to the management of disease with a driver mutation. Finally, we address future avenues in both diagnostics and therapeutics for patients with advanced and metastatic nsclc.

Homologous recombination deficiency (HRD) scoring in pancreatic ductal adenocarcinoma (PDAC) and response to chemotherapy

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Background: Whole genome sequencing (WGS) can reveal patterns of substitution base signatures and structural variation consistent with tumours deficient in homologous recombination repair. We evaluated the published HRDetect score and a novel HRD hallmark score (HS) in patients receiving combination chemotherapy (cCT) on the COMPASS trial for advanced PDAC. Methods: The HRD-HS incorporates 10 genomic characteristics of HRD-PDAC with a score ≥ 4 defining HRD. HRD-HS and an HRDetect score ≥0.7 were applied to WGS data and overall survival (OS) and response (ORR) evaluated. Sensitivity and specificity were ascertained. Results: As of 05/19, 205 eligible patients (pts) were enrolled and 186 received cCT including modified FOLFIRINOX n = 108 (58%) or cisplatin/gemcitabine n = 2 (1%) and gemcitabine/nab-paclitaxel n = 76 (41%). HRD-HS had a sensitivity of 87.5% and specificity of 100% in detecting HRD-PDAC. In contrast, HRDetect (≥0.7) had sensitivity of 51.9% and specificity of 100%; sensitivity increased to 73.7% when using a cutoff score of ≥0.99. 23/186 (12%) pts were classified as HRdetecthi and median OS was 15.3months (mo) vs 8.7mo in HRDetectlo pts (HR 0.44 95% CI 0.27-.70, p = 0.009). In platinum treated pts, median OS was 18.1mo (HRDetecthi) vs 9.3mo (HRDetectlo) (HR 0.38 95%CI 0.21-0.69, p = 0.02). HRD-HS predicted the longest median OS for platinum of 21.0mths. ORR in HRDetecthi was not different to HRDetectlo pts treated with cCT, however in those receiving platinum the ORR was 50% vs 19% respectively (p < 0.001). Of the false positives by HRDetect, 46% had a non-BRCA1 tandem duplicator phenotype (TDP). The TDP group comprised 8% of all patients enrolled. HRD-PDAC was caused by inactivation of BRCA1/2, PALB2, RAD51C and XRCC2; all germline variants were pathogenic. Pathogenic ATM and CHEK2 germline variants were present in 3 pts with evidence of a second somatic hit or LOH, none of these identified as HRD by either classifier nor considered a TDP. Conclusions: HRD-HS most correctly identified HRD-PDAC however the HRDetect score classifies additional patients sensitive to cCT, especially platinum. The TDP cohort may be responsive to DNA damaging agents warranting further evaluation. Clinical trial information: NCT02750657.

Efficacy of immune checkpoint inhibitors in older patients with non-small cell lung cancer: Real-world data from multicentric cohorts in Canada and France

BACKGROUND

Age-related immune remodelling is thought to be associated with resistance to immune checkpoint inhibitors (ICIs) in cancer. Patients older than 70 years, representing >50% of the population with non-small cell lung cancer (NSCLC) according to SEER database, are underrepresented in clinical trials exploring ICIs. The objective of this study was to determine if patients with NSCLC older than ≥70 years had inferior clinical outcomes with ICIs.

METHODS

We conducted a retrospective analysis of 381 patients treated with anti-PD-(L)1 ICI for advanced NSCLC at the Dijon Cancer Center (n = 177), University of Montreal Hospital (n = 106) and Quebec Heart and Lung Institute (n = 98). Age was considered as a categorical variable. Patients' baseline characteristics were compared using the Chi-squared test. Survival curves were estimated by the Kaplan-Meier method and compared with the Log-rank test in a univariate analysis. Multivariate cox regression model was used to determine hazard ratios and 95% confidence intervals for progression-free survival (PFS) and overall survival (OS) between the groups, adjusting for other clinicopathologic features.

RESULTS

Among 381 patients included, 335 (88%) received ICI after platinum chemotherapy. The median age was 66 (range 37-89) and 33% were older than 70 years of age. Considering age as a categorical variable, differences in age were not associated with PFS or OS. Subgroup analysis and multivariate cox regression did not reveal significant interaction of age with outcomes. ECOG performance status was the only significant factor in the three cohorts.

CONCLUSIONS

Unlike previously described in the era of chemotherapy, age was not associated with outcomes in NSCLC patients treated with ICI.