A multicenter study evaluating efficacy of immune checkpoint inhibitors in advanced non-colorectal digestive cancers with microsatellite instability

BACKGROUND

One randomized phase III trial comparing chemotherapy (CT) with immune checkpoint inhibitors (ICI) has demonstrated significant efficacy of ICI in deficient DNA mismatch repair system/microsatellite instability-high (dMMR/MSI-H) metastatic colorectal cancer. However, few studies have compared ICI with CT in other advanced dMMR/MSI-H digestive tumors.

METHODS

In this multicenter study, we included patients with advanced dMMR/MSI-H non-colorectal digestive tumors treated with chemotherapy and/or ICIs. Patients were divided retrospectively into two groups, a CT group and an immunotherapy (IO) group. The primary endpoint was progression-free survival (PFS). A propensity score approach using the inverse probability of treatment weighting (IPTW) method was applied to deal with potential differences between the two groups.

RESULTS

133 patients (45.1/27.1/27.8% with gastric/small bowel/other carcinomas) were included. The majority of patients received ICI in 1st (29.1%) or 2nd line (44.4%). The 24-month PFS rates were 7.9% in the CT group and 71.2% in the IO group. Using the IPTW method, IO treatment was associated with better PFS (HR=0.227; 95% CI 0.147-0.351; p < 0.0001). The overall response rate was 26.3% in the CT group versus 60.7% in the IO group (p < 0.001) with prolonged duration of disease control in the IO group (p < 0.001). In multivariable analysis, predictive factors of PFS for patients treated with IO were good performance status, absence of liver metastasis and prior primary tumor resection, whereas no association was found for the site of the primary tumor.

CONCLUSIONS

In the absence of randomized trials, our study highlights the superior efficacy of ICI compared with standard-of-care therapy in patients with unresectable or metastatic dMMR/MSI-H non-colorectal digestive cancer, regardless of tumor type, with acceptable toxicity.

Wnt, glucocorticoid and cellular prion protein cooperate to drive a mesenchymal phenotype with poor prognosis in colon cancer

BACKGROUND

The mesenchymal subtype of colorectal cancer (CRC), associated with poor prognosis, is characterized by abundant expression of the cellular prion protein PrPC, which represents a candidate therapeutic target. How PrPC is induced in CRC remains elusive. This study aims to elucidate the signaling pathways governing PrPC expression and to shed light on the gene regulatory networks linked to PrPC.

METHODS

We performed in silico analyses on diverse datasets of in vitro, ex vivo and in vivo models of mouse CRC and patient cohorts. We mined ChIPseq studies and performed promoter analysis. CRC cell lines were manipulated through genetic and pharmacological approaches. We created mice combining conditional inactivation of Apc in intestinal epithelial cells and overexpression of the human prion protein gene PRNP. Bio-informatic analyses were carried out in two randomized control trials totalizing over 3000 CRC patients.

RESULTS

In silico analyses combined with cell-based assays identified the Wnt-β-catenin and glucocorticoid pathways as upstream regulators of PRNP expression, with subtle differences between mouse and human. We uncover multiple feedback loops between PrPC and these two pathways, which translate into an aggravation of CRC pathogenesis in mouse. In stage III CRC patients, the signature defined by PRNP-CTNNB1-NR3C1, encoding PrPC, β-catenin and the glucocorticoid receptor respectively, is overrepresented in the poor-prognosis, mesenchymal subtype and associates with reduced time to recurrence.

CONCLUSIONS

An unleashed PrPC-dependent vicious circle is pathognomonic of poor prognosis, mesenchymal CRC. Patients from this aggressive subtype of CRC may benefit from therapies targeting the PRNP-CTNNB1-NR3C1 axis.

Efficacy of immune checkpoint inhibitors for metastatic colorectal cancer with microsatellite instability in second or latter line using synthetic control arms: A non-randomised evaluation

PURPOSE

Immune checkpoint inhibitors (ICIs) appeared active in single-arm trials for patients with chemoresistant metastatic colorectal cancer (mCRC) harboring microsatellite instability (MSI). Given the paucity of randomised controlled trials (RCTs) in this setting, we evaluated the effect size of ICIs using intra-patients comparison and ARCAD database as historical controls.

PATIENTS AND METHODS

Individual-patient data from NIPICOL and CheckMate 142 phase II trials that evaluated a combination of ICIs for MSI mCRC patients (N = 176) and from five non-ICI mCRC historical RCTs in second-line or latter (N = 4026) were analyzed. Firstly, promising of ICIs was identified using intra-patient comparison based on growth modulation index (GMI) defined the ratio of progression-free survivals (PFS) on ICIs and previous line of therapy. Survival outcomes of ICIs-treated patients were then compared with those matched non-ICIs treated from ARCAD database historical RCTs.

RESULTS

Among ICIs-treated patients, median PFS on ICIs was 32.66 (range 0.10-74.25) versus 4.07 months (range 0.7-49.87) on prior therapy, resulting on median GMI of 4.97 (range 0.07-59.51; hazard-ratio (HR)= 0.16 (95 %CI=0.11-0.22, P < 0.001)). Compared to matched non-ICI patients, in third-line, median overall survival (OS) was not reached with ICIs versus 3.52 months with placebo (HR=0.20, 95 %CI=0.10-0.41, P < 0.001), and 6.51 months with active drugs (HR=0.30, 95 %CI=0.15-0.60, P = 0.001). In second-line, median OS was not reached with ICIs versus 11.7 months with chemotherapy+placebo (HR=0.12, 95 %CI=0.07-0.22, P < 0.001), and 16.3 months with chemotherapy+targeted therapy (HR=0.10, 95 %CI=0.05-0.19, P < 0.001).

CONCLUSION

ICIs demonstrates high effect size for MSI mCRC patients in second-line and later. This work might be useful as an example of methodology to avoid RCTs when benefit from experimental therapy is likely to be high.

Deficient mismatch repair/microsatellite unstable colorectal cancer: therapeutic advances and questions

The microsatellite instability (MSI) phenotype is related to a deficiency of the DNA mismatch repair (dMMR) system and is observed in 5% of metastatic colorectal cancers (mCRCs). MSI/dMMR phenotype testing should be routine for all CRCs regardless of stage. Two complementary techniques with a high concordance (90-97%) allow us to determine the MSI/dMMR status of a tumor: immunohistochemistry and polymerase chain reaction. Since 2020 and the results of the phase III KEYNOTE 177 trial, pembrolizumab [anti-programmed cell death protein 1 (PD1)] is the new standard of care in first-line MSI/dMMR mCRC. To date, no combination of chemtotherapy ± targeted therapy with immune checkpoint inhibitors (ICIs) has been validated in the management of MSI/dMMR mCRC, and it is not known whether this combination would be beneficial. It is also unclear whether dual therapy with two ICIs is more effective than monotherapy. Several phase III trials are ongoing to answer these questions. Despite a high response rate and long-term benefit of a first line by anti-PD1, 30-50% of patients with MSI/dMMR mCRC experience an early or secondary progression. There are currently no validated predictive biomarkers of anti-PD1 ± anti-cytotoxic T lymphocyte antigen-4 resistance in patients with MSI/dMMR mCRC. In case of early progression on ICIs, the first two questions to consider are the possibility of pseudoprogression and the correct diagnosis of MSI/dMMR status. To date, there are no data on the use of adjuvant ICIs for MSI/dMMR resected colon cancers. By contrast, data are accumulating regarding the efficacy of neoadjuvant ICIs, with at least two-thirds of patients in the different trials in pathological complete response, making it possible to envisage 'Watch and wait' strategies in future.

KEYSTEP-008: phase II trial of pembrolizumab-based combination in MSI-H/dMMR metastatic colorectal cancer

Robust clinical activity has been observed with the immune checkpoint inhibitor pembrolizumab in patients with microsatellite instability-high/mismatch repair-deficient (MSI-H/dMMR) metastatic colorectal cancer (mCRC). However, given the response rate of 45% and a median progression-free survival of 16.5 months with first-line pembrolizumab demonstrated in KEYNOTE-177, there is room for improvement. Targeting a second immune receptor, such as CTLA-4, LAG-3, TIGIT, or ILT-4 may improve efficacy of PD-1 inhibition. Here we describe the design and rationale for the open-label, randomized, phase II KEYSTEP-008 trial, which will evaluate the efficacy and safety of pembrolizumab-based combination therapy compared with pembrolizumab monotherapy in chemotherapy-refractory (cohort A) or previously untreated (cohort B) MSI-H/dMMR mCRC. Clinical Trial Registration: NCT04895722 (ClinicalTrials.gov).

Antitumor Activity and Safety of Dostarlimab Monotherapy in Patients With Mismatch Repair Deficient Solid Tumors: A Nonrandomized Controlled Trial

Importance

Mismatch repair deficiency (dMMR) occurs in various cancers, and these tumors are attractive candidates for anti-programmed cell death 1 therapies, such as dostarlimab, a recently approved immune checkpoint inhibitor.

Objective

To assess the antitumor activity and safety of dostarlimab in patients with advanced or recurrent dMMR solid tumors.

Design, Setting, And Participants

The GARNET trial was a phase 1, open-label, single-group, multicenter study that began enrolling May 8, 2017. Participants had advanced or recurrent dMMR and microsatellite instability-high (MSI-H) or polymerase epsilon (POLE)-altered solid tumors. The data cut for this interim analysis was from November 1, 2021, with median follow-up of 27.7 months.

Interventions

Patients received 500 mg of dostarlimab intravenously every 3 weeks for 4 doses, then 1000 mg every 6 weeks until disease progression, discontinuation, or withdrawal.

Main Outcomes and Measures

The primary objective was to evaluate objective response rate and duration of response in patients with dMMR solid tumors by blinded independent central review using Response Evaluation Criteria in Solid Tumors, version 1.1.

Results

The efficacy population included 327 patients (median [range] age, 63 [24-85] years; 235 [71.9%] female; 7 [2.1%] Asian, 6 [1.8%] Black, and 206 [63.0%] White patients), with 141 patients (43.1%) with dMMR endometrial cancer, 105 patients (32.1%) with dMMR colorectal cancer, and 81 patients (24.8%) with other dMMR tumor types. All patients had at least 1 previous line of therapy. Objective response rate assessed per blinded independent central review for dMMR solid tumors was 44.0% (95% CI, 38.6% to 49.6%). Median duration of response was not reached (range, ≥1.18 to ≥47.21 months); 72.2% of responders (104 of 144) had a response lasting 12 or more months. Median progression-free survival was 6.9 months (95% CI, 4.2 to 13.6 months); probability of progression-free survival at 24 months was 40.6% (95% CI, 35.0% to 46.1%). Median overall survival was not reached (95% CI, 31.6 months to not reached). The most frequent immune-related adverse events were hypothyroidism (25 [6.9%]), alanine aminotransferase increase (21 [5.8%]), and arthralgia (17 [4.7%]). No new safety concerns were identified.

Conclusions And Relevance

In this nonrandomized controlled trial, dostarlimab was a well-tolerated treatment option with rapid, robust, and durable antitumor activity in patients with diverse dMMR solid tumors. These findings suggest that dostarlimab provides meaningful long-term benefit in a population with high unmet need.

Trial Registration

ClinicalTrials.gov Identifier: NCT02715284.

Different prognostic values of KRAS exon 2 submutations and BRAF V600E mutation in microsatellite stable (MSS) and unstable (MSI) stage III colon cancer: an ACCENT/IDEA pooled analysis of seven trials

BACKGROUND

The prognostic value of KRAS and BRAFV600E mutations in stage III colon cancer (CC) remains controversial and has never been clearly analyzed in patients with microsatellite instability-high (MSI-H) tumors due to sample size limitations. Data are also lacking for KRAS submutations and prognosis.

PATIENTS AND METHODS

We examined clinicopathological variables and prognosis in patients with surgically resected stage III CC who participated in seven clinical trials from the ACCENT/IDEA databases. Associations between KRAS exon 2 and BRAFV600E mutations and time to recurrence (TTR), overall survival (OS), and survival after recurrence (SAR) were assessed using a Cox model. We also analyzed the prognostic value of KRAS exon 2 submutations.

RESULTS

Among 8460 patients, 11.4% had MSI-H status. In the MSI-H group, BRAFV600E, KRAS exon 2 mutants, and double-wild-type statuses were detected in 40.6%, 18.1%, and 41.3%, respectively, whereas and in the microsatellite stable (MSS) group, these were detected in 7.7%, 38.6%, and 53.8%, respectively. In the MSS group, 5-year TTR rates of 61.8%, 66.3%, and 72.9% were observed among patients with BRAFV600E, KRAS exon 2 mutants, and those who were DWT, respectively [adjusted hazard ratio (HR) = 1.58 and 1.31, both P < 0.001]. In the MSI-H group, 5-year TTR rates did not differ significantly among the mutated subgroups. Similar results were found for OS. However, survival after relapse was significantly shorter in the KRAS exon 2- and BRAFV600E-mutated patients in both MSS (adjusted HR = 2.06 and 1.15; both P < 0.05) and MSI-H (adjusted HR = 1.99 and 1.81; both P < 0.05) groups. In the MSS group, KRAS exon 2 mutations were associated with TTR, but only p.G12C, p.G12D, and p.G13D were associated with poor outcomes after disease recurrence.

CONCLUSIONS

Testing for both KRAS and BRAFV600E mutations in stage III patients should be considered as they can better define individual patient prognosis, and may also enable patient selection for (neo)adjuvant trials dedicated to specific molecular subtypes with poor prognosis.

[Safety and efficacy of immune checkpoint inhibitors in elderly patients]

Immune checkpoint inhibitors (ICI) are the standard of care for many solid tumors with specific physiopathology mechanisms and adverse events. While the percentage of elderly patients increase from years to years, these patients are underrepresented in clinical trials. Immunosenescence and inflammaging, two main components of the aging of our immune system, and their consequences on the safety and the efficacy are today major focus of clinical research. However, there are still no risk assessment score specific to ICI in elderly patients. In this review we showed the global reassuring data on safety from several retrospective and subgroup analysis, in elderly patients. In summary, impairment of the general state is an independent factor of occurrence of adverse events treatment related whatever the age. Here, we highlight the necessity to use of geriatric evaluation screening test in clinic, the need of specific risk score ICI use in the erdely population and mostly the inclusion of elderly patients in clinical trial to generate specific data.

Time to recurrence and its relation to survival after recurrence in patients resected for stage III colon cancer

BACKGROUND

It is intuitively thought that early relapse is associated with poor survival after recurrence (SAR) in resected colon cancer (CC) patients, but this has never been formally studied.

METHODS

We pooled data from stage III patients treated with oxaliplatin-based adjuvant therapy in two phase III trials, to analyse time to recurrence (TTR) and its relationship with SAR. TTR and SAR were also studied according to molecular status (mismatch repair (MMR), RAS, and BRAFV600E). Early relapsing patients were defined as patients having a TTR event within 12 months after starting adjuvant chemotherapy.

RESULTS

4548 stage III CC patients were included in the present analysis. Deficient MMR (dMMR) CC patients experienced fewer recurrences than proficient (p)MMR CC patients (18.8% versus 27.6%) but had a significantly shorter median TTR (mTTR; 0.74 versus 1.40 years, p < 0.0001). In pMMR patients, BRAF and RAS mutations were also associated with earlier mTTR as compared to double wild-type (WT) patients (0.99 versus 1.38 versus 1.54 years, respectively, p < 0.0001). Early recurrence occurred in 397 patients and was associated with a median SAR (2.2 versus 3.3 years, p = 0.0007). However, this association was mainly due to pMMR/RAS and BRAFV600E mutated tumours and was not confirmed in dMMR and pMMR/double WT subgroups.

CONCLUSION

In resected stage III CC treated with standard oxaliplatin-based adjuvant therapy, TTR varies between dMMR, pMMR/RAS, or BRAFV600E mutated and pMMR/double WT tumours. In addition, early relapse is associated with poor survival, mainly due to patients resected for a pMMR/RAS or BRAFV600E mutated tumour.

Avelumab vs Standard Second-Line Chemotherapy in Patients With Metastatic Colorectal Cancer and Microsatellite Instability: A Randomized Clinical Trial

Importance

Only 1 randomized clinical trial has shown the superiority of immune checkpoint inhibitors in patients with deficient mismatch repair and/or microsatellite instability (dMMR/MSI) metastatic colorectal cancer (mCRC) in the first-line setting.

Objectives

To determine whether avelumab (an anti-programmed cell death ligand 1 antibody) improves progression-free survival (PFS) compared with standard second-line chemotherapy in patients with dMMR/MSI mCRC.

Design, Setting, and Participants

The SAMCO-PRODIGE 54 trial is a national open-label phase 2 randomized clinical trial that was conducted from April 24, 2018, to April 29, 2021, at 49 French sites. Patients with dMMR/MSI mCRC who experienced progression while receiving standard first-line therapy were included in the analysis.

Interventions

Patients were randomized to receive standard second-line therapy or avelumab every 2 weeks until progression, unacceptable toxic effects, or patient refusal.

Main Outcome and Measures

The primary end point was PFS according to RECIST (Response Evaluation Criteria in Solid Tumours), version 1.1, evaluated by investigators in patients with mCRC and confirmed dMMR and MSI status who received at least 1 dose of treatment (modified intention-to-treat [mITT] population).

Results

A total of 122 patients were enrolled in the mITT population. Median age was 66 (IQR, 56-76) years, 65 patients (53.3%) were women, 100 (82.0%) had a right-sided tumor, and 52 (42.6%) had BRAF V600E-mutated tumors. There was no difference in patients and tumor characteristics between treatment groups. No new safety concerns in either group were detected, with fewer treatment-related adverse events of at least grade 3 in the avelumab group than in the chemotherapy group (20 [31.7%] vs 34 [53.1%]; P = .02). After a median follow-up of 33.3 (95% CI, 28.3-34.8) months, avelumab was superior to chemotherapy with or without targeted agents with respect to PFS (15 [24.6%] vs 5 [8.2%] among patients without progression; P = .03). Rates of PFS rates at 12 months were 31.2% (95% CI, 20.1%-42.9%) and 19.4% (95% CI, 10.6%-30.2%) in the avelumab and control groups, respectively, and 27.4% (95% CI, 16.8%-39.0%) and 9.1% (95% CI, 3.2%-18.8%) at 18 months. Objective response rates were similar in both groups (18 [29.5%] vs 16 [26.2%]; P = .45). Among patients with disease control, 18 (75.7%) in the avelumab group compared with 9 (19.1%) in the control group had ongoing disease control at 18 months.

Conclusions

The SAMCO-PRODIGE 54 phase 2 randomized clinical trial showed, in patients with dMMR/MSI mCRC, better PFS and disease control duration with avelumab over standard second-line treatment, with a favorable safety profile.

Trial Registration

ClinicalTrials.gov Identifier: NCT03186326.

BRAF V600E/RAS Mutations and Lynch Syndrome in Patients With MSI-H/dMMR Metastatic Colorectal Cancer Treated With Immune Checkpoint Inhibitors

BACKGROUND

We pooled data from 2 cohorts of immune checkpoint inhibitors-treated microsatellite instability-high/mismatch repair-deficient (MSI/dMMR) metastatic colorectal cancer patients to evaluate the prognostic value of RAS/BRAFV600E mutations and Lynch syndrome (LS).

PATIENTS AND METHODS

Patients were defined as LS-linked if germline mutation was detected and as sporadic if loss of MLH1/PMS2 expression with BRAFV600E mutation and/or MLH1 promoter hypermethylation, or biallelic somatic MMR genes mutations were found. Progression-free survival (PFS) and overall survival (OS) were adjusted on prognostic modifiers selected on unadjusted analysis (P < .2) if limited number of events.

RESULTS

Of 466 included patients, 305 (65.4%) and 161 (34.5%) received, respectively, anti-PD1 alone and anti-PD1+anti-CTLA4 in the total population, 111 (24.0%) were treated in first-line; 129 (28.8%) were BRAFV600E-mutated and 153 (32.8%) RAS-mutated. Median follow-up was 20.9 months. In adjusted analysis of the whole population (PFS/OS events = 186/133), no associations with PFS and OS were observed for BRAFV600E-mutated (PFS HR= 1.20, P = .372; OS HR = 1.06, P = .811) and RAS-mutated patients (PFS HR = 0.93, P = .712, OS HR = 0.75, P = .202). In adjusted analysis in the Lynch/sporadic status-assigned population (n = 242; PFS/OS events = 80/54), LS-liked patients had an improved PFS compared to sporadic cases (HR = 0.49, P = .036). The adjusted HR for OS was 0.56 with no significance (P = .143). No adjustment on BRAFV600E mutation was done due to collinearity.

CONCLUSION

In this cohort, RAS/BRAFV600E mutations were not associated with survival while LS conferred an improved PFS.

DCF versus doublet chemotherapy as first-line treatment of advanced squamous anal cell carcinoma: a multicenter propensity score-matching study

Triplet DCF (docetaxel, cisplatin and 5-flurouracil) and doublet CP/CF (carboplatin and paclitaxel/cisplatin and 5-fluorouracil) regimens were prospectively evaluated in advanced squamous anal cell carcinoma (SCCA), and validated as standard treatments. Even though the high efficacy and good tolerance of DCF regimen were confirmed in 3 independent prospective trials, doublet CP regimen is still recommended in several guidelines based in its better safety profile with similar efficacy compared to CF regimen. We performed a propensity score-adjusted method with inverse probability of treatment weighted (IPTW) and matched case control (MCC) comparison among patients with metastatic or non-resectable locally advanced recurrent SCCA, treated with chemotherapy as first line regimen. The primary endpoint was the overall survival (OS), and the secondary endpoint was the progression-free survival (PFS). 247 patients were included for analysis. 154 patients received DCF and 93 patients received a doublet regimen. The median OS was 32.3 months with DCF and 18.3 months with doublet regimens (HR 0.53, 95%CI 0.38-0.74; p = 0.0001), and the median PFS was 11.2 months with DCF versus 7.6 months with doublet regimens (HR 0.53, 95%CI 0.39-0.73; p < 0.0001). The hazard ratios by IPTW and MCC analyses were 0.411 (95% CI, 0.324-0.521; p < 0.0001) and 0.406 (95% CI, 0.261-0.632; p < 0.0001) for OS, and 0.466 (95% CI, 0.376-0.576; p < 0.0001) and 0.438 (95% CI, 0.298-0.644; P < 0.0001) for PFS. The triplet DCF regimen provides a high and significant benefit in OS and PFS over doublet regimens, and should be considered as upfront treatment for eligible patients with advanced SCCA.

FOLFIRI Followed by FOLFOX6 or the Reverse Sequence in Advanced Colorectal Cancer: A Randomized GERCOR Study

PURPOSE

In metastatic colorectal cancer, phase III studies have demonstrated the superiority of fluorouracil (FU) with leucovorin (LV) in combination with irinotecan or oxaliplatin over FU + LV alone. This phase III study investigated two sequences: folinic acid, FU, and irinotecan (FOLFIRI) followed by folinic acid, FU, and oxaliplatin (FOLFOX6; arm A), and FOLFOX6 followed by FOLFIRI (arm B).

PATIENTS AND METHODS

Previously untreated patients with assessable disease were randomly assigned to receive a 2-hour infusion of l-LV 200 mg/m² or dl-LV 400 mg/m² followed by a FU bolus 400 mg/m² and 46-hour infusion 2,400 to 3,000 mg/m² every 46 hours every 2 weeks, either with irinotecan 180 mg/m² or with oxaliplatin 100 mg/m² as a 2-hour infusion on day 1. At progression, irinotecan was replaced by oxaliplatin (arm A), or oxaliplatin by irinotecan (arm B).

RESULTS

Median survival was 21.5 months in 109 patients allocated to FOLFIRI then FOLFOX6 versus 20.6 months in 111 patients allocated to FOLFOX6 then FOLFIRI (P = .99). Median second progression-free survival (PFS) was 14.2 months in arm A versus 10.9 in arm B (P = .64). In first-line therapy, FOLFIRI achieved 56% response rate (RR) and 8.5 months median PFS, versus FOLFOX6 which achieved 54% RR and 8.0 months median PFS (P = .26). Second-line FOLFIRI achieved 4% RR and 2.5 months median PFS, versus FOLFOX6 which achieved 15% RR and 4.2 months PFS. In first-line therapy, National Cancer Institute Common Toxicity Criteria grade 3/4 mucositis, nausea/vomiting, and grade 2 alopecia were more frequent with FOLFIRI, and grade 3/4 neutropenia and neurosensory toxicity were more frequent with FOLFOX6.

CONCLUSION

Both sequences achieved a prolonged survival and similar efficacy. The toxicity profiles were different.

Outcomes and a prognostic classifier in patients with microsatellite instability-high metastatic gastric cancer receiving PD-1 blockade

BACKGROUND

Subgroup analyses of randomized trials suggest the superiority of immune checkpoint inhibitor-based therapy over chemotherapy in patients with mismatch-repair deficient (dMMR) and/or microsatellite instability-high (MSI-high) advanced gastric or gastroesophageal junction adenocarcinoma. However, these subgroups are small and studies examining prognostic features within dMMR/MSI-high patients are lacking.

METHODS

We conducted an international cohort study at tertiary cancer centers and collected baseline clinicopathologic features of patients with dMMR/MSI-high metastatic or unresectable gastric cancer treated with anti-programmed cell death protein-1 (PD-1)-based therapies. The adjusted HRs of variables significantly associated with overall survival (OS) were used to develop a prognostic score.

RESULTS

One hundred and thirty patients were included. At a median follow-up of 25.1 months, the median progression-free survival (PFS) was 30.3 months (95% CI: 20.4 to NA) and 2-year PFS rate was 56% (95% CI: 48% to 66%). Median OS was of 62.5 months (95% CI: 28.4 to NA) and 2-year OS rate was 63% (95% CI: 55% to 73%). Among the 103 Response Evaluation Criteria in Solid Tumors-evaluable patients, objective response rate was 66% and disease control rate 87% across lines of therapy. In the multivariable models, Eastern Cooperative Oncology Group Performance Status of 1 or 2, non-resected primary tumor, presence of bone metastases and malignant ascites were independently associated with poorer PFS and OS. These four clinical variables were used to build a three-category (ie, good, intermediate, and poor risk) prognostic score. Compared with patients with good risk, patients with intermediate risk score had numerically inferior PFS and OS (2-year PFS rate: 54.3% versus 74.5%, HR 1.90, 95% CI: 0.99 to 3.66; 2-year OS rate: 66.8% versus 81.2%, HR 1.86, 95% CI: 0.87 to 3.98), whereas patients with poor risk score had significantly inferior PFS and OS (2-year PFS rate: 10.6%, HR 9.65, 95% CI: 4.67 to 19.92; 2-year OS rate: 13.3%, HR 11.93, 95% CI: 5.42 to 26.23).

CONCLUSIONS

Overall outcomes with anti-PD-1-based therapies are favorable in MSI-high gastroesophageal adenocarcinomas. However, within this overall favorable subgroup a more accurate prognostication using baseline clinical characteristics might identify patients at higher risk of rapid disease progression who may deserve intensified immunotherapy combination strategies.

Prediction of Response to Immune Checkpoint Blockade in Patients with Metastatic Colorectal Cancer with Microsatellite Instability

BACKGROUND

Mismatch repair deficient (dMMR) tumors displaying microsatellite instability (MSI) represent a paradigm for the success of immune checkpoint inhibitor (ICI)-based immunotherapy, particularly in patients with metastatic colorectal cancer (mCRC). However, a proportion of patients with dMMR/MSI mCRC exhibit resistance to ICI. Identification of tools predicting MSI mCRC patient response to ICI are required for the design of future strategies further improving this therapy.

PATIENTS AND METHODS

We combined high-throughput DNA and RNA sequencing of tumors from 116 patients with MSI mCRC treated with anti-PD-1 +/- anti-CTLA-4 of the NIPICOL phase II trial (C1, NCT03350126, discovery set) and the IMMUNOMSI prospective cohort (C2, validation set). The DNA/RNA predictors whose status was significantly associated with ICI status of response in C1 were subsequently validated in C2. Primary endpoint was iPFS (progression-free survival by iRECIST).

RESULTS

Analyses showed no impact of previously suggested DNA/RNA indicators of resistance to ICI, e.g., MSISensor score, tumor mutational burden, or specific cellular and molecular tumoral contingents. By contrast, iPFS under ICI was shown in C1 and C2 to depend both on a multiplex MSI signature involving the mutations of 19 microsatellites (HR_C2 = 3.63; 95% CI [1.65-7.99] ; p = 1.4x10^-3) and the expression of a set of 182 RNA markers with a non-epithelial TGFB-related desmoplastic orientation (HR_C2 = 1.75 ; 95% CI [1.03-2.98] ; p = 0.035). Both DNA and RNA signatures were independently predictive of iPFS.

CONCLUSIONS

iPFS in patients with MSI mCRC can be predicted by simply analyzing the mutational status of DNA microsatellite-containing genes in epithelial tumor cells together with nonepithelial TGFB-related desmoplastic RNA markers.

ANCHOR CRC: Results From a Single-Arm, Phase II Study of Encorafenib Plus Binimetinib and Cetuximab in Previously Untreated BRAFV600E-Mutant Metastatic Colorectal Cancer

PURPOSE

The positive BEACON colorectal cancer (CRC) safety lead-in, evaluating encorafenib + cetuximab + binimetinib in previously treated patients with BRAFV600E-mutated metastatic CRC (mCRC), prompted the design of the phase II ANCHOR CRC study (ClinicalTrails.gov identifier: NCT03693170). ANCHOR CRC aimed to evaluate efficacy, safety, and quality of life with first-line encorafenib + binimetinib + cetuximab in BRAFV600E-mutated mCRC.

METHODS

In this multicenter, open-label, single-arm study, patients with BRAFV600E-mutated mCRC received oral encorafenib 300 mg once daily and binimetinib 45 mg twice daily in 28-day cycles, plus intravenous cetuximab 400 mg/m2 once on day 1 of cycle 1, then 250 mg/m2 once weekly for the first seven cycles, and 500 mg/m2 once on Days 1 and 15 from cycle 8 onward. The primary end point was locally assessed confirmed objective response rate (cORR), and secondary end points included centrally assessed cORR, progression-free survival, overall survival (OS), quality of life, and safety and tolerability.

RESULTS

Among 95 patients, the locally assessed cORR was 47.4% (95% CI, 37.0 to 57.9) with all partial responses. Since the lower limit of the 95% CI exceeded 30%, the primary end point was met. With a median follow-up duration of 20.1 months, the median progression-free survival on the basis of local assessments was 5.8 months and the median OS was 18.3 months. Treatment was well tolerated, with no unexpected toxicities. Using Patient Global Impression of Changes, substantial improvement in symptoms was consistently reported in ≥ 30% of patients from cycle 3 to cycle 10.

CONCLUSION

The ANCHOR CRC study showed that the scientifically driven combination of encorafenib + binimetinib + cetuximab was active in the first-line setting of BRAFV600E-mutated mCRC with a manageable safety profile. Further first-line evaluation is ongoing (ClinicalTrails.gov identifier: NCT04607421).

Tucatinib plus trastuzumab for chemotherapy-refractory, HER2-positive, RAS wild-type unresectable or metastatic colorectal cancer (MOUNTAINEER): a multicentre, open-label, phase 2 study

BACKGROUND

HER2 is an actionable target in metastatic colorectal cancer. We assessed the activity of tucatinib plus trastuzumab in patients with chemotherapy-refractory, HER2-positive, RAS wild-type unresectable or metastatic colorectal cancer.

METHODS

MOUNTAINEER is a global, open-label, phase 2 study that enrolled patients aged 18 years and older with chemotherapy-refractory, HER2-positive, RAS wild-type unresectable or metastatic colorectal cancer at 34 sites (clinics and hospitals) in five countries (Belgium, France, Italy, Spain, and the USA). Initially, the study was designed as a single-cohort study, which was expanded following an interim analysis to include more patients. Initially, patients were given tucatinib (300 mg orally twice daily) plus intravenous trastuzumab (8 mg/kg as an initial loading dose, then 6 mg/kg every 21 days; cohort A) for the duration of treatment (until progression), and after expansion, patients were randomly assigned (4:3), using an interactive web response system and stratified by primary tumour location, to either tucatinib plus trastuzumab (cohort B) or tucatinib monotherapy (cohort C). The primary endpoint was confirmed objective response rate per blinded independent central review (BICR) for cohorts A and B combined and was assessed in patients in the full analysis set (ie, patients with HER2-positive disease who received at least one dose of study treatment). Safety was assessed in all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT03043313, and is ongoing.

FINDINGS

Between Aug 8, 2017, and Sept 22, 2021, 117 patients were enrolled (45 in cohort A, 41 in cohort B, and 31 in cohort C), of whom 114 patients had locally assessed HER2-positive disease and received treatment (45 in cohort A, 39 in cohort B, and 30 in cohort C; full analysis set), and 116 patients received at least one dose of study treatment (45 in cohort A, 41 in cohort B, and 30 in cohort C; safety population). In the full analysis set, median age was 56·0 years (IQR 47-64), 66 (58%) were male, 48 (42%) were female, 88 (77%) were White, and six (5%) were Black or African American. As of data cutoff (March 28, 2022), in 84 patients from cohorts A and B in the full analysis set, the confirmed objective response rate per BICR was 38·1% (95% CI 27·7-49·3; three patients had a complete response and 29 had a partial response). In cohorts A and B, the most common adverse event was diarrhoea (55 [64%] of 86), the most common grade 3 or worse adverse event was hypertension (six [7%] of 86), and three (3%) patients had tucatinib-related serious adverse events (acute kidney injury, colitis, and fatigue). In cohort C, the most common adverse event was diarrhoea (ten [33%] of 30), the most common grade 3 or worse adverse events were increased alanine aminotransferase and aspartate aminotransferase (both two [7%]), and one (3%) patient had a tucatinib-related serious adverse event (overdose). No deaths were attributed to adverse events. All deaths in treated patients were due to disease progression.

INTERPRETATION

Tucatinib plus trastuzumab had clinically meaningful anti-tumour activity and favourable tolerability. This treatment is the first US Food and Drug Administration-approved anti-HER2 regimen for metastatic colorectal cancer and is an important new treatment option for chemotherapy-refractory HER2-positive metastatic colorectal cancer.

FUNDING

Seagen and Merck & Co.

Fluoropyrimidine-induced hand-foot syndrome and cardiotoxicity: recommendations for the use of the oral fluoropyrimidine S-1 in metastatic colorectal cancer

BACKGROUND

Fluoropyrimidines (FPs) are an essential part of the majority of systemic regimens in the treatment of metastatic colorectal cancer (CRC). The use of the oral FP S-1 has been approved by the European Medicines Agency as monotherapy or in combination with oxaliplatin or irinotecan, with or without bevacizumab, for the treatment of patients with metastatic CRC in whom it is not possible to continue treatment with another FP due to hand-foot syndrome (HFS) or cardiovascular toxicity (CVT). Subsequently, this indication has been included in the 2022 ESMO guidelines for metastatic CRC. Recommendations for use in daily practice are not available.

PATIENTS AND METHODS

Based on peer-reviewed published data on the use of S-1 in Western patients with metastatic CRC who switched from infusional 5-fluorouracil (5-FU) or capecitabine to S-1 for reasons of HFS or CVT, recommendations for its use were formulated by an international group of medical oncologists with expertise in the treatment of metastatic CRC and a cardio-oncologist.

RESULTS

In patients who experience pain and/or functional impairment due to HFS during treatment with capecitabine or infusional 5-FU, a switch to S-1 is recommended without prior dose reduction of capecitabine/5-FU. S-1 should preferably be initiated at full dose when HFS has decreased to grade ≤1. In patients with cardiac complaints, in whom an association with capecitabine or infusional 5-FU treatment cannot be excluded, capecitabine/5-FU should be discontinued and a switch to S-1 is recommended.

CONCLUSIONS

These recommendations should guide clinicians in daily practice in the treatment of patients with metastatic CRC with FP-containing regimens.

Prognostic Impact of Early Treatment and Oxaliplatin Discontinuation in Patients With Stage III Colon Cancer: An ACCENT/IDEA Pooled Analysis of 11 Adjuvant Trials

PURPOSE

Oxaliplatin-based adjuvant chemotherapy in patients with stage III colon cancer (CC) for 6 months remains a standard in high-risk stage III patients. Data are lacking as to whether early discontinuation of all treatment (ETD) or early discontinuation of oxaliplatin (EOD) could worsen the prognosis.

MATERIALS AND METHODS

We studied the prognostic impact of ETD and EOD in patients with stage III CC from the ACCENT/IDEA databases, where patients were planned to receive 6 months of infusional fluorouracil, leucovorin, and oxaliplatin or capecitabine plus oxaliplatin. ETD was defined as discontinuation of treatment and EOD as discontinuation of oxaliplatin only before patients had received a maximum of 75% of planned cycles. Association between ETD/EOD and overall survival and disease-free survival (DFS) were assessed by Cox models adjusted for established prognostic factors.

RESULTS

Analysis of ETD and EOD included 10,447 (20.9% with ETD) and 7,243 (18.8% with EOD) patients, respectively. Compared with patients without ETD or EOD, patients with ETD or EOD were statistically more likely to be women, with Eastern Cooperative Oncology Group performance status ≥ 1, and for ETD, older with a lower body mass index. In multivariable analyses, ETD was associated with a decrease in disease-free survival and overall survival (hazard ratio [HR], 1.61, P < .001 and HR, 1.73, P < .001), which was not the case for EOD (HR, 1.07, P = .3 and HR, 1.13, P = .1). However, patients who received < 50% of the planned cycles of oxaliplatin had poorer outcomes.

CONCLUSION

In patients treated with 6 months of oxaliplatin-based chemotherapy for stage III CC, ETD was associated with poorer oncologic outcomes. However, this was not the case for EOD. These data favor discontinuing oxaliplatin while continuing fluoropyrimidine in individuals with significant neurotoxicity having received > 50% of the planned 6-month chemotherapy.

Impact of mismatch repair deficiency on tumour regression grade after neoadjuvant chemotherapy in localized gastroesophageal adenocarcinoma

BACKGROUND

The use of neoadjuvant chemotherapy (NAC) in patients with mismatch repair (MMR) deficient (dMMR) localized gastric and oeso-gastric junction (OGJ) adenocarcinoma is subject of debate. Histological response assessment might help to better evaluate the impact of dMMR on response to NAC.

METHODS

Patients with localized gastric/OGJ adenocarcinoma resected after NAC were retrospectively identified. MMR protein expression status was assessed by immunohistochemistry. The primary objective was the frequency of histological responders to NAC defined by tumour regression grade (TRG) using Mandard's (TRG1-2) and Becker's (TRG1) classifications, according to the MMR status.

RESULTS

In total, 247 patients with 43 dMMR and 204 pMMR gastric/OGJ adenocarcinoma were identified. Among dMMR tumours, 18 (42%) arose from the OGJ. Histological response (Becker TRG1-2) was observed for 28% and 35% of dMMR and pMMR tumours, respectively (p = 0.35). Similar results were observed with Mandard classification. With a median follow-up of 37.5 months, median disease-free and overall survival were not reached for the dMMR group.

CONCLUSION

Histological response after NAC in patients with localized dMMR gastric/OGJ adenocarcinoma is not statistically different to those with pMMR tumours. This study provides additional data for the discussion about avoiding NAC in patients with dMMR gastric/OGJ adenocarcinomas.

Trifluridine-tipiracil plus bevacizumab versus capecitabine plus bevacizumab as first-line treatment for patients with metastatic colorectal cancer ineligible for intensive therapy (SOLSTICE): a randomised, open-label phase 3 study

BACKGROUND

Trifluridine-tipiracil plus bevacizumab has shown efficacy in previous phase 2 studies including patients with unresectable metastatic colorectal cancer. We aimed to investigate first-line trifluridine-tipiracil plus bevacizumab versus capecitabine plus bevacizumab in patients with unresectable metastatic colorectal cancer ineligible for intensive treatment.

METHODS

In this open-label, randomised, phase 3 study, we enrolled patients aged 18 years and older with histologically confirmed metastatic colorectal cancer, ineligible for full-dose doublet or triplet chemotherapy and curative resection across 25 countries and regions. Participants were randomly allocated (1:1) to trifluridine-tipiracil plus bevacizumab or capecitabine plus bevacizumab until disease progression or unacceptable toxicity using an interactive web response system, stratified by Eastern Cooperative Oncology Group (ECOG) performance status (0 vs 1 vs 2), primary tumour location (right vs left colon), and the main reason for not being a candidate for intensive therapy (clinical condition vs non-clinical condition). The primary endpoint was investigator-assessed progression-free survival, defined as the time from randomisation to radiological progression or death from any cause, in the intention-to-treat population. Safety was assessed in all patients having taken at least one dose of the study drug. The trial is ongoing, findings presented here are those of the primary analysis of progression-free survival, conducted after 629 events had occurred. This study is registered with ClinicalTrials.gov, NCT03869892.

FINDINGS

Between March 21, 2019, and Sept 14, 2020, 856 patients (54% male, 46% female) were randomly assigned to trifluridine-tipiracil plus bevacizumab (n=426) or capecitabine plus bevacizumab (n=430). After a median follow-up of 16·6 months (95% CI 16·5-17·1), the hazard ratio for progression-free survival for trifluridine-tipiracil plus bevacizumab versus capecitabine plus bevacizumab was 0·87 (0·75-1·02; p=0·0464; protocol-defined significance level of p=0·021 not met). Investigator-assessed median progression-free survival was 9·4 months (95% CI 9·1-10·9) with trifluridine-tipiracil plus bevacizumab versus 9·3 months (8·9-9·8) with capecitabine plus bevacizumab. The most common grade 3 and higher treatment-emergent adverse events were neutropenia (220 [52%] of 423 patients in the trifluridine-tipiracil plus bevacizumab group vs six [1%] of 427 in the capecitabine plus bevacizumab group), decreased neutrophil count (78 [18%] vs four [<1%]), anaemia (60 [14%] vs 16 [4%]), and hand-foot syndrome (none vs 61 [15%]). Nine deaths (five in the trifluridine-tipiracil plus bevacizumab group and four in the capecitabine plus bevacizumab group) were treatment related.

INTERPRETATION

First-line trifluridine-tipiracil plus bevacizumab was not superior to capecitabine plus bevacizumab in this population. As expected, the safety profile differed between the two treatments, but there were no new safety concerns. Trifluridine-tipiracil plus bevacizumab represents a feasible alternative to capecitabine plus bevacizumab in this population.

FUNDING

Servier International Research Institute, Suresnes, France.

Pembrolizumab for previously treated, microsatellite instability–high/mismatch repair–deficient advanced colorectal cancer: final analysis of KEYNOTE-164

BACKGROUND

Pembrolizumab demonstrated durable clinical benefit and manageable safety in previously treated advanced or metastatic microsatellite instability-high (MSI-H)/mismatch repair deficient (dMMR) colorectal cancer (CRC) in the phase 2 KEYNOTE-164 study. Results from the final analysis are presented.

METHODS

Eligible patients had unresectable or metastatic MSI-H/dMMR CRC and ≥2 prior systemic therapies (cohort A) or ≥1 prior systemic therapy (cohort B). Patients received pembrolizumab 200 mg intravenously every 3 weeks for ≤35 cycles. The primary end-point was objective response rate (ORR) assessed per Response Evaluation Criteria in Solid Tumors, version 1.1 by blinded independent central review. Secondary end-points included duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety and tolerability.

RESULTS

Sixty-one patients in cohort A and 63 patients in cohort B were enroled; median follow-up was 62.2 months and 54.4 months, respectively. ORR was 32.8% (95% CI, 21.3%-46.0%) in cohort A and 34.9% (95% CI, 23.3%-48.0%) in cohort B. Median DOR was not reached (NR) in either cohort. Median PFS was 2.3 months (95% CI, 2.1-8.1) in cohort A and 4.1 months (95% CI, 2.1-18.9) in cohort B. Median OS was 31.4 months (95% CI, 21.4-58.0) in cohort A and 47.0 months (95% CI, 19.2-NR) in cohort B. No new safety signals were observed. Nine patients who initially responded experienced disease progression off therapy and received second-course pembrolizumab. Six patients (66.7%) completed an additional 17 cycles of pembrolizumab, and 2 patients achieved a partial response.

CONCLUSIONS

Pembrolizumab continued to show durable antitumor activity, prolonged OS, and manageable safety in patients with previously treated MSI-H/dMMR CRC.

CLINICAL TRIAL REGISTRY INFORMATION

ClinicalTrials.gov, NCT02460198.

Neoadjuvant Nivolumab Plus Ipilimumab and Adjuvant Nivolumab in Localized Deficient Mismatch Repair/Microsatellite Instability-High Gastric or Esophagogastric Junction Adenocarcinoma: The GERCOR NEONIPIGA Phase II Study

PURPOSE

In patients with resectable gastric/gastroesophageal junction (GEJ) adenocarcinoma, surgery plus perioperative platinum-based chemotherapy is the standard of care. Perioperative chemotherapy remains debatable for gastric/GEJ adenocarcinoma with deficient mismatch repair (dMMR)/microsatellite instability-high (MSI-H).

PATIENTS AND METHODS

NEONIPIGA (ClinicalTrials.gov identifier: NCT04006262) phase II study evaluated neoadjuvant nivolumab 240 mg once every two weeks ×6 and ipilimumab 1 mg/kg once every six weeks ×2, followed by surgery and adjuvant nivolumab 480 mg once every four weeks (nine injections) in patients with locally advanced resectable dMMR/MSI-H, clinical (c) tumor (T)2-T4 node (N)x metastasis (M)0 gastric/GEJ adenocarcinoma. The primary end point was a pathological complete response (pCR) rate.

RESULTS

Between October 2019 and June 2021, 32 patients with dMMR/MSI-H gastric/GEJ adenocarcinoma were enrolled. The median age was 65.5 years (range, 40-80). Clinical stages were cT2-T3N0 (n = 9), cT2-T3N1 (n = 22), and cT3N1M1 (n = 1, wrongly included). With a median follow-up of 14.9 months (95% CI, 10.6 to 17.6), 32 patients received neoadjuvant immunotherapy (27 patients completed all cycles). Neoadjuvant therapy-related grade 3/4 adverse events occurred in six patients (19%). Twenty-nine patients underwent surgery; three did not have surgery and had complete endoscopic response with tumor-free biopsies and a normal computed tomography scan (two refused surgery and one had metastasis at inclusion). The rate of surgical morbidity (Clavien-Dindo classification) was 55% (one postoperative death occurred). All 29 patients had an R0 resection, and 17 (58.6%; 90% CI, 41.8 to 74.1) had pCR (pathological T0N0). Becker tumor regression grades 1a, 1b, 2, and 3 were observed in 17 patients, three (including two pathological T0N1), two, and seven patients, respectively. Of the 29 patients with surgery, 23 received adjuvant nivolumab. At database lock, no patient had relapse and one died without relapse.

CONCLUSION

Nivolumab and ipilimumab-based neoadjuvant therapy is feasible and associated with no unexpected toxicity and a high pCR rate in patients with dMMR/MSI-H resectable gastric/GEJ adenocarcinoma.

Association of Body Mass Index With the Safety Profile of Nivolumab With or Without Ipilimumab

Importance

Increased survival with immune checkpoint inhibitors has been reported for patients with obesity vs a normal body mass index (BMI). However, the association of obesity with the safety of immune checkpoint inhibitors warrants study.

Objective

To investigate associations between BMI and immune-related adverse events (irAEs) among patients with advanced cancers treated with nivolumab monotherapy and nivolumab plus ipilimumab combination therapy.

Design, Setting, and Participants

This study was a retrospective pooled analysis of 3772 patients from 14 multicenter CheckMate clinical trials across 8 tumor types. Patients with advanced cancers received nivolumab, 3 mg/kg (n = 2746); nivolumab, 3 mg/kg, plus ipilimumab, 1 mg/kg (n = 713); or nivolumab, 1 mg/kg, plus ipilimumab, 3 mg/kg (n = 313). Baseline BMI was categorized as normal weight or underweight (<25), overweight (25 to <30), or obese (≥30) according to World Health Organization criteria. The studies began patient enrollment between February 9, 2012, and May 21, 2015, and patients were followed up to database lock on May 1, 2019. Data analysis was conducted from May 1 to September 1, 2019.

Interventions

Nivolumab, 3 mg/kg; nivolumab, 3 mg/kg, plus ipilimumab, 1 mg/kg; and nivolumab, 1 mg/kg, plus ipilimumab, 3 mg/kg.

Main Outcomes and Measures

Odds ratios (ORs) and 95% CIs for incidence of any-grade and grade 3 or 4 irAEs were calculated for patients with obesity vs normal weight or underweight BMI in the overall cohort and in subgroups based on patient and tumor characteristics. Analyses for nivolumab plus ipilimumab cohorts were exploratory.

Results

A total of 3772 patients were included, 2600 were male (69%), and median age was 61 years (range, 18-90 years). For patients receiving monotherapy with nivolumab, 3 mg/kg (n = 2746), the incidence of any-grade irAEs was higher in patients with obesity (n = 543) vs those with normal weight or underweight BMI (n = 1266; OR, 1.71; 95% CI, 1.38-2.11). Incidence of grade 3 or 4 irAEs did not differ between patients with obesity and those with normal weight or underweight BMI (OR, 1.21; 95% CI, 0.92-1.61). Risk of any-grade and grade 3 or 4 irAEs appeared consistent with that in the overall population across all subgroups evaluated except for a higher likelihood of grade 3 or 4 irAEs among female patients with obesity vs normal weight or underweight BMI (OR, 1.73; 95% CI, 1.07-2.79). For patients receiving nivolumab plus ipilimumab, the incidence of irAEs appeared consistent across BMI categories.

Conclusions and Relevance

Obesity appeared to be associated with an increased incidence of any-grade irAEs among patients treated with nivolumab monotherapy and with grade 3 or 4 irAEs among female patients only. These findings may inform the monitoring of patients at high risk of developing irAEs.

Prognosis and chemosensitivity of non-colorectal alimentary tract cancers with microsatellite instability

BACKGROUND

Data on outcomes of microsatellite instable and/or mismatch repair deficient (dMMR/MSI) digestive non-colorectal tumors are limited.

AIMS

To evaluate overall survival (OS) of patients with dMMR/MSI digestive non-colorectal tumor.

METHODS

All consecutive patients with a dMMR/MSI digestive non-colorectal tumor were included in this French retrospective multicenter study.

RESULTS

One hundred and sixteen patients were included with a mean age of 63.6 years and 32.6% with a Lynch syndrome. Most tumors were oesophago-gastric (54.3%) or small bowel (32.8%) adenocarcinomas and at a localized stage at diagnosis (86.7%). In patients with localized tumors and R0 resection, median OS was 134.0 ± 64.2 months. Median disease-free survival (DFS) was 100.3 ± 65.7 months. Considering oesophago-gastric tumors, median DFS was improved when chemotherapy was added to surgery (not reached versus 22.8 ± 10.0 months, p = 0.03). In patients with advanced tumors treated by chemotherapy, median OS was 14.2 ± 1.9 months and median progression-free survival was 7.4 ± 1.6 months.

CONCLUSION

dMMR/MSI digestive non-colorectal tumors are mostly diagnosed at a non-metastatic stage with a good prognosis. Advanced dMMR/MSI digestive non-colorectal tumors have a poor prognosis with standard chemotherapy.

Immune checkpoint inhibitors for patients with isolated peritoneal carcinomatosis from dMMR/MSI-H colorectal cancer, a BIG-RENAPE collaboration

BACKGROUND

Immunotherapy with immune checkpoint inhibitors has significantly improved the survival of patients with MSI/dMMR mCRC. These tumors are associated with a specific metastatic spread, i.e. frequent peritoneal carcinomatosis (PC) that may be treated surgically when there is no other metastatic location. We aimed at evaluating the prognosis of patients treated with immune checkpoint inhibitors for MSI/dMMR mCRC with isolated PC.

MATERIAL AND METHODS

All consecutive patients with isolated PC from MSI/dMMR mCRC, initially considered as unresectable by multidisciplinary team meeting, treated with immune checkpoint inhibitors were included in this French multicenter cohort study.

RESULTS

Among 45 patients included, we observed 11 complete responses and 10 partial responses for an overall response rate iRECIST of 46%. After a median follow-up of 24.4 months, the median progression-free survival (PFS) and overall survival (OS) were not reached. Seven of the eight patients who underwent cytoreductive surgery after treatment with anti-PD1 ± anti-CTLA-4 were in complete pathologic response.

CONCLUSION

These results demonstrate long-term benefit of immune checkpoint inhibitors for patients with isolated PC from MSI/dMMR mCRC. Such treatment appears as the best therapeutic option for patients with isolated PC from MSI/dMMR mCRC. With a majority of pathological complete responses for patients who underwent surgery for residual lesions, the value of such therapeutic strategy remains unknown.

Prognostic role of HPV integration status and molecular profile in advanced anal carcinoma: An ancillary study to the epitopes-HPV02 trial

Squamous Cell Carcinoma of the Anal canal (SCCA) is a rare disease associated with a Human Papillomavirus (HPV) infection in most cases, predominantly the HPV16 genotype. About 15% of SCCA are diagnosed in metastatic stage and some will relapse after initial chemoradiotherapy (CRT). Treatment of patients by Docetaxel, Cisplatin and 5-fluorouracil (DCF) has been recently shown to improve their complete remission and progression-free survival. The aim of this retrospective study was to explore the impact of HPV infection, HPV DNA integration, TERT promoter mutational status and somatic mutations of oncogenes on both progression-free (PFS) and overall survivals (OS) of patients treated by DCF. Samples obtained from 49 patients included in the Epitopes-HPV02 clinical trial, diagnosed with metastatic or non-resectable local recurrent SCCA treated by DCF, were used for analyses. Median PFS and OS were not associated with HPV status. Patients with episomal HPV had an improved PFS compared with SCCA patients with integrated HPV genome (p=0.07). TERT promoter mutations were rarely observed and did not specifically distribute in a subset of SCCA and did not impact DCF efficacy. Among the 42 genes investigated, few gene alterations were observed, and were in majority amplifications (68.4%), but none were significantly correlated to PFS. As no biomarker is significantly associated with patients’ survival, it prompts us to include every patient failing CRT or with metastatic disease in DCF strategy.

Traitements péri-opératoires des adénocarcinomes œsogastriques localisés

Gastric cancer is the 6th most common cancer in the world. Gastric adenocarcinomas can be divided into two groups: gastroesophageal junction adenocarcinomas and distal gastric adenocarcinomas, with different risk factors and potentially different therapeutic strategies. Therapeutic strategy for esogastric adenocarcinoma is multimodal. Gastric adenocarcinomas are managed with surgery and peri-operative chemotherapy. Gastroesophageal junction adenocarcinomas can either be treated surgically after neoadjuvant chemoradiotherapy or in the same way than gastric adenocarcinomas. There is currently no evidence of superiority of either treatment strategy. Recently, nivolumab has been validated as an adjuvant therapy for patients with esophageal cancer who received preoperative chemoradiotherapy and had residual tumor on the surgical specimen. In the absence of preoperative treatment, adjuvant chemoradiotherapy or chemotherapy should be discussed on a patient-by-patient basis. Currently, there is not indication for targeted therapies, nor for adapting postoperative treatment according to the response to preoperative treatment. The only validated indication for immunotherapy is as adjuvant treatment of esophageal cancer, but many studies are ongoing and may change practices in the future. The objective of this review is to synthesize the literature concerning the management of localized esogastric adenocarcinoma.

Prognostic impact of performance status on the outcomes of immune checkpoint inhibition strategies in patients with dMMR/MSI-H metastatic colorectal cancer

BACKGROUND

Immune checkpoint inhibitors yielded unprecedented outcomes in patients with mismatch repair deficient/ microsatellite instability-high (dMMR/MSI-H) metastatic colorectal cancer (mCRC), but clinical decision-making in this rapidly evolving treatment landscape is challenging. Since performance status (PS) represents a well-established prognostic factor in clinical practice, we investigated whether worse PS, overall or related to either patients' frailty or high tumour burden, could affect the outcomes in this whole patients' population and according to immune checkpoint inhibitor treatment type.

METHODS

We conducted a global study at Tertiary Cancer Centres and collected data of patients with dMMR/MSI-H mCRC treated with anti- programmed-death (ligand)-1 (PD(L)-1) monotherapy or anti-PD-1/anti- cytotoxic T-lymphocyte antigen 4 combination.

RESULTS

The cohort included 502 patients. At a median follow-up of 31.2 months, worse PFS and OS were reported in patients with patient-related PS ≥ 1 (adjusted-HRs: 1.73, 95%CI: 1.06-2.83, p = 0.004 and 2.06, 95%CI: 1.13-3.74, p = 0.001, respectively) and cancer-related PS ≥ 1 (adjusted-HRs: 1.61, 95%CI: 1.19-2.17, p = 0.004 and 1.87, 95%CI: 1.32-2.66, p = 0.001, respectively). Anti-PD-1/anti- cytotoxic T-lymphocyte antigen 4 combination did not provide significantly better survival compared to anti-PD(L)-1 monotherapy in PS 0 subgroup (PFS HR = 0.62, 95%CI: 0.37-1.02, p = 0.059; OS HR = 0.59, 95%CI: 0.32-1.11, p = 0.100) and in patient-related PS ≥ 1 (PFS HR 0.93, 95%CI: 0.31-2.83, p = 0.899; OS HR 1.22, 95%CI: 0.34-4.37, p = 0.760), but the difference was significant and clinically meaningful in the subgroup with cancer-related PS ≥ 1 (PFS HR = 0.32, 95%CI: 0.19-0.53, p < 0.001; OS HR = 0.26, 95%CI: 0.14-0.48, p < 0.001).

CONCLUSIONS

In patients with dMMR/MSI-H mCRC, an extensive evaluation of clinical variables including PS may be implemented in the therapy decision-making.

Abstract 5135: Antitumor activity of dostarlimab by PD-L1 and tumor mutation burden (TMB) in patients (pts) with mismatch repair deficient and proficient (dMMR and MMRp) tumors in the GARNET trial

Background: Dostarlimab is a programmed death 1 (PD-1) inhibitor approved as monotherapy in pts with dMMR recurrent/advanced endometrial cancer (EC) that has progressed on or following treatment with a platinum-containing regimen or solid tumors that have progressed on or following prior treatment, with no satisfactory alternative treatment options. Here we report on a post-hoc analysis of antitumor activity by PDL1 expression and TMB in pts with dMMR and MMRp solid tumors in the GARNET trial.

Methods: GARNET (NCT02715284) is a phase 1, multicenter, open-label, single-arm study of dostarlimab in pts with advanced/recurrent solid tumors. Three expansion cohorts enrolled pts based on MMR status: dMMR (A1) and MMRp (A2) advanced/recurrent EC, and dMMR non-EC solid tumors (F). Pts received dostarlimab 500 mg IV Q3W for 4 cycles, then 1000 mg IV Q6W until progression or discontinuation. TMB and PDL1 were exploratory biomarkers. TMB status was determined by Foundation One test; TMB-high (TMB-H) was defined as ≥10 mutations/Mb. PDL1 expression was determined by combined positive score (CPS) by Ventana assay; PDL1-high (PDL1-H) was defined as CPS ≥1. The study was not powered to assess antitumor activity within subgroups.

Results: TMB-H and PDL1-H were common in dMMR solid tumors; PDL1-H was observed in 39.4% of MMRp EC tumors (Table). Objective response rate (ORR) was higher in pts with TMB-H/PDL1-H tumors (55.6% for all cohorts, combined; Table). Safety for each cohort was previously reported.1

Conclusions: PDL1-H and TMB-H were frequently observed in the dMMR EC and non-EC cohorts, regardless of tumor type; PDL1-H was also prevalent in MMRp EC tumors. Although not powered to assess antitumor activity, ORR by BICR per RECIST v1.1 was higher in pts with TMB-H and PDL1-H solid tumors. Across cohorts, dMMR status was predictive of response.

1.Andre T, et al. Ann Oncol 2021;32(suppl 5):S829-S866. 991P.

Table A1(dMMR EC)N=103 F(dMMR non-EC)N=106 A1+F(dMMR combined)N=209 A2(MMRp EC)N=142 A1+A2+F (Total)N=351 Biomarker distribution, n (%) TMB High 85 (82.5) 79 (74.5) 164 (78.5) 9 (6.3) 173 (49.3) Low 13 (12.6) 9 (8.5) 22 (10.5) 129 (90.8) 151 (43.0) Unknown 5 (4.9) 18 (17.0) 23 (11.0) 4 (2.8) 27 (7.7) PD-L1 High 56 (54.4) 52 (49.1) 108 (51.7) 56 (39.4) 164 (46.7) Low 23 (22.3) 17 (16.0) 40 (19.1) 45 (31.7) 85 (24.2) Unknown 24 (23.3) 37 (34.9) 61 (29.2) 41 (28.9) 102 (29.1) ORR by BICR per RECIST v1.1, n/N (%, 95% CI)a Overall 46/103(44.7, 34.9–54.8) 41/106(38.7, 29.4–48.6) 87/209(41.6, 34.9–48.6) 19/142(13.4, 8.3–20.1) — TMB-L/PDL1-L (L/L) 1/5(20.0, 0.5–71.6) 1/3 (33.3, 0.8–90.6) 2/8(25.0, 3.2–65.1) 2/43(4.7, 0.6–15.8) 4/51(7.8, 2.2–18.9) TMB-L/PDL1-H (L/H) 2/5(40.0, 5.3–85.3) 1/2(50.0, 1.3–98.7) 3/7(42.9, 9.9–81.6) 7/50(14.0, 5.8–26.7) 10/57(17.5, 8.7–29.9) TMB-H/PDL1-L (H/L) 5/17(29.4, 10.3–56.0) 3/14(21.4, 4.7–50.8) 8/31(25.8, 11.9–44.6) 0/1(0, 0–97.5) 8/32(25.0, 11.5–43.4) TMB-H/PDL1-H (H/H) 29/50(58.0, 43.2–71.8) 22/43(51.2, 35.5–66.7) 51/93(54.8, 44.2–65.2) 4/6(66.7, 22.3–95.7) 55/99(55.6, 45.2–65.5) aOnly those pts with both known TMB status and known CPS were included in ORR calculations

Citation Format: Thierry André, Susana Banerjee, Dominique Berton, Susan L. Ellard, Begoña Jimenez, Vanessa Samouëlian, Lucy Gilbert, Valentina Boni, Xinwei Han, Grace Antony, Jennifer Veneris, Ana Oaknin. Antitumor activity of dostarlimab by PD-L1 and tumor mutation burden (TMB) in patients (pts) with mismatch repair deficient and proficient (dMMR and MMRp) tumors in the GARNET trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5135.

Clinical Trial Endpoints in Metastatic Cancer: Using Individual Participant Data to Inform Future Trials Methodology

Meta-analysis based on individual participant data (IPD) is a powerful methodology for synthesizing evidence by combining information drawn from multiple trials. Hitherto, its principal application has been in questions of clinical management, but an increasingly important use is in clarifying trials methodology, for instance in the selection of endpoints, as discussed in this review. In oncology, the Aide et Recherche en Cancérologie Digestive (ARCAD) Metastatic Colorectal Cancer Database is a leader in the use of IPD-based meta-analysis in methodological research. The ARCAD database contains IPD from more than 38 000 patients enrolled in 46 studies and continues to collect phase III trial data. Here, we review the principal findings of the ARCAD project in respect of endpoint selection and examine their implications for cancer trials. Analysis of the database has confirmed that progression-free survival (PFS) is no longer a valid surrogate endpoint predictive of overall survival in the first-line treatment of colorectal cancer. Nonetheless, PFS remains an endpoint of choice for most first-line trials in metastatic colorectal cancer and other solid tumors. Only substantial PFS effects are likely to translate into clinically meaningful benefits, and accordingly, we advocate an oncology research model designed to identify highly effective treatments in carefully defined patient groups. We also review the use of the ARCAD database in assessing clinical response including novel response metrics and prognostic markers. These studies demonstrate the value of IPD as a tool for methodological studies and provide a reference point for the expansion of this approach within clinical cancer research.

Immune Checkpoint Blockade Therapy in Patients With Colorectal Cancer Harboring Microsatellite Instability/Mismatch Repair Deficiency in 2022

Immune checkpoint inhibitors (ICIs) are shown to be effective among patients with metastatic colorectal cancer (mCRC) harboring high microsatellite instability (MSI-H) and/or mismatch repair deficiency (dMMR), with U.S. Food and Drug Administration approvals for all lines of therapy. In Europe, only pembrolizumab in the first line and the combination of nivolumab and ipilimumab beyond the first line are approved. Many questions remain about the clinical management of MSI-H/dMMR CRC. Biomarkers predictive of immune checkpoint inhibitor resistance among MSI-H/dMMR tumors are needed (1) to select the best treatment for patients with CRC (anti-PD-[L]1 monotherapy alone or combined with anti-CTLA-4 or chemotherapy) and (2) to develop new treatment strategies for patients whose disease progressed after immune checkpoint inhibitor monotherapy. The development of immune checkpoint inhibitors in the adjuvant and neoadjuvant settings is also of great interest for patients harboring MSI-H/dMMR, especially as a substantial proportion have Lynch syndrome or are at high risk of developing cancers in their lifetime and sporadic MSI-H/dMMR cancers occur most frequently in elderly and frail patients. Thus, CRC is not one, but two different diseases: (1) MSI-H/dMMR CRC (seen in 5% of mCRC and 15% of non-mCRC), which is genetically unstable with a high mutational load and many neoantigens, and for which immune checkpoint inhibitors radically changed clinical management, and (2) microsatellite stable CRC with chromosomal instability, for which immune checkpoint inhibitors are not proven efficient.

Treatments after Immune Checkpoint Inhibitors in Patients with dMMR/MSI Metastatic Colorectal Cancer

Simple Summary

Several studies suggested an enhanced efficacy of conventional treatments (CT, i.e., chemotherapy +/− targeted therapy) administered after immune checkpoint inhibitors (ICI) in certain tumor types, but no data are available concerning metastatic colorectal cancer (mCRC) patients harboring mismatch repair deficiency/microsatellite instability (dMMR/MSI). The aim of our study was to assess the outcomes of dMMR/MSI mCRC patients receiving CT after ICI failure. We retrospectively collected clinical data from a multicentric cohort of 31 patients. Although limited by the small number of patients, our results did not suggest improved outcomes with CT in our population, and no significant association with previous ICI efficacy or with anti-VEGF agents was evidenced. However, prolonged disease control was observed in several cases, suggesting that some patients might derive an unexpected benefit from post-ICI treatments. With ICI becoming the standard of care in patients newly diagnosed with dMMR/MSI mCRC, these results might help to inform clinical decision-making and to guide future therapeutic strategies for these patients.

Abstract

Background: Several studies reported improved outcomes with conventional treatments (CT, i.e., chemotherapy ± targeted therapy) administered after immune checkpoints inhibitors (ICI) in certain tumor types. No data are available concerning patients (pts) with metastatic colorectal cancer (mCRC) harboring mismatch repair deficiency/microsatellite instability (dMMR/MSI). We aimed to assess the outcomes of dMMR/MSI mCRC pts receiving CT after ICI failure. Methods: We conducted a retrospective multicenter study investigating the outcomes of all dMMR/MSI mCRC pts who received post-ICI CT between 2015 and 2020. Results: 31 pts (male 61%, median age 56 years) were included. ICI was an anti-PD(L)1 monotherapy in 71% of pts, and 61% received >2 lines before post-ICI CT. The overall response rate and disease control rate were 13% and 45%, with a median progression-free survival (PFS) and overall survival of 2.9 and 7.4 months, respectively. No association of the outcomes with either ICI efficacy or anti-angiogenic agents was observed. Prolonged PFS (range 16.1–21.3 months) was observed in 4 pts (13%). Conclusions: Although conducted on a limited number of patients, our results do not support an association of previous ICI treatment with an enhanced efficacy of CT in dMMR/MSI mCRC. However, prolonged disease control was observed in several cases, suggesting that some pts might derive an unexpected benefit from post-ICI treatments.

The immune microenvironment in patients with mismatch‐repair‐proficient oligometastatic colorectal cancer exposed to chemotherapy: the randomized MIROX GERCOR cohort study

In the era of immune checkpoint inhibitors, understanding the metastatic microenvironment of proficient mismatch repair/microsatellite stable (pMMR/MSS) colorectal cancer (CRC) is of paramount importance to both prognostication and the development of more effective novel therapies. In this study, primary and paired metastasis tissue samples were collected from patients with resectable metastatic CRC treated with adjuvant FOLFOX or peri‐operative chemotherapy in the MIROX phase III prospective study. In total, 74 cancer tissues were stained for CD3, CD8, Forkhead box protein 3 (FOXP3), programmed cell death protein‐1 (PD‐1, invasive front, stromal, intra‐epithelial compartments), and programmed death‐ligand 1 (PD‐L1, tumor, immune cells). The immune profiling of primary CRC had a limited value to predict the immune context of paired metastases for all markers but CD3+. The expression of CD8 and PD‐L1 was higher in metastases after neoadjuvant FOLFOX. In metastases, both CD3 T cells at the invasive front and PD‐L1 expressions on immune cells were predictive of better disease‐free survival. These results show that the effect of FOLFOX on modifying the immune microenvironment in resected CRC metastases and measurement of PD‐L1 expression and tumor‐infiltrating CD8 T cells in pMMR/MSS metastatic tissue samples could improve treatment strategies of metastatic CRC patients.

Early-Onset Colorectal Adenocarcinoma in the IDEA Database: Treatment Adherence, Toxicities, and Outcomes With 3 and 6 Months of Adjuvant Fluoropyrimidine and Oxaliplatin

PURPOSE

Early-onset (EO) colorectal cancer (CRC, age < 50 years) incidence is increasing. Decisions on optimal adjuvant therapy should consider treatment adherence, adverse events, and expected outcomes in a population with life expectancy longer than later-onset (LO) CRC (age ≥ 50 years).

MATERIALS AND METHODS

Individual patient data from six trials in the International Duration Evaluation of Adjuvant Chemotherapy database were analyzed. Characteristics, treatment adherence, and adverse events in stage II or III EO-CRC and LO-CRC were compared. To reduce confounders of non-cancer-related deaths because of age or comorbidities, time to recurrence (3-year relapse-free rate) and cancer-specific survival (5-year cancer-specific mortality rate) were considered.

RESULTS

Out of 16,349 patients, 1,564 (9.6%) had EO-CRC. Compared with LO-CRC, EO-CRC had better performance status (86% v 80%, P < .01), similar T stage (% T1-3/T4: 76/24 v 77/23, P = .97), higher N2 disease rate (24% v 22%, P < .01), more likely to complete the planned treatment duration (83.2% v 78.2%, P < .01), and received a higher treatment dose intensity, especially with 6-month regimens. Gastrointestinal toxicity was more common in EO-CRC; hematologic toxicity was more frequent in LO-CRC. Compared with LO-CRC, significantly worse cancer-specific outcomes were demonstrated especially in high-risk stage III EO-CRC: lower 3-year relapse-free rate (54% v 65%; hazard ratio [HR] 1.33; 95% CI, 1.14 to 1.55; P value < .001) and higher 5-year cancer-specific mortality rate (24% v 20%; HR 1.21; 95% CI, 1.00 to 1.47; P value < .06). In this subgroup, no difference was observed with 3 or 6 months of therapy, with equally poor disease-free survival rates (57% v 56%; HR 0.97; 95% CI, 0.73 to 1.29; P value = .85).

CONCLUSION

Young age is negatively prognostic in high-risk stage III CRC and associated with significantly higher relapse rate; this is despite better treatment adherence and higher administered treatment intensity, suggesting more aggressive disease biology.

Peritoneal recurrence of colorectal cancer with microsatellite instability: Is immunotherapy alone more effective than surgery?

A 67-year-old man was treated with systemic chemotherapy and cytoreductive surgery for microsatellite instable (MSI), deficient mismatch repair (dMMR) right colonic cancer with peritoneal metastases. Disease was controlled only when anti-PD1 and anti-CTLA4 immune checkpoint inhibitors were introduced. The patient is in complete remission after five years of follow-up. First-line immunotherapy could have a central role in the management of patients with peritoneal recurrence from MSI/dMMR colorectal cancer even though amenable to surgical treatment.