scholarly journals Beyond Microsatellite Instability: Evolving Strategies Integrating Immunotherapy for Microsatellite Stable Colorectal Cancer

2021 ◽  
Vol 22 (8) ◽  
Author(s):  
Federica Pecci ◽  
Luca Cantini ◽  
Alessandro Bittoni ◽  
Edoardo Lenci ◽  
Alessio Lupi ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Microsatellite Instability ◽  
Mismatch Repair ◽  
Cancer Progression ◽  
Checkpoint Inhibitors ◽  
Tnm Classification ◽  
Standard Of Care ◽  
First Line Therapy ◽  
Combination Strategies ◽  
The Impact

Opinion statementAdvanced colorectal cancer (CRC) is a heterogeneous disease, characterized by several subtypes with distinctive genetic and epigenetic patterns. During the last years, immune checkpoint inhibitors (ICIs) have revamped the standard of care of several tumors such as non-small cell lung cancer and melanoma, highlighting the role of immune cells in tumor microenvironment (TME) and their impact on cancer progression and treatment efficacy. An “immunoscore,” based on the percentage of two lymphocyte populations both at tumor core and invasive margin, has been shown to improve prediction of treatment outcome when added to UICC-TNM classification. To date, pembrolizumab, an anti-programmed death protein 1 (PD1) inhibitor, has gained approval as first-line therapy for mismatch-repair-deficient (dMMR) and microsatellite instability-high (MSI-H) advanced CRC. On the other hand, no reports of efficacy have been presented in mismatch-repair-proficient (pMMR) and microsatellite instability-low (MSI-L) or microsatellite stable (MSS) CRC. This group includes roughly 95% of all advanced CRC, and standard chemotherapy, in addition to anti-EGFR or anti-angiogenesis drugs, still represents first treatment choice. Hopefully, deeper understanding of CRC immune landscape and of the impact of specific genetic and epigenetic alterations on tumor immunogenicity might lead to the development of new drug combination strategies to overcome ICIs resistance in pMMR CRC, thus paving the way for immunotherapy even in this subgroup.

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

2020 ◽  
Vol 38 (18_suppl) ◽  
pp. LBA4-LBA4 ◽  
Author(s):  
Thierry Andre ◽  
Kai-Keen Shiu ◽  
Tae Won Kim ◽  
Benny Vittrup Jensen ◽  
Lars Henrik Jensen ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Microsatellite Instability ◽  
Metastatic Colorectal Cancer ◽  
Mismatch Repair ◽  
Standard Of Care ◽  
First Line ◽  
Phase 3 ◽  
End Points ◽  
First Line Therapy ◽  
Line Therapy

LBA4 Background: KEYNOTE-177 (NCT02563002) is a phase 3, randomized open-label study evaluating the efficacy and safety of pembrolizumab (pembro) versus standard of care chemotherapy ± bevacizumab or cetuximab (chemo) as first-line therapy for patients (pts) with microsatellite-instability high/mismatch repair deficient (MSI-H/dMMR) metastatic colorectal cancer (mCRC). We present results of the final PFS analysis. Methods: A total of 307 pts with MSI-H/dMMR mCRC as determined locally and ECOG PS 0 or 1 were randomly assigned 1:1 to first-line pembro 200 mg Q3W for up to 2 years or investigator’s choice of mFOLFOX6 or FOLFIRI Q2W ± bevacizumab or cetuximab (chemo chosen prior to randomization). Treatment continued until PD, unacceptable toxicity, pt/investigator decision to withdraw, or completion of 35 cycles (pembro only). Patients receiving chemo could crossover to pembro for up to 35 cycles after confirmed PD. Primary end points were PFS (RECIST v1.1, central review) and OS. Key secondary end points included ORR (RECIST v1.1, central review), and safety. The data cutoff date for this interim analysis was Feb 19, 2020. The study will continue without changes to evaluate OS. Results: At data cutoff, 153 pts were randomized to pembro and 154 to chemo. Median (range) study follow-up was 28.4 mo (0.2-48.3) with pembro vs 27.2 mo (0.8-46.6) with chemo. Pembro was superior to chemo for PFS (median 16.5 mo vs 8.2 mo; HR 0.60; 95% CI, 0.45-0.80; P=0.0002). The 12- and 24-mo PFS rates were 55.3% and 48.3% with pembro vs 37.3% and 18.6% with chemo. Confirmed ORR was 43.8% vs 33.1%; median (range) duration of response was not reached (2.3+ to 41.4+) with pembro vs 10.6 mo (2.8 to 37.5+) with chemo. Grade 3-5 treatment related adverse event (AE) rates were 22% vs 66% for pembro vs chemo. One pt in the chemo arm died due to a treatment-related AE. Conclusions: Pembro provided a clinically meaningful and statistically significant improvement in PFS versus chemo as first-line therapy for pts with MSI-H/dMMR mCRC, with fewer treatment-related AEs observed and should be the new standard of care for these pts. Clinical trial information: NCT02563002 .

scholarly journals Current status and perspectives of immune checkpoint inhibitors for colorectal cancer

2020 ◽  
Vol 51 (1) ◽  
pp. 10-19
Author(s):  
Hidekazu Hirano ◽  
Atsuo Takashima ◽  
Tetsuya Hamaguchi ◽  
Dai Shida ◽  
Yukihide Kanemitsu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Microsatellite Instability ◽  
Metastatic Colorectal Cancer ◽  
Mismatch Repair ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Standard Of Care ◽  
High Level ◽  
Deficient Mismatch Repair

Abstract Immunotherapy, especially immune checkpoint inhibitors, has revolutionized the standard-of-care of multiple types of tumors. For colorectal cancer, the clinical development of immune checkpoint inhibitors is mainly separated according to the status of microsatellite instability or mismatch repair in a tumor. High-level microsatellite instability/deficient mismatch repair metastatic colorectal cancer generally has a tumor microenvironment with infiltration of T cells, associated with a favorable response to immune checkpoint inhibitors. Immune checkpoint inhibitors, including pembrolizumab (anti-PD-1 inhibitor) and nivolumab (anti-PD-1 inhibitor) with or without ipilimumab (anti-CTLA-4 inhibitor), have been integrated into the standard-of-care for high-level microsatellite instability/deficient mismatch repair metastatic colorectal cancer. Conversely, limited T-cell infiltration in the tumor microenvironment of microsatellite stable/proficient mismatch repair metastatic colorectal cancer, which constitutes the majority of metastatic colorectal cancer, is assumed to be a major resistant mechanism to immune checkpoint inhibitors. Currently, clinical trials to improve the clinical activity of immune checkpoint inhibitors by immunomodulation are ongoing for metastatic colorectal cancer. Furthermore, immune checkpoint inhibitors are under development in neoadjuvant and/or adjuvant setting. Here, we review the existing clinical data with ongoing trials and discuss the future perspectives with a focus on the immunotherapy of colorectal cancer.

scholarly journals Is There a Role for Programmed Death Ligand-1 Testing and Immunotherapy in Colorectal Cancer With Microsatellite Instability? Part I—Colorectal Cancer: Microsatellite Instability, Testing, and Clinical Implications

2017 ◽  
Vol 142 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Esmeralda Celia Marginean ◽  
Barbara Melosky
Keyword(s):  
Colorectal Cancer ◽  
Microsatellite Instability ◽  
Mismatch Repair ◽  
Tnm Classification ◽  
Therapy Response ◽  
Poor Response ◽  
Predictive Biomarker ◽  
Developed Countries ◽  
Programmed Death Ligand 1 ◽  
Programmed Death

Context.— Colorectal cancer (CRC) represents the third most-common cancer in developed countries and is a leading cause of cancer deaths worldwide. Two recognized pathways contribute to CRC development: a more-common chromosomal instability pathway and, in 15% of cases, a deficient mismatch repair or microsatellite instability–high (MSI-H) pathway. The MSI-H CRC can be associated with somatic or germline mutations. Microsatellite status has been recognized as a prognostic and predictive biomarker. Objectives.— To summarize the molecular pathways of CRC, with an emphasis on the MSI (mismatch repair) pathway; the recommended MSI testing algorithms and interpretation; and the prognostic and predictive role of MSI-H status in personalized treatment, including adjuvant chemotherapy, targeted therapy, and immune checkpoint inhibitor therapy. Data Sources.— A PubMed (US National Library of Medicine, Bethesda, Maryland) review was performed for articles pertaining to CRC, MSI and mismatch repair systems, molecular classification, immune response, programmed death receptor-1/programmed death ligand-1, and immunotherapy. Conclusions.— Although the TNM classification of malignant tumor stage remains the key determinant of CRC prognosis and treatment, there are considerable stage-independent, interindividual differences in clinical outcome and therapy response by patients. In addition, MSI-H status has an important role in CRC management and can be reliably detected by molecular and immunohistochemistry techniques and genetic testing. Efforts must be made to identify whether MSI-H CRC is germline or sporadic to ensure appropriate treatment, accurate prognosis, and risk assessment for relatives. Microsatellite status has been recognized as a good prognostic indicator and is predictive of a poor response to 5-fluorouracil–based chemotherapy and a good response to programmed death ligand-1 inhibitor pembrolizumab in metastatic/refractory MSI-H CRC.

scholarly journals Expanding the Scope of Immunotherapy in Colorectal Cancer: Current Clinical Approaches and Future Directions

2020 ◽  
Vol 2020 ◽  
pp. 1-24 ◽  
Author(s):  
Malek Kreidieh ◽  
Deborah Mukherji ◽  
Sally Temraz ◽  
Ali Shamseddine
Keyword(s):  
Colorectal Cancer ◽  
Microsatellite Instability ◽  
Mismatch Repair ◽  
Immune Checkpoint ◽  
Checkpoint Inhibitors ◽  
Treatment Strategies ◽  
Adoptive Cell Transfer ◽  
Durable Response ◽  
Novel Treatment Strategies ◽  
Tumor Types

The success of immune checkpoint inhibitors (ICIs) in an increasing range of heavily mutated tumor types such as melanoma has culminated in their exploration in different subsets of patients with metastatic colorectal cancer (mCRC). As a result of their dramatic and durable response rates in patients with chemorefractory, mismatch repair-deficient-microsatellite instability-high (dMMR-MSI-H) mCRC, ICIs have become potential alternatives to classical systemic therapies. The anti-programmed death-1 (PD-1) agents, Pembrolizumab and Nivolumab, have been granted FDA approval for this subset of patients. Unfortunately, however, not all CRC cases with the dMMR-MSI-H phenotype respond well to ICIs, and ongoing studies are currently exploring biomarkers that can predict good response to them. Another challenge lies in developing novel treatment strategies for the subset of patients with the mismatch repair-proficient-microsatellite instability-low (pMMR-MSI-L) phenotype that comprises 95% of all mCRC cases in whom treatment with currently approved ICIs has been largely unsuccessful. Approaches aiming at overcoming the resistance of tumors in this subset of patients are being developed including combining different checkpoint inhibitors with either chemotherapy, anti-angiogenic agents, cancer vaccines, adoptive cell transfer (ACT), or bispecific T-cell (BTC) antibodies. This review describes the rationale behind using immunotherapeutics in CRC. It sheds light on the progress made in the use of immunotherapy in the treatment of patients with dMMR-MSI-H CRC. It also discusses emerging approaches and proposes potential strategies for targeting the immune microenvironment in patients with pMMR-MSI-L CRC tumors in an attempt to complement immune checkpoint inhibition.

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