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Colorectal CancerBLOOMSINCT06414304

Dynamics of MSI and Genomic Profile of Colorectal Cancer In the Course of Immune Checkpoint Inhibitor Therapy

An observational study of Colorectal Cancer and Colorectal Cancer Metastatic, run by OncoAtlas LLC at 2 sites in Russia.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide. Microsatellite instability or mismatch repair deficiency occurs in 20% of CRC, and is predominantly found in non-metastatic tumors. Read more about this study

Who is it for?
Ages 18 years and older
How many people
30 participants
Where
2 sitesRussia
Study dates
1 Jun 2022to 1 Mar 2025
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: Patients with histologically confirmed colorectal cancer with microsatellite instability (MSI) or mismatch repair deficiency (dMMR)

Who may be able to join

  • Male/female participants must be at least 18 years of age on the day of signing informed consent and have a histologically confirmed diagnosis of colorectal cancer.
  • Verified MSI/dMMR positivity as measured by 5-loci PCR or 4-antibody IHC.
  • The patient is scheduled to start treatment with any of the immune checkpoint inhibitors 2-4 weeks after the inclusion in the study.
  • Have provided an archival tumor tissue sample obtained prior to the start of treatment with immune checkpoint inhibitor(s). Formalin-fixed, paraffin embedded (FFPE) tissue blocks are preferred to slides.
  • Patient has to be able to provide serial blood samples during the course of treatment, as well as on every follow-up tumor scan.
  • The participant (or legally acceptable representative if applicable) provides written informed consent to participate in the trial.
  • Have measurable disease based on RECIST 1.1.
  • Have adequate organ function.

Who cannot join

  • Prior treatment with immune checkpoint inhibitors.
  • For female participants: pregnancy or planned pregnancy.
  • The unavailability of the tumor or serial liquid biopsy samples.

Trial locations and contacts

2 sites in 1 country.

Russia2 sites
  • N.N.Blokhin National Medical Research Center of Oncology

    Moscow, 115478

  • State Budgetary Institution of Healthcare of the City of Moscow "Moscow Multidisciplinary Clinical Center "Kommunarka" of the Department of Health of the City of Moscow

    Moscow, 142770

Other trials in Russia

About this study

Official title: A Multi-center Observational Clinical Trial Evaluating the Dynamics of Microsatellite Instability and Genomic Profile of Colorectal Cancer in the Course of Treatment With Immune Checkpoint Inhibitors

Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide. Microsatellite instability or mismatch repair deficiency occurs in 20% of CRC, and is predominantly found in non-metastatic tumors. The success of the CheckMate 142 and KEYNOTE-177 clinical trials has shifted the treatment paradigm of the MSI/dMMR CRC, which has led to the adoption of immune checkpoint inhibitors (ICI) by international treatment standards. However, despite the encouraging effects of ICI, up to 30% of patients are resistant to treatment and exhibit rapid disease progression shortly after starting ICI. On the other hand, around 30% of patients treated with ICI demonstrate prolonged responses to the treatment with a duration of response of over 40 months. Furthermore, for ~10% of patients, treatment with ICI results in pseudo-progression - a phenomenon of a short-term increase followed by the decrease of the tumor volume.

Currently, the mechanisms and biomarkers associated with the response or resistance to ICI in MSI-positive CRC are largely unknown. Select studies suggest that BRAF mutations (specifically, BRAF p.V600E) might negatively affect the patients' progression-free survival following ICI, however, these data are premature.

The primary hypothesis is that the clonal heterogeneity and the evolution of MSI status of MSI-positive CRC will play a role in the development of ICI treatment resistance. The primary objective of the study is to investigate the dynamics of MSI status in serial liquid biopsy samples from patients with MSI-positive tumors receiving ICI.

Read the detailed description

This is a multicenter observational trial designed to evaluate the dynamics of microsatellite instability and the genomic profiles of CRC during immune checkpoint inhibitor treatment.

Patients with MSI/dMMR-positive tumors who are candidates for the ICI treatment will be included in the study. MSI/dMMR positivity should be confirmed with polymerase chain reaction-based (PCR) assays, immunohistochemistry (IHC) or Next-generation sequencing (NGS). Treatment with any ICI will be allowed. Upon inclusion in the study, patients will be asked to provide the pre-treatment FFPE tumor and liquid biopsy (LB) samples along with LB samples on the 14th, 28th days of ICI, and at every control study. LB samples will be collected until treatment discontinuation.

The pre-treatment FFPE samples will be tested with an alternative routine method (PCR and/or IHC, depending on what method was used for initial testing), as well as with the Solo Atlas Pro NGS panel covering common cancer-related genes and short tandem repeats for MSI detection. All LB samples will be tested with the Solo Atlas Pro NGS panel. Dynamics of MSI and genomic profiles will be correlated with the treatment outcomes.

Disease response to study treatment will be evaluated by imaging methods. Response to treatment will be determined by RECIST v1.1.

Keywords
MSI, dMMR, Microsatellite instability, Next-generation sequencing, Immunotherapy, Immune checkpoint inhibitors, Colorectal cancer
Medical subject headings
Colorectal Neoplasms, Neoplasms, Colonic Neoplasms, Microsatellite Instability

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Concordance of NGS and routine methods (PCR, IHC) for MSI analysis

    Concordance will be calculated using Cohen's Kappa (κ)

    Measured: Through study completion, an average of 3 years

Secondary outcomes (2)
  1. Concordance of MSI in tumor tissue and liquid biopsy (ctDNA)

    Concordance will be calculated using Cohen's Kappa (κ)

    Measured: Through study completion, an average of 3 years

  2. Qualitative and quantitative status of MSI in serial liquid biopsy (ctDNA) samples

    Liquid biopsy samples will be collected prior to the start of ICI, on the 14th and 28th days of therapy and at every follow-up tumor scan

    Measured: Through study completion, an average of 3 years

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 May 2024
  2. Study start1 Jun 2022
  3. Primary completion1 Sep 2024
  4. Study completion1 Mar 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
30 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06414304
Sponsor's protocol ID
BLOOMSI
Other IDs
22-75-10154
Acronym
BLOOMSI
Status last verified
Jun 2025
First submitted
7 May 2024
Last updated
27 Jun 2025
Results posted
No
Data monitoring committee
No

Questions about this trial

What is this clinical trial studying?

An observational study of Colorectal Cancer and Colorectal Cancer Metastatic, run by OncoAtlas LLC at 2 sites in Russia.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 8 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 27 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in Russia. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Concordance of NGS and routine methods (PCR, IHC) for MSI analysis (time frame: Through study completion, an average of 3 years). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Jun 2025.

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