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CompletedNCT06428487Updated Apr 27, 2026

Neoadjuvant Prolgolimab Monotherapy in Locally Advanced MMR-deficient Colorectal Cancer

A Phase 2 interventional study of Prolgolimab in Colorectal Cancer, sponsored by Blokhin's Russian Cancer Research Center. Completed at 1 site in Russia. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-04-27.

Sponsored by Blokhin's Russian Cancer Research Center · Phase 2, Interventional, and Treatment

From the registry’s dates

  • Registered 1 year 11 months after the study started (first participant enrolled Mar 2022, registered Mar 2024).
Phase
Phase 2
Study type
Interventional
Enrollment
30
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

In this phase II study patients with stage II-III MSI/dMMR colorectal adenocarcinoma with no signs of distant metastases will be treated with immunotherapy (prolgolimab). The duration of treatment is 6 months (12 cycles)

Read the detailed description

In this open-label phase II non-randomized study the investigators will enroll 30 patients with stage II-III MSI/dMMR colorectal cancer to receive anti-PD1 inhibitor prolgolimab.

Patients will be treated with 12 cycles (6 months) of prolgolimab 1 mg/kg every 2 weeks until surgery.

02

Conditions studied

  • Colorectal Cancer

Keywords

  • colorectal cancer
  • immune checkpoint inhibitors
  • microsatellite instability
03

In context

Colorectal Neoplasms

6,541 studies on the registry are indexed under Colorectal Neoplasms; 1,667 are open to participants now.

This study's enrollment of 30 is below the median of 76 across 4,800 interventional studies indexed under Colorectal Neoplasms.

Browse Colorectal Neoplasms studies →

Lead sponsor

Blokhin's Russian Cancer Research Center is the lead sponsor of 33 studies on the registry; 16 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Availability of voluntarily signed from the patient
  • confirmed adenocarcinoma of the colon or rectum;
  • Locally advanced tumor - cT3-4N0-2M0 according to CT for tumors of the colon and sigmoid colon; cT3 with a depth of tissue invasion ≥5mm (cT2N0 and higher for lower ampullary cancer) or T4 or involvement of the lateral resection margins according to MRI for rectal cancer;
  • Presence of MSI/dMMR in the tumor;
  • 0-2;
  • No to surgical treatment of

Exclusion criteria

Exclusion Criteria:

  • Previous therapy with the inclusion of monoclonal antibodies - anti-PD1, , anti PD-L2, anti-CTLA4 antibodies and other immunotherapy drugs
  • The presence of any other malignant tumor, with the exception of radically treated basal cell carcinoma, cervical cancer in situ, currently or within 5 years before inclusion in the study
  • Pregnant and lactating women, as well as planning pregnancy during the period of therapy in a clinical trial and 6 months after the end of therapy
  • Patients with preserved who refuse to use adequate methods of throughout the study and 6 months after the end of therapy or who agree to abstain from heterosexual contact.
  • Previous systemic therapy with drugs (including, but not limited to: prednisone, cyclophosphamide, azathioprine, methotrexate, thalidomide and TNF [tumor necrosis factor] antagonists) within 4 weeks before signing the form, or the need to use immunosuppressive therapy in during the first year of the study.
  • The use of systemic glucocorticosteroids (GCS) in replacement doses (for example, in a dose equivalent to 10 mg of prednisolone per day or less), short-term use of systemic GCS (≤7 days), inhaled and topical GCS are allowed.
  • Active, known or suspected diseases (patients with type 1 diabetes mellitus and hypothyroidism requiring only hormone replacement therapy, as well as autoimmune diseases with only skin manifestations [for example, vitiligo, alopecia or psoriasis without symptoms of psoriatic arthritis] are allowed to participate), that do not require systemic therapy);
  • Patients with infection, active , active .
  • less than 6 months.
  • The presence of a disease or condition that, in the opinion of the investigator, prevents the patient from participating in the study.
  • Complicated course of the primary tumor, requiring urgent surgical intervention.
  • Previously performed radiation or chemotherapy for colorectal cancer, with the exception of cases of metachronous tumors over 5 years ago;
  • Persistence, progression or recurrence of the underlying disease or the presence of distant
  • Conditions limiting the patient's ability to comply with the requirements of the protocol (in the opinion of the investigator);
  • Vaccination with within 28 days before randomization;
  • Participation in other interventional clinical trials less than 30 days before randomization (except in cases of dropout before the introduction of study therapy) and while participating in an ongoing clinical trial;
  • Significant adverse events from previous therapy, with the exception of chronic and/or irreversible events that cannot influence the assessment of the safety of the study therapy (for example, alopecia);
  • or allergic reactions to the administration of drugs manufactured using Chinese hamster ovary cells, severe allergic reactions, anaphylaxis or other hypersensitivity reactions to chimeric or humanized antibodies, prolgolimab or any of the components of the study drug.
Terms in these criteria, in plain language(17)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Histologically or cytologically confirmed

The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).

Your pathology report is the document that shows this.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

PD-1, PD-L1 and checkpoint inhibitors

PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.

PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.

Reproductive potential

Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.

Criteria about it usually ask for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

Life expectancy

The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

Live vaccines

Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
30 participants (actual)

Study arms

  • Experimental
    Prolgolimab monotherapy

    The patients will be treated with prolgolimab 1 mg/kg every 2 weeks during 6 months (12 cycles) until surgery

    Drug: Prolgolimab

Interventions

06

What researchers measure

Primary outcomes

  1. Pathological complete response (pCR)

    Absence of malignant cells on the specimen of colon/rectal resection in patients who were previously treated with neoadjuvant immunotherapy

    Time frame: up to 8 months

Secondary outcomes

  1. Durable complete clinical response rate (DRR)

    a continuous response \[complete or partial objective response\] beginning within 6 months of treatment and lasting ≥6 months

    Time frame: up to 12 months

  2. Progression-free survival (PFS)

    Time from initiation of treatment to the occurrence of disease progression or death.

    Time frame: 12 months

  3. Overall survival (OS)

    Time from initiation of treatment to death.

    Time frame: 12 months

  4. Objective response rate (ORR)

    percentage of patients who achieve a response, which can either be complete response (complete disappearance of lesions) or partial response (reduction in the sum of maximal tumor diameters by at least 30% or more)

    Time frame: up to 8 months

  5. R0 resection rate

    Rate of R0 resection indicates a microscopically margin-negative resection, in which no gross or microscopic tumor remains in the primary tumor bed

    Time frame: up to 8 months

  6. Major pathologic response (MPR)

    Rate of pathologic response TRG 1-2

    Time frame: up to 8 months

  7. Incidence of Treatment-Related Adverse Events as assessed by investigator

    Incidence of Adverse Events assessed according to CTCAE version 5

    Time frame: up to 6 months

07

Study locations

1 site
  • N.N. Blokhin NMRCO
    Moscow, Russia
08

References and documents

Publications

  • Kuznetsova O, Zagidullina A, Drobot N, Prokopiev A, Ivanov M, Fedyanin M, Mamedli Z, Aliev V, Polynovsky A, Dzhumabaev K, Aniskin A, Stroganova A, Karasev I, Tryakin A. Neoadjuvant Immunotherapy With Prolgolimab in Patients With Locally Advanced Microsatellite Instability/Defective Mismatch Repair Colorectal Cancer. JCO Precis Oncol. 2025 Dec;9:e2500602. doi: 10.1200/PO-25-00602. Epub 2025 Dec 10. PubMed 41370727 ↗

Individual participant data

Plan to share: Undecided

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 27, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06428487
Lead sponsor
Blokhin's Russian Cancer Research Center
Responsible party
Mikhail Fedyanin (Professor, Blokhin's Russian Cancer Research Center) — Principal investigator
First posted
May 24, 2024
Start date
Mar 31, 2022
Primary completion
Dec 31, 2024
Completion
Jun 30, 2025
Last update
Apr 27, 2026

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.

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Studies of the drug tested here: Prolgolimab

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