A Phase 2 interventional study of MK-1045 and Acetaminophen (or similar antipyretic) in Chronic Lymphocytic Leukaemia, Small Lymphocytic Lymphoma and Hematologic Malignancies, sponsored by Merck Sharp & Dohme LLC. Recruiting at 8 sites in 3 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-10.
Sponsored by Merck Sharp & Dohme LLC (part of Merck & Co., Inc) · Phase 2, Interventional, and Treatment
Researchers are looking for new ways to treat people with B-cell cancers. In this trial, researchers will look at chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL). These are blood cancers that affect B-cells in the blood, bone marrow, or lymph nodes.
The goals of this trial are to learn about:
2,036 studies on the registry are indexed under Leukemia, Lymphocytic, Chronic, B-Cell; 237 are open to participants now.
This study's planned enrollment of 60 is above the median of 39 across 1,603 interventional studies indexed under Leukemia, Lymphocytic, Chronic, B-Cell.
Browse Leukemia, Lymphocytic, Chronic, B-Cell studies →Merck Sharp & Dohme LLC is the lead sponsor of 2,166 studies on the registry; 132 are open to participants now.
Of its 501 completed or terminated interventional studies of FDA-regulated products, 370 (74%) have results posted.
Compared within Leukemia, Lymphocytic, Chronic, B-Cell, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Leukemia, B-Cell. The counts are of registry records indexed under each term, refreshed daily. How we classify →
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.
Exclusion Criteria:
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.
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.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
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 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 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.
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.
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.
After a transplant from a donor, the donor’s immune cells attack the recipient’s body, often the skin, gut or liver.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GVHD (graft-versus-host disease)
After a transplant from a donor, the donor’s immune cells attack the recipient’s body, often the skin, gut or liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive a step-up dosing regimen of MK-1045. During Cycle 1, participants will receive priming dose 1 of 1 mg MK-1045 on Day 1, priming dose 2 of 5 mg MK-1045 on Day 4, intermediate dose of 20 mg MK-1045 on Day 8, and then weekly (QW) target dose of 40-90 mg MK-1045 thereafter for up to approximately 2 years. At the discretion of physician investigator and after Sponsor consultation, participants who receive at least 3, 4-week treatment cycles and achieve a complete response may switch to an every two-weeks (Q2W) dosing regimen.
Biological: MK-1045 · Drug: Acetaminophen (or similar antipyretic) · Drug: Diphenhydramine (or similar antihistamine) · Drug: Dexamethasone · Biological: Tocilizumab · Biological: Tocilizumab biosimilar · Biological: Siltuximab
Participants will receive MK-1045 QW at the recommended dose determined in Part 1 for up to approximately 2 years. At the discretion of physician investigator and after Sponsor consultation, participants who receive at least 3, 4-week treatment cycles and achieve a complete response may switch to a Q2W dosing regimen.
Biological: MK-1045 · Drug: Acetaminophen (or similar antipyretic) · Drug: Diphenhydramine (or similar antihistamine) · Drug: Dexamethasone · Biological: Tocilizumab · Biological: Tocilizumab biosimilar · Biological: Siltuximab
Intravenous (IV) infusion
Also known as: CN201
Oral administration as a premedication
Per approved product label as a premedication
IV administration as a premedication
IV administration as a rescue medication
IV administration as a rescue medication
Also known as: Avtozma®, Tyenne®
IV administration as a rescue medication
Cohort A Part 1: Number of Participants Who Experience Dose-Limiting Toxicity (DLT)
DLT will be defined as any drug-related adverse event (AE) observed during the DLT evaluation period that results in a change to a given dose or a delay in initiating the next dose.
Time frame: Up to approximately 29 days
Cohort A Part 1: Number of Participants Who Experience an AE
An AE is defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.
Time frame: Up to approximately 27 months
Cohort A Part 1: Number of Participants Who Discontinue Study Treatment Due to an AE
An AE is defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.
Time frame: Up to approximately 24 months
Cohort A Parts 1 and 2: Objective Response Rate (ORR)
ORR is defined as the percentage of participants with complete response (CR), complete response with an incomplete recovery of the participant's bone marrow (CRi), nodular partial response (nPR), or partial response (PR), per International Workshop on Chronic Lymphocytic Leukemia (iwCLL) Criteria 2018 as assessed by blinded independent central review (BICR).
Time frame: Up to approximately 66 months
Cohort A Part 2: Number of Participants Who Experience an AE
An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.
Time frame: Up to approximately 27 months
Cohort A Part 2: Number of Participants Who Discontinue Study Treatment Due to an AE
An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.
Time frame: Up to approximately 24 months
Cohort A Parts 1 and 2: Duration of Response (DOR)
For participants who demonstrate a CR, CRi, nPR, or PR per iwCLL Criteria 2018 as assessed by BICR, DOR is defined as the time from the first documented evidence of CR, CRi, nPR, or PR until disease progression or death due to any cause, whichever occurs first.
Time frame: Up to approximately 66 months
Cohort A Parts 1 and 2: Area Under the Curve at Steady State (AUCss) of MK-1045
Blood samples will be collected at designated timepoints to estimate the AUCss of MK-1045.
Time frame: Predose and at designated time points post-dose (up to approximately 24 months)
Cohort A Parts 1 and 2: Maximum Concentration (Cmax) of MK-1045
Blood samples will be collected at designated timepoints to estimate the Cmax of MK-1045.
Time frame: Predose and at designated time points post-dose (up to approximately 24 months)
Cohort A Parts 1 and 2: Concentration Immediately Before the Next Dose Is Administered (Ctrough) of MK-1045
Blood samples will be collected at designated timepoints to estimate the Ctrough of MK-1045.
Time frame: Predose and at designated time points post-dose (up to approximately 24 months)
Cohort A Parts 1 and 2: Percentage of Participants Who Develop Antidrug Antibodies (ADA) to MK-1045
Blood samples collected at designated timepoints will be used to determine the percentage of participants who develop detectable ADAs to MK-1045.
Time frame: Predose and at designated time points post-dose (up to approximately 24 months)
Cohort A Parts 1 and 2: Percentage of Participants Who Develop MK-1045 Neutralizing Antibodies (NAb)
Blood samples collected at designated timepoints will be used to determine the percentage of participants who develop detectable NAbs to MK-1045.
Time frame: Predose and at designated time points post-dose (up to approximately 24 months)
Plan to share: Yes — https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Data sharing details ↗ · externaldatasharing-msd.com
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Anti-CD19/CD3 Bispecific Antibody MK-1045
Leukemia, Lymphocytic, Chronic, B-Cell →