A Study of Nemtabrutinib Plus Venetoclax vs Venetoclax + Rituximab (VR) in Second-line (2L) + Relapsed/Refractory (R/R) Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL) (MK-1026-010/BELLWAVE-010).

DRUG

Nemtabrutinib

5, 20, 45, and 65 mg tablets

DRUG

Venetoclax

10, 50, and 100 mg tablets

BIOLOGICAL

Rituximab

100 mg/10 mL, 500 mg/50 mL (10 mg/mL) IV Infusion

Part 1: Number of Participants Experiencing Dose-Limiting Toxicities (DLTs)

Time frame: Up to approximately 12 Weeks

DLT evaluation period is defined as 8 weeks after the first dose of the combination treatment of nemtabrutinib plus venetoclax Cycle 2 Day 1 in Part 1 + 4 weeks follow up. Each cycle is 4 weeks. DLTs are: Grade ≥3 nonhematologic toxicity (except Grade 3 nausea, vomiting, diarrhea, rash, fatigue, and uncontrolled hypertension which will not be considered a DLT unless lasting ≥72 hours despite optimal supportive care); Grade 4 hematologic toxicity lasting \>7 days (except Grade 3 lymphocytosis, Grade 4 platelet count decreased of any duration, or Grade 3 platelet count decreased if associated with bleeding); any Grade 3 or Grade 4 nonhematologic laboratory abnormality if values result in drug-induced liver injury, or medical intervention is required, or the abnormality leads to hospitalization, or the abnormality persists for \>1 week (with exceptions); missing \>25% of nemtabrutinib or venetoclax doses as a result of drug-related adverse events during the first 2 cycles; Grade 5 toxicity.

Part 1: Number of Participants Experiencing Adverse Events (AEs)

Time frame: Up to approximately 28 months

An AE is any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants experiencing AEs will be reported for Part 1.

Part 1: Number of Participants Discontinuing Study Treatment Due to AEs

Time frame: Up to approximately 25 months

An AE is any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants discontinuing study treatment due to AEs will be reported for Part 1.

Part 2: PFS per the 2018 International Workshop on Chronic Lymphocytic Leukemia (iwCLL) Criteria as Assessed by Blinded Independent Central Review (BICR)

Time frame: Up to approximately 71 months

PFS is defined as the time from randomization to the first documented disease progression per iwCLL criteria 2018 as accessed by BICR, or death due to any cause, whichever occurs first. PFS will be presented.

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.