A Clinical Trial of MK-1045 With Zilovertamab Vedotin in Participants With Diffuse Large B-cell Lymphoma (MK-1045-010) (WaveSpan-010)

Participants will receive escalating doses (2 to 120mg) of MK-1045 (or in Part 2, a dose of MK-1045 determined by Part 1) via intravenous infusion (IV) once weekly (q1w) for 48 weeks plus 1.5 or 1.75 mg/kg ZV via IV infusion once every 3 weeks (q3w) for 18 weeks. Participants may continue to receive MK-1045 once every 2 weeks (q2w) after 3 months if a Complete Response (CR) is achieved.

Intravenous (IV) administration

• CN201

1.5 or 1.75 mg/kg administered IV

• MK-2140

Participants may receive Tocilizumab (or biosimilar) after administration of MK-1045 in the event of cytokine release syndrome

Participants may receive the following rescue medications before administration of MK-1045: acetaminophen (or similar), diphenhydramine (or similar antihistamine), dexamethasone, Varicellazoster/herpes simplex virus prophylaxis (acyclovir, valacyclovir, famiciclovir), and pneumocystis jirovecii pneumonia prophylaxis (trimethoprim/sulfamethoxazole, dapsone, atovaquone, pentamidine).

Given as prophylaxis as listed in the National comprehensive Cancer Network guidelines.

Participants will receive physician's choice of: 12 mg/kg tafasitamab per labeling instructions plus 25mg lenalidomide once daily (qd) from Days 1-21 of each cycle (each cycle is 28 days) for up to 12 cycles followed by 12 mg/kg tafasitamab monotherapy q2w if stable OR 1.8 mg/kg polatuzumab vedotin plus 90 mg/m^2 bendamustine and 375 mg/m^2 rituximab (or biosimilar) q3w for 6 cycles (each cycle is 21 days).

375mg/m^2, administered IV

375 mg/m^2, administered IV

• TRUXIMA®
• RUXIENCIA®
• RIABNI®

1.8 mg/kg, administered IV

90 mg/m^2, administered IV for 2 consecutive days

25 mg, administered orally

12 mg/kg, administered IV, on Days 1, 4, 8, 15, and 22 for Cycle 1; Days 1, 8, 15, and 22 for Cycles 2 and 3; Days 1 and 15 for Cycles 4 to 12 (each Cycle is 28 days). After Cycle 12, administered once every 2 weeks

• Monjuvi

The following events, if considered drug related by the Investigator, will be considered a DLT: Grade (Gr) 5 toxicity; Gr 4 nonhematologic toxicity; Gr 4 hematologic toxicity lasting ≥7 days, except thrombocytopenia; Gr 4 thrombocytopenia of any duration; Gr 3 thrombocytopenia associated with any Gr2 or higher bleeding; Nonhematologic AEs ≥Gr 3 with exceptions; Gr 3 or Gr 4 non-hematologic laboratory values if requires medical intervention, leads to hospitalization, or persists for >72 hours; Gr 3 of 4 febrile neutropenia; Treatment-related toxicities that lead to discontinuation of study treatment or results in receiving incomplete planned doses of study treatment during DLT evaluation window (up to approximately 42 days).

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.

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.

ORR is defined as the percentage of participants with Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 50% decrease in the sum of diameters of target lesions) per Lugano response criteria. The percentage of participants who experience CR or PR as assessed by physician investigator will be presented.

PFS is defined as the time from randomization to the first documented disease progression per Lugano response criteria by Blinded Independent Central Review (BICR) or death due to any cause, whichever occurs first.

ORR is defined as the percentage of participants with Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 50% decrease in the sum of diameters of target lesions) per Lugano response criteria. The percentage of participants who experience CR or PR as assessed by physician investigator will be presented.

For participants who demonstrate a CR or PR per Lugano response criteria as assessed by physician investigator. DOR is defined as the time from the first documented evidence of CR or PR until disease progression or death due to any cause, whichever occurs first.

For participants who demonstrate a confirmed Complete Response (CR: disappearance of all target lesions) per Lugano response criteria. CR rate is defined as the percentage of participants who experience a CR. The CR rate as assessed by physician investigator will be presented.

Blood samples will be collected at designated timepoints to estimate the AUC of MK-1045.

Blood samples will be collected at designated timepoints to estimate the Cmax of MK-1045.

Blood samples will be collected at designated timepoints to estimate the Ctrough of MK-1045.

OS is defined as the time from randomization to death due to any cause.

ORR is defined as the percentage of participants with Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 50% decrease in the sum of diameters of target lesions) per Lugano response criteria. The percentage of participants who experience CR or PR as assessed by BICR will be presented.

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.

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.

For participants who demonstrate a confirmed Complete Response (CR: disappearance of all target lesions) per Lugano response criteria. CR rate is defined as the percentage of participants who experience a CR. The CR rate as assessed by BICR will be presented.

For participants who demonstrate a CR or PR per Lugano response criteria as assessed by BICR. DOR is defined as the time from the first documented evidence of CR or PR until disease progression or death due to any cause, whichever occurs first.

MRD is defined as the percentage of participants reaching MRD negativity by ctDNA clearance at predefined timepoints.