A Clinical Trial of MK-1045 and Rituximab in People With Follicular Lymphoma (MK-1045-007)

Participants will receive escalating doses of MK-1045 (from 2 mg to 90 mg) once weekly (QW) for up to approximately 12 months. Participants will also receive 375 mg/m\^2 rituximab (or biosimilar) once every 4 weeks (Q4W) for up to approximately 6 months.

Biological: MK-1045 · Biological: Rituximab · Biological: Rituximab biosimilar

Participants will receive MK-1045 QW at the dose determined in Part 1 for up to approximately 12 months. Participants will also receive 375 mg/m\^2 rituximab (or biosimilar) Q4W for up to approximately 6 months.

Biological: MK-1045 · Biological: Rituximab · Biological: Rituximab biosimilar

Participants will receive physician's choice of: 90 mg/m\^2 bendamustine on Days 1 and 2 of each 4-week cycle for up to 6 cycles (up to approximately 6 months) plus 375 mg/m\^2 rituximab (or biosimilar) Q4W for up to approximately 6 months OR 750 mg/m\^2 cyclophosphamide, 50 mg/m\^2 doxorubicin, and 1.4 mg/m\^2 vincristine on day 1 of each 3-week cycle (Q3W) and 100 mg/m\^2 prednisone (or prednisolone) once daily on days 1 through 5 Q3W for up to 6 cycles (up to approximately 4 months) plus 375 mg/m\^2 rituximab (or biosimilar) Q3W for up to approximately 4 months OR 750 mg/m\^2 cyclophosphamide and 1.4 mg/m\^2 vincristine Q3W and 40 mg/day prednisone (or prednisolone) once daily on days 1 through 5 of each 3-week cycle for up to 6 cycles (up to approximately 4 months) plus 375 mg/m\^2 rituximab (or biosimilar) Q3W for up to approximately 6 months.

Biological: Rituximab · Biological: Rituximab biosimilar · Drug: Bendamustine · Drug: Cyclophosphamide · Drug: Vincristine · Drug: Prednisone · Drug: Prednisolone · Drug: Doxorubicin Hydrochloride

Intravenous (IV) infusion

IV infusion

IV infusion

IV infusion

IV infusion

IV infusion

Per approved product label

Per approved product label

IV infusion

Plazo: Up to approximately 15 months

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.

Plazo: Up to approximately 12 months

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.

Plazo: Up to approximately 36 days

DLT will be defined as any drug-related AE observed during the DLT evaluation period that results in a change to a given dose or a delay in initiating the next cycle.

Plazo: Up to approximately 60 months

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.

Plazo: Up to approximately 63 months

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.

Plazo: Up to approximately 60 months

ORR is defined as the percentage of participants with CR (CR: disappearance of all target lesions) or Partial Response (PR: at least a 30% 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.

Plazo: Up to approximately 60 months

For participants who demonstrate CR (CR: disappearance of all target lesions) at end of treatment per Lugano response criteria, defined as the time from the first documented evidence of CR until disease progression or death due to any cause, whichever occurs first.

Plazo: Predose and at designated time points post-dose (up to approximately 12 months)

Blood samples will be collected at multiple time points to estimate the AUCss of MK-1045.

Plazo: Predose and at designated time points post-dose (up to approximately 12 months)

Blood samples will be collected at multiple time points to estimate the Cmax of MK-1045.

Plazo: Predose and at designated time points post-dose (up to approximately 12 months)

Blood samples will be collected at multiple time points to estimate the Ctrough of MK-1045.

Plazo: 30 months

For participants who demonstrate a confirmed CR (CR: disappearance of all target lesions) per Lugano response criteria. CR rate is defined as the percentage of participants who experience a CR by month 30. The CR rate as assessed by BICR at month 30 will be presented.

Plazo: Up to approximately 63 months

ORR is defined as the percentage of participants with CR (CR: disappearance of all target lesions) or PR (PR: at least a 30% 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.

Plazo: Up to approximately 63 months

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

Plazo: Up to approximately 63 months

EFS is defined as the time randomization to the first documented disease progression per Lugano response criteria by BICR, death due to any cause, initiation of a new anticancer therapy or a positive biopsy for residual disease, whichever occurs first.

Plazo: Up to approximately 63 months

For participants who demonstrate CR (CR: disappearance of all target lesions) per Lugano response criteria by BICR, defined as the time from the first documented evidence of CR until disease progression or death due to any cause, whichever occurs first.

Plazo: Up to approximately 15 months

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.

Plazo: Up to approximately 12 months

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.

Plazo: Baseline and up to approximately month 13

The FACT-Lym is a 42-item questionnaire designed to measure HRQoL and cancer-specific symptoms in non-Hodgkin lymphoma patients. Subscales include FACT-General (FACT-G), FACT-Trial Outcome Index (FACT-TOI), FACT-Lym total score (FACT-Lym TS), and the Lymphoma subscale (Lym S). The Lym S has a single domain consisting of 15 items specific to lymphoma burden with a score ranging from 0 to 60. FACT-G has 4 well-being domains, physical (7 items), social/family (7), emotional (6), and functional (7), with scores ranging from 0 to 108. FACT-TOI combines FACT-G's physical and functional domains with Lym S, with scores ranging from 0 to 116. FACT-Lym TS combines FACT-G with Lym S, with scores ranging from 0 to 168. The scoring of FACT-Lym is on a 5-point Likert scale from 0 to 4, with 0= not at all, 1= a little bit, 2= somewhat, 3=quite a bit, 4=very much. The higher the score the better the quality of life.

Plazo: Baseline and up to approximately month 13

The FACT-Lym is a 42-item questionnaire designed to measure HRQoL and cancer-specific symptoms in non-Hodgkin lymphoma patients. Subscales include FACT-General (FACT-G), FACT-Trial Outcome Index (FACT-TOI), FACT-Lym total score (FACT-Lym TS), and the Lymphoma subscale (Lym S). The Lym S has a single domain consisting of 15 items specific to lymphoma burden with a score ranging from 0 to 60. FACT-G has 4 well-being domains, physical (7 items), social/family (7), emotional (6), and functional (7), with scores ranging from 0 to 108. FACT-TOI combines FACT-G's physical and functional domains with Lym S, with scores ranging from 0 to 116. FACT-Lym TS combines FACT-G with Lym S, with scores ranging from 0 to 168. The scoring of FACT-Lym is on a 5-point Likert scale from 0 to 4, with 0= not at all, 1= a little bit, 2= somewhat, 3=quite a bit, 4=very much. The higher the score the better the quality of life.

Plazo: Baseline and up to approximately month 13

The FACT-Lym is a 42-item questionnaire designed to measure HRQoL and cancer-specific symptoms in non-Hodgkin lymphoma patients. Subscales include FACT-General (FACT-G), FACT-Trial Outcome Index (FACT-TOI), FACT-Lym total score (FACT-Lym TS), and the Lymphoma subscale (Lym S). The Lym S has a single domain consisting of 15 items specific to lymphoma burden with a score ranging from 0 to 60. FACT-G has 4 well-being domains, physical (7 items), social/family (7), emotional (6), and functional (7), with scores ranging from 0 to 108. FACT-TOI combines FACT-G's physical and functional domains with Lym S, with scores ranging from 0 to 116. FACT-Lym TS combines FACT-G with Lym S, with scores ranging from 0 to 168. The scoring of FACT-Lym is on a 5-point Likert scale from 0 to 4, with 0= not at all, 1= a little bit, 2= somewhat, 3=quite a bit, 4=very much. The higher the score the better the quality of life.

A Phase 2/3 Randomized, Open-label Study of MK-1045 in Combination With Rituximab in Participants With 1L Follicular Lymphoma