MK-1045

Researchers are looking for new ways to treat 2 types of non-Hodgkin lymphoma (NHL) called follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL). FL is a slow-growing type of NHL. DLBCL is a fast-growing type of NHL. NHL is a cancer in the lymphatic system that causes swollen lymph nodes. The lymphatic system is part of the immune system. In this study, researchers want to learn if MK-1045 can treat FL and DLBCL. MK-1045 is a study treatment that is an immunotherapy, which helps the immune system fight cancer. The goals of this study are to learn how safe MK-1045 is and if people tolerate it. Researchers also want to see if FL and DLBCL respond (the cancer gets smaller or goes away) to treatment.

Researchers are looking for new ways to treat people with a type of blood cancer called precursor B-cell Acute Lymphoblastic Leukemia (B-ALL) that is relapsed- the cancer has come back after treatment, or refractory - the current treatment has stopped working to slow or stop cancer growth. This study will have two parts. In the first part (dose escalation phase) the goal is to learn about the safety of a study treatment, MK-1045, and to find the best dose level of MK-1045 that is tolerated and may work to treat B-ALL. In the second part (Phase II) researchers want to learn how well MK-1045 works to treat B-ALL.

Researchers are looking for new ways to treat people with relapsed or refractory B-cell acute lymphoblastic leukemia (R/R B-ALL) that is CD19 positive using a medicine called MK-1045. MK-1045 is an immunotherapy, which is a treatment that helps the immune system fight cancer. This trial will compare MK-1045 to a standard immunotherapy called blinatumomab. The goals of this trial are to learn if more people who receive MK-1045 have no cancer cells in their bone marrow compared to people who receive blinatumomab and if people who receive MK-1045 live longer compared to people who receive blinatumomab.

Researchers are looking for new ways to treat follicular lymphoma (FL). A standard (usual) treatment for FL includes a targeted therapy called rituximab and chemotherapy. In this study, researchers want to learn if giving a study medicine called MK-1045 and rituximab can treat FL. MK-1045 is a type of treatment called immunotherapy. The goals of this study are to learn: * About the safety of MK-1045 and rituximab, and if people tolerate them when given together * If people who receive MK-1045 and rituximab have the cancer go away * If people who receive MK-1045 and rituximab live longer without their cancer getting worse compared to those who receive standard treatment (rituximab and chemotherapy)